BANGLADESH POWER DEVELOPMENT BOARD TENDER ... - BPDB

Volume - 2Technical RequirementsSection.1. Description of the Project.2. Scope of work.3. Power Plant Arrangement4. Generator and Ancillary Equipment5. Transformers6. 230 KV Outdoor Switchgear, Equipment7. 6.6 kV Switchgear and Low Tension Switchgear8. Control and Protection.9. Cabling and Grounding.10. DC Power Supply System.11. Lighting and Small Power Supply System.12. Fuel Handling Facilities.13. Fire Protection Facilities.14. Communication Facilities.15. Maintenance Facilities.16. Tests and Inspections.17. Civil works.18. Building Works.19. Spare Parts.20. Appendices [Data/ Drawings]PageGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)2

Section 1Description of The ProjectGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)3

GHORASAL 200 MW to 300 MW GAS TURBINE PEAKING POWER PLANTPROJECTTECHNICAL REQUIREMENTSDESCRIPTION OF THE PROJECT:A Gas Turbine Power Station of 200 MW to 300 MW capacity at site conditions (35 0 C,1.013 bar, 98% R.H.) is intended to be set up by Bangladesh Power Development Boardat the specified space within existing Ghorasal Thermal Power Station, Ghorasal,Narashingdi. Gas Turbines shall be designed to convert it to combined cycle mode infuture. It is required to keep provision so that one (1) unit of 210 MW of Ghorasal PowerPlant can be run by the steam generated in the future HRSG(s) using exhaust from theproposed Gas Turbines.The proposed Plant consisting of minimum 2 to maximum 6 identical units will beinstalled in the vacant space adjacent to the existing power station, as Shown at the sitelayout. The Project will be implemented on turnkey basis from GOB fund.The Power Station will be connected with the Ghorasal 230 kV Grid Sub-Station throughunderground cable and other electrical equipment as shown in the single line diagram.Fault Levels of existing Ghorasal Grid Sub-station’s 230 kV Busbar areMVA BASE MVA 3-PHASE MVA PHASE-GND........ 12123 13605Climatic Conditions: Sub-Tropical Monsoon[To be considered in Temperature: 5 0 C to 45 0 CPlant design] Relative Humidity: 36% to 100%Annual Rainfall: 120 cm to 345 cmWind Velocity: 160 km/hrSeismic Horizontal Ground Acceleration: 0.1gThe project may be classified into the following broad areas. Details are however givenlater in the scope of work.1. Survey preparation of drawing, land development, landscaping of theproposed site.2. The supply and construction of the Power plant equipment.3. Equipping of 230 KV material/equipment at the 230 switchyardpremises as per single line diagram enclosed.4. Supply and Construction of all civil work including control room,administrative building, internal roads, boundary etc.5. Supply and construction of entire Fuel system for the plant, fireprotection system etc.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)4

Section 2Scope Of WorkGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)5

2. Scope Of Work2.0 Scope of work2.1 Gas Turbine Generating Unit2.1.1 General2.1.2 Gas Turbine Generating unit2.1.3 Emergency Diesel Generating Set2.1.4 Natural Gas Booster Compressors2.2 230 kV Switchgear, equipment and Transformers2.2.1 230 kV Switchgear, equipment2.2.2 Step up Transformers and Associated equipment2.3 Unit Auxiliary Transformer, Station Transformers and Associatedequipment2.4 Control and protection Panels2.5 Other Mechanical system2.6 Other Electrical system2.7 Maintenance Facilities2.8 Fire Fighting Facilities2.9 Building and Civil works2.10 Training2.11 Submission of Engineering Data2.12 Manufacturer's Field Training Supervision2.13 Tests2.14 Commissioning2.15 Supervisions during warranty period2.16 First Inspection2.17 Transport2.18 Spare Parts2.19 Special Maintenance Tools2.20 Office Equipment2.21 Electrical Workshop Tools2.22 Machine Shop Equipment & Tools2.0 Scope of Work.The work stated in this specification shall cover the complete design, engineering(including supply of all calculation & settings), manufacturing, inspection, testing,supply, delivery to the site, construction, erection installation, testing &Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)6

k. Interconnection wiring in rigid metal conduits.l. Base-mounted terminal boxes.m. Vibration detectors.n. Thermocouples for measuring critical turbine temperatures.o. Boroscope openings for maintenance inspection.p. Closed, forced feed lubricating oil system including: Shaft driven main lube oil pump. AC auxiliary lube oil pump and DC emergency lube oil pump. Duplicate oil to coolant heat exchangers. Dual filters. Oil reservoir. Control and instrumentation.q. Closed loop coolant system including: Water to oil heat exchangers. Water to air/ Air to water heat exchangers Temperature control valves. Control and instrumentation.r. Inlet and exhaust plenums.s. Outdoor enclosure.t. Heating and ventilating system.u. Fire detection by flame detectors, UV detectors and CO 2 fire protectionsystem.v. On base piping.w. Load coupling.x Compartment lightingy. Compressor wet washing system (Off & On line)z. HRSG in the exhaust stack for steam generation (in case of steam injectionfor NOx supression)aa. Demi water plant for water/steam injection, water washing system etc.Note: For aeroderivative gas turbine all appropriate components including LPC,HPC, HPT, LPT, VSV, VG Control etc. All coolers/pumps shall be 2X100%capacity.2. Generator Packagea Outdoor enclosure.b. Stator winding with class F insulation.c. Cylindrical forged steel rotor with class F insulation.d. Air-cooled system.e. Lubrication system integral with gas turbine lubrication system.f. Platinum RTD temperature detectors imbedded in the stator windings.h. Structural steel base.i. Speed reduction gear. (if required)j. Excitation system (shaft mounted, Brushless).k. Strip heatersGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)8

3. Generator switchgeara. Outdoor enclosure.b. Generator Circuit Breaker [SF 6 only].c. Potential transformers.d. Current transformers.e. Lightning arresters.f. Neutral grounding transformers.g. Connections to generator power leads and unit step up transformers.h. Lighting and heating equipment.i. Ventilation system.j. Connections to auxiliaries transformer.k. 11 kV Generator circuit breaker having adequate capacity to meet therequirements (as per single line diagram).Note: Generator Voltage other than 11 KV, relevant parameters shall be submitted as perIEC.4. Inlet Air System.a. Filter compartment with: Support structure. Multi-Stage Air filtration system, complete in all respects. High efficiency media filtration. Pressure measuring instrumentation. Inlet ducting. Access door. Lighting. Air inlet system special corrosion protection. Air inlet system bypass door.b. Inlet silencing.c. Transition piece from inlet duct to inlet plenum.d. Structural support.5. Exhaust System (Vertical)a. Exhaust ducting.b. Exhaust silencing.c. Transition piece from exhaust plenum to exhaust ducting.d. Exhaust stack [as per environmental protection requirement butnot less than 30 m].e. Thermal insulation and lagging.6. Control Compartmenta. Outdoor enclosure.b. Turbine control panel.c. Generator control panel and protection panel.a. Motor control centre.b. air conditioning system.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)9

7. The bidder shall assess the potential impact of air quality, designs the air filtersystem appropriately and guarantees its long-term performance.The bidder shall also supply, install & commission (a) Continuous Emissions MonitoringModule; and (b) standard weather station for measuring wind velocity & direction andambient temperature, pressure & Relative Humidity. Sensors shall be installed in suitablelocation as per GT designer's recommendation and calibrated & interfaced with plantcontrol system. Ambient Temperature, Pressure & Relative Humidity shall be used duringperformance tests.2.1.3 Emergency Diesel Generating SetOne (1) set of emergency diesel generating set complete with ancillary equipment shallbe of minimum 500 kVA [pf 0.80] having diesel storage capacity for 8 hrs continuousoperation for supplying power to essential auxiliaries. EDG shall be of automatic startingsystem [compressed air/ Battery] including quick start & loading capability. The startingsystem shall be capable of carrying out at least five (5) consecutive start without auxiliarypower supply.2.1.4 Natural Gas Booster CompressorsThe Gas Booster Compressor (GCB) manufactured either by MAN Turbo, Germany orAtlas Coppco, USA , shall be of well proven design and the offered model of GCB shallhave satisfactory operating experience outside manufacturer's country for at least 2 (two)years. Tenderer shall have to submit at least one certificate (must be from outsidemanufacturer's country) from the end users in this respect. These certificate must benotarized or have authentication from the Chamber of Commerce of the Tenderer'scountry or the Embassy/High commission of the end user’s country situated in Dhaka. Inabsence of that in Dhaka, authentication from bidder’s Embassy/High Commission.The plant shall require centrifugal type gas booster compressors, as the supply pressureof natural gas at RMS is only 90-150 psig. The capacity of the compressors shall have tobe 2x100% (one in operation and one standby) and each shall be capable to meetmaximum gas requirement of the plant at all modes of operation [base & peak] & at anytemperature prevailing in the site. Appropriate control, sealing, cooling & anti-surgesystem shall have to be provided including compressor house.The gas booster compressors shall be 6.6 KV motor driven.2.2 230 Kv Switchgear, Equipment And Transformers2.2.1 230 Kv Switchgear Equipment(1) 1 (one) lot of 230 kV circuit breaker [3 phase trip, Dead Tank type] withthe following features :Type: SF6, Dead TankRated voltage: 275 kV(Max)Rated insulation levelLighting impulse withstand voltage : 1050 kV (Peak)(1.2/50 micro sec).Power frequency withstand voltage : Relevant IEC Standard(for 1 mm.)Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)10

Rated frequency: 50 HzRated nominal current: as requiredRated Interrupting current : Relevant IEC Standard kA rms [3 sec]Operating duty (2.5 cycle) : 0-0.3 sec-CO-3min-COInterrupting time : Relevant IEC Standard m sec (max.)Operating mechanism: Hydraulic & Spring latch2) One (1) lot of 230 KV Current Transformers.3) One (1) lot of 230 KV Voltage Transformers.4) One (1) lot of 230 KV Lightning Arresters.5) One (1) lot of of 230 KV Isolators.5) One (1) lot of steel structures for supporting the switchgear, equipment,posts and beams and gantry structures.6) One (1) lot of 230 KV XLPE (Single-Core) cable including supply,installation, testing & commissioning with Two end Termination and onespare core (3+1) with necessary hardware from unit transformers tohooking point [underground cable with RCC slab on three sides] ifrequired.XLPE Cable size: As required at any site conditionRated Voltage: 230kvMaximum permissible voltage: Relevant IEC Standard .Current Rating : As required at any site conditionShort Ckt. Current: Relevant IEC Standard kA for 1 s.Length of the Cable : as required.Cable should be Single point bonding at source end but provision should be madefor both ends with Link Box & Protective Device (Surge Voltage Limiter) for openend.7) One (1) lot of suspension/post insulator string sets, tension insulator stringsets and station post supporting insulator set with necessary hardware.8) One (1) lot of shield wire connectors and necessary hardware.9) One (1) lot [for interconnection] of equipment and materials formodification of existing facilities, re-arrangement, reconstruction, andreconnection with 230 kV switch gear as per requirement.2.2.2 Step-Up Transformers And Associated Equipment:1) One (1) lot of three phase bank of 3 single phase step-up transformersand one spare transformer (capacity as specified in Clause 5.2.2) and associatedequipment with the following features.Type: Oil immersed Single phase,outdoor power transformerGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)11

Rating: To meet the required ofthe specification as stated in Clause 5Voltage ratio of single phase 11 230transformer at full load : / KV√3Connection [HV-LV] :Ynd 1 as shown in singleline diagram.Rated insulation level: HV winding LV windingLighting impulse Withstand : .... kV (Peak) 75 kV PeakVoltage (1.2/50 micro sec.)Power frequency withstand : .......kV 28kVVoltage (for 1 min).Impedance voltage: Shall be within the range of15% and 18%Tap changer: On load at high tensionwinding ±8 x 1.25 %.TerminationHigh tension side:Outdoor bushing for Cable Pot HeadLow tension side:11 kV Isolated & insulated phase busduct and XLPE cables.2) One (1) lot of associated equipment.2.3. Unit Auxiliary Transformer, Station Transformers and AssociatedEquipment1) One (1) set of unit auxiliary transformer and associated equipment withthe following features:TypeRatingRated high voltageRated high voltage: Oil immerse, three phase andtwo windings, outdoor power transformer.: To meet the requirement of theSpecification:11 kV: 6.6 kVConnection : Ynd 11Rated insulation level :HV WindingLV WindingGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)12

Lighting impulseWithstand voltage(1.2/50 micro sec) : 75 kV (Peak) 60 kV(Peak)Power frequencyWithstand voltage(For 1 mm). : 28 kV 22 kVImpedance voltage : shall be within the range of 5% and 7.5%Tap changer : Off-current on high tension winding ±5%Neutral grounded: Solidify grounded2) Two (2) sets of station transformer and associated equipment with thefollowing features:TypeRatingRated high voltageRated low voltageConnectionRated insulationLighting impulseWithstand voltage(1.2/50 micro sec.): Oil immersed, three phase andtwo windings, outdoor power transformer: To meet the requirement of the specification:6.6 kV:415 V:Dyn11:HV Winding LV Winding: 60 kV(peak)Power frequencyWithstand voltage(for 1 mm). :28 kV(peak) 4kVImpedance voltage: Not less than 5 %, but notmore than 7.5 %.Tap changer : Off-current on high tension winding ±5%Neutral grounded: Solidly grounded2.4 Control And Protection SystemThe gas turbine generating plant shall be capable of semi-attended operationunder local unit control, and shall also be capable of remote control from thecentral control room within the site area. The automatic start-up and shut downsequences shall be initiated by push button on either the local control panel or thecentral control panel. Synchronisation shall be automatic with provision for localand remote manual control.In addition to the unit local control and protection panels/ HMI, the followingGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)13

panels shall be provided in the central control room.a. Gas turbine generating unit remote unit control desks/ HMI [Industrialgrade] including micro processor based control system. Detail of GTcontrol system shall have to be furnished as per designer'srecommendation including data logging, storage, printing facility etc.b. Required No. of control and protection panel for 230 KV circuits breaker(as required)c. One (1) 11 kV common switchgear control desk board.d. Required No. of auxiliary Power supply control desk boards.c. One (1) synchroniser panel (Swing type) with provision of Auto andManual synch System.2.5 Other Mechanical Systema. Piping between the on-base equipment and the off base Equipment.b. Painting, including finished coat and special paints required for corrosionprotection and high temperature resistance.c. Design, operation and maintenance manuals, including drawings inEnglish.d. All other work necessary for the proper operation and maintenance of thegas turbine generating plant.c. Lubricating oil for flushing and for the initial filling.f. All lubricant and chemical additives.g. Liquid Fuel handling facilities including metering & control.2.6 Other Electrical Systema. One (1) lot 6.6 KV switchgearb. One (1) lot 415V power Centre.c. One (1) lot 41 5 V common power Centre.d. One (1) lot 415 unit motor control centre for each GTe. One (1) Lot 11 kV XLPE power cables (copper) & isolated(Insulated) phase solid bus.f. One (1) Lot 6.6 kV XLPE power cables( copper).g. One (1) Lot Low Voltage power cables (copper).Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)14

h. One (1) Lot Control and instrument cables (copper).i. One (1) lot Race way materialsj. One (1) lot Grounding system.k. One (1) lot lighting and small power supplyl. One (1) lot Communication system including PLC, PABX, pagingSystemm. One (1) lot DC power supply system including 2(two) banks of125 V Battery (NiCd, Alkaline) and 2(two) sets of batterychargers (Thyristor type) and other associated facilities.n. One (1) lot UPS for GT control system in addition to Control &Communication system.2.7 Maintenance Facilitiesa. One (1) Set Overhead electric crane[Main hoist capacity 60 ton and auxiliary 10 ton;Main hoist capacity will be sufficient enough to liftthe weight of Generator rotor as well as weight ofthe fully bladed gas turbine rotor separately]b. One (1) 30 ton mobile cranes.c. One (1) 5 ton Fork lifterd. One (1) 5 ton Truck/ lorrye. One (1)lot Special tools etc.2.8 Fire Fighting Facilitiesa. One (1)lot Auto-Release C0 2 fire fighting facilities.b. One (1) lot Hydrant system including water main, hydrantStands, hoses, motor driven and engine driven fire fightingpumps, jockey pump etc.c. One (1)lot Portable fire fighting equipment.2.9 Building And Civil WorksAll necessary demolition work within the space designated and removal ofderbies.Site development (if required) up to same level of existing units, site preparation,soil investigation, cleaning, levelling of site, reclamation; setting out of plant,design and construction of all foundations for the equipment provided by theContractor. The design shall be as per BNBC [Bangladesh National Building Code].The design and construction of control room building, engine house, GBC, fueltanks (if required) guard rooms, fencing, boundary wall, road, water supplysystem, drainage & sewage system, etc. The design and construction of all majorGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)15

foundations and buildings shall include piling.Control building, Store/Warehouse (Total building area- 20,000 sqf/floor, 3 stored,lifting equipment with capacity 10/3 Ton must be incorporated), Fire Fightingpump house, Emergency Diesel Generator house, Guard house, water supplyhouse, fencing, boundary wall, road etc. shall be constructed by the Contractorwithin the Site area.- Outdoor lighting, passage ways, access ways for transporting ofequipment during overhaul, and re-routing of existing passage way for thesite if necessary.- Surface water drainage system including oil interceptors.- Removing of debris, surplus excavated materials and rubbish, etc.resulting from the works.2.10 TrainingThe training at the Contractor's factory including:- 15 (fifteen) round trip air fares from Dhaka, Bangladesh to theManufacturer's factory.- 15 (fifteen) Man-Months of training on GTG unit at Manufacturer's factory.- Local transportation, meals, lodging, medical costs, insurance and pocketexpenses @ US $ 100 per day per person etc.2.11 Submission of Engineering DataDrawings and other engineering data for the specified equipment and materialsare essential to the design and subsequent construction of the entire generatingunit.The contractor shall be required to submit drawings and engineering data inaccordance with the Schedule and requirements specified herein to assurecompliance with the overall construction and operating Schedule.2.12 Manufacturer's Field Training SupervisorFrom the date of commencement of initial operation of the major equipment, theContractor shall dispatch manufacturer's supervisor (s) who shall be technicallycompetent, factory trained, experienced in the operation and maintenance of theequipment to the site.The supervisor (s) shall be responsible for providing instruction and guidance toBOARD's staffs in the operation and maintenance of the equipment. Thesupervisor(s) shall not be responsible for any duties required by the test andcommissioning program of the equipment during training duty.The supervisor (s) must be able to fluently understand, speak, read, and write theEnglish language.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)16

2.13 TestsThe Contractor shall be responsible to all testing of equipment and systemssupplied under this contract. The Contractor shall submit with his proposal a list ofthose tests, which in his opinion will satisfactorily check the operatingcharacteristics of the equipment and determine all values necessary for evaluationof guarantees.In the event of an award of contract, the Contractor shall submit within sixty daysof the date of notice of award details of the proposed procedures for each test. Alltest procedures shall be subject to the Board's modification and approval.For start up and test, BOARD will supply operating staff who will operate theequipment as directed by the Contractor under the Contractor's responsibility.2.14 CommissioningThe Contractor shall be responsible for the commissioning of all equipment in hissupply, and shall provide necessary commissioning engineers to carry out alloperations from first making alive of auxiliary equipment until the fullcommissioning has been completed.The schedule shall cover all necessary inspections, adjustments and tests fromno load to full rated capacity.The BOARD shall provide his operating and maintenance staff to gain familiaritywith the installation but the Contractor shall remain fully responsible for safeoperation of all equipment in his supply during the commissioning periods, anduntil the completion certificate have been issued.2.15 Supervision During Warranty PeriodThe Contractor shall provide three (3) competent Engineers during warrantyperiod for smooth maintenance and operation on the site.2.16 First Inspection [CI's]The Contractor shall be responsible for execution of first inspections of the gasturbine unit during warranty period.2.17 TransportDeleted2.18 Spare PartsSpares during Warrantee periodThe Contractor shall submit a list of Essential spare parts with OEM Part No. andconsumables to be necessary for maintenance of the unit(s) and other plantequipment inclusive of emergency use that takes place in the course of operation(according to the Manufacture's recommendation and guideline) during theWarranty period (24 months). During the warranty period of 24 months, theContractor shall supply all necessary equipment, spare parts,Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)17

materials/consumables etc. at his own cost and whether it is listed or not in theirlist.Spares during Long Term Service agreement (LTSA)The Tenderer shall, in addition to essential spare parts and consumables forwarrantee period also submit a list of spares for LTSA period (next 4 years afterwarrantee period) which reflects the OEM's guidelines and Tenderer's experiencein the operation and maintenance of the type of equipment proposed. For LTSAperiod also the Contractor shall supply all necessary equipment, spare parts,materials/consumables at his own cost and whether it is listed or not in their list.2.19 Special Maintenance ToolsThe contractor shall provide all special tools including a boroscope set required formaintenance of the unit and hand them over in good condition to the BOARD. Alist of all such tools shall be incorporated with tender. Contractor shall not bepermitted to use any equipment/ machinery/ tools, which are to be suppliedunder the Contract.2.20 Office equipmentThe Contractor shall provide 3(three) Nos of Computer (latest model), each withLaser Printer, UPS (30 Minutes at full load, Min.), Stabiliser, Standard Tables &Chairs etc.2.21 Electrical workshop toolsCurrent injection test set, Megger, Multimeter, etc.2.22 Machine Shop equipment & Tools - DeletedLathe, Piller drill, Universal miller, Machine hacksaw, Grinding Machine,Small universal machine tools, Welding set etc.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)18

Section 3Power Plant ArrangementGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)19

3. Power Plant Arrangement3.1 General3.2 Guarantee3.3 Gas Turbine and Auxiliary Equipment3.3.1 Basic Equipment Requirement3.3.2 Gas Turbine and Auxiliaries3.3.2.1 Starting system3.3.2.2 Turning Gear3.3.2.3 Load Gear and Accessories drive Gear3.3.2.4 Compressor Wet Washing System.3.3.2.5 Governor System3.3.2.6 Lubrication Oil system3.3.2.7 Fuel system3.3.2.8 Air Inlet system3.3.2.9 Exhaust system3.3.2.10 Unit Enclosure3.3.2.11 Fire Protection Equipment.3.3.2.12 Casing design3.3.2.13 Insulation and laggingGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)20

3.0 Power Plant Arrangement3.1 GeneralThe arrangement of the plant equipment shall be generally as described below:Gas Turbine Power Plant with a continuous total net generating capacity of 200MW to 300 MW consisting of 2-6 identical units shall be accommodated in thelocation proposed. Gas Turbines will be converted to combined cycle mode infuture. It is required to keep provision so that one (1) unit of 210 MW of GhorasalPower Plant can be run by the steam generated in the future HRSG(s) usingexhaust from the proposed Gas Turbines.3.2 GuaranteeThe net output and heat rate of the Unit shall be guaranteed by the contractor atthe following conditions:a. Ambient temperature : 95 0 F (35 0 C)b. Site elevation : less than 100 ft(msl)c. Relative humidity : 98%d. Barometric pressure : 1.013 bare. Generation voltage : 11,000 Vf. Power factor : 0.8 lagging to 0.95 leadingg. Frequency : 50 Hzh. Cooling water temperature : 90 0 F (32.2 0 C)The contractor shall guarantee the starting reliability of the Unit including allancillary equipment. The guaranteed reliability shall be stated in the Bid formtogether with the number of consecutive starts to which the Unit will be subjectedto demonstrate this reliability. (This is for a starting reliability of 95 %, the Unitshall be subjected to 20 consecutive starts of which 19 shall be successful) themaximum speed rise after full load rejection is to be guaranteed.3.3 Gas Turbine And Ancillary Equipment3.3.1. Basic Equipment Requirements.The Gas Turbine Generating (GTG) unit shall be of well proven design and theoffered model of GTG unit shall have satisfactory operating experience outsidemanufacturer's country for at least 2 (two) years. Tenderer shall have to submitat least one certificate (must be from outside manufacturer's country) from theend users in this respect. These certificate must be notarized or haveauthentication from the Chamber of Commerce of the Tenderer's country or theEmbassy/High commission of the end user’s country situated in Dhaka. Inabsence of that in Dhaka, authentication from bidder’s Embassy/HighCommission.The extent of supply shall include, but not be limited to, the equipment describedherein. All equipment comprising the gas turbine package shall be pre-assembledin the factory.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)21

3.3.2 Gas Turbine And AuxiliariesThe gas turbine generating unit shall be of the simple cycle heavy-duty industrialpackaged type suitable for outdoor installation and operation under the siteconditions as specified in Clause B1 of schedule-B.Vibration Critical SpeedThe radial amplitude of vibration of any rotating shaft under steady stateconditions at normal operating speed shall not exceed the value specified in APIStandard 616 when measured at the shaft local to the bearing. The critical speedshall be beyond ± 20 % of the operating speed of the engine.All compartments in the gas turbine generating unit shall be accessible forinspection and maintenance.The gas turbine unit shall be designed to burn Liquid fuel as well as natural gas asspecified.The unit shall be capable of frequent starts and stops without damage to the hotgas path components and shall be able to run for base load.3.3.2.1 Starting SystemThe gas turbine shall have electric motor driven starting equipment capable ofsustaining the complete starting cycle. The starting motor shall be capable ofcarrying out at least Five (5) consecutive starting without any harmful effect.3.3.2.2 Turning GearA rotor turning gear shall be provided to minimise thermal distortion of the rotorafter operation and to permit rapid reloading of the unit after a shutdown.Necessary oil piping and appurtenances shall be included. Turning gear oil pipingsystem shall be a part of the turbine lubrication system and shall be completewith all necessary pressure switches or other interlocks to prevent turning gearoperation if lubricating oil pressure drops below than pre-set value. Suitablehousing and safety guard shall be provided for all moving parts of the turninggear. Turning gear operation shall be indicated on the remote control panels. Theturning gear shall have automatic engaging and disengaging mechanisms.Additional arrangement for hand turning shall be provided for use in case theautomatic turning system fails to operate.3.3.2.3 Load Gear and Accessories Drive GearThe turbine shall be equipped with good quality and suitable load gear equipmentof proper rating if required to match the generator speed for 50 Hz generation.Load gear shall be totally enclosed and be equipped with forced lubricating deviceto the gear.The turbine shall also be equipped with suitable accessories driven gear unit.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)22

3.3.2.4 Compressor Wet Washing System1. System DescriptionsThe compressor wet washing system (On & Off line) shall basically comprise ofwash water tank with accessories, detergent hopper, interconnecting piping &valves, spray water manifold and spray nozzles. The various components of thesystem are shown in schematic diagram enclosed. Wash water tank shall be usedto draw and mix wash water and detergent to the required dilution, compressedair taken from existing instrument air header shall be used to pressurise this fluidand to forward to the spray water manifold. The spray nozzles shall make a highvelocity jet spray to clean the compressor blades while the rotor shall be kept inspinning operation.i) Wash water tank shall be a cylindrical pressure vessel with dished ends onboth sides. This tank shall be provided with necessary appurtenances andaccessories such asa) Compressed air inlet.b) Water inlet with isolation valve and inlet strainer.c) Breather vent with isolation valve.d) Drain line with isolation valve.e) Detergent inlet nozzle with isolation valve.f) Pressurised water outlet with isolation valve.g) Level gauge glass with isolation valves.h) Hand holes with covers.i) Pressure relief valves.j) Pressure gauge connection.ii)iii)iv)Detergent hopper to hold the detergent for every wash cycle.Interconnecting piping between wash water tank and compressor spraysystem. This line shall be provided with strainer, drain valve, pressuregauge, and orifice plate.Water wash manifolds.This manifold shall be located within the compressor inlet and it shalldistribute the wash water into the compressor inlet air stream. Themanifold shall be equipped with a drain valve.v) Set of spray nozzles shall effectively spray water I detergent water forefficient cleaning.To introduce the above-mentioned wet washing system for compressorcleaning of gas turbine generating unit. The following works shall bereformed:a) Installation of the wash water system.b) Providing spray nozzle on compressor inlet manifolds.c) Taking a tapping from instrument compressed air header to supplycompressed air for washing system.d) Routing the wash water to the Gas Turbine Compressor.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)23

e) Providing various drain lines with isolation valves at drain points from thecompressor and turbine to drain the wash water during washing cycle.f) Providing bearing seal air piping to protect bearing during washing cycle.g) Drainage system to drain out the water.2. Compressor wash water qualityTotal trace elements in compressor wash water (after adding detergent)will preferably be limited as follows.No. Trace Metal For Million Parts ofWater by weightSodium & Potassium30 ppmCalcium10 ppmpH 7.5 to 8.0The bidder shall design, manufacture and supply all the components (Viz.water tank, piping, valves, strainer, drains, manifolds, injection nozzles etc.) ofthe above mentioned compressor wet washing system of suitable grade ofmaterial to handle the above wash water without any deterioration. The biddershall clearly specify the proposed grade of materials of the above components.The bidder shall provide complete system including Demi Water Plant as permanufacturer's recommendation (if required).3.3.2.5 Governor SystemThe gas turbine unit shall be provided with a complete governing system whichshall be capable of maintaining a required constant speed under conditions of loadvariations, control the turbine load, combustion gas temperatures and preventturbine over-speed. The characteristics of the turbine generator unit and itsgovernor shall be such that the machine operates satisfactorily in parallel withexisting generating unit in the system.The speed governing system shall be provided with speed changing devicecapable of local and remote control. Provision shall be made to shutdown theturbine under emergency by local and remote control. The speed regulation shallbe adjustable (from no load to full load) between plus and minus 5 %. The ratedspeed at no load condition shall be adjustable within ±0.5 % for easysynchronising. The governing system for the unit shall also be provided withautomatic over-speed trip devices adjustable up to 110 % of the rated speed, anda load limiter.The governing system shall include an adjustable load limit control, minimum fuelregulator, temperature limit control, temperature increment rate control andnecessary protection equipment.The governing system shall be suitable for parallel operation with a large powersystem and also for completely isolated and independent operation. In addition tothe automatic speed governing system, a separate emergency over-speed tripmechanism and over combustion gas temperature trip system shall be furnishedon the unit.These systems shall operate to shut the emergency fuel trip valves.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)24

The distillate fuel oil system shall consist of two pumps (One standby, oneoperative) of suitable capacity for the maximum output of the turbine at lowestambient temperature at the site, along with necessary valves, piping, regulatingdevices, metering device, instrumentation, pressure switches and indicators.Scope of supplyOne distillate fuel supply system shall include, at least, the following equipment:-One off-base standardized forwarding skid consisting of the pumping andregulating equipment- One off-base standardized filtering (duplex cartridge type filters) located nearthe unit-Piping between forwarding and filtering skid and from the filtering skid up to thegas turbine unit-Unloading Fuel skid-2(Two) 50.00 lac litre distillate fuel storage tank with fixed roof having floatingsuction type delivery-Piping from unloading area to fuel tank.-For unloading: Two 100% (100m 3 /h) transfer pumps + Filters-Piping between the 50.00 lac fuel storage tank and pumping skid- Rehabilitation of existing fuel unloading facilities including jetty.-Fuel strainers-Flow-meter and totalise to measure fuel consumption-Pressure gauges on each side of fuel strainers, at pump suctions and discharge,and other critical points- Fuel oil pumps-Over speed and emergency trip stop valves-Control valves for starting and operating-Necessary isolation valves-All piping-Automatic control valvesScope of workThe contractor shall design, manufacture, inspect, test, deliver to the site andinstall of liquid fuel oil handling, conditioning and regulating facilities with allaccessories as specified hereunder for the plant.The unit shall be furnished with a complete liquid fuel oil system. The liquid fueloil handling system shall also be provided.1. Fuel forwarding skidFuel forwarding skid brings liquid fuel to the gas turbine at a pressure consistentwith the gas turbine fuel supply requirements.Equipment list:-Two (2) 100% fuel forwarding AC motor driven centrifugal pumps (one duty, onestandby), each for the maximum fuel flow necessary to the gas turbine-Three suction StrainersGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)26

-One fuel pressure regulating valve-One relief valve-Complete set of piping including valves, gauges and fittings of all linesterminating at the skid boundary2. Fuel oil filters SkidThis unit provides liquid fuel filtration up-stream the unit turbine and includes thefollowings:-Two fuel filters (one duty, one standby) : Filter cartridge -5 microns-One pressure metering panel board including : one manostat (fuel pressurecontrol), one different pressure gauge-One fuel accumulator-One stop valve-Complete set of piping including valves, gauges and fittings of all linesterminating at the skid boundary3. Fuel storage tankThe fuel storage tank is a vertical with fixed roof tank. Its capacity of each tankshall be minimum 50.00 lac litre. The fuel storage tank will be assembled in siteand includes the followings:-One fuel inlet flange-One fuel outlet flange with floating suction-Two manholes located in shell and in roof-Two foam chambers for fire protections-One visual level gauge-Various levels switch to provide alarm at subsequent level-one gas vent-One water drain-One spiral stairway and one top peripheral hand railing4. Unloading Fuel skidRequired piping, along with, other facilities that will be required for the systemfrom unloading base to the fuel tank to be constructed for the proposed plantshall be made by the contractor.The unloading fuel skid includes the followings-2x100% fuel screw pumps (one running, one standby), capacity of each 100m 3 /h and driven by AC motor.-Two suction strainers-Two headers, each with five unloading points-One flow meter-Piping and valves between above equipment5. Renovation of existing fuel unloading facilitiesRenovation work of the existing facility (fuel unloading jetty, valves & piping, fueltanks ect.) in the power stationGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)27

6. Sump tankThe sump tank allows draining liquid fuel from combustion system and fromexhaust plenum when there is false start. It may be preassembled and includesthe followings-One tank of 1 m 3 capacity-One manual pumpGas Fuel SystemFUEL GAS HANDLING FACILITIESSCOPE OF WORKThe Contractor shall design, manufacture, inspect, test, delivery to the site andinstall of natural gas handling facilities with all accessories as specified hereunderfor the plant.The gas turbine unit shall be furnished with a complete gas fuel system. The gashandling system including Gas Booster Compressor shall also be provided.NATURAL GAS SUPPLY SYSTEMTo forward the natural gas from the main gas supply header to the gas turbineunit and to adjust its supply pressure to normal operating pressure, theContractor shall furnish one (1) complete factory assembled skid mounted gaspressure regulating unit including all accessories and necessary pipe connectionsto the BOARD's gas supply header for gas turbine unit.Each gas handling unit shall comprise at least the following major items:Gas Booster Compressors (one running and one standby, each having capacity formeeting total gas requirement at all ambient temperatures with 10% margin)with necessary sealing, cooling, anti-surge device, proven control system etc.Inlet strainerA flow meter with bypass system and with integrationPressure gaugesPressure regulating equipmentSafety valve and relief valveA gas conditioner (scrubber, separator and others as required)Other equipment for satisfactory completion of the work.Each unit shall have guaranteed capacity, which matches or exceeds the gasturbine needs under all load operating conditions at site conditions.Specification of natural gas is shown on Appendix (Vol 2 of 3)Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)28

3.3.2.8 Air Inlet SystemThe air filtration arrangement shall be multi stage (pre-filter and high efficiency).Brief technical specification:a) One filtration unit for compressor air intake of Gas Turbine.b) Flow rate :c) Pressure droop : clean: 38mm water anddirty :76 mm water.d) Filter type :Pre-filter: WashableHigh efficiency filter : Disposablee) Cartridges/each filter :f) Filter media : water resistant, synthetic.The bidder shall supply 1 filter unit for Gas Turbine complete in all respectsincluding necessary supporting structures, holding frames, fasteners, pressureswitches, gauges etc. whichever are necessary. The bidder shall also submitnecessary design documents and drawings for this filtration system.Each air inlet system shall be provided with silencer if required capable of keepingthe sound pressure level as required by environmental regulations whenmeasured at a distance of 100 meter from the plant operating at full load as perISO standard.3.2.2.9 Exhaust SystemThe gas turbine unit shall be equipped with an exhaust duct and a suitable stack(height should meet the environmental protection requirement but not less than30 m). The exhaust system shall have a silencer to reduce the sound level asrequired by environmental regulations when measured at a distance of 100 meterfrom the plant when operating at full load.The duct shall be supplied complete with all necessary expansion joints thermaland acoustic insulation, manholes, drains, supports, bolting and jointing. It shallbe arranged in such a way that normal maintenance can he carried out on anycomponent without dismantling the duct.The Emission levels of exhaust have to be within the limit of environmentalprotection regulations.3.3.2.10 Unit EnclosureExcept as otherwise specified, all equipment shall be enclosed in a minimumnumber of prefabricated metal enclosures. The enclosures shall be constructed ina neat and workman like manner and shall present an attractive appearance.Enclosures shall be weather proofed and shall for wind loading of 100 miles /hour.Enclosures shall be designed to permit easy accessibility to the equipment and toGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)29

provide necessary protection for maintenance personnel. Sound absorbinginsulation shall be provided on the enclosures, Enclosures shall be provided withwalkways, steps, strains, and equipment doors of the locking type.Enclosure insulation, ventilation, and cooling shall be provided to maintaintemperatures suitable for personnel and for all systems whether standby oroperating. Unit control rooms shall be ventilated and air-conditioned.Turbine compartment and generator compartment shall be adequately ventilatedutilising forced ventilation with louvers and bug screens as required for protectionof the houses equipment from outdoor environmental conditions.Adequate interior lighting shall be provided, and emergency DC lighting shall alsobe provided, and those shall be energised through an automatic throw overcontractor when AC source fails.Enclosures shall be provided with 240 volt AC service outlets.3.3.2.11 Fire Protection EquipmentThe entire gas turbine generating unit including all auxiliary compartment shall beautomatically protected from fire with complete fire protection system completewith C0 2 gas system, fire detectors, pipe works, control and safety device.Actuation of the fire protection system shall be indicated at the controlcompartment and by a visual and an audible alarm to warn any personnel in thecompartments.3.3.2.12 Casing DesignThe casings of all the rotary parts on the main unit shall be spilt horizontally foreasy dismantling and inspection. Lugs for lifting the upper casing shall beprovided at points which will lift the casing half well balanced. Complete liftinggear together with lifting drawing and instruction shall be furnished.3.3.2.13 Insulation And LaggingThermal insulation shall be provided where necessary and is to include such partsas the combustion chambers, exhaust ducts and hoods. Removable insulationblankets shall be provided in all parts where insulation must he removed formaintenance purposes.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)30

Section 4Generator And Ancillary EquipmentGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)31

4. Generator And Ancillary Equipment4.1 Generator4.1.1 General Requirement4.1.2 Generator Rating4.1.3 Voltage and Short Circuit Ratio4.1.4 Temperature Rise4.1.5 Insulation4.1.6 Stator4.1.7 Generator Leads4.1.8 Bearings4.1.9 Rotor4.1.10 Temperature detectors4.1.11 Insulation against shaft current4.1.12 Accessories4.2 Exciter and automatic voltage regulator4.2.1 Exciter4.2.2 Automatic voltage regulator (AVR)4.3 15 kV Generator switchgear4.3.1 General4.3.2 Type and rating4.3.3 Construction and fitting4.3.4 Circuit breaker4.3.5 Current transformer4.3.6 Voltage transformer4.3.7 Surge absorbing equipment4.3.8 Natural Earthing Equipment4.3.9 Composition of Cubicles4.4 6.6 KV Common Switchgear4.4.1 General4.4.2 Type and Rating4.4.3 Construction and Fittings4.4.4 Circuit Breaker4.4.5 Composition of CubiclesGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)32

4. Generator and Ancillary Equipment4.1 Generator4.1.1 General RequirementsThe generator shall be designed and manufactured in accordance withInternational Electro-technical Commission Publication IEC 34.The generator shall be cooled by air, which in turn shall be cooled by water andair to water heat exchanger having independent closed circuit cooling watersystem [TEWAC type only].The MVAR leading capability shall not be less than 30 % of the MVA rating of thegenerator at 0.8 leading power factor. The generator in conjunction with itsexciters shall be designed to operate stably at all loads up to the maximumcontinuous rating.The generator shall be capable of operating continuously under unbalance loadingconditions when the negative phase sequence current component is less than 8%of the rated current.The generator shall be so designed as to minimise the effect of torsional rotoroscillation due to system disturbances and rapid load change. The generator shallwithstand continuous over-speed of 1.2 times of the rated speed without damage.The generator shall withstand 120% of rated current for more than 15 seconds.4.1.2 Generator Ratinga. Capacity at Site : To match gas turbine peak output at anyambient temperature.b. Power factor : 0.80 (lagging) to 0.95 lead.c. Frequency : 50 Hzd. Rated rotating speed : 3000 rpme. Rated voltage : 11 kV4.1.3 Voltage and Short Circuit RatioThe generator shall be capable of supplying the rated output at rated speed andat rated power factor with a voltage variation between 90% and 110% of therated voltage.The generator shall be designed to guarantee that a nominal short circuit ratio isnot less then 0.55 according to IEC 34.1.The generator shall withstand the electro magnetic and thermal stresses causingfrom short circuit fault at generator terminal without damage.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)33

4.1.4 Temperature RiseThe temperature rise of the generator under the base and peak rating operationsat any ambient condition shall not exceed the values given below:at Baseat Peaka. Stator winding by resistance 95 0 C 100 0 Ctemperature detectors methodb Field winding by resistance method 100 0 C 105 0 Cc. Cores and mechanical parts incontact with or adjacent toinsulated winding by thermometer 95 0 C 100 0 Cd. Bearing when measured onthe surface 40 0 C 40 0 C4.1.5 InsulationThe insulation of the armature and field windings of the generator shallsatisfactorily withstand high voltage tests as specified in IEC standard. Insulationof the armature windings, field windings, and collectors shall be class F.4.1.6 StatorThe cores shall be made up of high permeability, low loss, stampings, tightlyclamped together to reduce noise and vibration to a minimum. All burrs oflaminations shall be removed after punching. Sufficient ventilation ducts to ensureuniform cooling shall be provided. Clamping of the laminations and securing to thestator frame shall be done by approved methods. Attention shall be given toprevent vibration being transmitted to the generator foundations or associatedequipment.Protective covers and air shields shall be made of steel plates, welded, stiffenedwith suitable angles and channels, and formed in segments for case of handling.The segments shall be bolted together and to the stator frame.The windings, terminals, and leads shall be fully insulated throughout and braced,blocked and supported against the single and three-phase short circuits fault atthe generator terminals under any operating conditions.The general construction of the stator and bracing of the winding overhand shallprovide adequate cooling surface and to avoid the hot stops. The stator coils shallbe either semi or completely pre-formed and shall be made up before insertion tothe slots.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)34

4.1.7 Generator LeadsThe neutral and output ends of each phase windings shall be brought out to thegenerator terminal cubicle.The generator neutral shall be grounded through suitable transformer withsecondary resistor.The connection between generator terminal and 11 kV generator switchgear &Unit transformers shall be 11 kV Isolated (insulated) phase bus duct.4.1.8 Bearing4.1.9 RotorBearings shall be pressure lubricated by pressured oil from the gas turbinelubricating oil system, and oil drain pipes shall be equipped with pockets forthermometer and suitable sight flow opening for observing bearing oil flow.The packing blocks used especially in the rotor winding shall be of approvedmaterial and entirely suitable for the high temperatures and mechanical forceswhich may cause on rotors.The rotor slot insulation shall be mainly of epoxy resin or other approved materialand particular attention shall be given to the insulating and securing of coil to coiland slip ring connections, if any, and to avoid vibration and the possible failure toeither the connector or its insulation.Adequate precautions shall be taken against local overheating of the rotor surfacewhen neutral short circuits and single phase loading and the Contractor shallsubmit data showing permissible single phase and unbalanced three phaseloading. The rotor shall be capable of withstanding an over-speed test of 1.2times rated speed for two minutes.If slip-rings are provided, a grinder for slip-ring maintenance shall be supplied bythe Contractor.4.1.10 Temperature DetectorsMore than nine (9) resistance type detectors shall be provided for monitoring ofgenerator stator winding temperatures. The detectors shall be built into thegenerator, fully protected from the cooling air, suitable distributed around thecircumstances, and embedded in the slots in positions normally having the highesttemperature in accordance with requirements of IEC standards. All detectors shallbe wired out to a terminal box.4.1.11 Insulation Against Shaft CurrentOne of the bearings shall be suitably insulated to prevent flow of shaft current.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)35

4.1.12 Accessoriesa. Temperature detector (Refer to Clause 4.1.10)- normal use :more than 6 (six)-Spare:more than three(3)b. Thermometers and thermocouples at bearing drain of generator andexciter bearings, and at any other location required for operation monitor.c. Pressure gauge at bearing oil feed, and at any other location requiredfor operation.d. Alarm contactse. Spare heaterThe stator shall be equipped with space heater. During the generator stop, thespace heater shall be in service automatically.f. OtherOther instrument, terminal box, hardware buried into the generator foundationand all other necessary accessories for generator.4.2 Exciter And Automatic Voltage Regulator4.2.1 ExciterA complete voltage regulating and excitation system shall be provided. A completeand details description of the proposed system that meets the requirements ofthese specification shall be submitted with the Tender.A shaft mounted brushless type with static type control shall be provided.The excitation system shall match the generator rating and shall maintain thevoltage of the unit within a tolerance of plus and minus 0.5% of rated voltageregulation. The exciter shall have capacity to supply not less than 110% of thefield current required by the generator at rated output, power factor, frequencyand voltage.The rated voltage of the exciter shall be 110% of the machine excitation voltageat the rated output of the machine.The ceiling voltage of the exciter shall not be less than 140% of the matchingexcitation voltage. Insulation of stator and rotor winding of the exciter shall beclass F. A field breaker and discharge resistance shall be provided or alternativelyspecial provisions must be taken to either discharge or suppress excitationfollowing generator fault.The excitation system shall have ample capacity to permit operation throughoutits capability up to over-excitation and under-excitation limit as shown in themanufacturer's capability curves.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)36

Over excitation limiter and under excitation limiter shall be provided.4.2.2 Automatic Voltage Regulator (AVR)A quick response continuously acting regulator having a negligible dead-band andcharacteristics enhancing the transient stability of the generator shall be provided.The regulator shall be responsive to the generator line-to-line voltage and shallrestore the exciter output voltage to range of plus / minus 2% of the nominal presetlevel in a response time of less than 50 milliseconds. The accuracy ofcontrolling the AVR shall maintain the generator terminal voltage within plusminus0.5 % of the pre-set value for gradual change of output within the specifiedload range of the machine. It shall have the capability to adjust the generatorvoltage between a minimum of 80% of rated voltage (open circuit) and amaximum of 110%of rated voltage (full load).The regulator shall be equipped with devices which will provide compensating oroverriding signals to the regulator in response to the following conditions.a. Excessive exciter output current in the event of fault in the field circuit.b. Pole slip due to reverse induced field voltages.c. Under excited reactive current in excess of generator capability limitsd. Voltage drop due to generator reactance.e. Dynamic variation of generator output.Manual control shall be provided to set the generator terminal voltage between0% and 110% of the rated voltage.Automatic change-over from Auto to Manual system shall be provided in case ofabnormal/faulty PT Voltage.4.3 11 Kv Generator Switchgear4.3.1 GeneralThe generator circuit breaker shall be provided, and it shall be accommodated inmetal clad switchgear cubicle arranged for local and remote control.The switchgear and the associated equipment shall be fully metal clad andshall comprise:-- Switchgear bus bar- Voltage transformers- Current transformers- Surge protective equipment- Generator circuit breaker- Power fuse switch for station transformers- Cable termination facilities for 11 KV circuitGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)37

- Secondary wiring including cable termination facilities- Earthing facilities.4.3.2 Type And Rating1) The switchgear shall be of the metal clad type and shall comply with thestandards given below and with the relevant requirements stated in thisspecification.IEC 298 AC metal-enclosed switchgearIEC 85 Insulating materialsIEC 51 Electrical indicating instruments2) The switchgear busbar and associated connections shall have theinsulation levels as given below:System highest voltage : 17.5Withstand voltageLighting (impulse)(11.2/50micro sec.)Power Frequency (rms.)(For 1 mm.): 75 KV (peak): 28 KV3) The rated service voltage shall be of 11 KV.4) The current rating of the main bus bars shall not be less than ratedcurrent of the related generator and rating of the associated connections shall bedetermined by the Contractor.(5) The short time three phase fault level rating for one second of theswitchgear shall be of 80 KA ( rms) . The Contractor shall check the system faultcurrent level.4.3.3 Construction And Fittings(1) The switchgear shall consist of rigid welded steel cubicles and shall housegenerator circuit breaker, bus bars, current transformers, voltage transformers,neutral grounding transformer, surge absorbing equipment etc, The generatorcircuit breaker and the voltage transformers shall be withdraw able type. All doorsshall be padlock able and readily removable when necessary.(2) The bus bar and its connections shall be of copper and all joint surfacesshall be silver plated.(3) All bus bar connections shall be by bolted type. Flexible joints shall beprovided wherever for thermal expansion will occur.(4) Safety shutters actuated by inserting or withdrawing of the circuit breakershall be provided in the circuit breaker compartment.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)38

(5) Control circuit isolating connector shall also be provided.(6) Clearly labelled mechanical interlocks shall be provided in each circuitbreaker compartment to prevent:- a close circuit breaker from being withdrawn from or inserted into theisolating contacts;- A circuit breaker from being moved into any location unless it is fullywithdrawn:- a circuit breaker from being inserted into the fixed position unless thesecondary isolating contacts are fitted.- a circuit breaker from being closed except when fully inserted or fullywithdrawn:- a circuit breaker from being inserted into the fixed position unless thesecondary isolation contacts are fitted.- a circuit breaker from being closed except when fully inserted or fullywithdrawn:- a circuit breaker from being inserted against a locked safety shutter.7) A common earth bus bar shall be provided in the switchgear. The bus barshall consist of one copper8) All secondary wiring shall be terminated on terminal blocks in an enclosureseparate from the high voltage compartment.4.3.4 Circuit BreakerThe circuit breaker shall be of SF 6 gas type only.The circuit breaker shall comply with the requirements of IEC 56 and the relevantrequirements of these Specifications.- Rated Voltage :11 kV- Rated Current : 10 kA- Interrupting Current : 80 KA (rms) or higherOnly fully type tested circuit breakers complying with IEC 56 will be considered,and a statement as to the availability of certificates of all such type tests includingimpulse tests on identical or similar circuit breakers shall be submitted withTender.4.3.5 Current TransformerThe current transformers in the generator switchgear shall be of the epoxy resininsulated and of the bar or wound primary type. The ratio, rating, polarity andaccuracy classes [tariff metering] of current transformers shall conform to IEC185.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)39

4.3.6 Voltage TransformerThe voltage transformers shall be of the horizontally with draw-out type and shallbe located on top parts of each unit switchgear. Padlocking facilities shall beprovided for both the services and isolated positions. The fixed isolating contactsshall be covered by a positively driven padlockable shutter when the voltagetransformer is withdrawn.The ratio, rating, polarity and accuracy classes [tariff metering] of voltagetransformers shall conform to IEC 186.The current limiting fuses shall be providedon high tension circuit of the voltage transformer.4.3.7 Surge Absorbing EquipmentThe surge arresters and capacitors for surge protection of the generator shall beprovided.4.3.8 Neutral Earthing Equipment(1) Neutral Earthing TransformerA single-phase, 50 Hz, dry or oil immerse type, naturally cooled neutral earthingtransformer conforming to IEC 76 shall be provided for generating unit.The voltage ratio of transformer shall be 11,000/ 240 V. The continuous rating inKVA appropriate to an earth fault duration of 30 seconds and a maximum primaryearth fault current of 10 A shall be determined by the Contractor.Insulation level of primary winding shall be of BIL 75 KV.(2) Earthing ResistorThe resistance of secondary resistor on neutral earthing transformer shall beequal to one third of the zero sequence capacitance per phase of the generatorplus the bus bar capacitors if provided. The current rating shall be suitable for asingle phase to earth fault on the generator circuit for 30 seconds and a maximumprimary earth fault current of 10 A.The terminals of the resistor shall be corrosion resistance.4.3.9 Composition of Cubicles(1) Incoming Circuit Breaker Cubicle for each unit- Circuit breaker : One(1)- Current transformer :Three(3) units40 VA, Cl 0.2 & 5P20- End terminal :One(1) lotGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)40

- Ammeter with selector switch :One(1) set- Protective relays :One (1) set- Control switch, etc. :One(1) lot2) Voltage Transformer Cubicle- Voltage transformer :One (1) three phase unit- Under voltage relay :One (1) unit- Voltmeter with selector switch :One (1) lot4.4 6.6 Kv Common Switchgear4.4.1 GeneralThe common switchgear shall be fully metal clad arrangement for local andremote operation, and shall comprise the following cubicles:- Incoming circuit breaker cubicle for the unit auxiliary transformer.- Outgoing power fuse switch cubicle to station transformers.- Voltage transformer cubicle.- Outgoing circuit breaker cubicles to starting motor, GBC motors etc.The circuit breaker shall be of SF 6 gas or vacuum type.The circuit breaker shall comply with the requirements of IEC 56 and the relevantrequirements of these Specifications.All circuit breakers shall be identical in arrangement and shall be interchangeable.4.4.2 Type And Rating1) The switchgear shall be of the metal clad type and shall comply with thestandard given below and with the relevant requirement stated in theSpecification.IEC 298IEC 85IEC 51AC metal enclosed switchgearInsulation materialElectrical Indicating Instruments2) The switchgear busbar and associated connections shall have theinsulation levels as given below:System highest voltage : 7.2Withstand voltageLighting (impulse)(11.2/50micro sec.)Power Frequency (rms.)(For 1 mm.): 60 KV (peak): 22 KVGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)41

3) The rated service voltage shall be of 6.6 KV.4) The current rating of the main bas bars shall not less than the rating ofthe unit auxiliary transformer and rating of the associated connections shall bedetermined by the Contractor.(5) The short time three phase fault level rating for one second of the switchgear shall be of 40KA (rms).4.4.3 Construction And FittingsThe 6.6 KV common switchgear shall be designed and constructed as same asthose for 15 KV generator switchgear specified in Section 4.3.4.4.4 Circuit BreakerThe circuit breaker shall be of SF 6 gas or vacuum type.The circuit breaker shall comply with the requirements of IEC 56 and with therelevant requirements of this specification.All circuit breakers shall be identical in arrangement and shall be interchangeable.- Rated Voltage : 6.6 KV- Rated Current : 1250A- Interrupting Current : 50 KA (rms)Only fully type tested circuit breakers complying with IEC 56 will be considered,and a statement as to the availability of certificates of all such type tests includingimpulse tests on identical or similar circuit breakers shall be submitted withTender.4.4.5 Composition Of Cubicles(1) Incoming Circuit Breaker Cubicle for unit(s)- Circuit breaker : One(1)1250 A, 50 KA (rms)- Current transformer :Three(3) units600/300- 5A, 40 VA- End terminal :One(1) lot- Ammeter with selector switch :One(1) set- Protective relays :One (1) set- Control switch, etc. :One(1) lot2) Incoming Circuit Breaker Cubicles as spare- Circuit breaker :One (1)Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)42

1250 A, 50 KA (rms)- Current transformer :Three (3) units600/300- 5 A, 40 VA- End terminal :One (1) lot- Ammeter with selector switch :One (1) set- Voltmeter with selector switch :One (1) set- Protective relays :One (1) set- Control switch, etc. :One (1) lot3) Voltage Transformer Cubicle- Voltage transformer :One (1) three phase unit- Under voltage relay :One (1) unit- Voltmeter with selector switch :One (1) lotGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)43

Section 5TransformersGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)44

5. TRANSFORMERS5.1 General5.1.1 Requirements for Characteristics5.1.2 Requirements for Construction-5.2 Generator Step-up Transformer5.2.1 Type and Ratio5.2.2 Output and Required Numbers5.2.3 Impedance Voltage5.2.4 Winding and Insulation5.2.5 On Load Tap Changer5.2.6 Cable Box5.2.7 Phase & Neutral Circuit Current Transformer5.3 Unit Auxiliary Transformer5.3.1 Type and ratio5.3.2 Output5.3.3 Impedance Voltage.5.3.4 Winding and Insulation5.3.5 Off Load Tap Changer5.3.6 Cable Box5.4 Station Transformer5.4.1 Type and Ratio5.4.2 Output5.4.3 Impedance Voltage5.4.4 Winding and Insulation5.4.5 Off Circuit Tap Changer5.4.6 Cable Box5.5 AccessoriesGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)45

5. TRANSFORMERS5.1 GENERALThe transformers shall be designed and tested in accordance with IEC 76(1) Generator Step-up TransformerSingle phase, oil immersed, self cooled / forced air cooled (ONAN / ONAF),outdoor use type for stepping up the voltage from 11 KV to 230 KV with on loadtap changer having uniform insulation.The maximum continuous rating of the transformer shall meet at any taps a totaloutput of the generator, as defined in Vol. 2 of 3 clause 4.1.2 Generator Rating,which is connected with the transformer in series as shown in the attached singleline diagram. The maximum continuous rating of each transformer (one threephasebank of three single-phase Transformers out of four single-phaseTransformers and Vector Group = Ynd 11 ) shall be 120% (one hundred and twentyper cent) of the corresponding MVA (pf=0.8) of the Guaranteed Net Generatoroutput at Site condition of 35 0 C, 1.013 bar and 98% RH.The self cooled capacity shall not be less than 75 % of forced air cooled capacity.(2) Station TransformersThree phase, oil immersed type, self air cooled (ONAN) for stepping down thevoltage from 6.6 kV to 415 V with off load tap changer. The capacity of eachauxiliary transformer shall enable to supply 120% of the required power for theunit 415 V system.(3) Unit Auxiliary TransformerThree phase, oil immersed type, self air-cooled (ONAN) for stepping up thevoltage from 15 kV to 6.6 KV with off circuit tap changer. The capacity of stationtransformer shall enable to supply start-up power, medium voltage loads andcommon station load.5.1.1 REQUIREMENT FOR CHARACTERISTICS(1) EfficiencyThe transformers shall be of highest efficiency that the Contractor can attain.(2) Temperature RiseThe temperature rise of the windings shall not exceed 55 0 C when measured by heresistance method, after circulating the rated current at rated frequency in thewindings under test.The temperature rise of top insulation oil shall not exceed 55 0 C when measuredby a thermometer in an oil filled thermometer pocket on the cover or in the outletpipe to the cooler, and the method of the test of temperature rise will be decidedin accordance with IEC 76-2 .(3) Dielectric Test VoltageThe transformers shall withstand the following test voltages in accordance withIEC 76-3.a. 230 KV CIRCUITGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)46

(peak)- lightning impulse withstand test voltage : Relevant IEC Standard KV(1.2/ 50 micro sec.)- Power frequency test voltage : Relevant IEC Standard kV for oneminute.b. 11 KV circuit- lightning impulse withstand test voltage : 75 KV (peak)(1.2/ 50 micro sec.)- Power frequency test voltage :28 kV for oneminutec. 6.6 KV circuit- lighting impulse withstand test voltage :75 kV(Peak)(1.2 / 50 micro sec.)- Power frequency test voltage :28 kV for oneminuted. 415 V circuit- lighting impulse withstand test voltage : Not applicable(1.2 / 50 micro sec.)- Power frequency test voltage : 4.0 KV for oneminute4) No Load Excitation Current : The no load excitationcurrent under the rated voltage and frequency shall be as small aspossible.5) Mechanical and Thermal Strength for Short CircuitThe transformers shall be designed and constructed to withstand for threeseconds without damage the thermal and dynamic effects of external shortcircuits under the most severe conditions.(6) TolerancesThe tolerances on the guarantee values shall be in accordance with IEC 76-1.(7) NoiseVibration and noise levels of transformers shall be in accordance with the bestcommercial practice.5.1.2 REQUIREMENTS FOR CONSTRUCTION(1) Tank and Interior Structurea. The power transformer shall be of such structure to permit installation atthe Site to be simple.Assembling work at the Site such as staking of core and insertion of coil shall notbe allowed.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)47

. The tank shall be of the welded steel plate structure and shall withstandand hold continuously a vacuum of 760 mm Hg.e. The sealed joint part of the tank shall be designed to prevent oil and gasleakage and shall be water light even after long term use, and careful attentionshall be paid to fastening methods of packing of bushing, bursting tube, coolingradiator, connecting pipes and other accessories.d. Looseness of core, yoke, coil and other parts shall not happen duringtransportation and long term use.e. The transformer shall be provided with a bursting tube to discharge thepressure in case of abnormal rise of the inner pressure. The tube shall beequipped with alarm contact. The tube shall be extended up to tile oil pit whichwill be constructed around the transformer.f. No corona shall be discharged inside and outside of the tank under theimposed primary voltage of 230√3 KV x 130%.g. All generated gas and oil flow under fault conditions shall be concentratedto the Buchholz or similar type relay so as to ensure the relay action.h. The transformer shall be provided with skid type base.i. Anti-vibration rubber or the equivalent shall be provided under the base soas to prevent propagation of transformer's vibration to the other Equipment, ifinstalled in the power house.j. Winding of coils shall be designed so as to make the initial potentialdistribution caused by impulsive travelling waves as uniform as possible, to avoidpotential oscillation and to withstand abnormal voltage due to switching.k. The ground terminals of the transformer shall be copper faced steelground pad, and shall be welded on the tank wall near the base. The groundterminal shall be of the bolt fastened type, suitable for 100-200 sq. mm hard orannealed copper stranded conductors.l. In designing the transformers, the Contractor shall refer to the generalarrangement of the transformer and shall consider the location of the lightningarrester.(2) Bushing and Connection230 KV line and neutral bushings of the generator step-up transformer shall be oilfilled nitrogen sealed draw lead type with an oil level gauge, and 15 kV bushingsshall be of the solid type. The glazing colour shall be of brown.The lighting impulse (1.2/ 50 micro see.) insulation level of bushingsshall be as follows:- 230 KV line bushings :1050 kV peak- 230 KV line neutral bushing :1050 kV peak- 11 KV bushings :75 kV peakGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)48

The creepage distance of bushings of outdoor use transformer except neutralbushing shall not be less than 25 mm / KV of rated phase to phase voltage.(3) Oil Preservation SystemOil immersed transformers shall be provided with an oil preservation system inwhich the insulating oil shall be isolated from atmospheric air. The oil preservationsystem shall be of the diaphragm seal or air seal cell type conservator with silicagelbreather. Oil level gauge with low level alarm contact shall be mounted on theconservator.(4) Cooling systemAn adequate number of unit coolers shall be fixed to the tank of oil immersedtransformers, and the cooling capacity shall be sufficient to operate thetransformer under the rated power. The coolers shall be of such structure that willnot be affected by the vibration of transformer. A valve shall be provided witheach pipe connecting a unit cooler to the tank. Fixing bolts and terminals shall besuch that will never get loosened after being fastened. The power source of thecooling fans shall be 415 V, 3 phase or 240 V, single phase. The fans shallnormally be controlled by its own winding temperature relaying device.(5) Temperature DetectorOne (1) temperature detector shall be installed at the point where the highesttemperature is anticipated.(6) Protective DeviceThe following protection system shall be provided:- Buchholz relay and Pressure Relieve Device (PRD) similar type for alarmand trip- High temperature alarm and trip (winding and oil)A Buchholz relay or oil pressure relay shall be fitted on between the conservatorand the tank. A dial type thermometer with hand resetting maximum indicatorshall be provided. A Pressure Relief Device (PRD) with operation indicator shall beprovided.The gas relay should be provided with double float (one operated by volume ofgas flow and other operated by mass gas flow). It should have followingprovision:a. Gas release valveb. Mechanical test buttonc. Provision for testing both the floats by injecting air from outside.d. Drain cocke. Transport graduated windowf. The relay should be mounted at such a place that can be visible fromthe ground without climbing on the transformer.(7) WiringAll wiring mounted on the transformer shall be drawn through conduit pipes oradequate protective tubes to the control cabinet which shall be properly locatedon the transformer.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)49

The wiring shall be connected at the terminal blocks terminating the outgoingcontrol cable. The flexible tube of the vapour tension thermometer shall becovered by a protective tube.(8) Insulating oilThe insulating oil shall have a sufficient insulation strength, and shall be excellentin heat conductivity, low in viscosity and pour point, and high in flash point. Theoil shall not cause any corrosion to insulating materials and structured materials ofelectrical equipment and shall be chemically stable for long years of use.Delivery shall be made to Site partly contained in the transformers and partly insteel drums, according to the method of packing employed. An excess of 10% ofthe quantity of oil required for filling transformers shall also be supplied and itscost shall be included in the price of each transformer.(9) Skid BaseThe transformer shall be provided with a skid base with four (4) steel wheels andnecessary jacks for setting and appropriate devices for locking in position of itsfoundation.5.2 GENERATOR STEP-UP TRANSFORMERS5.2.1 TYPE AND RATIOThe transformer shall be of single phase, oil immersed, self cooled / forced aircooled (ONAN/ONAF) by cooling fans, outdoor use type. Ratio of delta starconnection shall be 11 KV to 230 KV on full load condition.The connection of the three phase bank shall be arranged in vector symbol Ynd11according to IEC 74-4 and neutral of star connected high tension winding shall besolidly grounded.The on load tap changer shall be provided on the high tension winding, and theirratio shall be as follows:230 kV(±1.25% x 8)5.2.2 OUTPUT AND REQUIRED NUMBERSThe maximum continuous rating of the transformer shall met at any taps a totaloutput of the generator which is connected with the transformer in series asshown in the attached single line diagram.The self cooled capacity shall not be less than 75 % of forced air cooled capacity.5.2.3 IMPEDENCE VOLTAGEImpedance voltage (+ve seq.) shall be within the range of 15% to 18% on theforced air cooled rating on the rated tapping (11/230 KV ) and shall beguaranteed by the Contractor.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)50

5.2.4 WINDING AND INSULATIONThe full installation shall be applied on both 230 KV (phase & neutral) and 11 KVwindings and neutral point of 230 KV windings shall be solidly grounded.The winding conductors shall be of high conductivity copper.The insulation shall be designed not merely by normal voltage per turn, but alsoby variation of line voltage and the operating conditions including impulse surgecaused by lightning strokes on the transmission line and switching surges.5.2.5 ON LOAD TAP CHANGERThe on load tap changer shall be provided on neutral side of 230 KV winding andshall be designed to meet the requirement of IEC 76. OLTC shall be of MR,Germany or ABB, Sweden only. Provisions shall be made for padlocking in any tapposition.5.2.6 CABLE BOX/Isolated & Insulated Phase Bus DuctThe cable box shall be provided on each transformer so as to cover the 11 KVterminals and 11 kV power cables down to ground surface. Proper cable supportsand cleats shall also be provided.Isolated and Insulated Phase Bus Duct shall be provided from Generator terminalto Generator circuit breaker and Generator circuit breaker to LV side of UnitTransformers.5.2.7 PHASE & NEUTRAL CIRCUIT CURRENT TRANSFORMERCurrent transformer shall be provided on the high tension neutral circuit forRestricted Earth Fault & Stand by Earth Fault relays and ratio should match withphases (LV & HV) Differential protection circuit. If necessary Inter-posing currenttransformers may be used.1) Use : Protection2) RatingsRated primary currentRated secondary currentAccuracy classRated burden: 400 - 800 A(depends on rating of transformer): 1 A: 5 P20:15 VA3) Requirements for characteristics and ConstructionThe current transformer shall be designed to meet the requirements of latest IECstandard.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)51

5.3 UNIT AUXILIARY TRANSFORMER5.3.1 TYPE AND RATIOThe transformers shall be of three (3) phase, oil immersed, self air cooled (ONAN)type. Nominal no load ratio of delta star connection shall be 11 KV to 6.6 KV.The connection shall be arrangement in vector symbol Ynd 11 according to IEC 76-4 and neutral of star connected low tension winding shall be earthed solidly.The off load tap changer shall be provided on the high tension winding, and theirratio shall be as follows:11 kV ± 2.50 % x5/ 6.6 kV Output5.3.2 OUTPUTUnit auxiliary transformer shall enable to supply 120% of required power on unit6.6 KV for the gas turbine generating unit and required common power on stationservice.5.3.3 IMPEDENCE VOLTAGEThe impedance voltage shall not less than 5 %, but not more than 7.5 % on therated tapping (11 KV/6.6KV) and shall be guaranteed by the Contractor.5.3.4 WINDING AND INSULATIONThe requirements shall be in accordance with section 5.2.4 for LV side.5.3.5 OFF LOAD TAP CHANGERThe off load tap changer shall be provided on 11 kV winding and shall bedesigned to meet the requirements of IEC 76. The tap changer shall be of threephase resistor equipment with rotary diverter switch, and shall be designed toprovide 10 tapping steps, i.e. 11 positions as follows.Central tap: 11 kVStep voltage : 2.50%Upper side : 5 taps (+2.5%)Lower side : 5 taps (-2.5%)All the mechanical operating parts of the gear shall be self lubricated withtransformer oil, no special lubrication being necessary. The tap changercompartment oil shall be isolated from main transformer tank oil, and thecompartment shall be provided with proper protection facilities and accessories.5.3.6 CABLE BOXThe cable boxes shall be provided on both high tension and low tension terminalsto terminate high and low voltage power cables. Proper cable supports and cablecleats shall also be provided.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)52

Non segregated bus duct between low tension terminals of auxiliary transformerand power centre terminals instead of cables may be acceptable.5.4 STATION TRANSFORMERS5.4.1 TYPE AND RATIOThe transformers shall be of three (3) phase, oil immersed, self air cooled (ONAN)type. Nominal no load ratio of delta star connection shall be 6.6 kV to 415 VThe connection shall be arrangement in vector symbol Dyn11 according to IEC76-4 and neutral of star connected low tension winding shall be earthed solidly.The off circuit tap changer shall be provided on the high tension winding, andtheir ratio shall be as follows:6.6 kV (5%) /415V -240 V5.4.2 OutputEach auxiliary transformer shall enable to supply 120% of required power on 415V for the gas turbine generating unit.5.4.3 IMPEDENCE VOLTAGEThe impedance voltage shall not less than 5%, but not more than 7.5% on therated tapping (6.6 KV /415V) and shall be guaranteed by the Contractor.5.4.4 WINDING AND INSULATIONThe requirements shall be in accordance with section 5.2.4, except voltage rating.5.4.5 OFF CIRCUIT TAP CHANGERThe requirements shall be in accordance with Section 5.3.5.5.4.6 CABLE BOXThe requirements shall be in accordance with Section 5.3.6.5.5 ACCESSORIESThe following accessories shall be furnished for each transformer:a. Name plateb. Valves for oil filtering and samplingc. Air vent valved. Manhole and hand-hole including blind coverse. Ladder fixed to the transformer tank for inspection of the upper part of thetransformer.f. Hanging hookg. Grounding terminalsGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)53

h. Anchor devicei. Oil preservation system including oil conservatorj. Oil level gaugek. Dial type thermometer with hand resettingmaximum indicatorl. Breather with silica-gelm. Other necessary accessoriesn. Connecting conductors including flexible connectors amongthe single phase transformer to compose three phase bank.(Step-up transformer only)0. Rail track in the transformer yard.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)54

Section-6230 KV SwitchgearGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)55

6. 230 kV OUTDOOR SWITCHGEAR, EQUIPMENT6.1 General6.1.1 Design Requirement6.2 230 kV Switchgear, Equipment6.2.1 230 kV Circuit Breakers6.2.2 230 kV Disconnecting switches6.2.3 230 kV Voltage Transformer6.2.4 230 kV Current transformer6.2.5 230 kV Lightning Arresters6.3 Steel Structure6.3.1 Type6.3.2 Design Criteria6.3.3 Requirements for Design and Construction6.3.4 Design Items6.3.5 Accessories6.4 Insulators and Wiring Materials6.4.1 Insulators6.4.2 Fitting6.4.3 Standard Conductor for Over Head Line6.4.4 Miscellaneous MaterialGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)56

6. 230 kV OUTDOOR SWITCHGEAR, EQUIPMENT6.1 GENERALThe contractor shall furnish the 230 kV outdoor switchyard equipment which shallcomply with as listed below or relevant IEC standard and the 230 kV equipmentshall be arranged in the outdoor as shown on the attached drawings or asdirected by the Board.6.1.1 DESIGN EQUIPMENT(1) System VoltageThe system shall be as follows:- Nominal system voltage : 230 kV- Highest system voltage : 275 kV(2) Insulation levelThe insulation level of the switchgear, equipment shall be as follows:Lighting impulse withstand test: 1050 kV(Peak)Voltage (1.2 / 50 micro sec.)- Power frequency insulation level(for 1 mm.) : relevant IEC kV(3) Outdoor Conductor Clearance- Phase to phase, standard :3000 mm- Phase to phase, minimum :2100 mm- Phase to ground, Standard :1900 mm- Phase to ground, Standard :1200 mm(4) Design ConditionsSwitchgear equipment shall be designed to avoid local corona formation anddischarge likely to cause radio interface, and to endure short circuit currentwithout thermal and mechanical failure for one (1) second. All cubicles andenclosures shall be vermin proof, dust resistance and weatherproof.6.2 230 kV SWITCHGEAR, EQUIPMENT6.2.1 230 kV CIRCUIT BREAKERS(1) TypeThree (3) pole, dead Tank type, high speed, outdoor, trip free in any position,hydraulic & spring operated SF 6 gas puffer, single flow type complete withhydraulic pump, tank, piping, conduit, wiring, and all other necessary accessories.(2) UseFor paralleling, control and protection.(3) Ratingsa. Rated voltage : 230 kVb. Rated insulation level-Lighting impulse withstand test voltage(1.2/50 micro sec.): 1050 kV (peak)Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)57

-Power frequency withstand voltage(for 1 mm.) : (As per relevant IEC) kVc. Rated frequency : 50Hzd. Rated nominal current : 1,250Ae. Rated short circuit breaking current : (As per relevant IEC) kA [rms,3 sec]d. Rated transient recovery voltage forterminal faults and rated characteristicsfor short line faults shall be in accordancewith IEC 56.g. Rated short circuit making current : (As per relevant IEC) kAh. Rated duration of short circuit : 1 seci. Rated operating time : Less than 40 m secj. Rated operating sequence (

g. Integrating time register for hydraulic pump shall be driven by a selfstarting synchronous motor through mechanical gears to record operatinghours of hydraulic pump and shall be able to perform four operationswithout AC power.h. Gas circuit breaker shall be provided with gas density detector respondingto gas density and pressure. This gas density detector shall have two (2)different functions according to the gas condition: The first step givesalarm and the second step locks the operating mechanism. Operatingmechanism which employs compressed air or hydraulic for driving thecircuit breaker shall be provided with pressure detector which have two (2)different functions according to compressed air or hydraulic condition :The first step gives alarm and the 2nd step locks the operatingmechanism.i. The weather and dust proof type control box shall be furnished with thecircuit breakers. The control box shall be equipped with all necessary partsto operate the circuit breaker, such as control solenoids, operating switchof remote and local control, auxiliary switch, terminal blocks, protectivedevices, indicating lamp sockets, and other accessories. An anticondensation electric heater with thermostatic switch shall be providedinside the control box.j. The circuit breakers shall be provided with an emergency push buttonswitch with cover to prevent inadvertent switching.k. The circuit breakers shall be provided with an electrical anti pumpingrelay.l. The supporting structure shall be free from mechanical vibration andloosening under long term use.m. The circuit breakers shall be designed to facilitate inspection,especially for those parts which need inspection frequently.n. The circuit breakers shall be filled with sufficient SF 6 gas.o. SF 6 gas leak detector shall be furnished.p. The circuit breakers shall be driven by hydraulic and spring latch. Hydraulicsupplying system shall be furnished with the circuit breakers, and shall beinstalled in weather dust proof type housing. The operating mechanismshall be designed to meet the requirements of IEC 56q. Temperature limitation shall be in accordance with IEC 56.r. The Contractor shall furnish all control cables, pipes or ducts andfittings between each phase and control box.s. The indicating lamp signals which display " on (red) “ and " off green)" ofthe main contacts shall be furnished on the each control box of circuitGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)59

eaker.(6) Dielectric Test Voltagea. Power frequency withstand voltage : (As per relevant IEC) kV for oneminuteb. Lighting impulse withstand voltageFull wave (1.2 / 50 micro sec.):1050 kV PEAKc. Test voltage on control circuit :2.0 kV for one min.(7) Tools and AccessoriesThe following tools and accessories shall be supplied for each circuit breakers.a. Name plateb. Position indicating lamps (red and green) or flags.c. Operation counter.d. Grounding terminalse. Gas, and hydraulic pressure gaugef. Safety valves, if anyg. Pressure drop protecting deviceh. Manual operation device.i. Auxiliary switchj. Control box with locking devicek. Steel supporting structure with anchor bolts and nutsl. Operating mechanism.m. Special tools for checking and testingn. Power outlet, single phase, 132 V, 10 A in control box0. Conduit pipesp. Communication facilities between switchgear and control roomq. Other necessary accessories, if any6.2.2 230 kV DISCONNECTING SWITCHES(1) TypeFor busesOutdoor, three (3) pole, single throw, group operated, horizontal break, rotatinginsulator, remote controlled motor operated type.(2) Ratingsa. Rated voltage :230 kV.(3) Requirements for Design and Constructiona. The disconnecting switches shall be so designed and Constructed inaccordance with IEC 129.b. The contact part of the blade shall be silver electroplated.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)60

c. The porcelain insulator shall be an outdoor and post type, and shall havecreepage distance not less than 25 mm/ kV of phase to phase voltage age.The glazing colour shall be of brown.d. An electrical or mechanical interlocking device shall be equippedbetween its related circuit breaker.e. Revolving parts shall be so designed that operation will be sure andsmooth under long term use without necessity of inspection, oiling.f. Auxiliary switches with three (3) spare parts “ a-b “ contacts, terminalblocks, indicator lamp sockets, etc. shall be accommodate in a control box shall beof the weather and dust proof type with locking device.(4) Dielectric Test Voltagea. Power frequency withstand voltage : (As per relevant IEC) kV for oneminuteb. Lighting impulse withstand voltageFull wave (1.2/ 50 micro sec.): 1050 kV PEAKc. Test voltage on control circuit :2.0 kV for one min.(5) Accessoriesa. Nameplateb. Control box with locking devicec. Grounding terminald. Auxiliary switchese. Steel supporting structure with anchor bolts and nutsf. Manual operation handleg. Motor operating mechanism with manual operationinter-lockh. Conduit pipesi. Other necessary accessories, if any6.2.3 230 kV VOLTAGE TRANSFORMER(1) TypeOutdoor, single phase, oil immersed with level indicator or gauge, N 2 gas sealedElectromagnetic type voltage transformer.(2) UseFor metering and protection(3) Ratingsa. Rated voltages- Primary :230/√3 kV- Secondary : 110/√3 V- Tertiary : 110/ 3 VGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)61

. Rated insulation level- Lighting impulse withstand voltage :.1050 kV peakFull wave (1.2 / 50 micro sec.)- Power frequency withstand voltage : (As per relevant IEC) kVfor one minutec. Rated frequency :50 Hzd. Rated burden- Secondary : (As per relevant IEC) VA- Tertiary : (As per relevant IEC) VAe. Accuracy class :1.0 (secondary):3 P (tertiary)(4) Requirements for Design and Constructiona. The voltage transformers shall be of hermetically sealed andaccessories shall be of weatherproof type. The glazing colour shall be of brown.b. Creepage distance of bushing shall not be less than 25 mm / kV of phaseto phase voltage.c. A protection device shall be provided against short circuit of thesecondary circuits of the voltage transformers.Unless otherwise specified, the characteristic and others shall comply with therequirements of IEC 186.(5) Dielectric Test Voltagesa. Power frequency withstand voltage: (As per relevant IEC) kV for oneminute on primary windingsb. Lighting impulse withstand voltageFull wave (1.2 / 50 micro Sec.):1050 kV PEAKc. Power frequency withstand voltage :2.0 kV for one minute.on secondary windings(6) AccessoriesThe following accessories shall be provided for each voltage transformer.a. Nameplatesb. Grounding terminalsc. Lifting lugsd. Steel supporting structure with anchor bolts and nutse. Junction boxesf Conduit pipesg. Other necessary accessories, if anyGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)62

6.2.4 230 kV CURRENT TRENSFORMERS(1) TypeOutdoor, single phase, oil immersed with level indicator or gauge, N 2 gas sealedporcelain clad type, quadruplicate cores.(2) UseFor metering and protection(3) Ratingsa. Rated current- Primary :1200-800 A [to be at actualrequirement]- Secondary : 1-1-1-1 Ab. Rated insulation level-Lighting impulse withstand voltageFull wave (1.2 / 50 micro sec.): 1050 kV PEAK-Power frequency withstand voltage : (As per relevant IEC)KV for one min.c. Rated frequency :50 Hzd. Rated burden :60 VA for protection and:30 VA for measuring.e. Rated continuous thermal current :120%f. Short time current ratings-Thermal rating (r.m.s. for one sec.)-Dynamic rating (peak)g. Accuracy classes-For metering :0.2, n‹5-For protection: (As per relevant IEC)(4) Requirements for Design and Construction: (As per relevant IEC) KA:2.5 times the thermalratingsa. The current transformer shall be of oil immersed hermetically sealedstructure type.b. Internal conductor shall be adequately reinforced taking into account overcurrent intensity.c. The junction box with terminals shall be provided for the secondary circuitconnections.d. Each current transformer shall be equipped with terminal block of shortcircuiting type.e. Creepage distance of bushing shall not less than 25 mm / kV of phase tophase voltage. The glazing colour shall be of brown.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)63

f. Unless otherwise specified, the characteristics and others shall comply withIEC 185 .(5) Dielectric Test Voltagesa. Power frequency withstand voltage : (As per relevant IEC) kV for oneminuteon primary windingsb. Lighting impulse withstand voltageFull wave (1.2/ 50 micro sec.):1050 kV PEAKc. Power frequency withstand voltage :2.0 kV for one minute.on secondary windings(6) AccessoriesThe following accessories shall be provided for each current transformer.a. Nameplatesb. Grounding terminalsc. Lifting lugsd. Steel supporting structure with anchor bolts and nutse. Junction boxesf. Conduit pipesg. Other necessary accessories, if any6.2.5 230 kV LIGHTNING ARRESTERS(1) TypeOutdoor, single phase, self standing, Metal-Oxide type with surge operatingcounter.(2) UseFor protection of 230 kV outdoor switchyard equipment and transformer windings.(3) Electric system to be protectedThree (3) phase, three (3) wire, neutral point solidly grounded system.(4) Ratings and Performancesa. Rated voltage : (As per relevant IEC) kVb. Rated frequency : 50 Hzc. Nominal discharge current : (As per relevant IEC) KAd. Type of duty : Heavy, Long durationDischargee. Pressure relief class : Cf. Lighting impulse insulation level : 1050 KV peak(1.2 / 50 micro sec.)g. Maximum residual voltage : (As per relevant IEC) KVh. Power frequency spark-over voltage : (As per relevant IEC) KV(5) Operating dutyThe arrester shall successfully interrupt the dynamic current repeatedlyconducted by impulse wave.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)64

(6) Requirements for Design and Constructiona. The series gaps shall be so designed that for practical purposes thevarious characteristics will not alter under the change of weather conditionsb. The various parts of the lightning arrester shall be of complete moistureproof construction so that the characteristics shall not be impaired under longterm use. Sealed parts shall be so designed to prevent to ingress of moisture orwater under long term use.c. The operation counter shall be equipped on the lightning arrester in eachphase and consist of a sure current recording and measuring device, such as amagnetic link surge crest ammeter, and counter for the number of discharges ofthe lightning arrester. It shall be located at the position convenient for inspection.d. Creepage distance of bushing shall not be less than 25 mm/ kV of phaseto phase voltage. The glazing colour shall be of brown.e. Unless otherwise specified, tile characteristics and others shall comply withIEC 99-1(7) Dielectric Test Voltagea. Power frequency withstand voltage : (As per relevant IEC) kV for oneb. Lighting impulse withstand voltage :1050 kV (peak)(1.2 / 50 micro sec.)(8) AccessoriesThe following accessories shall be provided for each lightning arrester.a. Nameplatesb. grounding conductor to grounding terminalc. Operating counterd. Grounding terminale. Steel supporting structure with anchor bolts and nutsf. Other necessary accessories, if any6.3 STEEL STRUCTURE (Busbar)6.3.1 TYPEThe steel structure shall be lattice truss construction made of galvanised formedsteel and assembled by bolts and nuts.The component members of steel structure shall have inter-changeability withother identical members. The basis framing of the steel structure shall be identicalon all four (4) faces below the bend line.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)65

6.3.2 DESIGN CRITERIAThe steel structure shall be designed in accordance with the following criteria.(1) Load due to the tension of conductor and wire.- 230 kV bus and outgoing conductor : 900 kg per conductor- Overhead grounding wire : 450 kg per wire(2) Vertical loadsThe weight of the conductors, grounding wires, insulator strings and steelstructures shall be taken into consideration.(3) Human Loads120 kg at the centre of the beam.(4) Wind loadsWind loads shall be calculated with wind speed of 100 miles / hr, but the windloads on unit projected area shall not be less than the followings:- On conductors and grounding wires :125 Kg/sq.m- On insulators and other circular section :130 Kg/sq.m- On lattice structures or beam structure :230 Kg/sq.m(5) Seismic Coefficient (Horizontal) : 0.10 g6) Working ConditionsThe normal working condition for various loads shall be deemed to worksimultaneously. The wind direction shall be classified into transverse, longitudinaland oblique components to the line route and the largest load acting on the lineshall be taken as the design stress of the component material.(7) Combination loadsThe Contractor shall calculate the maximum and minimum stresses at anycombination of loading conditions. The design of each type of steel structure shallbe made by the same manner of analysis. The design stresses of individualcomponents shall be largest value of maximum stresses in the respective loadingconditions.(8) Safety FactorsThe safety factors shall not be less than two (2) under the normal workingconditions.(9) Minimum Thickness and Size of Steel MembersMinimum thickness and size of steel members shall be as follows:a. Formed steel : not less than 45 x 45 x 4 mmb. Plate : not less than 4 mm thick.(10) Slenderness RatioGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)66

The slenderness ratio shall not exceed 120 for main members, 200 for bracingand 250 for other members.6.3.3 REQUIREMENTS FOR DESIGN AND CONSTRUCTION(1) WorkmanshipWorkmanship shall be first class throughout. All pieces shall be straight, true todetailed drawings and free from lamination, flaws and other defects. All clippings,back nuts, grindings, bends, holes, etc. shall be true to detailed drawings and freeof burrs.(2) GalvanisingThe steel structure shall be completely galvanised (Hot-Deep), except for partwhich shall be embedded in concrete foundation. All ferrous materials shall begalvanised to meet the requirements of IEC .(3) Materials of Steel StructureAll materials shall be hot rolled structural steel and or high strength structuralsteel.(4) MarkingAll products shall be marked with systematic numbers and / or colours forconvenience of assembly.(5) Future Extension of StructureIn designing the steel structure, consideration shall be given in the design criteriato permit easy extension of steel structure in the future and same loadingconditions shall be taken into account in accordance with the Specifications.(6) Bolts and NutsAll the members shall be connected by bolts and nuts. The diameter of theconnection bolts and step bolts shall not be less than 16 mm.6.3.4 DESIGN ITEMSThe Contractor shall submit to the Board for approval design sheets and drawingsincluding calculation of Loads, selection of constitution and members, selection ofconnecting bolts and calculation of reaction load against base concrete.6.3.5 ACCESSORIESThe following accessories shall be provided, but not be limited.a. Anchor bolts and nuts : One (1) lotb. Gauge plate for anchor bolt : For (4) of each kindc. U-hook bolts and nuts : one (1) lotd. Grounding terminals : one (1) lote. Step-bolts : one (1) lotf. “Roval” paint for repair : Five (5) Kgg. Phase identification plates : one (1) loth. Other necessary accessories, if any : one (1) lotGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)67

6.4 INSULATORS AND WIRING MATERIALS6.4.1 INSULATORS(1) Type and requirementsa. The insulator assembles shall consist of suspension insulator discs,hardware, strain or suspension clamps as required.b. The suspension insulators shall he of ball and socket type and shallconform to the requirement of IEC 120.c. The insulator unit shall be standard 254 mm porcelain disc type or fogtype 254 mm porcelain disc type, and have a spacing of 146 mm between discs.d. Total creepage distance of the insulator assemblies shall not be less than3300 mm.e. The insulators shall be wet-process porcelain of the highest glade, denseand homogeneous. The glaze shall be smooth, hard, dense and uniform and shallnot be effected by weather or sudden change in temperature, salty atmosphereand lighting during certain periods of the year. Colour of porcelain surface shall bebrown. All ferrous metals shall be galvanised except for female thread andstainless steel. Each insulator shall bear symbols identifying the manufacturer andindicating the year of manufacturer and tension proof test load.(2) Characteristics of Suspension Insulatorsa. Porcelain disc diameter : 254 mmb. Unit spacing : 146 mmc. Minimum electromechanical failing load : 21000 Kgd. Dimension of ball socket and pin : Conform to IEC(3) Characteristic of Insulator Assembliesa. Nominal system voltage : 230kVb. Highest system voltage : 275 kVc. Creepage distance not less than : 3300 mmd. Breaking strength of complete set : 1200kge. System insulation level- Basic impulse insulation level(1.2120 micro sec.) : 1050 kV peak- Power frequency withstands voltage(For 1 mm.): (As per relevant IEC) kV6.4.2 FITTINGThe suspension and tension clamps for bus works and outgoing feeders, tensionclamps for overhead grounding wires, U-bolts, ball eyes, anchor shackles, etc. forwiring of switchyard shall be furnished by the contractor. Unless otherwisespecified, all hardwire fittings shall be made by malleable iron or forged steel hotdip galvanised or aluminium alloy.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)68

All metal shall be free from rust, burrs, sharp edges, lumps and dross and shall besmooth so that interconnecting parts will fit properly and the parts may beassembled and disassembled easily. Hardware shall have ultimate strengthsexceeding three (3) times tension load of bus work and overhead ground wire.The cramps shall not be occurred in excessive heating by magnetising or othercauses.6.4.3 STANDARD CONDUCTORS FOR OVER HEAD LINES(1) 850 mm 2 , hard drawn aluminium conductorThe hard down aluminium stranded conductor of 850 mm 2 shall be used for 230kV bus bars and for outgoing feeder circuit. The conductors shall comply with therequirements of IEC .(2) Galvanised Steel WireThe galvanised steel wire of 55 mm 2 shall be used as overhead grounding wire.(3) Spools for ConductorsThe spools for conductors shall be made of steel and treated against corrosionand rust, and the following marking shall be indicated on an appropriate side ofthe spool.- Conductor number- Kind and cross sectional area of conductor- Conductor length- Spool weight- Name of manufacturer or abbreviation- Date of production- Position of beginning of conductor- Direction of rotation of spool- Indicator showing the remaining length of conductor6.4.4 MISCELLANEOUS MATERIALSAll miscellaneous materials such as phase mark plates, angle steel, C-shapedsteels, conduit pipes, cable cleats, bolts, nuts, and other materials for completionof the switchyard shall be provided by the Contractor.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)69

Section 76.6 Kv SwitchgearAndLow Tension SwitchgearGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)70

7. 6.6 kV SWITCHGEAR AND LOW TENSION SWITCHGEAR7.1 6.6 kV SWITCHGEAR7.1.1 CONSTRUCTION7.2 415 V SWITCHGEAR AND MOTOR CONTROL CENTRES7.2.1 SWITCHGEAR (POWER CENTRE)7.2.2 MOTOR CONTROL CENTERGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)71

7. 6.6 kV SWITCHGEAR AND LOW TENSION SWITCHGEARAs shown in the Auxiliary One Line Diagram, the auxiliary Power system shallconsist of the following equipment, but not be limited to:- 6.6 kV Switchgear- 415 V Switchgear and Motor Control Centres7.1 6.6 kV SWITCHGEAR7.1.1 CONSTRUCTIONType and Rating- TypeIndoor, steel sheet formed cubicle, single bus draw-out type- RatingRated voltage: 6.6 kV- Rated insulation levelLighting impulse withstand voltage : 60 KVPower frequency withstand voltage : 22 KV(1 min)- Rated frequency :50Hz- Rated normal currentIncoming and bus tie circuitFeeder circuitRated short circuit currentRated short circuit making currentNumber of circuit: 600 A: 600 A: 40 kA (rms.): 100 kA (peak): Determined by the Contractor buttwo (2) Spare feeders shall beincluded.(2) Draw-out SystemCircuit breakers shall be drawn out horizontally by hand, and primary and controlcircuits shall be disconnected from the buses automatically.(3) CompartmentCircuit breaker chamber and bus chamber shall be isolated by groundedsteel plates, and bus conductors shall be installed.(4) Front DoorEach compartment shall have hinged door mounted with instruments switches,indicating lamps and test terminals.(5) Rear PanelEach compartment shall have removable covers.(6) Leading of CableGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)72

Control cables shall be led from terminal blocks through front bottom offront bottom of cubicle.(7) Bus bar3-phase, 3-wire system. Copper bar, totally insulated. Buses shall besuitable for capacity continuous duty.a. Main bus, more than 1000Ab. Branch bus, more than 600 A(8) Control Power Bus2-wires DC 250 volt insulated wire.Branched circuit shall consist of two circuits of closing and tripping for everycircuit breaker.(9) Neutral Grounding ResistorLow tension winding of the station transformer shall be grounded throughneutral grounding resistor which is accommodate in the compartment of 6.6 kVswitchgear. The current rating shall be suitable for a single phase to earth fault on6.6 kV circuit for 30 seconds and a maximum neutral current shall not beexceeded 10 A.7.2 415 V SWITCHGEAR AND MOTOR CONTROL CENTRESAs shown in the Auxiliary One Line Diagram, 415 V switchgears and motor controlcentres shall be supplied to control all electric motor driven auxiliaries and supplypower to the other electric load of the generating plant. If control centres ordistribution panels not described in this Specification be needed, they shall besupplied with each facility.The switchgears and motor control centres are classified into the following:- One (1) sets of 415 V common switchgear- Three (3) sets of 415 V unit switchgears- Four (4) sets of 415 V motor control Centres7.2.1 SWITCHGEAR (POWER CENTER)(a)Type and Rating- TypeIndoor, steel sheet formed cubicle, single bus draw out type.- RatingRated voltage:415 VRated frequency:50 HzRated normal currentIncoming and bus tie circuit:2,500 AFeeder circuit:600 ARated short circuit current:40 KA(rms)Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)73

- Number of circuit :Determined by thecontractor, but 2(two)spare feeders shall beprovided.(b)Kind of UnitDetermined by the Contractor, but 2 (two) spare feeders shall be provided oneach switchgear. The switchgear shall be of 3 phase, 4 wire, neutral solidlygrounded, 415 V power centre type with circuit breakers 40 kA interruptingcapacity. The switchgear shall contain the following kind of circuits as general.Incoming and bus tie circuit2,500 A, 40 kA (rms) ACB- Motor feeder circuit600 A, 40 kA (rms) ACB- Feeder for motor control center600 A, 40 kA (rms) ACB- Voltage transformer unitAll circuit breaker shall be able to draw out horizontally.C. CompartmentGrounded metal plate shall be provided to separate between the units and circuitbreaker section and bus bar section.Conductor shall be insulated.(d) BusBarsBus bars shall be copper bars with insulating cover.(e) Cable ConnectionPower cables and control cables will be led from the terminals through rearbottom of cubicle.(f) Control PowerThe switchgear7.2.2 Motor Control Centrea. Type and Rating- TypeIndoor, steel sheet formed, self standing dual face type motor control centre.- RatingRated voltageRated voltage- Rated normal currentIncomingFeeder circuit: 415 V: 50 Hz: 2,500 A: 450, 200 or 100 A- Rated short circuit current : 40 KA(rms)- Number of circuit : as requiredGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)74

including two(2)spare feeders oneach motor control centre.b. Kind of UnitThe motor control centre shall be of 3 phase, 4 wire, neutral solidly grounded,415 V motor control centre type and shall contain the following circuits asrequired.- Incoming2,500 A, 40 kA (rms), moulded circuit breaker.- Motor feeder circuit400, 200 or 100 A, 40 kA (rms) moulded circuit breaker, contactor, and reserveunits if required.- Non- motor feeder circuit400, 200 or 100 A, 40 kA (rms) moulded circuit breaker.c. CompartmentGrounded metal plate shall be provided to separate between the unit and C B.section and bus bar section conductors shall be insulated.d. Draw-out systemControl centre unit and incoming circuit breaker shall be drawn out horizontally byhand and main circuits shall be disconnected from bus bar.e. Motor Feeder UnitEach unit shall have hinged door on which circuit breaker operating handles,indicating lamps, operating push button and miscellaneous attachment shall bemounted.f. Non-motor Feeder UnitEach unit shall have hinged door on which circuit breaker operating handles andmiscellaneous attachment shall be mounted.g. Cable connectionPower cables and control cables will be led from the terminals through frontbottom of cubicle.h. BusbarsBus bars shall be copper bars with insulating cover.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)75

Section 8Control And ProtectionGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)76

Page8. CONTROL AND PROTECTION EQUIPMENT8.1 General requirements8.1.1 Control Functions of Gas Turbine Generating8.2 Gas Turbine Generating Unit Local Control8.3 Gas Turbine Generating Unit Protection8.4 Gas Turbine Generating Remote Unit Control8.4.1 Gas Turbine Generating Unit Remote Control Switch8.4.2 Gas Turbine Generating Unit Remote Indication8.4.3 Gas Turbine Generating Unit Remote Metering8.5 Local Control and Instrument Panel for Gas Turbine GeneratingUnit8.6 230 kV Switchgear Control and Protection8.6.1 230 kV switchgear, equipment panel8.6.2 Step up Transformer Panel8.6.3 Synchronising Panel8.6.4 Modification of existing Protection Panels8.7 Desk Board 15 kV Common Switchgear8.8 Desk Board for Auxiliary Power Supply8.9 Instrumentation and Controls8.9.1 Design Requirements8.9.2 Control8.9.3 Control Equipment8.10 Panel ConstructionGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)77

8. CONTROL AND PROTECTION EQUIPMENT8.1 GENERAL REQUIREMENTSThe Contractor shall supply and install all control, protection and instrumentpanels with measuring instruments, relays, control switches, automaticcontrollers, annunciator, etc. necessary for proper operation and monitoring of thegas turbine generating units, switchyard equipment and their associated facilities.All Control & Protection System must be Micro-Processor based [Numerical] andProtective Relays shall be from ABB/ALSTOM/SIEMENS.8.1.1 CONTROL FUNCTIONS OF GAS TURBINE GENERATING UNIT [HMI,Computers]Gas Turbine Control System shall be of latest type and all Human MachineInterface [HMI] shall be of industrial grade. Detail of GT control system shall haveto be furnished as per designer's recommendation including data logging, storage,printing facility etc.The unit shall be furnished with an automatic control system suitable forunattended operation in base load or peak load operation. The automatic controlsystem shall have a sequence the unit for normal start-up, emergency start-up,synchronisation, operation, spinning reserve, voltage control, load control, stationperformance monitoring, normal shutdown, emergency shutdown, and return tostandby status.Upon actuating the normal start control, the unit shall be started, come up to therated speed, synchronised, closed the main circuit breaker and, when paralleloperation, picked up a preset base load which can be adjusted fromapproximately zero to the full capability of the unit. A" Base-Peak” selector switchlocated on the control panel shall permit the operator to select the loading of theunit at base or peak rating.During either parallel or isolated operation, loading shall be manually controllablein addition to the automatic controls provided during either parallel or isolatedoperation, voltage shall be manually controllable in addition to the automaticcontrols provided.Upon actuating the stop control the unit shall be reduced its load gradually bypre-set programming, the generator circuit breaker shall be opened, speed shallbe reduced to turning gear rotational speed, the turning gear shall be engagedand the unit shall be returned to standby status. An emergency stop control shallbe provided.The units shall be automatically prevented from starting, or if operating, shall beautomatically shut down upon the occurrence of abnormal conditions ormalfunctions, which would be injurious to the unit.All auxiliary sequence, timing voltage, synchronising, load sensing and protectiverelays required for complete automatic control and protection of the unit shall beprovided.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)78

8.2 GAS TURBINE GENERATING UNIT LOCAL CONTROLThe unit shall have its own local unit control panel which is completelyindependent of the control panels for the other unit.Equipment, materials, accessories furnished, mounted, and connected on the localunit control panel shall include, but not limited to, the following.- Normal start-stop switch- Emergency stop switch- Base- peak load selector switch- Manual load control- manual voltage control- Synchroscope switch- Synchroscope, synchronising lights, and incoming and running voltmeters- Status lights to indicate: Standby, starting, on-line, Emergency shutdown,etc.- Speed indicators- Frequency meters- Fired time indicator in both base load operation and peak load operationThree start counters:No. of start signalsNo. of fired startsNo. of breaker closing- Generator ammeter with selector switch- Generator voltmeter with selector switch- Bus voltmeter with selector switch- Generator watt meter- Generator voltmeter with selector switch- Bus voltmeter with selector switch- Generator watt meter- Generator var meter ( zero centre)- Generator watthour meter with indicating lamp for voltage failure(Class 0.2).- Generator varhour meter(Class 0.2).- Watt and Var strip chart recorder- Power Factor Meter.- Test switch- Multipoint recorder for: Air temperature Lube oil temperature Bearing temperature Critical turbine gas temperatures Bearing vibration- Integrator for fuel flow- Annunciator with test, acknowledge and reset push buttons and horns toIndicate malfunction of the unit.- Synchronising auto/ manual selector switchGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)79

- Automatic synchronising equipment for synchronising to energised or deenergisedthe system.- Voltage regulator- Vibration monitor- Temperature meter with selector switch (generator, etc.)- Excitation voltmeter- Excitation ammeter- Field breaker control switch and lights- Control switches and lights for generator breaker- Engraved nameplate for each itemThe automatic synchronising equipment shall include, but not be limited tothe following.- Automatic synchroniser- Speed matching- Voltage matching- Voltage acceptance- Synchronising check or synchro- acceptorThe contractor shall furnish all control equipment, meters, relays or similardevices not specifically listed but those are required for the sound operation of theunit.8.3 GAS TURBINE GENERATING UNIT PROTECTIONAutomatic protection devices complete with annunciator system shall be providedto protect the gas turbine generating unit at all items, regardless of weatherlocally or remotely controlled, against any mal function of the unit or controlsystem and shall, at least, include the following:Alarm Alarm & Gen AlarmCB Trip & GT shutdowna. Unit DC Supply under-voltageand ground faultxb. Auxiliary motor overload xc. Inlet air filter differentialpressure highxd. Cooling liquid level low xe. Fuel oil inlet pressure low xf. Fuel(Liquid/gas) inlet pressure low xg. Rotor vibration high:-1st stagex2nd stage x xh. Turbine over-speed x xi. Generator under frequency x x xj. Incomplete start sequence xk. Bearing temperature high:1st stagex2nd stage x xAlarm Alarm & Gen AlarmCB Trip & GTshutdownGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)80

1. Exhaust temperature high:1st stagex2nd stage x xm. Exhaust temperature unbalance xn. Generator stator temperature:1st stage x2nd stage x x0. Lube oil pressure low:1st stage x2nd stage x xp. Lube oil temperature high:1st stage x2nd stage x xq. Lube oil tank level abnormal xr. Generator differential x xS. Generator over-current xt. Generator reverse power xu. Loss of excitation xv. Negative phase sequence current:1st stage2nd stagexxw. Generator over voltage xx. Generator under frequency xy. Generator under-voltagexz. Generator ground:1st stage x2nd stage x xaa. Generator field ground xbb. Generator breaker ground xcc. Field breaker trip x xdd. Exciter trouble xAlarmAlarm & Gen AlarmCB Trip & GT shutdownGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)81

ee. AVR failure xff. Emergency Trip (Manual) x xgg. Fire x xThe above alarms shall be indicated individually, and arranged formanual resetting and remote acceptance.8.4 GAS TURBINE GENERATING REMOTE UNIT CONTROL [HMI(industrial grade), Computers]The bench board type remote unit control panels shall be provided so as to allowthe following minimum features of remote operation, indications and alarms.(1) Start the unitThe operation shall bring the unit automatically through all the stages of start upand synchronize the generator to the system, and taking the load.(2) Stop the unitThe generator shall be automatically unloaded, tripped off the circuit breaker andthe turbine shutdown.(3) Active load controlActive load raise or lower control shall be connected to the governor speed controlcircuit.(4) Reactive load and voltage controlReactive load and voltage raise or lower control shall be connected to thegenerator AVR system.(5) Base load / peak load selection(7) Emergency stop8.4.1 GAS TURBINE GENERATING UNIT REMOTE CONTROL SWITCHTile following control switches shall be provided, but not be limited to, on theremote unit control panel.a. Unit start / stopb. Active load raise / lowerc. Voltage raise / lower (Reactive load control)d. Mode changeover base / peake. Fuel changeover base / loadf. Synchroniser switch manual / off / autog. Generator operation modeGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)82

8.4.2 GAS TURBINE GENERATING UNIT REMOTE INDICATIONThe following remote indications shall be provided, but not be limited to, on theremote unit control panel.a. Ready to startb. Auxiliaries runningc. Normal start sequence in progressd. Start sequence completede. Shutdown sequence in progressf. Generator breaker open / closeg. Flame indicationh. Temperature control indicationi. Fuel selection Liquid Fuel / Gasj. Mode selection indication base / peakk. Generator operating model. All trip cause.8.4.3 REMOTE METERINGThe following metering instruments shall be provided, but not be limited to, onthe remote unit control panel.a. Generator active power outputb. Generator reactive power output ( MVar)c. Generator Power Factorc. Generator bus voltaged. Speed indicatore. Generator coolant and stator temperature (deg. C)f. Generator frequencyg. Generator stator currenth. Filed current and voltage (A and V)i. Averaged exhaust temperature ( deg. C)8.5 LOCAL CONTROL AND INSTRUMENT PANEL FOR GAS TURBINEGENERATING UNITThe local control panel shall be installed near the associated auxiliary equipment.The type of the panel shall be decided depending on the installed locations.(1) Local Control Panela. Indoor type panelIt shall be of steel made totally enclosed, front door type. Operation indicatinglamps, operating switch, name plate, etc. shall be fitted on the front door.b. Outdoor type panelIt shall be of steel made totally enclosed weatherproof type with double frontdoor. Operation indication lamps, operating switch, name plate, etc. shall be fittedon the inside door so as to prevent them getting wet on rainy days. The outsidedoor shall be with glass window so that the instruments fitted on the inside doorGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)83

can be seen through the window without opening the outside door. And thestructure of the panel shall be so designed as to be of rainwater proof and toprevent rusting on the hinges due to rainwater.(2) Local instrument PanelIt shall be of steel made for indoor use, vertical and self-standing type withdouble swing door on the back. Indicating instruments such as pressure gauges,etc. shall be fitted on the front panel and the pressure switches and thetransmitters for recorder, etc. shall be fitted inside the panel. Accessories such astest valves, orifice, etc. necessary for the various tests shall be installed inside thepanel so that calibration of instruments, confirmation test of setting value forpressure switches, etc. could be carried out without removing the instruments.The connection of electrical wiring and instrument pipes between inside andoutside panel shall be made at terminal block. The instruments and devices shallbe so arranged that in case of any leakage of oil or water from the instrumentpipes in the panel will cause no damage to the electrical equipment inside thepanel.8.6 230 kV SWITCHGEAR CONTROL AND PROTECTION8.6.1 230 kV SWITCHGEAR EQUIPMENT PANELThe following panels for controlling, indicating and protecting of 230 kVswitchgear equipment shall be provided, but not to be limited to, in the centralcontrol room:A. One (1) no of step-up Transformer panelB. Synchroniser PanelAll front panels of the above shall be equipped with control and metering facilities,and all rear panels shall be equipped with protection relays. The relays to beprovided under this Project shall be suitable for proper coordination with theexisting relays of the System.8.6.2 STEP UP TRANSFORMER PANEL [for GTG](1) FRONT PANELThe front panel shall be equipped with the following items of controls andinstruments, but not be limited to:One (1) lot 230 kV circuit breaker control switch.One (1) lot 230 kV disconnecting switch control switch.(optional)One (1) lot Ammeter selector switchOne (1) lot Synchronising key switch, removal types.One (1) lot Ammeter (230 kV side) (0-600 A), Voltmeter & pf meterTwo (2) sets Unidirectional watt hour meter (230 kV side) with provision ofreserve stop for export and import of energy and with indicating lamps forvoltage failure [Cl 0.2].One (1) lot Mimic busOne (1) lot Annunciators (minimum 15 windows)(2) REAR PANELGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)84

The rear panel shall be equipped with the following items of protection, but notbe limited to:One (1) lot Overall differential relayOne (1) lot Step-up transformer primary over-current relayOne (1) lot Step-up transformer neutral over-current relayOne necessary auxiliary relays, test terminal blocks, lockout relays, etc. shall alsobe provided.Step Up Transformer (s) protection & integration of the new 230 KV feeder (s)within existing 230 KV Busbar protection scheme is within contractor scope.8.6.3 SYNCHRONIZING PANELSwing type synchronising panel shall be equipped with the following itemsinstruments, but not be limited to:One (1) SynchroscopeTwo (2) Voltmeter (0-150 kV)Two (2) Frequency meter (45-55 Hz)8.6.4 MODIFICATION OF EXISTING CONTROL & PROTECTIONPANELS AT GHORASAL POWER STATION (n/a)8.7 DESK BOARD FOR 11 KV COMMON SWITCHGEARThe desk board for 11 KV, instruments, and other necessary things:One (1) lot Control switch for 11 kV circuit breaker for incomingOne (1) lot Control switch for spare 11 kV circuit breakerOne (1) lot 11 kV bus voltmeter selector switchOne (1) lot Incoming circuit ammeter selector switchOne (1) lot 11 kV bus voltmeter (0-11 kV)One (1) lot Incoming ammeter (0-6000 A)One (1) lot Spare breaker watt meterOne (1) lot Spare breaker Var meterOne (1) lot Spare breaker watt-hour meter with indicating lamp for voltagefailureOne (1) lot Mimic busOne (1) lot Annunciators (minimum 15 windows)One (1) lot Test terminal blocksFor starting motor control switch , one (1) ammeter with selector switch for themotor shall also be provided on this panel.8.8 DESK BOARD FOR AUXILIARY POWER SUPPLY Required no. of 6.6 kV and 415 V incoming circuit breaker control switch. Required no. of 6.6 kV and 415 V bus tie circuit breaker control switch. Required no. of 6.6 kV and 415 V feeder circuit breaker control switchGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)85

Required no. of 6.6 kV and 415 V voltmeter selector switch. Required no. of 6.6 kV and 415 V incoming circuit ammeter selectorswitch.Required no. of 6.6 kV and 415 V bus voltmeter. Required no. of 6.6 kV and 415 V incoming circuit ammeter. Required no. of 6.6 kV and 415 V incoming circuit watt-hour meter ( forAuxiliary transformer and one common auxiliary transformer) withindicating lamps for voltage failure. One (1) lot Annunciators (minimum 15 windows). One (1) Mimic bus. One (1) Test terminal blocks8.9 DESK BOARD FOR HRSG CONTROL (in case of steam injection)One (1) set of water/steam pressure monitorsOne (1) set of water/steam temperature monitorsOne (1) lot of control switches.8.10 INSTRUMENTATION AND CONTROLS8.10.1 DESIGN REQUIREMENTSControl signals and instrumentation signals shall not be affected by stray ACvoltage or other interface of any type normally found in a power station. TheContractor shall supply shielded cables and surge arresters where necessary.Shock absorbing mountings shall be supplied for instrumentation equipmentwhere required.Each component shall be identified and tagged with a designation number.Instrument scale ranges shall be expressed in SI units metric units.8.10.2 MEASUREMENTSMeasurements shall be taken for plant operation and control, and forheat balance and equipment's performance & efficiency calculationsincluding supply of software on on-line plant performance monitoring &optimisation to interface with Plant Control, Protection, Monitoringsystem.The main modules of on-line plant performance monitoring & optimisationpackage shall comprise of 1) Data Acquisition; 2) Data Validation & on-line HeatBalance; 3) On Line Performance Module & 4) On Line Optimisation Module.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)86

(1) Pressure MeasurementPressure shall be measured near the pump discharges, pump suctions whereNPSH availability is critical, at either side of equipment where pressure drop idsignificant, pressure regulated process, remote end of service lines, and near flowand level measurements affected by compressibility or density changes.Normal operating point shall be approximately 60% of the range, over-rangeprotection of at least 1.3 times the maximum scale reading shall be furnished onall pressure instruments. Accuracy shall be plus / minus 0.5% of calibrated spanfor bellows or bourdon tube transmitters at the minimum.(2) Temperature MeasurementTemperature at appropriate locations at compressor discharge, turbine wheelspace, exhaust gas, rotor shaft bearings, stator windings, critical turbine metalpoints, lube oil, radiators, etc. shall be measured.In general, temperature element shall be thermocouples, resistance temperaturedetectors may be used as sensors for control loops. Thermocouples shall becooper-constan for temperatures upto 200 0 C iron constantan up to 750 0 C, andchromel alumel up to 950 0 C. Cold junction compensation shall be achieved in thecontrol room. All extension wires from thermocouples and resistance temperaturedetectors shall be shielded. Thermocouples shall be accurate to plus / minus 0.75% maximum measured temperature.Resistance temperature detectors shall have platinum resistance windings andshall be connected by the three-wire method. Resistance temperature detectorsshall have an accuracy of plus / minus 2 0 C. Local temperature gauge shall bebimetal thermometers and shall have 80 mm round dial at minimum with blackand white markings.Welded wells for temperature element shall be the same material as theassociated piping systems. All screwing wells shall be stainless steel.(3) Level measurementLevel shall be measured in all tanks and vessels. Measurement of level in large orpressurised vessels shall be by differential pressure. Local level indication of smallbe by gauge glass for clear liquids, and by a top mounted float or bubbler forviscous liquids. Level controllers shall be of the differential pressure, or externalcage displacement type.(4) Flow measurementFlowmeters shall, with the exception of the area meter, operate on therelationship which exists between differential pressure and fluid velocity.Flowmeters shall have liner outputs. Accuracy for fuel flow meter shall be within2.0% at rate of flow higher than 80%.Flow metering of fuel shall be temperature and / or pressure compensated & withintegration.For flow-metering of oil, positive displacement meters or area meters shall beused.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)87

8.10.3 CONTROL EQUIPMENT(1) TransmittersIndicating transmitters shall be provided for control loops as required.Transmitters shall be substantially unaffected by changes in temperature and inprocess static pressure over a range from zero to twice the normal operatingpressure. Transmitter shall feature accessible zero. and span adjustment.(2) Final Control ElementsControl valves and damper actuators shall be pneumatic, where necessary,provided with electric- to-pneumatic converters. The response of final controlelements shall have minimum time lag.a. Control ValvesControl valves rated at 2,00 kN/ sq.m (300 lbs ASA) and below shall be flangedand higher rating shall be welded. Valves shall with stand shock loads imposed bythe processor. control valve actuators shall be sized to overcome packing frictionand dynamic stem forces. Unbalanced force shall be kept to a minimum levelconsistent with efficient operation in service.b. Damper ActuatorsDamper actuators shall be fully enclosed and supplied with all accessoriesincluding special mounting brackets if required. A solenoid operated, four waypneumatic valve plus open and close limit switches shall be included.(3) RecordersThe recording instruments shall be of the multi or single point strip chart type.Circular chart recorders shall not be used. The recorder shall display the previousfour hours. Roller type charts shall have a duration of 30 days as minimum. Thewhole of the recording mechanism shall be withdrawable from its case from thefront for maintenance.Micro-processor based recording and data acquisition system with printer alsomay be provided.Positioners and E/P Converters(4) Positioners shall be furnished with final control elements where:- small change in pneumatic signal are to be amplified- Split range control is required- valve pressure drop is greater than 280 kN/sq.mPositioners shall have a feedback cam to characterize relationship between inputsignal and final element position.E / P converters shall be provided to convert electronic control signals topneumatic output signals. Converter accuracy shall be plus / minus 0.5% ofoutput span.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)88

(5) Solenoid ValvesAll solenoids shall have class F insulation or higher class and solenoid enclosureshall be of weatherproof construction.Solenoid for operation on AC shall give satisfactory operation over the range of 75% to 120 % AC supply voltage.Solenoid for operation on DC shall give satisfactory operation over the range of 85% to 115 % DC supply voltage.8.11 PANEL CONSTRUCTIONAll panels except local control box shall be constructed using steel plate not lessthan 3.2 mm thick.(1) Vertical Panel of Front FaceThe panel shall be fitted with indicating instruments, annunciator lamps, operatingindicators, watt-hour meter and recorders (for generator's output, voltage andfrequency) etc. necessary for operation.(2) Slant PanelThis panel shall be fitted with control switch, indicating lamps and mimic bus, etc.,necessary for operation.(3) Vertical Panel of Rear FaceThis panel shall be fitted with protection relays, etc.(4) Panel Interior Space (230 kV switchgear control and protection panelsonly)Sliding type doors shall be furnished on the both sides of panel for access to paceshall be provided in the middle of front and rear faces of the panel to enable aman to pass through it. Chequered plate shall be furnished at the bottom of thepanel.(5) Type of Indicating Meters110 mm square with about 240 0 C of seal angle, flush mounting type with 1.5class accuracy, or other approved type by the Board.(6) Testing Power sourceAs a result power source for protective relay, meters, etc., one set of 50 Amoulded case circuit breakers of 3 phase 415 V and DC 125 V shall be provided.(7) Test BlocksTest blocks for P.T. and C.T. circuits, shall be provided on the panel as required.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)89

The test block shall be of the back- connected plug or stud type with removalcovers. All test blocks shall be provided with suitable circuit identification and shallbe arranged to isolate completely the instrument from the instrumenttransformers and other external circuits so that no other device will be affected,and means shall be provided for testing either from an external source of energyor from the instrument transformers.The test blocks shall be arranged so that the current transformer secondarycircuits cannot be open circuited if any position while the test plugs are in place,being inserted, or being removed. Three test plugs for each type of blockfurnished shall be furnished.(8) Control SwitchThe handles of control switches for circuit breakers, disconnecting switches andauxiliary equipment shall be of the stick type, the handles of the control switchesfor adjustment shall be of the oval type, and the handles of the selector switchesshall be of the flower type. Every switch shall have engraved identification numberon the knob in white.(9) Internal wiringa. WireThe internal wiring shall be made with PVC wire of 2.5 sq. mm copper stranded orlarger, and solder- less terminals shall be used for connection.The secondary circuit of C.T. and P.T. shall be wired with PVC wire 4.0 sq. mm(minimum) copper stranded.b. Colour CodingThe colour-coding shall be made as follows:- Secondary circuit of potential transformer Red-Secondary circuit of current transformer Black- DC control circuit Blue- AC control circuit Yellow- Main circuit Yellow- Earthing circuit Greenc. Terminal blocksTerminal blocks to be connected with internal wiring and external wirings shallhave the cover (s) and identification numbers.(10) The secondary circuit of P.T. for metering shall be provided with fuse.Earth The C.T. and P.T. secondary circuits shall only be grounded inside the paneland appropriate Testing facility shall be provided.A handset of flush type for paging system shall be installed on the slant part ofGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)90

emote unit panel.A battery quartz clock and system clock shall be mounted on the upper part of theunit step up transformer control panel.Switches such as circuit breaker controlling switch, annunciator test switch,emergency stop switch, etc., which may be unwillingly operated by accident dueto mechanical or human contact, shall be protected by transparent plastic switchcover.(15) Name PlateSwitchgear, panels , equipment and power and control circuits shall be providedwith an engraved name plate or with other suitable means of identificationapproved by the Board. The nameplates shall be made of nickel frosted sheetplastic or of anodised aluminium approximately 2 mm thick engraved with blackletters on a white background. Nameplates of all panels, switches, etc. shall bewritten in English.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)91

Section 9Cabling And GroundingGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)92

9. CABLING AND GROUNDINGPage9.1 General9.2 Cable Types9.2.1 230 KV & 11 kV XLPE Power Cable9.2.2 6.6 KV KLPE Power Cable9.2.3 600 V Power Cable9.2.4 Control and Instrument Cable9.3 Raceway9.3.1 Raceway9.3.2 Raceway Fittings and Supports9.4 Cable Erection9.5 GroundingGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)93

9. CABLING AND GROUNDING9.1 GENERAL(1) ScopeThe Contractor shall design, supply, install, terminate and commission all thecables for the plant.(2) Voltage DropThe maximum permissible voltage drop shall be such that in on case shall thedrop exceed 2.5% under normal running condition and 10% under motor starting.(3) ArmouringAll cables except 230 KV power cables, control and instrument cables shall beprovided with galvanised steel wire or steel tape armour and PVC cover sheath.9.2 CABLE TYPES9.2.1 11 kV XLPE POWER CABLE & ISOLATED PHASE SOLID BUS.(1) The cable shall be stranded annealed copper conductor.The construction of the conductor shall be the compacted circular single coretype. The size of the conductor shall be capable to carry the rated capacity ofeach feeder and at specified site conditions without exceeding its maximumtemperature i.e. 90 0 C. The minimum size of 11 KV cable shall not be less than100 sq. mm. The copper conductor shall comply with latest IEC Standard.(2) InsulationThe insulation material shall be extruded cross linked polyethylene of lowdielectric loss, high dielectric strength, low thermal resistivity and long termstability. It shall be free from contamination by oil, chemical and moisture. Theextrusion process shall ensure that the insulation is homogenous and The singlecore 11 kV XLPE Copper conductor power cable and other necessary items for thecompletion of the cable system.The power cable and accessories shall be designed and constructed in accordancewith the requirements of latest IEC Standard. High Voltage Cross linkedPolyethylene Insulated cable" and the most up-to-date experience for a system ofthis voltage level and shall incorporate the latest improvements of design andmanufacture for the type of cables and accessories required.Free from voids and impurities. The process shall be dry method. The averagethickness of insulation measured at section shall not be less than the valuespecified in the standard.(3) TerminationsThe end terminating materials shall be supplied for the termination of 11 KVcables.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)94

9.2.2. 6.6 kV XLPE POWER CABLESThe single or triplex core 6.6 kV XLPE copper conductor power cable and othernecessary items for the completion of the cable system.The power cables and accessories shall be designed and constructed inaccordance with the most up-to-date experience for a system of this voltage leveland shall incorporate the latest improvements of design and manufacture for thetype of cables and accessories required.(1) The cable shall be stranded annealed copper conductor.The construction of the conductor shall be the compacted circular single or triplexcore type. The size of the conductor shall be capable to carry the rated capacity ofeach feeder and at specified site conditions without exceeding its maximumtemperature i.e. 90 0 C. The minimum size of 6.6 kV cable shall not be less than 60sq. mm.(2) InsulationThe insulation material shall be extruded cross-linked polyethylene of lowdielectric loss, high dielectric strength, low thermal resistivity and long termstability. It shall be free from contamination by oil, chemical, and moisture. Theextrusion process shall ensure that the insulation is homogeneous and free fromvoids and impurities, and it shall be dry method.(3) TerminationsThe end terminating materials shall be supplied for the termination of 6.6 kVcables.9.2.3 600 V Power CablesThe cables shall be rated 600 volts for installation in cable trays, conduits andcable ducts.All auxiliary power cable with a nominal conductor area of 60 sq. mm and aboveshall be stranded annealed copper conductor, XLPE insulated with galvanised steelwire or steel tape armour and PVC sheathed. All other auxiliary power cables shallbe stranded annealed copper conductor, PVC insulated with galvanised steel wireor steel tap armour and PVC sheathed. All auxiliary power cables shall bedesigned, fabricated and tested in accordance with the latest IEC Standard.The cables shall have copper conductor and shall be selected with dueconsideration to load requirements of each feeder and short circuit currentcapacity of the cable in order to prevent premature insulation failure. Theconductor insulation shall be numbered or colour coded.For motor circuit, the cables shall have a current carrying capacity of at leastequal to 115% of the full load current rating of the motor after application of theappropriate derating factors.Cable supports shall be provided for the cables and shall be at least one cablesupport bracket per vertical section for interconnection between adjacentsections. The minimum size of power cable shall be of 10 sq.mm.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)95

9.2.4 CONTROL AND INSTRUMENT CABLESIn general, control and instrument cables shall be rated 600 volt and shall havecopper conductor with either PVC overall jacket, unless specified otherwise. Allcontrol and instrument cables shall be designed, fabricated, and tested inaccordance with the latest IEC Standards.All cables shall be of oil-resisting, heat-resisting and flame-retardant type(armoured) and shall be stranded copper conductor. The minimum size of controlcables shall be as follows: For CT circuit- For PT circuit- Other circuit -5.0 sq. mm2.5 sq. mm2.5 sq. mm [min.]Wiring for circuits such as the circuits to be connected to electronic circuit,telephone circuit, etc. adversely influenced by stray electric field shall be providedwith suitable shielding.-PVC Insulated and Jacket CablesPVC insulated control cables shall be used in the area of installation where theambient temperature is normally lower than 40 0 C.-Cross linked polyethylene Insulated Cables.Cross linked Polyethylene insulated control cables shall be used in the areaof installation where the ambient temperature is normally between 40 0 C and 55 0 C.-Mineral Insulated (MI) Cables.Mineral insulated control cables shall be used in the area of installationwhere ambient temperature is normally above 55 0 C. Where instrumentjunction boxes such as for limit switches, pressure switches, transmitters,resistance temperature detectors etc. are at high ambient temperature, theyshall be wired with MI cables up to a junction box.(1) Insulation requirementsAll control cables, with the exception of equipment internal wiring and panelwiring, shall be installed in conduits, cable ducts or cable trays.Cables contained in cable trays, conduit or cable ducts shall be continuos with nosplices permitted between loads and supply location. Methods for installation ofcables shall be such that there will be no cuts or abrasions in the insulation orsheath or break in the conductor. Conductors used for AC and DC circuits shall notbe mixed in the same multi-conductor cable.In general, conductors and cables shall be supported and terminated so that nostrain is imposed on the terminations. Insulated clamped jugs shall be used for allcontrol cable terminals.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)96

9.2.5 230 kV XLPE POWER CABLE(1) The cable shall be stranded annealed copper conductor.The construction of the conductor shall be the compacted circular single coretype. The size of the conductor shall be capable to carry the rated capacity ofeach feeder and at specified site conditions without exceeding its maximumtemperature i.e. 90 0 C. The minimum size of 230 KV cable shall not be less than800 sq. mm. The copper conductor shall comply with latest IEC Standard.(2) InsulationThe insulation material shall be extruded cross linked polyethylene of lowdielectric loss, high dielectric strength, low thermal resistivity and long termstability. It shall be free from contamination by oil, chemical and moisture. Theextrusion process shall ensure that the insulation is homogenous and The singlecore 11 kV XLPE Copper conductor power cable and other necessary items for thecompletion of the cable system.The power cable and accessories shall be designed and constructed in accordancewith the requirements of latest IEC Standard. High Voltage Cross linkedPolyethylene Insulated cable" and the most up-to-date experience for a system ofthis voltage level and shall incorporate the latest improvements of design andmanufacture for the type of cables and accessories required.Free from voids and impurities. The process shall be dry method. The averagethickness of insulation measured at section shall not be less than the valuespecified in the standard.(3) TerminationsThe end terminating materials shall be supplied for the termination of 230 KVcables.(4) LayingUnder-Ground Cable from 230 KV side of Unit Transformers to 230 switchyard andalso re-routing of 230 KV OHL by cable shall be provided with RCC slab on threesides.9.3 RACEWAY9.3.1 RACEWAYRaceway shall be provided for all cables, and these shall be rigid conduit metalthrough type cable trays.9.3.2 RACEWAY FITTINGS AND SUPPORTSRaceway shall include all fittings, junction boxes, flexible attachments, racewaysupport hardware, etc.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)97

9.4 CABLE ERECTIONConcrete lined cable trenches shall be provided within the power station. All suchtrenches shall be provided with covers to form a flush finish with the finished floorlevel. Cables shall be secured by non-corrodible cleats supporting steelwork, or ontrays. Wooden cleats shall not be used. Cables shall not be clipped or cleateddirectly to masonry. All cable supporting steelwork racks cleats trays and fixings intrenches or elsewhere shall be supplied under this contract.Where the cables are to be installed on racks, these racks shall be of galvanisedsteel angles or aluminium and designed such that the spacing and type ofsupporting cleat ensure that no undue pressure is exerted on the sheath orarmour of any cable.Cables tray shall be of the first grade perforated galvanised steel with folded sidemembers and supported on steel work or masonry is required. Segregation of thevarious services shall be achieved by use of separate trays for each voltage gradeof cable used. The design of the cable tray system shall make due allowance forthe future installation of at least 10 percent spare cables and also for theinstallation of cables supplied by others.All cables in vertical runs shall be supported to ensure that no strain due to theweight of the cable is taken by any terminating box. Each cable when erectedshall have permanently attached to it at each end, non-corrodible metal markersshowing the cable identification number, voltage, rating, size and make up.Single core cables shall be laid up in close trefoil 3-phase groups and erected inseparate non-magnetic clamps to the approval of the Board.Where cables are erected on outdoor steelwork supporters, sun shades ofapproved design and materials shall be included and erected as necessary toprotect the cables.9.5 GROUNDINGThe Contractor shall provide all grounding cable, equipment, and materialsrequired for a complete installation including the direct buried ground mat for thepower station,. This shall include, but not be limited to, all facilities for groundingof panel boards, control panels, transformers, switches, lighting poles, lightingstandards, and all electrical equipment enclosures. Two point grounding for eachequipment, panel board and steel structure shall be provided.(1) Grounding wire for ground gridHard drawn copper stranded wire in accordance with latest IEC Hard DrawnCopper wire for electrical purposes.Nominal cross sectional area: 200-sq. mm.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)98

(2) Grounding wire of the equipment to be connected with grounding grid.Annealed copper standard wire in accordance with latest IEC Annealed copperstranded wire for electrical purposes.Nominal cross sectional area:100 sq. mm.Ground grid shall be mesh type and be laid so that the completed earthing systemshall have a maximum earth resistance value of less than 0.5 ohms, at any pointon the system. The contact voltage at any point inside the power station at theincidence of an earth fault shall not exceed 50 volts. The power station groundingshall be embedded to a minimum depth of 800 cm. The grounding rods additionto the above grid shall be provided, if required. The minimum outer diameter ofgrounding rod shall not be less than 15 mm.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)99

Section 10DC Power Supply SystemGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)100

10. DC POWER SUPPLY SYSTEMPage10.1 Batteries10.2 Battery Charger10.3 DC Distribution BoardGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)101

10 DC POWER SUPPLY SYSTEM10.1 BATTERIES(1) Scope of workThe Contractor shall design, manufacture, delivery to the site and install Two (2)sets of 125 V , Ni-Cd, Alkaline storage batteries, complete with all accessories, asspecified, hereunder for the plant.The Contractor shall provide two (2) sets of 125 V, Ni-Cd, Alkaline storagebatteries, complete with stands, inter-cell connections, battery moulded circuitbreakers and maintenance equipment. For design purposes the ambienttemperature in the battery room shall be taken to range from 10 0 C to 45 0 C. Eachbattery shall be associated with battery charger (s) and DC distribution board (s).The rated voltage at the batteries shall be 125 V. The Contractor shall furnishcharacteristics and performance curves of both for batteries and chargers.(2) Description of the EquipmentTwo (2) 125 V battery set for gas turbine generating units with stands andinternal connections.Two (2) sets of accessories comprising:Two (2) HydrometersTwo (2) cell voltmeters, plus / minus 3 V, portable type, accuracy Class 1.0complete with leads and probes.Two (2) - Alcohol -in - glass thermometers to cover the range 0 0 C to 55 0 COne (1) Supply of battery record log books for at least 15 separate recordings foreach batteryOne (1) Plastic case to contain the above accessories.Three (3) Connector bolt wrenches.One (1) set of electrolyte filling tools.(3) Technical descriptiona. The batteries shall be of the Ni-Cd, Alkaline. The cell containers shall be ofthe fully enclosed vented type made of transparent plastic material with clearlyvisible high and low electrolyte limits indelibly marked on the container. Each cellshall have a large electrolyte reserve capacity above the plates to allow forminimum maintenance, The Contractor shall determine the ampere-hour rating ofthe batteries based on the battery being capable of supplying the loads connectedto the associated DC busbar continuously for 5 (five) hours at 35 0 C without thevoltage dropping below 90 per cent of the nominal values. But the capacity of thebatteries shall not be less than followings.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)102

- 125 V battery : 200 AHNumber of cells of each battery set shall be as follows:- for 125V battery set :Minimum 108 cellsCells shall be numbered consecutively and terminal cells marked to indicatepolarity.b. These batteries shall be used for supplying power for DC controls,alarms indication and for emergency lighting and power equipment to be installedwithin the power station.c. Each cell shall be sealed type, assembled in heat-resistant, shockabsorbing clear plastic containers with covers cemented in place to form apermanent leak proof seal. Vent plug and filler cap shall be provided in the cover.d. Separators between plates shall permit free flow of electrolyte.e. The weight of the battery elements shall be supported from ledgesmoulded in the jar walls or from the cover.f. Cell posts shall be sealed against electrolyte creepage.g. Cell terminal posts shall provided with connector clamps, bolts and nuts.h. Sufficient sediment space shall be provided so that the cells will not haveto be cleaned out during normal life.i. Electrolyte level limits shall be marked on the cell container.j. The battery shall be shipped uncharged with the electrolyte shipped inseparate containers.k. The battery shall be furnished complete with cell inter-connectors and atwo-step steel rack.l. The battery shall be suitable for operating satisfactorily in an ambient of45 0 C.10.2 BATTERY CHARGER(1) Scope of worksThe Contractor shall design, manufacture, deliver and install the battery chargers(Thysistor type), complete with all accessories, as specified, hereunder for theplant.The Contractor shall provide two (2) 125 V chargers, in the auxiliary room of thecontrol building to be used for automatic charging of 125 V. The electricalconnections between the batteries, the DC distribution boards and the chargersshall be as shown on the attached single line diagram. Only charger with fullyproven design shall be provided. The shall be capable of performing continuouslyGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)103

float charge as well as boost charge (with timer).(2) Description of the EquipmentTwo (2) 125 V DC output, 415 V, three phase input, battery chargers withautomatic regulator and filters to maintain the performance. One (1) set for one(1) battery set and other set as standby. The continuous current rating of thebattery chargers shall be determined by the Contractor so as to meet the capacityof related battery.But the continuous current rating of the chargers shall not be less than thefollowing:-125 V battery : 180A(3) Performancea. Constant Voltage CharacteristicThe chargers shall normally have a constant voltage characteristic and shall bedesigned to carry the load current while the battery floats and to replenish thebattery after intermittent discharge. The set voltage shall be adjustable between1.20 V / cell and 1.70 V/cell by means of a potentiometer located inside thecubicle.The DC voltage shall be maintain within plus / minus 1 per cent of the set voltagefor all loads from zero to rated output for any variation of between plus / minus10 percent of the nominal AC input voltage or between 48 and 52 Hz infrequency.The proper voltage adjusting means such as silicon dropper shall be provided tokeep the DC terminal voltage within a permissible range.If there is a prolonged failure or heavy discharge which causes the battery voltageto fall below the pre-set value, the charger shall operate at the maximum currentoutput not exceeding 250 percent of the rated output to restore the voltage to thepre set value. Constant voltage charging shall recommence automatically whenthe battery voltage reaches the pre-set value.The current limit setting shall be adjustable down to 80 percent rated output.c. ControlThe chargers shall be provided with an automatic / manual control selector switchand the facility by which the output voltage can be adjusted when on manualcontrol. On manual control the charger shall be capable of delivering 50 per centof its rated output at 1.55 V / cell to enable charging of the battery when isolatedfrom the DC distribution board.d. Ripple Voltage LimitsWith the battery connected and with any non-destructive load between zero andrated the peak value of the ripple voltage (unweighted) measured across theGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)104

output terminals shall not exceed the followings:Charge nominal(DC voltage)Ripple voltagelimit: 125 V: 2.0 V peak to peak10.3 DC DISTRIBUTION BOARDThe Contractor shall provide the DC distribution board in the gas turbine unitcontrol package and in the auxiliary room of the control building. The Contractorshall determine the continuous current rating of the distribution boards.Number of the feeders and current rating of feeders shall be determined by theContractor. Five (5) spare feeders on each distribution board shall be provided.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)105

Section 11Lighting And Small Power Supply SystemGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)106

11. LIGHTING AND SMALL POWER SUPPLYPageGeneralDistribution BoardsCablesLighting and Small PowerEmergency LightingMiscellaneous MaterialsGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)107

11. LIGHTING AND SMALL POWER SUPPLY SYSTEM11.1 GENERAL(1) Scope of WorksThe Contractor shall design, manufacture, deliver and install power stationlighting and small power supply complete with all the accessories at the site asspecified hereinafter.(2) DetailsDetail description and drawings of all lighting fittings, distribution boards,switches, DC equipment, socket outlets, poles, glands, etc., comprising the offershall be submitted with Tender.(3) Electricity SupplySupplies for lighting distribution boards of 415 Volts 3 phase 4 wire 50 Hz shall betaken from the station auxiliary switchboard.The 125-volt DC supply required for emergency lighting services shall be obtainedfrom the batteries supplied under the Section 10. Under AC failure conditions forthe DC, emergency lighting to be installed shall be automatically switched on.11.2 DISTRIBUTION BOARDSThe distribution boards and all component parts shall be manufactured and testedin accordance with the latest IEC standard. Distribution boards shall have dustproof sheet steel, galvanised, weatherproof cases. The metal casing is to beprovided with knockouts or other approved form of cable entries, correspondingto the circuit capacity, together with a suitably screened brass earthing stud.The distribution boards shall be either double pole and neutral types as requiredand shall be equipped with means to provide over load protection to each circuit.This protection shall comprise moulded case circuit breaker.11.3 CABLESAll cabling associated with the lighting and small power socket outlets servicesshall be stranded annealed copper conductor, PVC insulated galvanised steel wireor steel tape armoured and PVC sheathed as appropriate or mineral insulatedcopper sheathed cable depending upon the service required.The Contractor shall select conductor sizes for the respective circuits to mcc thefollowing conditions:a. Minimum conductor sizes for lighting circuits shall be 2.0 sq. mm and forsocket outlets 3.5 sq. mm.b. The size shall be adequate for the current to be carried.c. The size shall be adequate to limit the voltage drop in phase and neutralGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)108

conductor to the farthest lighting or power point under normal full load conditionsto within 2.5 %.11.4 LIGHTING AND SMALL POWERThe following lighting and small power arrangements shall be provided as aminimum by the Contractor.No Location IlluminationLevel (Lux)a. Power Generating AreaType of FittingbcInside of packing exceptcontrol package100 Fluorescent lamp orincandescent lamp with reflectorand guard if necessary explosionproof type shall be used.Inside of control package 500 Fluorescent lamp with reflectorInside of crane rainshelterguard20 Fluorescent lamp or mercuryvapour lamp with reflector anddiffuserAround GT unit 20 Mercury vapour lamp withfloodlight fittingRoad or path 10 Mercury vapour lamp withhighway fitting or floodlightfitting230 KV SwitchyardAround Switchgear 20 Mercury vapour lamp withfloodlight fittingRoadways 10 mercury vapour lamp withhighway fittingControl buildingControl room 500 Fluorescent lamp with reflectorand diffuserElectrical room and cableroom50 Fluorescent lamp with reflectorand guardOffice 500 -do-Toilet, corridor, etc. 50 -do-f. Plug SocketsPlug sockets shall be located so that any point inside the GTG package, inside abuilding or outside in the high voltage areas can be reached within the followingdistances from a plug socket.(i)Single phase plug socketIndoor -Outdoor-:10.0 m:20.0 mGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)109

(ii)Three phase plug socketOutdoor-:45.0 mAt least two plug sockets shall be installed within the vicinity of an indoor controlboard and no plug socket shall be installed with in a battery room.11.5 EMERGENCY LIGHTINGThe Contractor shall design DC emergency lighting and power supply system forthe power station, and illumination level of DC emergency lighting shall be asfollows.The lighting shall consist of 125 V DC operated incandescent luminaries.LocationIlluminationLevel (Lux)Control room and inside : 15of control packageInside of other package : 1The other area surrounding : 0.5GTG unitsAdditional emergency lighting arrangement, independent emergency light unitsoperated from built in charger and batteries charged by 230 V AC shall also beprovided strategically. Total ten units shall be included in the Tender.11.6 MISCELLANEOUS MATERIALS(1) Lighting PolesLighting poles shall comprise tubular or octagonal metal or reinforced concreteconstruction with a base of sufficient section to house an inspection trap, lockabledoor, cable entry and terminations suitable for the incoming cables and thesecondary cables feeding the light sources, all of which shall be supplied with thepole. All poles shall be suitable for burying to a depth of 1.5 m and have anadequate concrete foundation.Metal poles shall be either hot dip galvanised or covered with a bituminous baseprotective area with the fitting erected and a safety factor of 2.5 allowed.(2) Conduits PipesThe rigid steel conduit pipes shall be galvanised and have a minimum thickness of2.3 mm and minimum inside diameter of 16 mm.(3) Outlet Switches, Junction Boxes and FittingsGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)110

The boxes to be concealed in the concrete shall be of galvanised sheet steel andshall be fitted with appropriate covers so as to be flush with the finished surfaceof the concrete structure. The boxes in the exposed work shall be of galvanisedsteel or alloy fitted with appropriate covers.(4) Tumbler SwitchesThe wall switches shall be of the enclose flush or surface mounting tumbler type,single pole, 250 V, 10A and fully installed in the boxes fitted with suitable platesfor covering them.(5) MiscellaneousAll apparatus, accessories and materials which have not been specificallymentioned but which are necessary for the completion of the work shall beprovided by the Contractor.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)111

Section 12Fuel Handling FacilitiesGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)112

12. FUEL HANDLING FACILITIESPage12.1 Fuel System12.1.1 Liquid Fuel Oil System12.2 Liquid Fuel Handling SystemGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)113

12. FUEL OIL SYSTEM AND HANDLING FACILITIES12.1 Fuel systemAt present HSD (High Speed Diesel) will be used as fuel along with natural gasfuel. So provision of dual fuel system (Liquid fuel system and natural gas fuelsystem) shall be made in the fuel system of gas turbine unit.12.1.1 Liquid Fuel oil systemThe unit shall be provided with liquid fuel oil system. The liquid fuel oil systemshall have the necessary heating arrangement, pressure regulating valves, shutoffvalves, pipes, pumps, metering device, pressure gauge and other indicatinginstruments. The liquid fuel system shall be provided with necessary protectiveequipment for proper control and safe operation of the unit.The distillate fuel oil system shall consist of two pumps (One standby, oneoperative) of suitable capacity for the maximum output of the turbine at lowestambient temperature at the site, along with necessary valves, piping, regulatingdevices, metering device, instrumentation, pressure switches and indicators.Scope of supplyOne distillate fuel supply system shall include, at least, the following equipment:-One off-base standardized forwarding skid consisting of the pumping andregulating equipment- One off-base standardized filtering (duplex cartridge type filterss) located nearthe unit-Piping between forwarding and filtering skid and from the filtering skid up to thegas turbine unit-Unloading Fuel skid-2 (Two) 50.00 lakh litre distillate fuel storage tank with fixed roof having floatingsuction type delivery (if existing tanks are not serviceable)-Piping from unloading area to fuel tank.-For unloading: Two 100% (100m 3 /h) transfer pumps + Filters-Piping between the 50.00 lac fuel storage tank and pumping skid-Fuel strainers-Flowmeter and totalise to measure fuel consumption-Pressure gauges on each side of fuel strainers, at pump suctions and discharge,and other critical points- Fuel oil pumps-Over speed and emergency trip stop valves-Control valves for starting and operating-Necessary isolation valves-All piping-Automatic control valvesGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)114

12.2 Liquid Fuel Handling systemThe contractor shall design, manufacture, inspect, test, deliver to the site andinstall of liquid fuel oil handling, conditioning and regulating facilities with allaccessories as specified hereunder for the plant.The unit shall be furnished with a complete liquid fuel oil system. The liquid fueloil handling system shall also be provided.12.2.2 Fuel forwarding skidFuel forwarding skid brings liquid fuel to the gas turbine at a pressure consistentwith the gas turbine fuel supply requirements.Equipment list:-Two (2) 100% fuel forwarding AC motor driven centrifugal pumps (one duty, onestandby), each for the maximum fuel flow necessary to the gas turbine-Three suction Strainers-One fuel pressure regulating valve-One relief valve-Complete set of piping including valves, gauges and fittings of all linesterminating at the skid boundary12.2.3 Fuel oil filters SkidThis unit provides liquid fuel filtration up-stream the unit turbine and includes thefollowings:-Two fuel filters (one duty, one standby) : Filter cartridge -5 microns-One pressure metering panel board including : one manostat (fuel pressurecontrol), one different pressure gauge-One fuel accumulator-One stop valve-Complete set of piping including valves, gauges and fittings of all linesterminating at the skid boundary12.2.4 Fuel storage tankThe fuel storage tank is a vertical with fixed roof tank. Its capacity of each Tankshall be minimum 50.00 lac litre if existing tanks are not serviseable. The fuelstorage tank will be assembled in site and includes the followings:-One fuel inlet flange-One fuel outlet flange with floating suction-Two manholes located in shell and in roof-Two foam chambers for fire protections-One visual level gauge-Various levels switch to provide alarm at subsequent level-one gas vent-One water drain-One spiral stairway and one top peripherical handrailing12.2.5 Unloading Fuel skidRequired piping, along with, other facilities that will be required for the systemGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)115

from unloading base to the fuel tank to be constructed for the proposed plantshall be made by the contractor.The unloading fuel skid includes the followings-2x100% fuel pumps (one running, one standby), capacity of each 100m 3 /h anddriven by AC motor.-Two suction strainers-Two headers, each with five unloading points-One flow meter-Piping and valves between above equipment12.2.6 Sump tankThe sump tank allows draining liquid fuel from combustion system and fromexhaust plenum when there is false start. It may be preassembled and includesthe followings-One tank of 1 m 3 capacity-One manual pumpGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)116

Section 13Fire Protection FacilitiesGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)117

13. FIRE PROTECTION FACILITIES13.1 General13.2 Design Requirements13.3 C0 2 Gas Fire Protection System13.4 Hydrant System13.4.1 Hydrant13.4.2 Piping13.5 Portable EquipmentPageGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)118

13. FIRE PROTECTION FACILITIES13.1 GENERALThe Contractor shall design, manufacture, deliver to the Site, install, test andcommission the fire fighting and fire detection equipment to protect the gasturbine generating unit and all associated equipment. In particular, the followingshall be included: C0 2 Gas fire protection system for the gas turbine packaged unit. Water hydrant system including motor & diesel engine driven pumps,jockey pumps etc.Portable fire fighting equipment13.2 DESIGN REQUREMENTSThe general design of the fire protection facilities shall take into account that thebasic operating policy for the power station will have the minimum of personnelsupervision for the gas turbine.Where automatic systems are provided, alternative manual initiation facilities shallalso be provided.All fire protection installations shall comply with the requirements of the codes ofpractice of the National Fire Protection Association, Boston, Massachusetts,U.S.A., as appropriate for the respective systems, to the approval of the Board.The codes and practice of the Japanese Fire Protection may also be considered.13.3 CO 2 GAS FIRE PROTECTION SYSTEMAn automatic Carbon Dioxide (CO 2 ) gas fire protection system shall be provided inall machinery enclosures of gas turbine generating units except in the unit localcontrol package. The fire protection system shall comply with the requirements ofNational Fire Code No. 12A published by the National Fire Protection Association,Boston, Massachusetts, U.S.A. or equivalent.The equipment shall consist essentially of fire detectors distributed strategicallywithin the enclosures which, on sensing a dangerous condition at any location,will initiate audible and visual alarms, trip all running plant including ventilationequipment, and release C0 2 gas into the affected enclosure. Actuation of the fireprotection system shall also. trip gas turbine generating unit and immediately shutoff the fuel supplies to the unit at a point external to the enclosures. There will betime lag of 30 seconds between the ringing of alarm and discharge of C0 2 gas, sothat the personnel working in the package could leave safely.Facilities for alternative manual actuation of the fire protection system shall alsobe provided such that, when the manual mode has been selected the protectionsequence will not proceed beyond the alarm stage without manual action by anoperator.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)119

System of lock off to (but not exit from) the enclosure affected shall also beprovided.The fire protection system shall be segregated into separate zones so that at leastthe protection for any one compartment can be selected to the manual modewhilst, at the same time, retaining the automatic mode for the remainingenclosures.Lock-off boxes shall be provided at all entries to enclosures, with switcheswhereby an operator may inhibit automatic release of extinguishant. These boxesshall be provided with status indicators signifying 'Auto on' 'Auto-off' and'Extinguishing Released' and a red lamp shall also be illuminated at the box In theevent of' extinguishing release. The status shall be indicated at the control panelof the control building also.Fire detection shall be by means of ultra violet flame detectors with a backupsystem utilising rate-of-rise temperature detectors. The use of smoke detectorsshall be subject to specific approval by the Board as regards their type andlocation.Audible and visual fire alarms shall be provided in all machinery en-, closures, thelocal control cabs and in the control room of the control building. Additionalaudible alarms shall also be provided external to the turbine generator enclosures.Particular areas of high fire risk such as confined spaces where lubricating oilcould possibly come into contact with high temperature ,surfaces shall receivespecial consideration. Such areas shall be treated as separate fire protectionzones with detection and C0 2 gas injection facilities operating independently of thesystem provided for the machinery enclosure concerned.The fire protection equipment shall be complete in all respects including pipework,valves, fire detectors, nozzles, control equipment, fully charged C0 2 gas cylindersand cylinder racks.13.4 HYDRANT SYSTEMFire hydrant of water type shall be provided in the power station.13.4.2 HYDRANTHydrants shall be installed at required places around the gas turbine generatingunit, electrical building, and 230 kV switchyard. Each hydrant stand shall be fittedwith an isolating valve and approved type of instantaneous hose complying 30-mhose with combined jet/water-fog nozzle shall be provided in the cabinet adjacentto each hydrant.13.4.2 PIPINGThe fire fighting water mains shall consist of buried piping of at least 120 mmdiameter. The underground pipework shall be provided with an approvedprotective coating unless the pipe is manufactured from an approved noncorrosivematerial.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)120

13.5 PORTABLE EQUIPMENTThe following portable fire fighting equipment or equivalent shall be provided:(1) Twenty-four 5 kg C0 2 extinguishers(2) Five 20 kg C0 2 extinguishers with trolley(3) Twenty-four 5 kg Dry chemical extinguishers(4) Five 10 kg Dry chemical extinguishers.The portable equipment offered shall be of a type for which replacementcartridges and dry powder refills shall be readily available locally.13.5 FOAM BASED FIRE FIGHTING SYSTEM FOR FUEL TANKS (IF REQUIRED)Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)121

Section 14Communication FacilitiesGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)122

COMMUNICATION FACILITIES14.1 General14.2 Internal Telephone System14.2.1 Private Automatic Branch Exchange14.2.2 Telephone Facilities14.3 Paging SystemPage14.3.1 General14.3.2 Function14.3.3 Equipment14.3.4 Locations of Handsets and Speaker14.4 Coaxial Cable14.5. Power Supply14.6 PLC system14.7 Telemetering facilityGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)123

14. COMMUNICATION FACILITIES14.1 GENERALThe Contractor shall design, manufacture, deliver to the Site and install thefollowing communication facilities:a. Internal telephone systemb. Paging system14.2 INTERNAL TELEPHONE SYSTEM14.2.1 PRIVATE AUTOMATIC BRANCH EXCHANGEThe exchange shall be of a PABX type approved by the Ministry ofCommunications for connection to the public telephone network and in-stalledwith in the central control room of the power station.The initial installed capacity shall be 10 exchange lines and 50 extension lines.The exchange shall be capable of expansion to a capacity of more than 20exchange lines and 100 extension lines. A single operator's position shall beprovided.All internal telephone connections within the power station boundary shall be theresponsibility of the Contractor, but the interconnecting cables between the PABXand the public telephone network shall not be the responsibility of the Contractorexcept all facilities for the connection of this service within the building.(1) FunctionsThe PABX system shall be provided with the following functions:a. Extension to extension calls shall be made by direct dialling.Extension to exchange lines and PLC lines for dialling a single access digit shallmake outgoing calls.Operator access from extension by dialling a single digit shall be required.Trunk barring on outgoing calls shall be provided as required on selectedextensions.Provision for limited barring on outgoing calls from selected extensions shall beprovided.Operator recall from an extension engaged with an incoming or outgoing call shallbe effected by operation of a recall button followed by dialling the operator accessdigit.Call transfer between extensions on incoming and outgoing public ex-change callsshall be provided.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)124

Operator intrusion into an established call in order to offer an exchange call orurgent message shall be provided. An intrusion tone shall be introduced.i. Exchange alarms shall be extended to the operator's console orswitchboard.ii.Six (6) extensions shall have a priority facility to intrude into extension toextension calls. An intrusion tones shall be introduced.(2) Equipment to be provided shall include, but not limited to:a. A main distribution frame of sufficient size to accommodate the futureexpansion.b. Automatic switching equipment.c. Manual switchboard or console.d. A necessary inters unit cabling and cables supports.e. Concealed wiring to each office, workshop, administration building, etc. toaccommodate a single instrument at each point.f. 50 telephone instruments complete which will be connected at telephonepoints to be advised by the Board.14.2.2 TELEPHONE FACILITIESPABX telephones should be located as follows:a. Control room (2)b. Control package of gas turbine unitc. Telephone cubicle (1)d. Auxiliary room (1)e. Office, Managers room, Workshop, etc (Total 10)f. Administration building, guard houses and other buildings (Total 25)g. SpareTotal: 50 Numbers14.3 PAGING SYSTEM14.3.1 GENERALThe paging system, which shall consist of amplifiers, control equipment, handsetsand speakers, shall be provided.The system shall be provided with one channel.14.3.2 FUNCTION(1) Commanding CommunicationCommanding and paging shall be made from any handsets through the localspeaker sets.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)125

(2) General CommunicationWhen the other party answers the paging, general communication is establishedby releasing the page button. Simultaneous two way conversations shall bepossible on one same channel.(3) Emergency Alarm1,000 Hz alarm note shall be sound from all speakers by pushing the buttonlocated on the control panel and desk in the central control room14.3.3 EQUIPMENT(1) HandsetFlush typeIndoor wall typeOutdoor wall type: 5 sets:12 sets: 7 setsHandsets installed indoors shall be of noise-proof type.(2) Speaker Set15 W outdoor type :10 sets5 - 10 W indoor type :13 setsAll speaker shall be able to adjust their output.(3) Amplifier CubicleAll Silicon transistor amplifiers shall be mounted in the amplifier cubicle. Theamplifiers shall be suitable for the driving of the above speakers all together andshall be divided into adequate capacity.One set spare amplifier shall be furnished and it shall be put into operationautomatically when the normal use amplifier fails.(4) Control Panela. Relay PanelRelays shall be provided for the starting and stopping amplifier and toestablish the commanding talk from the handsets. The talking shall be indicatedwith a lamp on all handsets. The relays shall be of semi conductor static type orwire spring relay with sulphuric acid proof type.b. Change-over PanelWhen one set amplifier fails, the failed amplifier's circuit shall be transferred tothe spare amplifier's circuit with relays. Manual change-over switch shall also beprovided.c. Amplifier ProtectionGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)126

Protection for the amplifier shall be provided according to the manufacturer'sstandard.d. Test deviceAmmeter for measuring the emitter current of each transistor and changeoverswitch and power source voltmeter shall be provided on the front of the panel.Red lamps for the indication of operation and orange lamps for the warming shallbe provided on the front panel.e. Terminal blockTerminal block shall be provided in order to connect the incoming cables fromhandsets and speakers.14.3.4 LOCATIONS OF HANDSETS AND SPEAKERThe location of handsets and speakers will be advised by the Board after award ofthe Contract.14.4 COAXIAL CABLECoaxial cables shall be of stranded copper conductor (7/0.4 mm), solid dielectriccoaxial type with polyethylene insulated, annealed copper wire braided and withPVC sheathed.The electric characteristics at 20 deg. C shall be as follows:Dielectric strength (for 1 minute)Between conductor and outer conductorInsulation resistanceAttenuationImpedance (nominal): 6KV AC: More than 10 Mohms / km: 3.2dB/km at 3OOkHz: 77ohms at 300 kHzSufficient length of the coaxial cables and cords with all the necessary cableconnectors shall be supplied to each station for making connections between thecoupling capacitors and the coupling filters, the coupling filters and the lineprotective devices, and the line protective devices and the PLC telephoneterminals.14.5 POWER SUPPLYThe communication facilities to be furnished shall be operated by a 240 V, 50 Hzsingle phase AC (with UPS) and/or DC 50 V. These power supply facilities shall beprovided by the Contractor.DC 50 V system shall be designed and provided based on the followingrequirements:Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)127

(1) BatteryType of batteryCapacityNumber of cells: Ni-Cd Alkaline.: Capable of loads continuouslyfor five(S) hours without voltage dropping90% of nominal voltage, but not lessthan 50 AH (5 hr rate).: 48 cells.(2) Battery ChargerTypeCapacityPerformanceRequired Number: Thyrister type with automatic voltageregulator, 240V single phase input.:120% current of battery 5 hourrate charging current at minimum.: Performance shall be same as these shown onSection 10.2 (3).: 1 set.14.6 PLC (Power Line Carrier) SystemThe PLC System to be provided [extension from existing sytem] shall include allnecessary equipment (such as PLC exchange, telephone sets, line extension, 1 no.of RTU, 1 pair of Multiplexer equipment etc.) and have to be matched with thesystem exists in the grid sub-station. The existing PLC [Power Line Carrier]equipment shall be from ABB and PLC exchange of Siemens.14.7 Telemetering FacilitySeparate Marshalling Kiosk shall be provided for Telemetering terminal for futureconnection with SCADA.14.8 OthersThe following equipments/system are to be supplied and install.1. Compatible Multiplexer with optical fiber.2. RTU (Remote Terminal Unit) with IEC60870-5-104 interoperability if ECS(Electrical Control System) with the protocol 104 is not present.3. One IP telephone set (Cisco) with accessories.4. Two general telephone sets for Administrative Telephone system with accessories.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)128

Section 15Maintenance FacilitiesGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)129

15. MAINTENANCE FACILITIESPage15.1 Overhead Electric Crane15.1.1 Scope15.1.2 Extent of Supply15.1.3 Type of Crane15.1.4 Rating15.1.5 Requirements for Characteristics15.1.6 Requirements for Materials15.1.7 Structural Design15.1.8 Electrical Design15.1.9 Gantry Structure, Rails and Girders15.1.10Site Tests15.2 Mobile Cranes15.2.1 General15.2.2 Type and Rating15.3 Tools15.3.1 General15.3.2 Special tools15.4 Hoist/ EOT15.5 Fork lift15.6 Truck/ lorryGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)130

15. MAINTENANCE FACILITIES15.1 Over head Electric Crane15.1.1 SCOPEThe Contractor shall provide and install one (1) Overhead crane for the powerstation, complete in all respects including longitudinal gantry structure, gantryrails, conductors, power supply, weather protection shed etc.15.1.2 EXTENT OF SUPPLYThe equipment to be supplied by the Contractor under this specification shallinclude, but shall not be limited to, the following:-a. Capacity shall be 60 ton & auxiliary 10 ton [Main hoist capacity 60 ton andauxiliary 10 ton; Main hoist capacity will be sufficient enough to lift theweight of Generator rotor as well as weight of the fully bladed gas turbinerotor separately].b. Sufficient sets of steel wire hoisting ropesc. All integral electric cabling and wiringd. All limit switchese. One (1) set of gantry structure, gantry rails, girders, holding down bolts,securing plates, abutments, and weather protection shed.f. One (1) set of power supply cables and trolley conductors complete withsupporting brackets and one (1) set of power supply indication lampg. One (l) alarm bellh. All lifting eyes, rings and bolts to facilitate erection and maintenancei. All catwalks, ladders, platforms and handrails to provide safe access toitems requiring regular maintenanceJ. Special tools required for the maintenance of the cranek. All other equipment required for the safe and efficient operation of thecrane15.1.3 TYPE OF CRANEThe crane shall be of the semi-indoor and low speed overhead electric," travellingtype equipped with single trolley, one(l) main and one(l) auxiliary hoist.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)131

15.1.4 RATINGThe rating of the crane shall be as follows:(1) Hoisting capacity(2) Span :Not less than 11.5 m(3) Lift :Not less than 10 m(4) Speeda. Hoisting speedMain hoist:5 m/minAuxiliary hoist :10 m/minb. Trolley travel :15m/minc. Bridge travel :15 m/min(5) Operating power sourceand terminal voltage :3 phase, 4 wire, 415 V AC, 50 Hz(6) Bridge travelling rail :37 kg/m(7) Space limit of the crane : Determined by the requirement of the plant.15.1.5 REQUIREMENT FOR CHARACTERISTICS(1) The brake for hoisting shall be capable of stopping and holding 120% ofthe rated capacity.(2) Deflection of bridge girder under load on main hook at the centre of thebridge girder shall not more than 1/500 of the span.(3) The crane shall be capable of raising, lowering, holding and transportingthe rated load without damage to, or excessive deflection of any craneparts.(4) Operation of HoistsEach hoist shall be controlled individually by the relevant controllerequipped in the operator's cab.15.1.6 REQUIREMENTS FOR MATERIALS(1) All materials used for the crane shall be new and conform to the latestrevision of ISO or approved equivalent standards.(2) Safety factors shall not be less than the following:-Shaft and axles : 5.0-Gears and pinions : 5.0-Wire rope : 6.0-Steel structure : 3.0Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)132

15.1.7 STRUCTURAL DESIGN(1) Bridge and End Truck FramesThe bridge structures shall be of welded construction, but with all fieldconnections designed for high-strength bolting. The various parts of the mainstructure of the crane shall be sub-assembled and the field connections reamed.The end truck frames shall be either one-piece steel castings or built-up structuralsteel members.(2) Trolley FrameThe trolley frame shall be fabricated from steel sections or cast steels and shall bedesigned to support the hoisting machinery.(3) Walkway and LaddersSteel safety tread walkways and ladders shall be provided to allow access to allparts of the crane for inspection, repairs and maintenance. Where required, crosswalkways shall be provided, connecting walkways on opposite sides of the crane.Walkways shall be at least 0.70 m wide and provided with a substantial toe-guardat least 0.10 m high and hand-railing not less than 1 m high over the entire lengthand ends. Ladders shall be provided where required for access between the walkwaysand operator's cab. The Contractor shall prepare access from the floor tothe operator’s cab.(4) Operator's cabAn operator's cab shall be located on each crane and in such a manner as to allowmaximum travel of the hooks and maximum visibility for the operator. The cabframe shall be fabricated from steel. All the enclosed walls of the cab shall be oftransparent material.The following controls shall be located inside of cab:a. Manually operated controllers and master switchesb. Main air circuit breakerc. Push - button switch for main contactord. Individual switches for lighting, warning signal, etc.e. Volt meter for power source15.1.8 ELECTRICAL DESIGNThe Contractor shall furnish and install all electrical equipment on the craneincluding all motors, electrically operated brakes, air circuit breakers, switches,contractors, controllers, resistors, control panels, relays, limit switches, trolleytravel conductors, current collectors, transformers, complete lighting system,receptacles, conduit, wiring, cabling, insulators, anchors and other electricalequipment necessary for the safe and proper operation and control of the crane.The Contractor shall also supply the main runway conductors, insulators, bracketsand associated accessories.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)133

The main power supply shall have a short circuit capability of 50 kA.All electrical equipment shall conform to the appropriate IEC.All motors, controllers, auxiliary apparatus and conduit shall be substantiallygrounded to the structural parts of the crane.(1) Motors :All electric motors shall be of the wound rotor, drip-proof, protected type andtropicalized. They shall be in accordance with the latest edition of IEC Standardfor crane motors.(2) ControllerThe controllers shall be readily accessible for maintenance and inspectionpurposes. The nominal 415 volts, three phase, 50 Hz power supply from the maincollectors shall be controlled by means of a suitable manually operated main aircircuit breaker located in the operator's cab.The main power supply breaker shall be identified by a nameplate instructing theoperator to open the breaker when leaving the cab upon completion of work.a. Bridge and Trolley TravellingThe travel motion of the bridge and trolley shall be controlled by the normalmethods of acceleration, reversing and plugging the motor. Multi-pole contactorsmay be used.Within limits of each required speed, the drive shall be controlled to providesubstantially uniform speed regardless of load. The control shall include allnecessary relays, timers, and limit switches required, for smooth and safeoperation.b. Hoisting and Lowering ControlThe hoist drive shall be controlled to provide substantially uniform speed on eachmaster switch step regardless of load.(3) Main Circuit ContactorA main circuit contactor shall be provided in common for main power supplycircuit of main and auxiliary hoists, and for bridge and trolley travel.The main circuit contactor shall be controlled manually by a pushbutton switchlocated in the operator's cab and it's control circuit shall have necessaryinterlocking circuit as follows, but not limited to these.(4) Master SwitchThe master switches for the main hoist, auxiliary hoist, trolley travel, and bridgetravel shall be on the cam operated type, with a contact operating mechanism toensure, positive operation of the contracts in both directions. Contacts shall bedouble break, spring-operated, readily renewable without disturbing the wiringand with automatically adjusting fingers to reduce wear.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)134

(5) Limit SwitchAutomatic reset, totally enclosed, heavy duty, adjustable limit switches shall beprovided to limit the travel of the trolley and the bridge. The switches shalldisconnect power supply to the motor when either the bridge or the trolley hastravelled to within braking distance of its respective stop at either end of thetravel. A warning signal, preferably a buzzer installed in the cab, shall alert thecrane operator when the trolley approaches its stops. The signal shall be activatedahead of the trolley's limit switch.(6) Protective PanelAll power circuits to motors and all secondary circuits such as lighting shall beplaced in the panel. The panel shall also include all overload relays, low voltagecontrol, and all other necessary equipment recommended by the Contractor.(7) Runway Conductors and Trolley ConductorThe Contractor shall furnish the main runway conductors, insulators, supportbrackets, and all other necessary equipment required for installation. TheContractor shall also furnish and install the trolley conductors, insulators andaccessories required for the complete operating system. The insulators shall bebrown glazed porcelain insulators. The size of conductor shall not be less than125 sq. mm solid copper.(8) CablingAll cabling, collector gear and power supply conductors required for the operationof the crane shall be supplied by the Contractor. The crane shall be capable oftravelling the full length of the turbine area.Support brackets, suitably insulated, shall be supplied by the Contractor for powersupply conductors. Power cables and isolation switch for the supply to the powersupply conductors shall also be supplied by the Contractor.15.1.9 GANTRY STRUCTURE, RAILS AND GIRDERSThe Contractor shall supply a set of gantry structure complete withweather protection shed, rails and girders holding down bolts and abutmentplates located at the ends of each rail. Gantry rails and girders shall run over thefull length of the turbine area and adequate allowance for thermal expansion shallbe provided in the design. The structural steel shall be designed and fabricatedconform to the Section 18.5.1.The weather protection shed shall be provided to cover the working area of thecrane. The material of the shed shall be corrugated asbestos cement sheet. Thethickness of asbestos cement sheet shall not be less than 5 mm.15.1.10 SITE TESTS(1) Control and protective equipmentGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)135

Static tests of all automatic sequences.(2) Running testsThe assembled crane shall be load tested including overload test with a load equalto 125% full lifting capacity after erection by the Contractor and all tests shall bein accordance with the relevant IEC Standard.The Engineer and the Board shall witness these tests.The Contractor shall supply all equipment including weights for the above tests.The Contractor shall also be responsible for the disposal of the materials used forthe test load.15.2 Hydraulic Mobile Crane15.2.1 GENEELALThe Contractor shall provide the following mobile cranes which will be utilised forerection works and for maintenance works after Taking over of the Plant. Capacitywill be 30 ton.15.2.2 TYPE AND RATING15.3 TOOLS15.3.1 GENERALThe crane shall have following features at the minimum.a. Maximum lifting capacity : not less than 30 tonb. Basic boom length : approx. 12 mc. Maximum boom length : not less than 45 md. Wire speed for lifting : max. Approx. 50 m/mine. Wire speed for boom : max. Approx. 40 m/minf. Crane turning speed : max 5 rpmg. Type of carrier : Diesel engine driven truck typewith Rubber tires. Dimension of thecrane including basic boom shall bewithin the road limit in Bangladesh.Crawler type carrier shall not be accepted.h. Maximum running speed : not less than 40 km/hrI. Climbing capacity (tan 0) : not less than 0.30J. Minimum rotating radius : not exceed 12 mk. Type of outer rigger : Hydraulicl. Safety apparatus : Over load limiter, safety interlocks,etc. shall be providedThe following tools and equipment shall be supplied under this Contract and theTenderer is required to give a full list with details in the Schedule of Tools andAppliances when submitting his Tender.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)136

Each set of tools and appliances shall be provided with conveniently sized, robust,lockable boxes suitably inscribed with the name of the Plant for which they are tobe used.The tools and appliances with the boxes shall be handed over to the BOARD atthe time of issue of the Taking Over Certificate.15.3.2 SPECIAL TOOLSOne set of special tools, gauges and equipment required for the normalmaintenance of the whole of the Plant shall be provided by the Contractor.One set of special lifting and handling appliances required for the normalmaintenance of the whole Plant and equipment shall be provided by theContractor.Special tool list with unit price shall be submitted with Tender.15.4 HOIST/EOTThe hoist shall be of chain- block type and the capacity shall be selected takinginto consideration of weight of object. The hoist shall be provided with themonorail, supporting materials for rail and anchor bolts. The hoists shall beinstalled in the following area, but not be limited to, for the convenience ofmaintenance [ EDG etc.].- Auxiliary compartment15.5 One number Fork Lifter of capacity 5 ton.15.6 one number truck/lory (05 ton) for transportation of material.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)137

Section 16Tests And InspectionsGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)138

16. TESTS AND INSPECTIONS16.1 General16.2 Workshop Test16.2.1 Gas Turbine16.2.2 Generator16.2.3 Exciter16.2.4 Step-up Transformer16.2.5 230 kV Switchgear Equipment16.2.6 Control and Protection System16.2.7 Other Materials and Equipment16.3. Tests at Site16.3.1 Tests and Completion16.3.2 Field Inspections and Tests on Gas Turbine Units16.3.3 Field Inspections and Tests on Switchgear Equipment16.4. Acceptance and interim Operation16.5. First Inspections16.5.1 Responsibility During Guarantee Period16.5.2 First InspectionPageGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)139

16 TESTS AND INSPECTIONS16.1 GENERALThe Contractor shall perform all tests and inspections necessary to ensure thatthe material and workmanship conform to the Contract and design drawings.Those tests and inspections shall demonstrate that the equipment will complywith the requirements of this Specification and meet the specified guarantees.The Board and the Engineer shall have a right to access the Contractor or sub-Contractor's works to determine or assess compliance with the provisions of thisSpecification or to witness the Contractor's inspections or tests.The contractor shall supply to the Board as soon as practicable which shall containdetails of each test performed and shall be prepared as required by the Board,records, results and calculation of all electrical tests shall be provided.16.2 WORKSHOP TEST(1) All plant shall be subjected to type, sample and routine tests at themanufacturer's factory in accordance with these clauses and conditions of theContract.(2) Type, sample and routine tests shall be to the relevant ISO and IECStandards or other approved international standards for equipment where the testrequirements are not specified in these clauses.(3) The Contractor may offer type test results for identical equipment in lieu ofthe type tests specified, in which case the Board may waive the specified typetests. If type test results for identical equipment are offered in lieu of the specifiedtype tests, the Contractor shall also provide evidence as to the similarity of theequipment tested and the Contract equipment.(4) The Contractor shall submit evidence to the Board & Engineer that the instrumentsused for the testing shall have been calibrated at an approved testinglaboratory within a period of up to six months for a portable instrument andtwelve months for a fixed instrument.16.2.1 Gas TurbineThe gas turbine unit shall be assembled as a complete unit and run undersimulated operating conditions at the manufacturer's works. The unit shall betested to ensure smooth running and satisfactory operation of the accessories.Necessary tests shall also be performed for GBC & EDG as per relevant standard.The Contractor shall state in his proposal the performance and reliability tests tobe carried out in the works. The Contractor shall give the Board & Engineer noticeof the tests at least six(6) weeks in advance. The tests to be carried out shallinclude, but not be limited to, the following:-Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)140

a. Dynamic balancing together with over-speed tests of the turbine andCompressor rotorsb. Bench testing of all accessoriesc. No load operation of the turbine assembly to test the followings:-- Vibration- Lubrication system- Fuel system- Wheel space temperature- Exhaust temperature- Governor system- Temperature control system- Air system- Over-speed trip- Water system- Individual accessories16.2.2 GENERATOREach generator shall be operated at no-load on the factory test floor with thefollowing observations and respective data so reported and reference to IECStandard shall be made:-16.2.3 EXCITERa. Measurement of resistance of armature and field windings.b. Mechanical inspection and balance.c. No-load field current at rated voltages and frequency.d. Voltage phase balance and phase sequence.e. Dielectric tests.f. Insulation resistance of field and armature.g. Standard no-load and short circuit tests.h. Characteristic "V' curve test and efficiency tests.i. Generator fixed losses.J. Generator variable losses (at loads available with driving motor).k. Measurement of vibrationl. Temperature rise testEach exciter shall be operated at no-loads on the factory test floor with thefollowing observations and respective data so reported and reference to IECStandard should be made:-a. Saturation run.b. Mechanical balance.c. Resistance.d. Dielectric tests.e. Insulation resistance of windings.f. Exciter characteristics tests16.2.4 STEP-UP TRMSFORMERSThe transformers shall be completely assembled at the factory and shall beGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)141

subjected to the following tests by the Contractor, in accordance with the latestrevisions of IEC 76 "Power transformers" and 551 "Measurement of transformerand reactor sound levels".a. General inspectionb. Measurements of Winding resistancec. Voltage ratio measurement and check of polarityd. Measurement of impedance voltagesC. Measurement of load lossf. Measurement of no-load loss and currentg. Test of temperature riseh. Induced over-voltage withstand testi. Separate-source voltage-withstand testJ. Insulation resistance measurement (megger)k. Results of shop tests to be submitted.- Results of type tests of lightning impulse-voltage withstand test- Test of protective relays- Characteristic test of bushing type current transformers16.2.5 230 KV SWITCHGEAR EQUIPMENT(1) Circuit BreakersThe tests shall be performed in accordance with the latest revisions of IEC 56-4'High-voltage alternating-current circuit breakers, Part 4: Type tests and routinetests'.- General inspection- Insulation resistance measurement- Dielectric withstand voltage test- Operation testIn accordance with the requirements of IEC 56, details of the transient recoveryvoltage to which the circuit breaker will be subjected during short circuit testingshall be submitted to the Board for approval.The Board may require in addition any of the following tests to be carried out, thedetails of which will be agreed between the Board and the Contractor:-- Earth fault interruption tests- Out of phase switching tests according to IEC 267- Capacitance switching tests- Small inductive breaking current switching tests- Tests under environmental conditions- Voltage withstand test after breaking capacity tests(2) Isolators and Earthing SwitchThe tests shall be performed in accordance with the latest revisions of IEC 129"Alternating current disconnectors (isolators) and earthing switches".- General inspection- Insulation resistance measurement- Dielectric withstand voltage test- Operation testGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)142

(3) Current TransformersThe test shall be performed in accordance with the latest revisions of IEC 185"Current transformers".- General inspection- Polarity test- Insulation resistance measurement- Dielectric withstand voltage test- Characteristic test(4) Voltage TransformersThe test shall be performed in accordance with the latest revisions of IEC 186"Voltage transformers”- General inspection- Polarity test- Insulation resistance measurement- Dielectric withstand voltage test- Characteristic test(5) Lightning ArrestersThe test shall be performed in accordance with the latest revisions of IEC 99-1"Lightning arresters, Part 1: Non-linear resistor type arresters for AC system".- General inspection- Power frequency spark-over voltage test- Lightning impulse spark-over voltage test- Measurement of leakage current and insulation resistance(6) Steel StructuresGeneral inspectionMaterial quality and quantity check(7) Bus Support, Insulators and Wiring MaterialsThe following shop tests shall be performed by sampling inspection method andnumber of samples for the test shall be decided after award of the Contract.a. Bus Supports- General inspection- Dielectric test of power frequency- Tension proof testb. Insulator Assemblies and Grounding Wire Attachment- General inspection- Dielectric test of power frequency- Breakdown test of insulator- Dimension measurement of hardware- Tension proof testGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)143

c. Stranded Conductors for Overhead Line and Grounding System- General inspection- Tensile strength testd. Other Materials-General inspection16.2.6 CONTROL AND PROTECTION SYSTEMThe following tests for the control and protection system shall be performed atthe workshop.- General inspection- Measurement of insulation resistance- Dielectric withstands voltage test- Performance test of relay Error test of meter- Sequential operation test of Control & Protection System.16.2.7 OTHER MATERIALS AND EQUIPMENTAll other materials and equipment shall be tested at the Contractor's workshops inaccordance with latest IEC, ISO, other approved international Standard and/or therequest of the Board.16.3 TESTS AT SITEResponsibility for Testsa. The Contractor shall conduct the tests at the Site in accordance with theseclauses and the conditions of the Contract.b. The Contractor shall provide all equipment and personnel required to carry outthe tests, including the provision, installation and removal of all test instruments,the connection and disconnection of plant items and obtaining of all records. TheBoard will provide electricity, fuel and water required for the tests on completionwithout charge to the Contractor.c. The Contractor shall prepare and submit to the Board at least three monthsprior to the commencement of testing, schedules in approved format for each testtogether with a programs provided by all Contractors.The Board & the Engineer will be responsible for overall co-ordination and safetycontrol of tests.d. The Contractor shall submit one copy of the results of each of the tests at theSite to the Project Director within one week of the tests being carried out. Fourcopies of the certificates shall be provided to the Board within one month of thetests being carried out.e. The BOARD's staff will observe and participate in the tests on completion.f. The Contractor shall submit evidence to the Board that the instruments used forthe tests have been calibrated at an approved testing laboratory within a period ofGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)144

up to six months.(2) Scope of TestsThe tests to be carried out and passed before taking over of the works by theBoard shall be deemed to comprise two main stages of testing as follows:a. Preliminary tests which are tests performed prior to rotation or energising atnormal voltage or admission of normal water or air pressure to the main orauxiliary plant under test.b. Tests on completion which are tests to progressively prove the correctoperation of complete auxiliary systems and of the main plant items. These testsshall be carried out in accordance with the conditions of the Contract.(3) Reliability Test Perioda. The tests on completion shall include a reliability test period [InitialCommercial Operation "ICO"] for each generating unit and auxiliaries, which shallcommence when the Contractor has notified the Board that the unit is ready forcommercial operation. During this period, the unit and auxiliaries will be requiredto operate under the working conditions of the station, within their operatinglimits, either continuously or intermittently as required by the operation of thestation, without failure or interruption of any kind for a period of one hundredsixty eight (168) hours. The units will be operated by the station staff and theContractor shall provide at his own expense a suitable representative during eachoperating shift to direct the station staff on the operating techniques and therunning of the units. The Contractor may make minor adjustments to the units,provided that such adjustments do not in any way interfere with or prevent thecommercial use of the units by the Board or result in reducing the output orefficiency.b. Should any failure or Interruption occur in the operation of the units dueto faulty design, materials or workmanship under the Contract but not otherwise,sufficient to interrupt the commercial operation of the units, the reliability testperiod of one hundred sixty eight (168) hours shall recommence after theContractor has remedied the cause of the defect.16.3.1 TESTS ON COMPLETION(1) The Contractor shall give to the Board in writing twenty one (21) day'snotice of the date after which he will be ready to make the tests on completion.Unless otherwise agreed, the tests shall take place within ten (10) days after thesaid date, on such day or days as the Board shall in writing notify the Contractor.(2) If the Board fail to appoint a time after having been asked to do so or toattend at any time or place duly appointed for making the said tests theContractor shall be entitled to proceed in their absence, and the said tests shall bedeemed to have been made in the presence of the Board's representative.(3) If, in the opinion of the Board, the tests are being unduly delayed he mayby notice in writing call upon, the Contractor to make such tests within ten (10)Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)145

days from the receipt of the said notice and the Contractor shall make the saidtests on such day within the said ten(10) days as the Contractor may fix and ofwhich he shall give notice to the Board. If the Contractor fails to make such testswithin the time aforesaid the Board may himself proceed to make the tests. Alltests so made by the Board & the Engineer shall be at the risk an expense of theContractor unless the Contractor shall establish that the tests were not beingunduly delayed in which case tests so made shall be at the risk and expense ofthe Board.(4) The Board except where otherwise specified, shall provide free of charge,such labour, materials, fuel, water, as may be requisite and as may be reasonablydemanded to carry out such tests efficiently. However all the calibration devices,standard or sub-standard special test instruments, stores, apparatus etc., requiredto conduct all the tests would be provided, arranged and installed by theContractor at his own cost and expenses. The Contractor will pay all expenses includingthe custom duties etc. on the import or export of all such instruments etc.(5) If any portion of the works fail to pass the tests, tests of the said portionshall, if required by the Board or by the Contractor, be repeated within areasonable time upon the same terms and conditions save that all reasonableexpenses to which the Board may be put by the repetition of the tests shall bededucted from the Contract price.16.3.2 FIELD INSPECTIONS AND TESTS ON GAS TURBINE UNITSThe following field inspections and tests will be carried out in the sequencedetailed below, and the successful performance and completion of all the teststaken together shall constitute the BOARD's acceptance tests:-(1) Inspection and Checking of UnitsAfter completion of erection and/or installation, and before put into operation,each unit and all its appurtenances (compressor, gas turbine, motors, pumps,heaters, fans, piping, valves and all other mechanical and electrical equipmentand material) shall be thoroughly cleaned and then inspected under thesupervision of the Engineer and in presence of the BOARD's Engineer forcorrectness and completeness of installation and acceptability for placing inoperation. The time consumed in the inspection and checking of the units shall beconsidered as a part of the erection and installation period.(2) Start-up and Trial OperationFollowing the satisfactory completion of the inspections and checking of gasturbine units, the same will be placed in trial operation during which all necessaryadjustments, repairs etc. shall be made as required, then the unit being shutdown as required. When the equipment is operating properly its characteristicsshall be recorded on the start-up report sheets. Start-up reports for all theequipment must be completed before the start of the initial commercial operationperiod.The time consumed in start-up and trial operation shall be considered as a part ofthe erection and installation period.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)146

The following test shall be carried out. Start-up mechanical running test, adjustment of turbine inlet guide vanecontrol and interlocking, etc. The measured data such as pressure,temperature, vibration, adjustable speed range etc. shall be observed andrecorded. Checking of cooling system and lube oil system. Checking of over-speed tripping devices, protection and interlocking system,start-up and shut-down sequence of auxiliary system. Noise, NO X and vibration level measurement. Manual and automatic synchronization. Generator Protection relay testing. Checking of base load and peak load capability. Load rejection and governor tests. Testing of start-up times.(3) Initial Commercial Operation (ICO)The Contractor shall be responsible for running on initial commercial operationperiod at the Site, including all auxiliaries and controls for the Plant. TheContractor shall operate the units at various loads as specified by the Board aftersynchronising the system.The initial commercial operation shall start on the specified date and shall last forone hundred sixty eight (168) hours during which time the unit and auxiliaries willoperate continuously, uninterrupted without adjustment or repair to thesatisfaction of the Board & Engineer at all loads up to and including the maximumloads.On the completion of continuous operation for one hundred sixty eight (168)hours on all automatic and supervisory controls, the Board & Engineer will instructcycling operation, shutdown and start-up during the next seven (7) days. Aftersatisfactory completion of these observations, the unit shall be considered to havebeen put on initial commercial operation from the date of start of the initialcommercial operation.(4) Performance and Acceptance TestsSoon after the initial commercial operation tests have been run, performance testsshall be run to determine whether the equipment complies with the guaranteeprovided that unit is made ready for performance test by the Contractor andcertified by Board & Engineer. The tests shall be conducted in accordance withthe latest ISO 2314 or ASME PTC 22 Performance Test Codes using previouslyapproved correction curves and complying with the following special conditionsunless otherwise specified. The chemical analysis and lower heating values of thefuels shall be determined from two laboratories to be chosen respectively, one bythe BOARD, the other by the Contractor.The BOARD shall provide without charge such labour, material, fuel and water asmay be reasonably required to conduct the performance and acceptance tests.The gross station efficiencies under different load conditions established during afour (4) hours continuous test, shall be calculated in a manner as approved by theBoard. Power measurements at the generator terminals and at the incomingGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)147

circuit of unit motor control centre shall be made with totalising meters.Generator power output shall be held as constant as possible during theperformance test.The gas turbine generator shall run at 25%, 50%, 75% and 100% of base ratingand peak load prior to placing the unit into commercial operation and to provethat sudden load rejections from loads up to maximum capability can beaccommodated by the turbine without the speed rise being sufficient to cause theover-speed trip to initiate.The output and heat rate tests will be carried out on each unit in the followingmanner:i) 1/2 hour at 1/4 loadii) 1/2 hour at 1/2 loadiii) 1 hour at 3/4 loadiv) 1 hour at 4/4 loadv) 1 hour at peak loadFull load at the generator terminal for the purpose of the test will be calculatedfrom the guaranteed output according to the site ambient installation conditions.Correction factors for variations of test conditions from the specified designconditions shall be stated in the Tender.(5) Test ReportsThe Contractor shall submit to the Board within three(3) months after the signingof the Contract, the detailed procedure for the conductance of the performanceand acceptance tests for approval.The procedure shall include the following for such test or group of tests:-a. The time duration of each test at each load.b. The number of test runs at each load.c. The sequence of the tests to be conducted.d. A list of instruments that will be used for each test.The list shall designate which instruments are:i) Special test instrumentsii) Certifiediii) To be calibrated before and after each testiv) Check instrumentsv) Station supply instruments.Schematic diagrams showing all test points and cross references to the instrumentlist shall also be included.e. All formulas, calculations, conversion factors, curves, correction curves,etc., to be used in the conductance of the tests and the calculations of the testresults.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)148

f. Sample test reports or data sheets and all specific result sheet forms thatwill be used for the test.g. Written procedure and description of conducting the test.h. All test data to be recorded by the Contractor and the Board & Engineer.Necessary tests shall also be performed for GBC & EDG as per relevant standard.16.3.3 FIELD INSPECTIONS AND TESTS ON SWITCHGEAR, EQUIPMENTThe following site tests shall be performed by the Contractor.(1) Protection, Control, Alarm, Measurement and Indication Equipmenta. WiringInsulation resistance test using 500 V Megger shall be carried out on all AC andDC protection, control, and alarm and indication circuit.The insulation of all circuits shall be checked before proceeding with other testsand it is also essential that all AC wiring is correctly connected relay contacts,auxiliary contacts, etc., being closed, as necessary, to verify this. Checks shall bemade on cable glands, cable jointing, fuse or circuit breaker and small panelitems, such as indicating lamps. Static equipment which may be damaged by theapplication of test voltage shall have the appropriate terminals short circuited.Inter relay, inter unit and cubicle wiring carried out at the Site shall be checked tothe appropriate circuit and/or wiring diagram.Where, it is found necessary during pre commissioning work to effect sitemodifications to the secondary wiring, site copies of the appropriate schematicand wiring diagrams shall be suitably marked as agreed with the Board before thecircuit is commissioned.Loop resistance measurements shall be made on all current transformer circuits.Separate values are required for current transformer circuits.b. Mechanical CheckAll relays shall be examined to ensure that they are in proper working conditionand correctly adjusted, correctly labelled, and the relay case, cover, glass andgaskets are in good order and properly fitting.c. Secondary InjectionSecondary injection shall be carried out on all AC instruments and relays, usingvoltage and current of sinusoidal waveform and rated power frequency.(2) Current Transformer Magnetising TestsThe magnetisation characteristic of all current transformers shall be checked atthe minimum of two points to identify the current transformers with reference tothe manufacturer's estimated design curve, and to determine the suitability of thecurrent transformer for its intended duty. It may be noted that it is not normallynecessary to check the characteristic up to the knee-point for this purpose.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)149

Special measures may have to be taken to ensure that the core is fully demagnetisedbefore commencing the test.aPrimary InjectionPrimary current injection tests shall be carried out by the Contractor. The primaryinjection methods employed for a particular installation shall therefore be agreedwith the Board.Tests shall be carried out as follows:--Local primary injection to establish the ratio and polarity of currentTransformers of similar ratio.-Overall primary injection to prove correct inter-connections betweencurrent transformer groups and associated relays.-Fault setting tests to establish, where practicable, the value of currentnecessary to produce operation of the relays. If not practicable, thesetests are to be carried out by secondary injection applied at the wiringclose to the current transformer.(3) DC OperationsTests shall be carried out to prove the correctness of all DC polarities, theoperating levels of DC relays and the correct functioning of DC relay schemes,selection and control switching, indicating and alarms.(4) On Load TestsIn view of the hazards inherent in these tests, they shall be carried out under thedirect supervision of the Board & Engineer.An operation and stability test shall be carried out for on load commissioning ofunit type protection.Test for restraint shall be carried out to prove the characteristics of protectivesystems with directional/differential characteristics,On load checks shall be made after the protection gear has been placed in serviceto ensure that all connections and test links have been replaced and test leadsremoved, as well as to confirm the integrity of the current transformer circuits.Where necessary voltage readings shall be taken at the terminals on each relay &meters to ensure that loop connections between the relays & meters arecomplete. Special attention shall be paid to broken delta voltages and residualcurrent circuits where zero voltage or current respectively may not be proof of thecompleteness of the circuit.(5) Step-up Transformersa. General mechanical checks.b. Core and winding insulation tests.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)150

c. Ratio and HV magnetizating current tests.d. Vector group cheek.e. Motors overload protection tests.f. Buchholz device tests.g. Temperature instrument calibration and tests.h. Operational tests on tap change equipment.i. Dielectric strength tests of insulation oil.The above tests shall be recorded on approved test sheets, two signed copies ofwhich shall be forwarded to the Board immediately after a test or series of testshas been completed.The Board & Engineer shall countersign the test sheets if found to be satisfactoryand retain one copy. The Contractor shall provide to the Board six bound copiesof all site test sheet as final records.(6) 230 kV Switchgeara. General CheekA general check of all the main switchgear and ancillary equipment shall be madeand shall include a check of the completeness, correctness and condition of earthconnections, arcing ring and horn gaps, painted surfaces, cables, wiring,pipework, valves, blanking plates and all other auxiliary and ancillary items.Checks shall be made for oil and gas leaks and that insulators are clean and freefrom external damage. A check shall be made that loose items which are to behanded over the BOARD, e.g. blanking plates 3 tools, spares, are in order and arecorrectly stored or handed over.b. Circuit BreakersFollowing completion of erection of circuit breakers and all high voltage circuits,power frequency withstand voltage test at a level to be agreed shall be applied.Local air components associated with pneumatic operation, including aircompressors, shall be tested and air loss measurements and pressure and alarmsettings checked. Tests shall be made also on mechanical and hydraulic operatingsystems.Contact resistance tests shall be carried out with not less than 15 amperespassing through the contacts. In the case of multi-interrupter circuit-breakers,resistance tests will be required at each interrupter or pair of interrupters as wellas through the series of interrupters on each pole.Operational tests will include local and remote trip/close. SF6 gas type circuitbreakerstesting shall be required on the gas system to prove the gas quantity, itsdryness and its dielectric strength. The gas leakage shall also be measured.c. Isolators and Earthing SwitchesManually operated equipment shall be subject to operational tests to confirmcontact pressures, contact resistance, synchronism of operation of all phases andthe ease of operation.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)151

Checks shall be made of the local and remote indications and operation ofauxiliary contacts.Motorised equipment shall be tested to prove the motor operation, including localand remote operation. Timing tests shall also carried out.Earth switches and maintenance earthing devices shall be tested to confirm theopening and closing sequences and checks shall be made on the earth mat,indications and manual locking devices.d. Voltage TransformersAll voltage transformers shall be checked for polarity phasing and for secondaryoutput.e. Lightning ArrestersGeneral inspection shall be carried out to verify the condition and satisfactorymounting of the arrester and its earth connections and electrodes.(7) InterlockingAll interlocking arrangements both electrical and mechanical shall be fully checkedand tested.(8) Earthing SystemTests shall be made on the effectiveness of the bonding and earthing which willinclude conductivity tests on selected joints, on the main earthing system, and atthe connections to equipment and structures. Checks shall also be made onprecautions taken to avoid corrosion attack on the earthing system.(9) OthersAll other equipment and/or systems shall be tested in accordance with theinstruction by the Board.16.4 ACCEPTANCE AND INTERIM OPERATION(1) After the performance tests, if the equipment supplied by the Contractor isfound to meet the guarantees and any other specified requirement, and if allother work called for hereunder has been completed, the BOARD's acceptance willbe forthcoming. This acceptance shall, however, not relieve the Contractor of hisresponsibility for first inspection.Should the equipment furnished by the Contractor fail to operate as required, orin case of failure to meet any of its guarantees, the BOARD shall have the right tooperate the equipment, using the Contractor's supervisory operating personnel,until such defects have been remedied and guarantees met with. In the eventthat defects necessitate to the rejection of the equipment or any part thereof, theBoard shall have the right to operate the equipment until such time as newequipment is provided to replace the rejected equipment. Such operation shall notGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)152

e deemed an acceptance of any equipment.16.5 FIRST INSPECTION16.5.1 RESPONSIBILITY DURING GUARANTEE PERIODThe Contractor shall be responsible for operation during the period commencingwith initial start-up and extending through trial operation and all performancetests. The Contractor shall also be responsible for two(2) years operation andmaintenance after satisfactory performance test by providing supervisory staff ofthe required number to be fixed by the Board. During the trial operation period,the Contractor will furnish the supervisory operating personnel; In addition, anycalibration device, special test instruments, etc., required preparing for andconducting the performance tests.Contractor's supervisory personnel shall conduct instruction sessions in Englishlanguage for the BOARD's personnel prior to and during this period and shallotherwise train them so that they will be able to operate and maintain the newequipment satisfactorily after acceptance by the Board. The training programmeof BOARD's personnel shall be conducted to meet the satisfaction of the Board &Engineer. The Contractor shall provide the service of competent personnelknowing English language to assist the BOARD's engineers in training the staff.16.5.2 FIRST INSPECTIONThe first Inspections after the completion of recommended hours of operationshall be undertaken by the Contractor and the charges on this account Includingall corrections, repairs and replacements made by him shall be entirely at his owncost.For the first inspection the Contractor will provide the supervisors with specialtools and the Board will provide labour, normal tools, crane with driver under theresponsibility of the Contractor. Fuels, lubricants and wages for the local staff forcrane will be paid by the Contractor.First inspection will in any case be carried out before expiry of the guaranteeperiod of twenty four(24) months, according to a programme to be mutuallyagreed between the Contractor and the Board. The scope of first inspection willinclude, but will not be limited to, the item specified in Appendix-2.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)153

Section 17Civil WorksGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)154

17 CIVIL WORKS17.1 General17.1.1 General Requirement17.1.2 Topographic Surveys17.1.3 Site Investigation17.1.4 Site Laboratory17.1.5 Records and Drawings17.1.6 Samples, Testing and Inspection17.1.7 Standards and Codes of Practice17.1.8 Preparation of Design and Drawings17.2 Scope of Civil Works17.3 Earthworks17.3.1 General17.3.2 Excavation17.3.3 Filling17.3.4 Backfilling17.3.5 Measurement and Payment17.4 Foundation17.4.1 General17.4.2 piling17.4.3 Foundation of Gas Turbine Generator17.4.4 Foundation for Building and Other Equipment17.4.5 Hardcore17.4.6 Replacement of Unsuitable Materials17.5 Deleted.17.6 Concrete Works17.6.1 General17.6.2 Composition17.6.3 Tests17.6.4 Cement17.6.5 Admixture17.6.6 Water17.6.7 Aggregate17.6.8 Standard Grading17.6.9 Concrete Mixing17.6.10 Placing17.6.11 Transportation17.6.12 Curing17.6.13 Eormwork and Timbering17.6.14 Waterstops and Expansion Joints17.6.15 Finish and Repair of Concrete17.6.16 Reinforcement Bar17.6.17 Payment17.7 Roads and Surfacings17.7.1 Concrete Pavement17.7.2 Gravel Surfacing17.7.3 Landscaping and Turfing17.8 Drainage System17.8.1 Design Conditions17.8.2 Drain LayingPageGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)155

17.9 Sewage Works17.9.1 General17.9.2 Sewer, Manholes and Septic Tanks17.10 Water Reticulation System17.10.1 Internal Water Reticulation System17.10.2 Water requirement.17.10.3 Design Parameters and Standard17.10.4 Materials and Workmanship17.10.5 Deepwell and Deepwell Pumps17.11 Ducts17.12 Fencing and Gates17.12.1 Fencing17.12.2 Gates17.12.3 Flag, PolesGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)156

17. CIVIL WORKS17.1 GENERALThe General Conditions, Tender Drawings and Schedules shall be read inconjunction with this Specification. Matters described in one are not necessarilyrepeated in the others.17.1.1 GENERAL REQUIREMENTSThe Tenderer's proposal shall cover all requirements of the Tender Documentsand any other items not specifically mentioned but which arc deemed to benecessary for the satisfactory design, supply of materials, construction,supervision of the civil works on the basis of a turnkey contract.The Contractor shall upon examining the design of the foundations and majorstructures, develop and prepare the detailed design and the construction drawingsof all civil structures for the approval of the Board which shall meet the equipmentand structures specification, to be supplied by the Contractor for the Project.The Board shall reserve the right to examine the Contractor's design and toinstruct a change or modification by the Contractor.These modifications shall be carried out by the Contractor without additional costas a result of any claims made by the Contractor on the Board.Approval of the design by the Board shall not relieve the Contractor of liability forthe construction works.The Tenderer shall familiarise himself with the site levels, subsoil and an otherdata necessary to enable him to estimate the bearing capacity and foundationrequirements, for use in the preparation of his tender.It is the Contractor's entire responsibility to search for filling material for landreclamation work and to make all arrangements necessary for the satisfactorycompletion of the land reclamation work within the Project. His tender shallinclude for all local eventualities.The Tenderer shall quote firm prices which shall remain valid through-out theContract Period on all items in the Price Schedule unless other-wise stipulated.17.1.2 TOPOGRAPHIC SURVEYSThe Contractor shall carry out surveys as are necessary for the proper design andexecution of the Works. The results of such additional surveys together with thesurvey drawings shall be submitted to the Board for approval.17.1.3 SITE INVESTIGATIONThe Contractor may conduct soil investigation if deemed necessary at his owncost before submission of the bid. However, after signing of contract the soilinvestigation at the cost of the contractor is mandatory for detailed design of thecivil work.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)157

17.1.4 SITE LABORATORYThe Contractor shall provide a site laboratory with a concrete floor space of notless than 4m x 6m adequately equipped to carry out quality control tests ofmaterial and workmanship in accordance with the procedures and tests asdescribed in the relevant ASTM Standard or other approved Standard. He may asan alternative to the provision of laboratory equipment, make arrangement for allnecessary tests to be carried out by personnel with relevant experience from anapproved laboratory.17.1.5 RECORDS AND DRAWINGSThe Contractor shall keep at the Site accurate and upto-date records anddrawings of the Works, and shall submit these records to the Board at the end ofevery week. Such record shall include the amount of labour, plant and materialsemployed upon the Site during that week.17.1.6 SAMPLES, TESTING AND INSPECTIONThe Board may request at any time to test or inspect sample of material andworkmanship proposed and the Contractor shall furnish these immediately. Whenthe Board & Engineer has approved the samples, material, and workmanship notcorresponding in quality and character with the samples approved shall berejected. The costs of all sampling and testing to be conducted either on the Siteor in an approved laboratory shall be borne by the Contractor.17.1.7 STANDARDS AND CODES OF PRACTICEThe Civil Works shall be designed and constructed in accordance with theSpecifications, relevant Standards and Codes of Practice of Bangladesh NationalBuilding Code. The Contractor shall submit together with his bid a schedule ofstandards and codes of practice to be followed in the design and construction ofthe Works. Copies of these codes and standards shall be made available to theBoard & Engineer during the design and construction period. In the case of theStandards and Codes not published in English, the Contractor shall obtain Englishtranslations when required and send them to the Board.The Contractor shall be responsible for the establishment of design parameters tosatisfy the requirement of the project.Basic design conditions shall be as follows: -a. For Seismic horizontal ground acceleration: 0.10gb. Design Storm : Based on frequencyintensityDuration curves preparedfor ......6hc. Wind velocity : 100 miles/hrd. Design load for road : H-15 (AASHTO)e. Standards and codes of practice : ASTM, ACI, and inter-nationalcodes of practice and otherStandards to be approved by theBoardGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)158

17.1.8 PREPARATION OF DESIGN AND DRLKWINGSThe Contractor shall prepare all designs and detailed working drawings asdeemed necessary for the execution and completion of the Works.The Contractor shall be responsible for ensuring that the design satisfies therequirements of all local and national authorities. Design calculations shall be inaccordance with an approved method and should take into account the mostcritical combination of dead load, wind load, and seismic load. Design calculationsand detailed drawings shall be submitted to the Board for approval. TheContractor may commence construction on the Site only after drawings areapproved by the Board & Engineer.17.2 SCOPE OF CIVIL WORKSThe civil works shall include collection of site data, detailed design, production ofworking drawings, provision of labour, supply of construction plant and materials,construction and rectification of defects during the Warranty Period of the Works.The Scope of Work shall include, but not be necessarily limited to, the following:a) Demolition of existing structures and removal of debris from the site specified.b) Site Works: Site clearance, excavation and filling of the Site to formation level(Site development up to same level of existing power plants) including runningsurplus excavated materials to disposal area, sheet piling work, site roads andsurfacing, water supply, sewage treatment cable ducting, pipe ducting, drainage,landscaping, fencing, boundary wall and gates.c) Foundation: For all plants and structures supplied under this Contract. Suitablefoundations shall be provided for the gas turbine generating unit(s), GBC, 230 kVswitchgears, transformers, elevated water tank, overhead travelling crane,buildings, Oil storage Tank, Fuel oil Handling System, gas generator, equipmentand structures.d) Temporary works as necessary to construct the permanent works. Provision ofsite office for the Engineer and the Project Director including all services,furnishings, and attendance for the period required by the Engineer but notexceeding one month after the final taking-over date.17.3. EARTHWORKS17.3.1 GENERALThe Contractor shall prepare the drawing necessary for his construction purposebased on drawings and the specification, and submit them to the Board forapproval. The Contractor shall be responsible for and shall complete all theearthworks as shown on the approved drawings or as directed by the Board.17.3.2 EXCAVATIONBefore commencing any excavation on the Site, the Contractor shall notify theBoard at least 48 hours before starting any additional surveys. He shall carry out,Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)159

where directed by the Board extra surveys required resolving any doubts whichmay arise as to correctness of any surveys or record. Thereafter the decision ofthe Board & Engineer regarding what shall be recorded as the correct survey shallbe final.Excavations shall be carried out to the width, lengths and depths shown on theapproved drawings. The Contractor may excavate by any method he considerssuitable, subject to the approval of the Board.Selected granular materials from the excavation as approved by the Board shallbe used in the embankment construction and filling.Unsuitable materials shall be removed from the Site to disposal areas.Cut and fill slopes shall be designed for to be thorough stability. Unless otherwiseindicated On the Drawing the exposed surfaces of all cuttings and embankmentsshall be soiled and turfed to the satisfaction of the Board.The Contractor shall take particular care during the excavation of the foundationto avoid deterioration of the ground due to exposure to the weather. The final120 mm of excavation above formation level shall be carried out by handimmediately before the next stage of construction is to start. A similar methodshall be adopted in the ease of the sides of excavation against which the structureis to bear.The Contractor shall provide all strutting and shoring necessary for the safeexecution of the Works and shall provide the necessary pumps, de-wateringfacilities, and temporary drains to ensure that all excavation shall be carried out inthe dry.The rates for excavation and filling shall be deemed to have included for the fullcost of excavation and filling of the materials including site clearing, stripping oftop soil, all pumping and temporary works necessary to keep the excavation andfilling free from water, temporary shoring and timbering, trimming to line andlevel, stock-piling, handling, compaction, cutting, slope protection, removingsurplus excavated material to spoil tips, together with all other costs incurred incom--plying with the contract requirements.17.3.3 FILLINGThe area to be filled shall be cleared of vegetation and the top soil shall bestripped and stockpiled. All soft yielding material shall be removed and replacedwith granular selected material. Where fill has to be deposited against the hillslope, the Contractor shall take all necessary precautions to ensure that a goodbond is achieved between the fill and the original ground.No fill shall be deposited in the area to be filled until the Board & Engineer hasinspected and given approval. Filling to the formation level shall be brought upform the bottom in uniform compacted layers. Excavated material obtained fromthe Site may be used for embankment construction and filling.Filling, levelling and compaction on the Site shall be carried out in layers notexceeding 300 mm thickness. The Contractor shall carry out all necessary qualityGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)160

control works including in-situ soil density tests, moisture content and otherlaboratory testing to ensure that all materials used in the embankment or fillingelsewhere are compacted in accordance with the specified requirements.The maximum dry density (MDD) for the purpose of this specification shall bedetermined by the following procedures or equivalent.a. Selected materials used in the embankment other than below buildingsshall be compacted to a density not less than 95% MDD.b. Sub-grade for road below formation level to a depth 650mm shall becompacted to a density not less than 95% MDD or as approved by theBoard.c. Location of buildings and equipment foundations shall be compacted to adensity not less than 95% MDD or as approved by the Board.The following standards tests (any one) shall be conducted for determination ofMDD.(1) Standard Proctor Method(2) Modified AASHTO Test17.3.4 BACKFILLINGThis section shall apply to the performance of all work in connection with therequired backfill for the permanent works.(1) MaterialMaterial for backfill shall be obtained from excavated soil or other sourcesapproved by the Board(2) WorkmanshipBackfill to all foundations trenches, pits, etc., shall not be placed until the workhas been inspected and approved Backfill around sewers, water mains and otherutility lines shall be carefully placed so that the piping will not be displaced ordamaged. Fill in contact with pipes shall be entirely free of rocks. Backfill aroundservice pipe shall be of sandy material. The backfill shall be compacted atoptimum moisture content in layers not exceeding 15cm to 92% of the maximumdry density. Compaction shall be carried out by vibratory plate compactor.17.3.5 MEASUREMENT AND PAYMENT(1) Land reclamation worksMeasurement by volume, for the payment of filling for the land reclamation worksshall be made on the basis of the original ground surf ace and the site formationlevels shown on the approved drawings. The quantity of filling given in theSchedule was estimated for Tendering purposes. If the final quantity of the fillingwork varies beyond 10 (ten) percent, the Contractor shall notify the Board forGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)161

approval regarding the re-measurement and subsequent a variation the contractamount will be adjusted. Payment for the filling of the land reclamation worksshall be made based on the unit price fixed by the Tenderer.(2) Foundations and Ducts etc.All expenses required for excavation and backfiling of foundations, ducts,trenches, roads and all other structures shall be included in the lump sum pricebid for the respective work item in the Schedule. The lump sum price bid shall notbe modified or subject to adjustment for any design variation due to a change ofgeological or other conditions.17.4 FOUNDATION17.4.1 GENERALThe Contractor shall take full responsibility for the suitability of the type offoundations he proposes to use and shall guarantee the performance of thefoundations.All foundation shall be designed in accordance with the requirement as laid downin CP2004: 1972 Foundation" or other approved Standards and Codes ofPractice/BNBC.17.4.2 PILINGPile foundations shall be designed and applied to buildings, equipment, andstructure where required based on available information obtained from the subsoilinvestigation to be carried out at the Project Site by the Contractor.In the event that piled foundations are proposed, the Contractor shall submit adetailed design for piled foundations to the Board for approval. The Contractorcan apply any type of pile design to satisfy the soil condition. The bid price forpiling shall be lump sum and shall remain firm irrespective of the type of design.(1) GeneralThe Contractor shall supply, install and test at least one of the types of pilespecified herein, or in accordance with the approved design and the drawingshowing the piling arrangement. Each pile shall be suit existing the sub-strata atthe Site. The Board reserves the right to order additional test piles at no extracost if the type of pile or the sub-strata differs from the one originally driven andtested.The Contractor shall take full responsibility for the suitability of the type of pileshe proposes to use and shall guarantee that each pile will carry a test load equalto twice the working load in accordance with this specification.The standard of workmanship shall be as laid down in CP.2004; 1972"Foundations" or other approved standard/BNBC.(2) Pre-cast PilesGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)162

The Contractor's arrangements for the provision of piles shall be to the approvalof the Board. The Contractor shall submit full details of the manufacture includingdetails of formwork, placing of concrete, vibrators, curing, handling, storage, andtransport.All concrete, reinforcement and other materials used for the manufacturing ofpiles shall comply with the requirements of the relevant sections of theSpecification. Concrete may need to be made from sulphate resisting cementwhere necessary.The reinforcement for a pile shall be fabricated to form a rigid cage. The mainlongitudinal reinforcement shall be in one continuous length except whereotherwise approved and shall be finished level and cut square at the head of thepile, and shall bear against pile shoe. The minimum cover to the mainreinforcement shall be 65mm. The spacer blocks shall be made of concrete of thesame grade as that used in piles. Cast-in threaded inserts or metal tubes of anapproved type shall be used to form holes in the piles where required.Pile shoes shall be firmly fixed during concreting to prevent any displacement. Thewhole of the concrete in any pile shall be poured continuously. After a pile hasbeen cast, the date of casting and reference number shall be clearly inscribednear the pile head.The maximum variations permitted on the specified cross section dimensions shallbe -3mm to +6mm. The maximum departure from alignment on the face of thepile shall not exceed +6mm over a 3-metre length and 12 mm over the totallength of the pile.Piles shall not be lifted without permission of the Board and such permission willnot normally be given until the concrete in the pile has attained a strength of175kg/cm 2 During lifting, adequate precautions shall be taken not to cause unduestress to the piles. Piles shall be stored on adequate supports correctly locatedand spaced to avoid undue bending in the piles. Due consideration shall be givento future handling, curing and withdrawal of older piles without disturbing newerpiles.All piles shall be kept continuously wet for a minimum 7 days from the date ofcasting, or as directed by the Board.No pile shall be driven until the concrete has reached the strength specified onthe drawings or as otherwise described.(3) Driving PilesThe Contractor shall submit with his tender full details of the performance, sizeand type of his driving plant together with information on the type of hammer andthe number of rigs he proposes to employ on the works.The driving rig shall be approved by the Board.Piles shall be adequately guided whilst being driven and the guides shall be heldGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)163

igidly in position down to the lowest level reached by the hammer.The maximum departure of any pile head at cut-off level from the positionindicated on the drawings shall not exceed 75mm. The Maximum departure fromthe vertical or the correct angle of rake shall not exceed 1 in 50.The Contractor shall provide the Board with three copies of the driving record foreach pile, these records shall reach the BOARD's Representative not later than theday following the driving of the relevant pile and shall contain details of thefollowing(a)(b)(c)(d)(e)(f)(g)(h)(i)LocationPile details such as reference number, date of casting, length, anddimensions.Date and time of drivingType, weight and drop-of hammer or equivalent information if other typeof equipment is used.Information on number and thickness of packing used during the drivingof the pile and their condition after removal from the pile head.Number of blows per 300mm over the last 3 meters of penetration.Number of blows per 50 mm over the last 300 mm of penetration.Toe level of pile.Other relevant information as may be required by the Board.If any pile is in any way considered unsatisfactory by the Board, he reserves theright to order the Contractor to remove the pile and/or to install replacement pilesat positions selected by the Board, all at the cost of the Contractor.(4) In-Situ PilesBefore commencing the piling, the Contractor shall submit details of the type andnumber of rigs to be used for in-situ piles.Jetting shall be permitted only with the approval of the Board.The spoil from the pile holes and material remaining from the cutting of piles shallbe removed by the Contractor to a tip to be provided by him.Before pouring concrete into the core, the reinforcement for each pile shall bemade up to form a rigid cage and lowered into the core. Arrangements are to bemade to ensure that the minimum cover to the main reinforcement is 50 mm. Themain longitudinal reinforcement shall be in one continuous length except whereotherwise approved and the main bars shall extend at least 1 metre above cut-offlevel.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)164

The concrete for the pile cores shall comply with the concrete specification.Concrete may need to be made from sulphate resisting cement where necessary.Concreting of the core shall not commence until the Board has inspected.The concrete shall be transported and placed in such a way that it ishomogeneous with a high density, and care shall be taken to avoid segregation.The method of placing and compacting the concrete shall be to the completesatisfaction of the Board. Care shall be taken that harmful materials do not fallinto the pile hole during concreting.Curing of pile-heads expose to the atmosphere below cut-off level shall complywith the concrete Specification where practicable.The concrete shall be finished 40 mm above cut-off level. Concrete shall notnormally be placed in or through water. In particular circumstances only, theBoard may allow the Contractor at his own expense to place concrete (usingsuitable mix) through water by means of a termite pipe. If the Contractor's pilingsystem does not normally exclude water during concreting, he should allow in histender for the use -of compressed air or other method to keep the pile hole free'from water whilst the concrete is being placed.(5) Steel PilesThe Contractor shall take all necessary precautions to prevent damage to steelpiles and fittings when handling, pitching and driving piles. Adequate bearers shallbe provided under stacks of piles at positions to prevent distortion of the piles.Any piles which are permanently deformed will be rejected.Details and jointing lengths- of piles will only be permitted with the Board'sapproval. The type of joint and weld details shall be in accordance with the pilemanufactures recommendations.Where the completed pile will be subjected to long term corrosion adequatemeasures shall be taken to protect the surface of the exposed pile by casing inconcrete or such other means satisfactory to the Board.(6) Miscellaneous Piling Systems and Subsoil Improvement MethodThe Contractor can propose any system of piling or subsoil improvement methodnot covered by the foregoing specification and shall submit his proposal thereonto the Board for approval in sufficient time to allow the suitability of the system inthe ground conditions prevailing on this Site to be investigated fully.(7) TestingThe Contractor shall install at least two piles solely for testing purposes and shallsubmit a detailed driving record and other data as directed by the Board for thepurpose of proving the proposed pile design. If this pile test does not satisfy thespecified settlement, further piles shall be installed and tested.The Contractor shall provide all the equipment required for carrying out load testsGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)165

on piles together with the apparatus for measuring shall be to the satisfaction ofthe Board.Measurement of pile movement during testing shall be by a means capable ofreading to 0.1 mm. This shall be related to a benchmark situated at a sufficientdistance from the pile to ensure a permanent datum.The loading system shall incorporate a proving ring, load cell or other apparatuscapable of measuring the load to an accuracy with 2%.(8) Test Pile LoadThe test pile load shall be twice the specified working load and shall be applied insteps not exceeding 10 tons. Displacement readings shall be taken every 5minutes after application of the load increment until two consecutive readingsshow that the displacement has ceased. When the test load reaches the specifiedworking load, the displacement readings shall continue until it is established thatno further displacement has occurred over a 15 minute period.The working load shall be then maintained for a further 24 hours, displacementreadings taken every 2 hours.When no further displacement is apparent on completion of the 24 hour period orwhen approved by the Board, the load shall be removed in one stage and therecovery readings taken every 15 minutes until recovery has ceased.The pile shall then be reloaded in one stage to the specified working load,readings being taken every 15 minutes until displacement has again ceased.The load shall be then increased in equal increments up to twice the specifiedworking load, the same procedure being followed as stipulated for the beginningof the test. The maximum load shall be maintained for 24 hours or as directed bythe Board after all displacement has, ceased, and readings shall be taken every 2hours during this period.On completion of this period or when approved by the Board, all loads shall beremoved and the displacement on recovery noted.(9) Settlement Under Test LoadsThe settlement of the pile head under test load shall not exceed -the followingfigures under the loads stated :Under 120% working load, settlement of 8mm.Under 200% working load, settlement of 25mm.After removal of test load immediate residual settlement of 3m m for 120%working load and 15mm for 200% working load.On completion of each pile test the Contractor shall supply the Board with twocopies of a complete report which shall include graphs of load-settlement, load-Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)166

time-settlement and recovery of the pile as the load is removed.(10) Rejection of PilesIf any pile is in any Fay unsatisfactory to the Board he reserves the right to orderthe Contractor to install replacement piles at the locations selected by the Boardat no extra cost.17.4.3 FOUNDATION OF GAS TURBINE GENERATOR, Fuel Oil Tank,Emergency Diesel Generator, Transformers, Switchgears etc.Appropriate foundations shall be provided for the gas turbine generating units.The gas turbine generating units shall be supported by the reinforced blockfoundation.The Tenderer shall together with his Bid provide adequate information and datarequired for the design of the gas turbine generating units foundation.The design drawings and calculation sheets shall be submitted to the Board forapproval prior to commence the construction.(1) Design load and CombinationThe following loads and external forces shall be considered for structural analysisof the gas turbine generating unit foundations.a. Concrete weightb. Machine weightC. Dynamic load (vertical direction)d. Dynamic load (horizontal direction)e. Short circuit force of generatorf. Seismic horizontal ground acceleration : 0.15gIn following load cases, the worst case shall be selected for the design of the gasturbine generating unit foundation.Long terma+b+c or a+b+d- short terma-b+e or a+b+c+f or a+b+d+f17.4.4 FOUNDATION FOR BUILDING AND OTHER EQUIPMENTSuitable foundations shall be provided for the elevated water tank, switchyardequipment, radiators, overhead travelling crane, buildings, transformersequipment, and miscellaneous structures.17.4.5 HARDCOREThe Contractor shall place where required hardcore under the foundations of theequipment. The material shall be crushed rock or natural rubble stone not largerGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)167

than 15 cm in size containing suitable quantities of fines to a grading and qualityapproved by the Board.17.4.6 REPLACEMENT OF UNSUITABLE MATERIALIn a case where the in-situ soils are found unsuitable for proper construction ofthe foundations, such materials shall be excavated and replaced with sand orother suitable granular material to be approved by the Board. The Contractor shallsubmit materials samples, laboratory test results and the proposed method ofcompaction and construction to the Board for approval prior to commence theconstruction.17.5 Deleted17.6 CONCRETE WORKS17.6.1 GENERALStandards of design, materials, and workmanship shall be in conformity with thisSpecification, ACI Standard or other internationally accepted Standards approvedby the Board.For the purpose of the Contract, this Specification shall be applicable to allconcrete works to be included in the civil engineering and building works.17.6.2 COMPOSITIONThe Contractor shall make trial mixes using samples of aggregates and cementstypical of those to be used at least four weeks before commencing any concretingin the Works. The strength requirements for each grade of concrete proposed inthe design shall be determined by the Contractor by means of trial mixes tosatisfy the conditions specified in Table 17.1.Table 17.1Class A B CMaximum size ofaggregate (mm) 20 – 40 20 20Water-cement Less than Less than Less thanratio 0.55 0.55 0.55Maximum slump 7 - 10 7 7(In cm)Compressive strengthat 28th day 240 210 160(kgf/sq. cm)ApproximatePercentage of aircontent 2 ± 1 2 ± 1 2 ± 1Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)168

Fineness Modulus offine aggregate 2.3 - 2.4 2.3-2.4 1.8Applicable to Foundation, Trenches, LevellingColumn, slab, drain-channel,beam, wallcorner stone,pile, road,ductspavement17.6.3 TESTSIn order to control the quality of concrete to be placed, samples of concrete fortesting shall be taken and cubes made as and when directed by the Board. Testsshall be done in accordance with this Specification or equivalent Standardsapproved by the Board.a. Slump testb. Compression testC. Air testFor each grade of concrete, six test cylinders conforming to ACI or equivalentshall be prepared for each 30 cubic meters of concrete in each day's work. Threecylinders shall be tested on the 7th day and the remaining three on the 28th day.The slump and compression tests shall be carried out and the results shallsubmitted to the Board in written form.The cost of preparing, storing and transporting test specimens to the place oftesting and testing shall be borne by the Contractor.17.6.4 CEMENTAll cement shall be of normal Portland cement complying with BSTI or otherapproved standard. When required by the Board, the Contractor shall obtain forhim the manufacturer's test certificate prior to any delivery. All cement shall bestored dry in a well-ventilated and weatherproof building. The cement shall befurnished either in bulk or in bags from the cement factory approved by theBoard.17.6.5 ADMIXTUREThe Contractor may use water-reducing and set-retarding agents, but the use ofadmixture must have the prior approval of the Board.17.6.6 WATERThe water used for making concrete, mortar and grout shall be clean, fresh andfree from injurious amounts of oil, organic-matter or any other deleterioussubstance.17.6.7 AGGREGATEThe fine and coarse aggregates shall be durable, non-reactive hard materialscomplying with internationally accepted standards approved by the Board. AllGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)169

aggregates shall be washed prior to use in order to remove clay, silt, dust andadherent materials.The aggregates shall be stored on drained concrete paved areas in such a mannerthat intermingling of different sizes and types of aggregates is prevented. Thestock piles of the aggregates shall be protected from rubbish or wind blown dust.Coarse and fine aggregates shall be well graded within the standard limitsspecified as follows.17.6.8 STANDARD GRADINGa. Coarse aggregatePERCENTAGE BY WEIGHTSieve size 50.8 38.1 31.7 25.4 19.1 15.9 9.52 4.72 2.38Size ofCoarse 100 95-100 - - 37-70 - 10-30 0-5 -Aggregate(40-5 mm)(20-5 mm) - - 10095-100 - 30-70 - 0-10 0-5b. Fine aggregateSieve size (mm)Percentage passing by weight9.52 1004.76 90 - 1002.38 80 1001.19 50 900.595 25 650.297 10 350.149 2 20Limits of injurious material content Maximum (percent by weight)Silt/ClayVolume lost by Less than specificwashing test gravityCoarse aggregate 0.25 1.5 1.0Fine aggregate 1.0 7.0 1.017.6.9 CONCRETE MIXINGAll concrete except where specifically approved by the Board shall be mixed inweigh batch mixing machines. The machine shall have a Water storage tank withGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)170

a gauge so that a predetermined quantity of water can be injected direct into themixer drum. If concrete is to be mixed by hand, it shall be approved by the Board.The Contractor shall take all precautions to protect the concrete from the effectsof injurious materials.17.6.10 PLACINGThe concrete shall be placed in the positions and sequences indicated on theapproved drawings immediately after mixing under the supervision of the Boardor his representative.Prior to placing the concrete all deleterious substance such as organic matter,standing water, flowing water, wood fragments shall be removed from the surface against which the concrete is to be placed. When concrete is to be placedagainst a construction joint or adjacent to a set surface the whole surface shall bethoroughly roughened. It shall be cleared of all loose and foreign matter andwashed with water immediately before fresh concrete is placed.The concrete shall be fully compacted throughout the layer and it shall bethoroughly worked against the formwork and round the reinforcement withoutdisplacing them Unless otherwise directed by the Board, approved power drivenvibrators of the immersion type shall be used. Vibrators shall penetrate to the fulldepth of the concrete layer and shall re-vibrate that layer to ensure that thesuccessive layers are well knitted together. The placing of concrete shall not bepermitted under the following conditions unless specifically approved by theBoard.a. If it rainsb. If it is poorly illuminated during night workC. If ordered to stop by the Board or his representative.17.6.11 TRANSPORTATIONReady mixed concrete shall be transported speedily to the point of placing by ameans that shall be approved by the Board and which shall give little chance forsegregation of materials. Generally, the transportation of ready mixed concreteshall be limited to within one hour. Concrete delivered in excess of the time limitshall be rejected. When concrete is observed to have segregated or startedsolidifying at the transportation of placing, it shall be rejected and replaced.17.6.12 CURINGConcrete shall be protected during the first stage of hardening from the harmfuleffects of sunshine, drying winds, hot weather and rain or running water. Theconcrete shall generally be wet-cured for at least 7 days. The curing method forconcrete shall be submitted to the Board for approval.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)171

17.6.13 FORMWORK AND TIMBERINGFormwork and timbering shall be so designed and constructed that the requiredfinishes in concrete works are achieved. Formworks shall be constructedaccurately to the required shape, position and level and shall have sufficientstrength to withstand the compaction pressure. The materials to be used forformwork, shall be approved by the Board.Forms shall be removed without damage to the concrete. The use of form oil orother release agents shall be approved by the Board.The removal time of formwork and timbering shall be as followsWalls, beams, columnBeam soffits (props left under)Slab soffits (props left under): 3 days: 3 days: 4 days17.6.14 WATERSTOPS AND EXPANSION JOINTSThe Contractor shall place waterstops, water proofing membranes and expansionjoints at locations as are necessary for the proper construction of the concretestructure. The materials to be used shall be submitted in advance to the Board forapproval.17.6.15 FINISH AND REPAIR OF CONCRETE(1) GeneralThe classes of finishes and the requirement for finishing concrete surfaces shallbe as specified in this clause or as shown on the approved drawings. Surfaceirregularities in finishes shall be distinguished from construction tolerances, whichare allowable deviations from established lines, grades and dimensions, asdescribed herein.Surface irregularities are designated "abrupt" and "gradual" for purposes ofclassifying finishes. Offsets resulting from displaced, misplaced, or mismatchedforms or by loose knots in forms, or other similar forms of defects shall beconsidered "abrupt" irregularities and will be checked by direct measurement. Allother surface irregularities shall be considered "gradual" irregularities and will bemeasured as a departure from the testing edge of three meter template.Finishing of concrete surfaces shall be performed only by skilled workmen.Concrete surfaces shall be free from imperfections such as honeycombs andcracks. The Contractor shall at his own expense repair honeycombs, cracks, andirregularities promptly as directed by the Board.(2) Concrete Construction TolerancesVariations in alignment, grade and dimensions of the structures from theestablished alignment, grade and dimensions shown on the approved drawingsshall be within the tolerances specified in the following tables. Concrete work thatGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)172

exceeds the tolerance limits specified herein may be required by the Board to beremedied or removed and replaced by the Contractor.Construction Tolerances for Concretea. -Variation from vertical:In the lines & surfaces of In 3 m 5 mmcolumns, walls and towers In 6 m 10 mmIn 12m or more 20 mmFor exposed columns, In 6 m max, 10 mmjoint grooves and other In 12 m or more 15 mmConspicuous linesb. Variation from the level or In 3 m 5 mmfrom the grades indicated On In any bay or 15 mmthe approved drawings:6 m max.- In floors, inverts, In 12m or more 20 mmc. Variation of the linear In any bay or 20 mmstructure lines from estabt- 6 m max.lished position in plan andrelated position of wallsIn 12m or more 30mmd. Variation in locations of 10 mmsleeves and sizes and locationsof floor openings andwall openingse. Variation in cross-section @1 minus 10 mmdimensions or columns, beams Plus 15 mmand in the thickness of slabsand wallsf. Variation in steps:In a flight of stairs Rise 3 mmIn consecutive steps Tread 5 mmRise 2 mmTread 3 mmg. Variation in other structure 30 mmConstruction Tolerance forPlacing Reinforcing Steela. Variation of protective 50 mm cover or less 10mmcovering more than 50 mm cover 15mmVariation from indicatedspacing (any one bar)25mm(3) Repair of concreteGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)173

he Contractor shall repair at his own expense the imperfections of concretesurfaces and the irregularities which do not meet the allowance specified in thepreceding item. Repairing works shall be performed and completed within 24hours after the removal of forms, in accordance with the direction of the Board.17.6.16 REINFORCEMENT BARThe reinforcement bars for the gas turbine generating units foundation blocksshall be deformed steel bars. Dimension, shapes, tensile strength, yield point andother mechanical properties of the reinforcement bars shall comply with relevantapproved standards. All reinforcement must be free from oil, grease, paint, dirt,loose scale or rust at the time of concreting.The physical properties of the reinforcement bar shall have the following valuesYield point : more than 2400 kg/cm 2Ultimate tensile strength : more than 4000 kg/cm 2Reinforcement bars shall be stacked of f the ground on sufficient sup-ports toprevent distortion of the bars. Prior to fabricating and placing the reinforcement,the Contractor shall prepare a bar bending schedule, and drawings for submissionto the Board for approval. Reinforcement shall generally be bent cold by anapproved means to the dimensions shown on the approved bar bending scheduleand shall be rigidly fixed in the positions shown on the approved reinforcementdrawings using annealed soft black iron binding wire to prevent movement duringconcreting. The Board shall have the right to select at any time samples ofreinforcement bar for testing for compliance with the Specifications. The spacerblocks, prior to using, shall be submitted to the Board for approval.17.6.17 PAYMENTAll costs associated with concrete work and reinforcing bar for equipmentfoundations, duets, roads, buildings, drainage system and all other structuresshall be deemed to include in the lump sum price bid for the respective work itemin the Schedule. The lump sum price bid shall not be modified or subject to anyadjustment for design variations due to changes of geological and otherconditions.17.7 ROADS AND SURFACINGSThe Contractor shall furnish all designs and construct the roads, yards, paths,surfacing as necessary for the proper functioning of the power station.The roads and yards as indicated in the Drawings or directed by the Board shallbe generally designed with raised kerb, in compliance with the approved Standardand to satisfy the following basic design requirementMaximum grade : 7%Pavement width: as directed by Board.Turning radius: more than 10 mm.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)174

17.7.1 CONCRETE PAVEMENTThe roads and yards shall be paved with reinforced cement concrete and shall bedesigned in accordance with the procedures as outlined in the AASHTO Standardor any other acceptable international standard or Design of Pavement Structuresor other internationally accepted methods approved by the Board. Basic designconditions are as followsDesign loadMinimum thickness ofconcrete pavement:Minimum 15 ton axle weight: 20cm17.7.1.1 Sub-grade Preparation and TestThe aggregate sub-base for the concrete pavement shall be prepared by bringingthe sub-grade to a firm and unyielding surface by rolling the entire area with anapproved roller weighing not less than ten (10) tons. The sub-grade shall besprinkled with water, if necessary, to attain satisfactory compaction. All soft,yielding material which will not compact readily when rolled shall be removed asdirected. All holes or depressions shall be filled with suitable material and thewhole surface compacted uniformly. In cut, sections, the ground below thesurface of the sub-grade, shall not be plowed or disturbed, except as otherwisedirected by the Board. When necessary, additional approved material shall beadded to bring the sub-grade to the desired elevations and cross section, and thewhole shall be rolled until compacted thoroughly.The Contractor shall perform a bearing test by a method to be instructed by theBoard on the surface of the sub-grade and he shall examine the thickness of subbase.The Board may instruct a modification to the design of pavement, if requiredbased on test results without any claim on the Board.17.7.1.2 Aggregate Sub-base Materials for Concrete PavementAggregate sub-base material for concrete pavement (roadways, parking areas,etc.) and roadway shoulder shall consist of hard, durable fragments of crushedgravel and stone or other similar materials, including additional selected filler forblending under the direction of the Board. The maximum dimension of anyparticle shall not be greater than two-thirds of the required thickness in which it isto be placed. Oversized material, if present, shall be removed at the quarry byscreens, grizzlies, or by hand. When necessary to obtain proper uniformity,additional filler shall be blended by mixing on the roadway. The faction of theaggregate sub-base material, including any additional filler passing the No.200sieve shall not be more than of that passing the No.40 sieve. The fraction of thematerial passing No.40 sieve shall have a liquid limit not greater than 25 and aplasticity index of not more than 6.The following gradation requirements shall apply to the sub-base for concretepavement and the thickness of sub-base shall be not less than 20 cm after it iscompacted or as otherwise agreed with the Board.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)175

Sieve designationPercentage by(Square Mesh Sieves)Weight Passing38.1 mm (1 1/2") 95 10019.1 mm (3/4") 60 902.5mm (No.8) 20 500.074 mm(No.200) 2 1017.7.1.3 Construction of Aggregate Sub-base for Concrete PavementThe aggregate sub-base material shall be placed on the prepared and approvedsub-grade. The deposition and spreading of the material shall bc as directed bythe Board. It shall start at the point farthest from the point of loading, and shallprogress continuously without breaks. The materials shall be deposited andspread in a uniform layer and without segregation of size, to such a loose depthof not more than 15 cm each layer, making allowance for any filler to be blendedon the road, that when compacted, the layer shall have the required thickness.Spreading shall be from spreader boxes or from moving vehicles, or by placing ina windrow followed by spreading to required depth and width by means of ablade grader. After the sub-base material has been spread, it shall be bladed toa smooth surface conforming to the cross section.The Contractor shall schedule his operations so as to assure completion ofspreading within 48 hours after processing. Immediately following the finalspreading and smoothing, all materials placed shall be compacted to the full widthby rolling with a power roller weighing not less than 10 tons. The rolling shall startlongitudinally at the sides and shall progress toward the centre, overlapping onsuccessive trips by at lest one-half of the width of the roller unit. In confinedareas the direction of rolling shall be as ordered by the Board. Alternate trips ofthe roller shall be slightly different in length. The rollers, unless directedotherwise, shall operate at a speed between 3 to 5 kilometres per hour. Rollingshall be accompanied by watering if necessary and as directed by the Board.17.7.1.4 Concrete Pavement(1) Materials(i) Cement and reinforcing steel will be furnished by the Contractor. Theconcrete to be used for concrete pavement shall be not less than 240kg/sq.cm inthe strength at 28 days. The concrete pavement shall be 20cm in thickness or asdesigned.(ii) Fine and coarse aggregates, and water shall conform to the applicableSection of the Specification.(iii) Preformed Expansion Joint Filler Board - The preformed expansion jointfiller for the concrete pavement shall be l9mm (3/4") in thickness, non-extrudingtype, shall conform to the requirements of ASTM Dl 752-67, "Specifications forPreformed Expansion Joint Fillers for Concrete Paving and Structural Construction,Non-extruding and Resilient Non-bituminous Types", Type II.(iv)Dowel bars All dowel bars except at the expansion joints, shall beGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)176

deformed steel bars and shall conform to ASTM A6 15 Grade 60.(v) Joint Sealer Concrete joint bituminous sealer for all joints shall conform toASTM Dl 850-67, "Specifications for Concrete Joint Sealer, Cold-Application Type".(vi) Slab reinforcement The slab reinforcement shall be made of steel bars of10 mm conforming to ASTM A615 Grade 60. The longitudinal and transversespacing shall be 15cm respectively or as design each intersection shall be firmlybound by binding wires or fixed by an adequate method approved by the Board.It shall be embedded in the concrete at 6cm below the surface.(2) Construction Method(i)FormworkThe concrete pavement shall be constructed one lane at a time. The side formsfor the concrete pavement shall be made of shaped steel sections which shallhave sufficient strength when staked down to resist the pressure of the concretemixer and finishing machine, or finishing tools, without springing. They shall bestraight and of a depth equal to the thickness of the pavement at the edge andfree from warps or bends at all times. Flexible or curved forms of proper radiusshall be used for curves 30 metres radius or less. The form base shall not be lessthan twenty (20) centimetres wide for forms twenty (20) centimetres or more inheight. Flange braces shall extend outward on the base not less than two-thirds(2/3) of the height of the form. The use of wooden side forms may be permitted.Timber formwork shall be oiled or greased at all times to prevent warping orcracking.When placing the forms, they must be seated firmly and in contact with the subbasesurface for their entire length, exactly on the desired line and grade.Before the mixing of concrete, forms shall have already been set for a sufficientlength well in advance of the forward end point where the concrete is to beplaced, but in no case less than the length between expansion joints, except forclosures which may require a shorter length. Sufficient forms shall be provided sothat it will not be necessary to move those in place within twenty four (24) ormore hours after the concrete has been poured. All forms shall be cleaned andoiled each time they are used. In the pouring of sections, construction joints shallbe located at expansion joints. Should it be necessary to make construction jointsbeyond the expansion joint, such construction joints shall be made at the locationof contraction joints.(ii)Joints(a) Longitudinal Joint: The longitudinal joint running at the centre line of thepavement shall be formed in accordance with the section and dimension shownon the approved drawings. Before concreting the next lane, the longitudinal jointshall be painted with two (2) coats of liquid asphalt applied at a temperature of65 0 to 135 0 Fahrenheit. The asphalt should be completely dry before commencingpour to the next lane.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)177

(b) Transverse Joints: The transverse joints consist of the expansion jointsand contraction joints. The expansion joint shall in principle be formed at every40m and the contraction joint shall be formed at an interval of every 8m betweenthe expansion joints. In the expansion joints, 19 mm (3/4") preformed expansionmoulding strip shall be placed and bituminous Dealer shall be poured afterremoving the strip and before opening the road to traffic.(c) Dowels :In all longitudinal joints, 75cm long tie dowel bars of 3/4" ddiameters shall be used for concrete pavements. In all contraction joints, 75cmlong slip dowel bars of 3/4" diameter shall be embedded in the concrete. All dowelbars shall be placed at an interval of 75 cm. The remaining half of the dowel barsfor the transverse joints shall be painted, greased, and wrapped with wax paperbefore concreting the next slab. The slip dowel bars in the expansion joints shallprovide a cap having adequate size and type at the end of the bars.(iii)MixingHand mixing of concrete will not be permitted. Machine mixers, if used, shall havea standard mixer of an approved type with a capacity of at least 0.76cu.m. (1cubic yard). Truck mixers, if used, shall be of the revolving drum type, watertight,and so constructed that the concrete can be mixed to ensure uniform distributionof material throughout the mass. The procedures of concrete mixingshall be in accordance with the Specification for Concrete Work Section.(iv)PlacingConcrete shall be placed only on aggregate sub-base that has been prepared aspreviously prescribed and approved by the Board. The concrete shall be depositedin such a manner as to require as little handling as possible, and shall immediatelybe distributed or spread by shovelling or by other approved methods, to suchdepth, and grade, that when compacted, the finished grade of the pavement willbe attained correctly. Vibrators of approved type and capacity for the purposeintended shall be used to sufficiently compact the concrete.(v)FinishingAfter the concrete has been deposited, distributed and vibrated, the concrete shallbe struck off and screeded by mechanical means approved by the Board. Thefinishing machine shall be of the screeding and trowelling type designed andoperated both to strike off and to compact. Hand finishing may be employed inlimited areas where finishing machines can not be operated. Finishing of concreteshall be done, as directed to the satisfaction of the Board. All finished surfacesshall be tested with a 3-meter straight edge and it shall not vary more than 1cmin 3m from the designed surface. Any variation of the surface from the desiredcrown or cross-section shall be properly corrected.(vi)Removal of Formwork and RepairAll forms for concrete shall remain in place undisturbed for not less than twentyfour(24) hours after the concrete is placed, after which the forms may beremoved. In the removal of formwork, care should be taken so as not to breakthe edges of the pavement. In case portions of the concrete are spalled, theyGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)178

shall be immediately repaired, at the expense of the Contractor, with fresh mortarmixed in the proportion of one (1) part cement to two (2) parts clean sand. Majorhoneycombed area will be considered as defective work and shall be removed andreplaced at the expense of the Contractor. Any area or section removed shall notbe less than 3 meters in length nor less than the full width of the lane involved.The Contractor shall repair at his own expense all imperfections, or irregularitiesof the concrete pavement in accordance with the direction of the Board.(vii)CuringAs soon as the concrete has sufficiently set, and to prevent the marring of thesurface, the pavement shall be covered with burlap or canvas, which shall be keptwet with clean water for a period of not less than twenty-four (24) hours.After removing the burlap, the pavement shall be covered immediately with eithera layer of earth or sand four (4) centimetres in thickness and shall be kept wet fora period of not less than fourteen (14) days. Ponding of the surface of thepavement may also be adopted for curing the concrete, in which case, the pavementshall be kept under water during the same length of time.(viii)Opening to TrafficFrom the start of curing, the pavement shall be closed entirely to traffic untiltwenty-eight (28) days have elapsed after the concrete was poured.(ix)Cleaning and Sealing JointsAfter completion of the required curing and before opening the pavement totraffic, all Joints shall be thoroughly cleaned of all concrete or aggregatefragments, earth or other foreign material. Longitudinal, expansion andcontraction Joints shall be poured with bituminous sealant to the depth of 40mmfrom the top concrete surface. Only after the joint sealant has thoroughlyhardened shall the pavement be opened to traffic.(x)Protection of Adjacent ConstructionAny adjacent construction such as concrete pavement, curb and gutter, stonemasonry and handrails shall be protected by shields, covers or other means. Ifconcrete is applied to adjacent construction either by accident or because ofinadequate protection, the Contractor shall remove such material as directed andat his expense.(xi)MaintenanceThe Contractor shall be responsible for the maintenance of the surface for aperiod of twenty eight (28) days or until such time as the Board may direct, afterwhich the work shall be accepted in writing by the Board.No extra compensation will be made to Contractor for any maintenance workrequired as specified. All costs attendant thereto shall be included in the lumpsum price bid for Road and Parking Area in the Schedule.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)179

17.7.2 Gravel SurfacingThe Contractor shall supply and place a layer of gravel not less than 10cm inareas other than the paved and lawned areas in the power station as shown onthe Drawing or as directed by the Board. Materials for graveling shall be 3 to 7cmin size conforming to the grading requirement of the Specification.17.7.3 Landscaping And TurfingAreas around the power house building, administration building shall he turfed asshown on the Drawings or as directed by the Board.Turf shall be freshly cut approved carpet grass free from thorns and weeds. Thearea to be turfed shall be provided with a layer of 20cm top soil suitable for thegrowth of the lawn. The Contractor shall maintain and replace all dead turf at hisown expense until the end of maintenance period.The Contractor shall submit a detailed proposal on landscaping for the Site. Trees,flowers and other plants adaptable to the climate and soil conditions of the Siteshall be planted in the open spaces provided adjacent to the control andadministration building area and along the perimeter of the boundaries to form agreen belt around the power station. A proposal which shall include a landscapedrawing with a schedule showing types of trees, planting positions and otherdetails shall be submitted to the Board for approval.17.8 Drainage System17.8.1 Design ConditionsThe design of the storm water drainage system comprising the interceptor,roadside and perimeter drains for buildings, powerhouse, and switchyard shall besubmitted to the Board for approval.The Contractor shall carry out detailed designs of the storm water drains usingthe rational method or other approved procedures. The work shall be carried outin accordance with the rules and regulations of the local and other authorities.Design conditions for drainage system shall be as follows :Rainfall intensity100 mm/hrRun-off coefficient 0.6Manning's roughness coefficient 0.013for concrete lined channelAll drains or channels shall be concrete lined. Concrete sumps, silt traps, screensand drain covers shall be incorporated in the design where it is appropriate.17.8.2 Drain LayingAll trenches and drains are to be set out accurately to line and fall as specified.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)180

Trenching for pipes shall be excavated with sufficient width to allow adequateworking space for pipe jointing. Backfilling of trenches to a height 300 mm abovethe top of the pipes using selected materials shall be hand packed and wellrammed against the side of the pipes.The laying of each length of drain is to be commenced at the lower end andsocketed pipes shall be laid with their sockets at the higher end Each pipe is to beaccurately levelled and securely held in position be fore the joint is made.All surface water channels shall be made from concrete grade B as described inSection 17.6.The Contractor shall keep sumps, drains, trenches and ditches free from water atall times until, in the opinion of the Board, the concrete works has hardened.Man-holes, inspection chambers and catch-pits shall be constructed.17.9 Sewage Works17.9.1 GeneralAs there is no existing government central sewage treatment system operating inthe vicinity of the Site, individual septic tanks shall be provided in the Site.17.9.2 Sewer, Manholes And Septic TanksPipes proposed for use in the sewer shall be approved by the Board, cast ironpipes and fittings complying in all respects with B.S.78 and/or B.S.437 shall beused. Manholes or inspection chambers with covers shall be provided at everychange in direction or gradient to satisfy the requirement of the Local Authority.The sewer shall be laid accurately to the design levels and gradient. Each lengthof sewer shall be carefully water tested to the satisfaction of the Board before theconcrete haunching is placed and before the trench is back filled. Septic tanksshall be constructed in accordance with the details shown on the approveddrawings.17.10 Water Reticulation System17.10.1 Internal Water Reticulation SystemThe water supply system shall be designed to serve a dual purpose of providingpotable water for domestic consumption, fire-fighting and plant.17.10.2 Water RequirementThe system shall be designed to meet the project requirement as follows:1. PlumbingThe facilities for general plumbing comprises two (2) deep wells not less than 120m in depth with pump and G.I pipes of appropriate sizes connecting the supply tothe internal plumbing facilities provided for electrical building connection withexisting water supply system at a suitable point. The supply system shall beGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)181

extended with sufficient number of taps to provide water for lawns.17.10.3 Design Parameters And StandardThe water reticulation system shall be designed and installed in compliance withthe requirement of the local and other authorities. The parameters and criteria tobe adopted for design are:a. Design population : 100 personsb. Storage requirement for plumbing system :3 times the averagedaily demandc. Minimum fire flow : 2.5 m3/mind. Minimum diameter of fire-fighting main (steel):120 mme. Pressure in pipe : 7 barf. Maximum spacing of fire hydrant : 60 m17.10.4 Materials And WorkmanshipAll pipes, fittings, jointing materials and valves which are necessary for thecomplete installation of the system shall be supplied and installed in compliancewith the approved standards and workmanship.The Contractor shall supply all pipe, special fittings, valves, joints, jointingmaterials and other necessary materials for the complete installation of thesystem as shown on the approved drawings.The installed system shall be tested to the satisfaction of the Board.17.10.5 Deep-well And Deep--well Pump17.10.5.1 General(1) Scope of WorkIn accordance with the Specification and as shown on the bid drawings or asdirected by the Board, the scope of this work shall cover the supply, fabrication,construction, installation, erection and all the necessary materials, labour, toolsand equipment for the complete and satisfactory operation of the domestic watersupply system from deep-well [2X100% capacity] to storage tank. Water qualityfor Plant/ Fire Extinguisher shall be as per Plant/Equipment manufacturer'srequirement. Water for drinking purpose shall be as per WHO's standard.Contractor shall design the reservoir/ storage tank as per requirement of theTender.All materials, equipment and accessories shall be new and unused, free fromdefects and imperfections and best suited for the purpose intended. Materialsused in the manufacture and installation of all equipment to be furnished shall beof the required quality used in commercial products of reputable manufacturers.All equipment or substitute materials and equipment to be used shall conform toGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)182

the latest specifications and provisions of approved Standards of the EngineeringInstitutes or other equivalent standards approved by the Board.One deep-well pump shall be installed for each well.(2) Instruction BookThe Contractor shall submit ten (10) copies of instruction books on the operationand maintenance of equipment furnished and installed by him under this clausetwo (2) months before he starts on the installation work.(3) PaintingAll metal, wooden and textile surfaces of materials furnished and installed by theContractor under this Section shall be painted in accordance with Section 18.6,except as listed below. Performance of painting work shall be as specified in theSection 18.6 of the Specifications.a) Portions to be embedded in concrete or in the soilb) Plated surfaces other than zinc platingc) Concealed zinc plated portionsd) Surfaces treated with special decorative finishese) Surfaces where so indicated by the BoardColour of paint shall be as directed by the Board.(4) Concrete, Plastering and Earth WorkConcrete, reinforcing, plastering and earth work to be executed under this clauseshall be performed according to the applicable provisions of the relevant clausesof the Specifications.17.10.5.2 Drilling, Developing And Testing The Deep-well(1) GeneralThe Contractor shall provide plant, labour, material, equipment and perform alloperations in connection with the drilling, developing, placing of casings and wellscreens, and pumping tests for the deep-well which shall be drilled to a depth asindicated below.(2) DrillingDrilling of the deep-well shall be carried out by an appropriate method mostsuited to the conditions of the deep-well site to be drilled. When necessary,temporary casings shall be used in sections of the hole through over burden orunstable material to prevent the caving-in of the well. The location of the welldrilling site shall be as shown on the bid drawings or as directed by the Board.(3) Well LogGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)183

A written record of the drilling information which is called a Well Log shall be keptby the drillers and shall be available for examination by the Board at any timeduring the work and a complete typewritten copy of the well log shall besubmitted to the Board within ten (10) days after completion of the work. Thewell log shall show amongst other things the type of materials encountered,colour of the return water, depth at which circulation as lost, manner of drilling,length of casings installed, and other pertinent drilling data.(4) Well Completion and DevelopmentThe Contractor shall undertake all operations pertaining to the completion anddevelopment of the well which shall consist of the installation of casings, installingwell screen within a sand and gravel formation, developing the water-bearingformation, grout filling of the upper section of the well casing (from collar to atleast 6m deep), surging and back-washing.The well casings to be installed shall be carbon steel, ASTM A-53, seamless,Grade B or equivalent. Openings of the well screens shall be so designated toprevent clogging and shall be free from jagged edges and irregularities so as toavoid clogging and corrosion.(5) Pumping Test for Yield and Draw-downPumping tests shall be performed to determine the deep-well capacity and otherhydraulic characteristics of the water-bearing strata.The Contractor shall furnish and operate a pump for this purpose that is capableof continuous operation at a sustained delivery of 380 lit/mm or more in aduration of at least five (5) hours of pumping test operation. Measurements of thevolume of water pumped per minute, the depth of static water level beforepumping started, the depth of the pumping level at one or more constant rates ofpumpage, the rate of recovery of the water level after pumping test stopped andthe length of pumping time of each pumping rate shall be made by the Contractorin the presence of the Board & Engineer. The Contractor shall construct any otherstructures necessary to conduct water away from the deep-well.For a comprehensive test of the well, the pump shall be operated continuously atabout 1/3 of its capacity until pumping level is attained. After making thenecessary measurements, the pump rate is adjusted to about 2/3 of the pumpcapacity and measurements are repeated when the pumping level becomesconstant. By increasing the rate of pumpage to produce maximum draw-down; orincreasing it to the full capacity of the pump and making measurements a thirdtime when the pumping level becomes stable.All the necessary equipment the measuring devices for testing the deep-well shallbe calibrated and provided by the Contractor at his own expense.After developing and testing operations are completed to the satisfaction of theBoard, the Contractor shall measure the depth of the well and record the totalopen depth of the casing. Sterilisation of the well is done by pouring a solution of450 grams of high test Calcium Hypochlorite (HTH) in 45 litters of water.Upon completion of the drilling, the Contractor shall submit to the Board theGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)184

complete well-draw-down test results for check and determination of the actualhead and setting of the deep well pump.(6) Data to be Submitted with BidsA complete list and description of equipment, plant and tools for executing thework in accordance with these Specifications and their location at the time ofopening of bids in order that they may be inspected by the Board.17.10.5.3 Deep-well Pump(1) GeneralThe Contractor shall furnish, deliver, install and test a motor-driven pumps (2X100% capacity) complete with accessories and housing at the top of the well in accordancewith these Specification.(2) Type and DescriptionThe deep-well pump shall be a submersible type with a cast iron body, bronzeimpeller, high-grade steel discharge column and stainless steel shaft. Thedischarge pipe column and drive shaft of ample size shall be supplied withinterchangeable sections of not greater than 3.0 m in length.This pump shall be operated in conjunction with the float switch to be installed inboth the elevated water tank and fire fighting storage tank.All water passages of the pump shall be smooth and long term corrosionresistanceof dependable operation.(3) Rated CapacityThe deep-well pump shall be rated to a discharge capacity of approximately, 600lit/m against a total dynamic head of the system as determined. The total head ofeach pump may vary and it is required that the pump be capable of satisfactoryoperation within fluctuations of head.The pump shall be guaranteed to circulate not less than the specified quantity ofwater when pumping and without producing excessive vibration and noise. Theefficiency of the unit shall be as high as good engineering practice will permit.(4) Electrical Worksa) Pump MotorThe motor shall be submersible type, full voltage starting and with torque-lockedrotor current and slip characteristics conforming to standard equivalent to thoseof the IEC Standard.It shall be of the continuous duty type for operation on 415 volt, 3-phase, 50-flz.Motors shall be capable of operating continuously at rated output plus or minus5% of the rated frequency and at any voltage within plus or minus 10% of therated value.185Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)

) Control EquipmentThe control equipment shall be of the float-switch actuated control type installedin the water storage tanks and shall be of suitable switch for draw-down in thedeep-well. One of the two deep-well pumps shall start operation alternately whenthe water level in the water storage tank goes down to the designated level.When the water level of the deep-well goes down to the designated level, thedeep-well pump shall be stopped immediately, and the other deep-well pumpshall be started automatically. Breakdown of deep-well pumps shall be connectedto an alarmed on the control board in the control room.c) Control BoardThe control board shall be installed in the fire pump-house.A boxed knife switch shall be provided in the fire pump-house for each pump.d) Signal Indicatorsi) All indicator lights shall be of AC type with coloured glass or plastic lensand shall be so constructed that the lamp can be readily fitted and removed andthe lens changed from the front of the boards.ii) Ammeters shall be capable of accepting the starting current characteristicsof the corresponding motor and shall be suitably calibrated to indicate the fullload running current at three quarter full scale deflection.e) Conduit Piping and WiringConduit piping and wiring for the work shall comply with the applicable provisionsof the Specification.(5) InstallationThe Contractor shall construct a concrete base foundation for accurate mountingof the pumping unit and shall provide foundation bolts for anchoring the pump,which shall be carefully levelled and grouted in place.The pumping unit and control equipment shall be housed for all weatherprotection.(6) AccessoriesThe following accessories shall be equipped for each pump:Sluice valveCheck valveAir release valvePressure gauge with cockWater pipeWell cover: 1 Pc: 1 Pc: 1 Pc: 1 Pc: Required Length: 1 PcGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)186

Submersible cableFlangesFoundation boltsOther necessary accessories: Required Length: 1 Set: 1 Set17.11 Ducts(7) Data to be submitted with BidsComplete specifications of the supply including the physical dimensions andmaterials used for the principal parts of the supply.Pump discharge capacities, efficiencies, horsepower input and performancecharacteristic curves at various heads on pump settings.Guaranteed brochures, catalogues and other related technical data concerning theoperation of the supply.(8) PipingMaterials and Performance of piping for the work shall be in accordance with theapplicable provisions of the Specification.The concrete ducts to install cables and pipes shall be provided. The ducts shallbe covered with concrete or steel checkered plate, both having enough strength,and shall be provided with the, necessary number of racks for cable and pipes.The thickness of the concrete ducts shall be not less than 18cm, width and depthof ducts shall be more than 40 cm respectively and an appropriate drainagesystem shall be designed within the duct.The Contractor shall submit design drawing to the Board for approval.17.12 FENCING AND GATES, FLAG POLES AND SITE BOUNDARY WALL17.12.1 FencingChain link fencing shall be installed as directed by the Board. The chain linkfencing shall be 2.4 m high with 3 strands of barbed wire at the top, generallycomplying with B.S. 1722 or other approved Standards.Posts and struts shall be fabricated from 100 mm x 100 mm x 6.5 mm thickangles and set in concrete. The struts shall be fitted to all end and corner postsat changes in direction or acute variations in levels and at intervals notexceeding 9 meters in straight lengths of fence. All posts shall be hot dipgalvanised.Prior to the supply and installation, the Contractor shall submit samples offencing materials, structures and colour to be adopted to the Board forapproval.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)187

17.12.2 GatesSliding metal gates of 2.4 meter high and pedestrian swing gates of 2.0 meterheight shall be constructed at suitable locations as directed by the Board.Decorative brick walls to be incorporated in the work next to the pedestrian gateat the power station shall have the following dimensions:Height :Length :Thickness:2.4 metres5.0 metres0.25 metreThe Contractor shall submit design drawings showing details of the gates forapproval of the Board.17.12.3 Flag PolesThree (3) flag poles shall be erected at locations as directed by the Board.The poles shall be of tapered steel pipe, about 15 m in height with a diameter of20 cm at the bottom. The pole shall be firmly held to a concrete foundation.It shall be equipped with a brass pulley near the top and nylon rope for hoistingthe flag.The pole shall be painted in accordance with the specification for painting to thesatisfaction of the Board.17.12.4 Site Boundary WallThe site boundary wall shall be installed around the power station as directed bythe Board. The site boundary wall shall be of brick wall with RCC frame inaccordance with KPI Standard and 2.40 m high and 0.25 m thickness.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)188

Section 18Building WorksGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)189

18 Building WORKS18.1 General18.1.1 Contractor's Responsibilities18.1.2 Building Sub-contractor18.1.3 Construction Schedule18.1.4 Records18.1.5 Samples Testing and Inspection18.1.6 Temporary Services18.2 Scope of The Works18.3 Design of The Works18.3.1 Designs and Drawings18.3.2 Standards and Codes of Practice and Other DesignConditions....18.3.3 Submission of Designs and Drawings18.4 Building and Services18.4.1 Electrical Building18.4.2 Rain Water Leaders18.4.3 Air Conditioning System18.4.4 Ventilation System18.4.5 Plumbing and Sanitary Installation18.4.6 Lighting18.5 Materials and Workmanship18.5.1 Structural Steel18.5.2 Concrete18.5.3 Grouting of Structural Steelwork18.5.4 Roofing and Brickwork18.5.5 Carpentry and Joinery18.5.6 Doors and Windows18.5.7 Glazing Works18.5.8 Metal Works18.5.9 Floor-laying18.5.10 Wall and Ceiling Finishes18.6 Painting18.6.1 Materials18.6.2 Surface Preparation18.6.3 Workmanship18.6.4 Priming18.6.5 Number of Coats18.6.6 StorageGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)190

18. Building Works18.1 GeneralThe General Conditions, Tender Drawings, relevant Specifications On materialsand workmanship described elsewhere in this Documents, Schedules shall be readin conjunction with this Specification.18.1.1 Contractor's ResponsibilitiesThis is a turnkey contract which includes all building works and services. TheTender shall cover all requirements of the Tender Documents and any other itemsnot specifically mentioned but which are deemed to be necessary for the completeexecution of the Works to the entire satisfaction of the Board. No additional costwill be considered for any item which the Contractor has over looked but areessential for the full completion of the Project in every respect.The Tender shall include the building works proposal complete with out-linedrawings indicating any variation or improvement which he deems technically orfinancially justified for the works mentioned in the Tender Document, schedule ofmaterials and finishes on which the tender has been based. The Building shallgenerally conform to the sizes shown below & as per approval of the Board.The Contractor shall be responsible for all performance in the detailed design,supply of material, labour, plants and equipment, construction and relevant worksincidental to the completion of the Building Works.The Contractor shall perform the Works thoroughly in accordance with the agreedconstruction schedule and direction to be made by the Board during the ContractPeriod.18.1.2 Building Sub-ContractorThe Contractor may employ a building subcontractor for building works. If theContractor intends to subcontract the building works design and/or construction,his tender shall include full details of comparable works carried out elsewhere bythe subcontractor, together with details of the financial stability and generalefficiency of the proposed subcontractor.18.1.3 Construction ScheduleA preliminary building construction schedule showing the completion time for thebuilding works shall be submitted by the Tenderer based on the overall projectimplementation schedule. The Contractor shall prepare and submit to the Boardfor approval a detailed construction schedule for the building works developedfrom the preliminary building construction schedule before commencement of theWork on the Site. The approved construction schedule shall not be altered withoutthe written consent of the Board.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)191

18.1.4 RecordsThe Contractor shall keep accurate and up-to-date records and drawings of theWorks at the Site and shall provide the Board with copies of these records. TheContractor shall submit to the Board weekly reports of labour, plant and materialsemployed on the Site.18.1.5 Samples Testing And InspectionThe Contractor shall perform testing and inspection of materials and shall submitsample materials, test certificates and workmanship details to the Board forapproval. The costs of all samples and testing shall be borne by the Contractor.18.1.6 Temporary ServicesThe Contractor shall be responsible for arranging the provision of electricity,water, drainage, etc. necessary for the proper execution of the Works. All costsfor these services shall be borne by the Contractor.18.2 Scope Of The WorksThe building works shall include collection of the Site information, detailed design,production of working drawings, provision of labour, plant and materials,tests/inspection, construction and remedy of defects during the Warranty Period.The Building shall generally conform to the sizes as mentioned below.a) Control building, Store/Warehouse (Total building area- 20,000 sqf each floor,3 stored, lifting equipment with capacity 10/3 Ton must be incorporated), FireFighting pump house, Emergency Diesel Generator house, Guard house, watersupply house, fencing, boundary wall, road etc. shall be constructed by theContractor within the Site area.b) Dimensions and number of rooms of the Buildings mentioned shall be to thestandard practice based on the size and number of Equipment and acceptable toBoard.However, dimension of 1) control building [two storied, 10 (ten) air-conditionedrooms including control room, battery room, auxiliary room] shall not be less than13 Metres × 24 Metres;18.3 Design Of The Works18.3.1 Designs And DrawingsThe Contractor shall design in accordance with this Specification and preparecomplete working drawings as necessary for the construction of the Works. Alldrawings shall be submitted for the approval of the Board.18.3.2 Standards And Codes Of Practice And Other Design ConditionsDesign and construction of building works shall conform to recognise authoritativeGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)192

intentional or national standards and codes of practice [BNBC]. The adoptedstandards or codes shall be consistent throughout any section of the works unlessotherwise specified. The Contractor shall have full responsibility to investigate theexistence of any decrees and local bylaws governing the proposed works and tofully comply with such requirements which are effective when the date of tendersubmission.As described elsewhere in the documents the Contractor shall indicate in histender standards and codes to be conformed in design and construction of theWorks. Copies of these codes and standards shall be made available to the Boardduring the design and construction period.a. Basic design conditions for buildings are outlined as follows:-Design wind speed: 100 miles/hr.Seismic horizontalground acceleration : 0.10g- Ditto - (vertical) : Nilb. Live load of each floor shall be more than as follows : -Auxiliary roomCable spreading room: 500 kg/sq.m: ditto18.3.3 Submission Of Designs And DrawingsThe Contractor shall be required to produce full design calculations for thefoundations, building structures, and detailed working drawings and reinforcementbar bending schedule etc. Design calculations shall be prepared in accordancewith an approved method of computation based on the most unfavourablecombination of dead load, live load or crane load and wind load. The Contractorshall be responsible for the detailed design, strength and safety of the structures,and ensuring that the design satisfies the requirements of all authorised local andinternational bodies.Design calculations and detailed drawings shall be submitted to the Board forapproval in accordance with the requirement set out in Section 18.3.1 of theTender Documents. Construction on the Site shall only commence after drawingsare finally approved.Notwithstanding the Board's approval, the Contractor shall be held responsible forthe accuracy of his submitted information, designs and drawings.18.4 Building And Services18.4.1 Control Room BuildingConstruction Control Room Building(1) Main construction materialsGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)193

FrameRoofExterior wallPartition wallFloor: Reinforced concrete: Reinforced concrete roof withlime concrete water proofing.: Reinforced concrete and/or brick.: Brick: Concrete with plastic tile, ordinarytile, trowelled mortar finish, etcFoundation: The Contractor shall examine subsoilcondition for design of foundation. Properfoundation shall be designed by theContractor in accordance with theSpecifications(2) Windows:Aluminium sash shall be provided. Window area shall be generally more than 1/10of the room floor area unless otherwise indicated. All windows except toilet, store,and cable spread mg room windows shall be fitted with sun blinds of approvedmade.(3) Machines and utilities:Air conditioning system, ventilation system, water supply system, power supplysystem, drainage system, sanitary system and lighting system shall be provided.(4) Finishes and room sizes:The Contractor may submit the layout to suit any particular requirement subjectto the approval of the Board.(5) Other Requirement:a. Control room : Noise level shall be kept to avalue less than 45 db(A).b. Toilets : Toilets shall be providedwith sanitary fittings as follows:WaterclosetUrinalWashbasin with hot and cold waterand mirrorGround floor 2 2 1First floor 1 1 1Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)194

c. Ventilation and air conditioningAll rooms shall be provided proper ventilation system. The control room, relayroom, electronics spares store, shall be provided air conditioning system.18.4.2 RAIN WATER LEADERSRain water leaders to be provided according to international norms and standards.18.4.3 AIR CONDITIONING SYSTEMThe detail design of air conditioning system for control building shall be based onthe following criteria :Outside temperature: 36 0 CInside temperature: 20 0 CRelative humidity : 60%Type of system: Package air conditioning unitsDesign calculations and drawings shall be submitted to the Boardfor approval prior to commencement of the work.Details of the equipment proposed shall be submitted with the Tender.18.4.4 Ventilation SystemAll rooms in the control building, guard house etc. shall be designed and furnishedproper ventilation system in principle.Unless otherwise specified, natural ventilation will be acceptable for the minorbuildings. All toilets, battery room and shall have exhaust fans of approved made.All fans shall be statically and dynamically balanced to avoid vibration and shallhave blades to secure quiet efficient operation.18.4.5 Plumbing And Sanitary InstallationThe whole of the plumbing works in the buildings shall be provided in accordancewith the relevant bylaws and to the complete satisfaction of the Board. Pipes shallbe connected to each point where water is required, with a minimum head of 2metres at all outlets.All cast iron pipe works and fittings as are necessary for the complete installationof the sanitary system shall be supplied and installed in accordance with therequirement of the local authorities and other standards approved by the Board.18.4.6 LightingThe whole of the power supply and lighting system for the buildings shall bedesigned and installed in accordance with the Section 11.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)195

18.5 Materials And Workmanship18.5.1 Structural Steel(1) GeneralStructural steel, bolts and nuts shall comply with the requirement of an approvedstandard and this Specification in all respects and those shall be fabricated fromhot rolled sections unless other wise specified or agreed in writing by the Board.(2) MaterialsThe materials to be used shall be free from harmful defects and rust. Samples ofmaterials shall be tested, and copies of the test reports giving physical andchemical properties shall be submitted to the Board for approval. The Contractorshall carry out all necessary tests, at his own expenses, to prove that thematerials offered for the intended purpose are in compliance with the approvedStandard.In lieu of these tests, mill sheets issued by the authorised manufacturers will beacceptable. The characteristic strength of the structural steel shall have thefollowing values regardless of the standard and code used: -a. Yield Point : not less than 2400 kg/sq.cmb. Tensile Strength : not less than 4100 kg/sq.cmc. Elongation : not less than 20%(3) Bolt and Shear ConnectorHigh strength bolts, anchor b6lts, ordinary bolts and shear connectors to besupplied for the erection of structures shall conform to the Standard approved bythe Board and shall be of an approved manufacturer. Specially devised highstrength bolts, if used, shall tightened in accordance with the manufacturer'sinstructions. Any bolt that has been fully, tightened and then un-tightened shallnot he used in the permanent Works.(4) FabricationFabrication and erection drawings shall be submitted to the Board for approvalprior to commencement of any fabrication and erection work. Steelwork shall befabricated to the required details in a manner approved by the Board. TheContractor shall provide adequate facilities for the Board to inspect materials andfabrication works in the shop and at the Site when required.(5) WeldingWelding of structural steel shall be performed to the required type and size by anelectric arc process by qualified welders under approved conditions. The plant,equipment and the adopted testing and inspection method shall conformgenerally with the relevant approved standard and other details in thisSpecification and shall all be to the satisfaction of the Board.Welding shall not be performed when the ambient temperature is less than 0 degGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)196

C; when surf aces are wet or exposed to rain, or strong wind; or when weldersare exposed to inclement weather conditions.Surfaces to be welded shall be free from loose or thick scale, slag, rust, moisture,grease and other foreign material that will prevent proper welding or produceobjectionable fumes. Welding shall be principally carried out in workshops. Wherenecessary the Board may approve site welding, subject to the satisfactoryprovision of effective protection and safeguards for welding works by theContractor.(6) Welding ProcedureDetails of the proposed welding procedure, manufacturer, classification on, codetype and size of electrodes to be used shall be submitted to the Board forapproval. When necessary, welding tests shall include specimen weld detailsrepresentative of the actual construction which shall be welded in a mannersimulating to most unfavourable conditions liable to occur in the particularapplication. All costs of the tests shall be borne by the Contractor. All welds shallbe finished full and made with correct number of runs. Slag and other inclusionsshall be cleaned from all welds.Notwithstanding the approval of welding schedule and procedure by the Board,the Contractor shall bear full responsibility for correct welding and for minimisingthe distortion in the finished structure.a. Preparation of Base MetalSurface and edges to be welded shall be smooth, uniform, and free from fins,tears, cracks, and other discontinuities, which will adversely affect the quality orstrength of the weld. In the preparation of the fusion faces, shearing shall belimited to metal thickness not greater than 8 mm. All fusion faces shall be preparedby machining shall be limited to metal shall be prepared by machining orflame cutting, or where approved, by special oxygen cutting apparatus. Fusionfaces, angle of level, root radius, and the like shall be properly prepared to givethe approved weld forms. The parts to be jointed by fillet welds shall be broughtin-to contact as close as practicable. The gap between parts shall normally notexceed 4.8 mm (3/16 in.). A butting parts to be joined by butt welds shall becarefully aligned and the correct gap and alignment maintained during thewelding operation.b. Butt Welded JointEnds of the welds shall have full throat thickness by means of runoff tab.Additional metal remaining after the removal of the tab shall be removed bymachining, or by other approved means. Ends and surfaces of the welds shall besmoothly finished. All main butt welds shall have complete penetration and,except on tubes or partial penetration Joint, shall be welded from both sides. Theback of the first run shall be suitably gouged out.c. Intermittent WeldsIntermittent welds shall not be permitted without the approval of the Board.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)197

(7) PaintPrior to delivery after shop inspection, the whole of the steelwork shall beprepared for painting by an approved blast cleaning method.All rust, grease, mill scale and harmful matter shall be removed. The surface shallbe blast cleaned to:-a. Swedish Standard Sa 2 1/2 SIS OS 5900 1967b. British Standard 4232 Second Qualityc. U.S.A. Standard commercial blast finishSSPC-SP-6-63The first coat of primer of recommended by the manufacturer as suitable for useunder the prevailing condition at the application site shall be applied immediatelyafter blast cleaning (or within two hours).No paint shall be applied to the surfaces to be embedded in concrete, to contactsurfaces for joints using high strength friction bolts and to surfaces within 50 mmeither side of joints to be welded.Painting shall be carried out in a clean, dry building where air temperature shallnot be allowed to drop below 5 deg.C. No paint shall be applied on the steelworkwith condensation. Painting shall not be carried out when the relative humidity isover 90%, or if in the open, during rain, fog or mist. The welded areas and theedges of site joints shall be cleaned down, primed and painted' all in accordancewith the standards specified, after erection.Each coat of the paint will be applied in different colour. When paintwork isdamages it shall be cleaned and re-painted following the procedures as approvedby the Board. The manufacturer's instructions regarding inter-coat intervals shallbe strictly observed.(8) Transportation and Storage of SteelworkThe whole of the steelwork shall be handled in such a manner that the shape andsurfaces of the section shall not be damaged during lifting and transportation. TheContractor shall take all necessary measures, to ensure that steelwork membersshall be handled, stored and erected without their being subject to stresses inexcess of those for which they were designed. Chains and hooks will not be usedin contact with the steel work and lifting slings shall be of nylon rope. Steel workshall be stored in clean, dry conditions off the ground. Separate pieces ofsteelwork shall have spacer blocks between them.(9) ErectionThe Contractor shall ensure the correctness of alignment, plumbing and stabilityof the various frames and members. He shall also take all necessary measures, byadequate resistance to wind and stability against collapse, during construction.No permanent bolting and site welding shall be carried out until proper alignmenthas been obtained.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)198

18.5.2 ConcreteThe specifications for concrete works under Section 17 are applicable to buildingworks.18.5.3 Grouting Of Structural Steelwork(1) Materials for GroutingThe aggregate for grouting shall consist of hard siliceous sand, and grained chips,gravel or crushed stone, or other approved inert materials with similarcharacteristics. The materials shall be clean, free from lumps, soft or flakyparticles, shale, crusher dust, silt, alkali, loam, organic matter or other deleterioussubstances. The aggregate shall be of uniform grading and shall be of such a sizethat 100% will pass through a 10 mm mesh and not more than 10% will passthrough a 120 micron mesh. A pre-mixed non-shrink resin grout may he used.The manufacturer's instructions on mixing and the placing of the grout shall beobserved.(2) AdmixturesAn admixture which acts as a non-shrinking agent shall be added to the groutonly with the Board's approval. All proprietary admixtures shall be added andmixed strictly in accordance with the manufacturer's instructions.(3) Surface TreatmentConcrete surface which is to be grouted shall be thoroughly cleaned and alllaitance removed from the surface by means of a hammer and chisel. A powerhammer shall not be used.(4) MixingThe Contractor shall submit to the Board for approval details of the mix and themethods he intends to use, prior to the commencement of the grouting.(5) PlacingFor cement based grouts the concrete surface to be grouted shall be thoroughlysaturated with water at least two times before the commencement of grouting.18.5.4 Roofing And Brickwork(1) RoofingRoofing material for administration building shall be of corrugated galvanised ironsheet. The Contractor shall submit samples and technical details of the roofingmaterial for approval of the Board.An insulation layer of glass fibre or rock wool board of minimum 25 mm thick shallbe incorporated in the roofing system. The thermal conductance of the compositeGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)199

oof cladding shall be less than 1.10 kcal/sq.m hr-deg C at 25 0 C.All accessories and the method of fixing shall be strictly in accord-dance with themanufacturer’s instructions and to the satisfaction of the Board.(2) WaterproofingWaterproofing for reinforced concrete flat roofs shall be of lime concrete. Theminimum thickness of lime concrete shall be 10 cm.(3) Eaves Gutters and Down PipesEaves gutters shall be of PVC or galvanised steel sheet coated with bitumasticpainting to be approved by the Board. Where large section is required, steel sheetis preferable for strength. Down pipes shall be of PVC pipe, galvanised steel pipeor cast iron pipe to be approved by the Board.(4) Brick Walls -Bricks to be used for walls shall be Bangladesh made. Unless otherwise specifiedor as shown in drawing, the thickness of brick-wall shall be more than 15 cm.Mortar for use with brickwork shall be mixed in the proportions of 1:3cement, sand or 1:2:5 cement, lime and sand by volume. Mortar may be mixed byhand or machine. Hand mixing shall be carried out on a clean, watertightplatform. Cement shall be of a quality as described in the Section 17 for concrete.Sand shall be well-graded (2.5 mm down) hard and free from deleterioussubstances. Lime for mortar shall be pure calcium carbonate properly burned,then hydrated, and finely ground. All joints shall be completely filled with mortar.The thickness of the horizontal mortar Joints shall not exceed 40 mm to everyfour joints. The mortar shall be used within 2 hours of mixing with water and anymortar not used then shall be discarded.All brick-walls are to be reinforced with approved reinforcing material at everyfourth course.The damp proof course shall be provided at joint and intersections laid on a bedof cement sand (1:1), bedded in and coated on the upper surface with liquidbitumen.External fair faced wall shall be weather struck; faces or wall which are to beplastered or rendered shall have their joints raked out to form key.(5) CalkingThe Contractor shall calk the joints to ensure water tightness of the buildingstructures. Prior to calking materials and working method shall be approved bythe Board.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)200

18.5.5 Carpentry And Joinery(1) TimberAll timber shall be of best quality, perfectly dry and well seasoned, sawn diesquare, free from sap, shakes, wanly edges, large loose or dead knots and allother defects and shall be to the approval of the Board.(2) PreservativeTimber to be used in shower rooms or in contact with the ground floor, shall betreated with an approved preservative against rot or termite attack. The backs orframes to be fixed to walls and all other bedding surfaces shall be painted withtwo coats of preservative before fixing. All fixing blocks, pallets, and other hiddentimber shall be so treated prior to fixing.(3) Joinery FittingsAll timber for Joinery fitting shall be of selected type properly seasoned and dry toa agreed moisture content not exceeding 18%. The Board shall have the right tocheck all timbering used and to reject any timber found to have a moisturecontent exceeding 18%.Joinery fittings and built-in cabinet are to be constructed exactly as shown on theapproved drawings.All work must be carried out by experienced cabinetmakers in a sound andworkmanlike manner with properly fabricated joints, dovetailed, mitred ormortised and with concealed pins and screws. All joints shall be glued beforepinning or screwing.(4) FaultsAny defect in the wood works such as shrinks splits, fractures, etc shall beremoved and replaced to the satisfaction of the Board.18.5.6 Doors And WindowsPrior to furnishing and installing, the Contractor shall submit the shop drawingsindicating shape, dimensions, material including hard wares and locking methodof doors and windows for all buildings for the approval of the Board.The standard requirements of doors and windows are as follows :a. Steel doorsFrame and Stile PlatesStile and PanelThicknessSize: more than 2.3 mm thick: more than l.6mmthick: 80 mm: double door 2.0 x 2.0 msingle door 1.0 x 2.0 m orGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)201

. Wooden doorsPlywood for panelThicknessSizeother sizes as shown on theapproved drawing: more than 5 mm thick: 40 mm: 0.9x2.0 m or other sized asshown on the approveddrawingHollow flush door shall be painted 2 coats of rust resistant paint and finish coat.Hollow flush door shall be of the waterproof type.c. Aluminium window : 70mmThickness: AlumiteFinishing: double window 0.9 x 1.8 m eSizesingle window 0.9 x 0.9 m or othersizes as per approveddrawingGlass (tinted): 6mmdAluminium swing doorsFrame and stile plateThicknessSize: More than 2.3 mm thick: More than 45 mm: As directed by the Board.All other type of doors, windows, which are not specifically mentioned, shall beprovided to the satisfaction of the Board.18.5.7 Glazing Works(1) MaterialsSheet glass shall be of good quality, free flow unevenness and strain of bubbles.All the glass used on the ground floor shall be tinted glass (salon-radiationabsorbing glass), and all the glass used on the first floor shall be clear glass.Where so required figured glass shall be used. Minimum thickness of tinted glassand clear glass shall be 6 mm. Glazing beads, sealant, putty, clips and settingblock shall be of good quality and those recommended by the glass manufacturer.All the glass used in the following rooms shall be tinted wire glass.Auxiliary room and cable spreading room Warehouse and workshops Stores(2) All glass shall be installed tightly in accordance with the instructions of theglass manufacturer.Upon completion of the works, glass shall be wiped clean and shall be inspectedby the Board.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)202

18.5.8 Metal Works(1) GeneralThe metal works will include handrails, drain pipes, steel ladders, step ladders,cable duct hatch cover plate, removable hatch cover plate, rain water leader, airduct, louver and others. Prior to fabrication work drawings and quality ofmaterials shall be submitted to the Board for approval.(2) MaterialsThe materials to be used in the Works shall be free from defects and conform toJIS Standard or relevant Standards approved by the Board.(3) WorkmanshipAll plates and sections shall be true to form, free from twist and straightenedbefore any fabrication work is started on them. The works of cutting, fabrication,welding, installation and painting shall be done in accordance with thisSpecification and relevant Standard. If difference quality metals are in contactwith each other, these contact surfaces shall be separated by means ofbituminous paint, felt strip, rubber sheet and other material to be approved by theBoard.18.5.9 Floor-laying(1) PVC FlooringPVC flooring shall be heat resisting vinyl tiles obtained from an approvedmanufacturer. The tiles shall be not less than 2.4 mm thick and laid by anspecialist to a jointing layout approved by the Board. A matching PVC cove-typeskirting is to be used in conjunction with the floor tiles. The tiles and skirting shallbe laid on a flat, clean concrete floor, in strict accordance with the manufacturersinstructions, using the recommended adhesive.(2) Unglazed Vitreous Ceramic TilesThe tiles shall be plain and of manufacture and colour approved by the Board.The tiles shall be laid by experienced craftsman, on a concrete slab accuratelyformed with a true, smooth surf ace. Joints shall be accurately aligned in bothdirections and matching covered skirtings. Expansion Joints shall be the samewidth as tile Joints, approximately 5 mm, and filled with approved filling material.The surface of the base shall be cleaned of all dirt, grease, grit, etc. and the tilesshall be dry and clean.(3) In-situ TerrazzoIn-situ terrazzo paving is to consist of2 1/2 parts 6.5 mm 9.5 mm approvedmarble chippings, clean and free from dust, mixed with one part of "concrete" or"snowcrete" or approved equivalent according to the background required. Theterrazzo shall be laid by a specialist.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)203

The terrazzo is to be trowelled to a dense even surface, rubbed down andpolished to approval. Where surface are required to be left rough finish thefinishing coat shall be brushed with wire brush while still green to expose theaggregates.Brass dividing strips 25 mm x 3.2 mm shall be provided at junctions of differentfloor finishes, finishing flush with flooring non-slip nosing tiles of approvedmanufacture and colour shall be provided in finishing works for steps and stair.(4) Damp-Proof MembraneAn approved bitumen/PVC water-proof membrane shall be placed on the blindingconcrete under concrete slabs, to exclude rising moisture.18.5.10 Wall And Ceiling Finishes(1) MaterialsCement, sand, hydrated lime, gypsum plaster, expanded metal lathing, flatheaded galvanised nails, galvanised staples and wire shall all comply withapproved standards. Materials shall be carefully store in a dry weatherproof storeuntil required for use.(2) Preparation of BackgroundsBackgrounds for plaster work shall be carefully brushed out and removed dustand other deleterious matter likely to impair the bond of the under coat with thestructure. When the background surface is dry and undue suction occurs, thisshall be sprinkled with water to, prevent drying the applied plaster.(3) PlasterworkUndercoat shall consist of Portland Cement, hydrated lime and sand gauged in theproportions 1:1:6. The undercoat shall be keyed to take the finishing coat andallowed to dry out completely before the latter is applied.Finishing coats shall be applied in accordance with the recommendations of themanufacturer of the particular brand to be used. The total thickness of the twocoats shall not be less than 15 mm thick.(4) External RenderingExternal rendering shall be applied in two coats, with an approved waterproofagent added to the mixes. The walls shall be wetted before the application of thefirst coat, which shall be finished flat and vertical by straight edge, and scored toform a key. The second coat shall not be applied until the first coat has dried outcompletely. Immediately before application of the second coat, the surface of thefirst coat shall be wetted, and the second coat shall be applied by machine, togive a "Tyrolean" finish of uniform thickness and texture.An approved plasticizer may be used in both coats. All external rendering shall beprotected from rain and direct sunlight for period of 7 days.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)204

(5) Glazed Ceramic TilingGlazed ceramic wall tiles shall be of nominal size 100 mm x 100 mm x 5 mm,colour to be selected. Fittings shall be obtained from a supplier approved by theBoard. The ceramic tile fixing and grouting materials shall be obtained from thesame source.The Contractor shall ensure that the rendering is accurately formed and has atrue plumb surface which is free from all high spots and depressions.The rendered backing for tiling shall be cleaned and will be wetted (just enoughto prevent it from absorbing water from the fixing bed) immediately prior to tiling.All tiles shall be dipped in water to ensure that they are completely clean prior tofixing. All tiles shall be immersed in water in clean containers for at least half anhour before use. Tiles shall then be stacked lightly together on a clean surfaces todrain with the end tiles, turned glaze outwards. They shall be fixed as soon as allsurfaces water has evaporated they must not be allowed to dry out more thanthis.Approximately two days after the fixing of the tiles, all joints shall be pointed withneat white grouting cement; the finish shall be flushed and free from all voids andirregularities.All wall faces shall be finished plumb and flush throughout free from unevennessand irregularities of plain; all angles shall be straight and true. The finished workshall be left clean and free from all materials, which will scratch or in any wayimpair the finished work. Final polishing shall be done with a dry cloth. TheContractor shall be responsible for the adequate protection of the tiling from alldamage until the handling over. Any damage which does occur shall be madegood by the Contractor at his own expense. The whole of the work shall be left ina state satisfactory to the Board.(6) Suspended CeilingMaterials, samples and drawings showing details of construction of all types ofceiling required shall be submitted to the Board for approval.Appropriate size of aluminium tees shall be grided to the module of standardpanels to accommodate acoustic boards, or approved equivalent, the odd sizepanels at perimeter shall then be arranged to equal dimension.Fixing of hanger to beams, floor slab and soffits must be capable of carrying theload of ceiling boards and ventilation grill should be supported from thestrengthened aluminium tee grids.(7) Gypsum Board PartitionsGypsum panels shall be 1000 mm wide by 12 mm thick obtained from an approvedmanufacturer.The stud partition shall be extended from floor to ceiling with variation in heightsGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)205

to suit. Stud shall be formed of approximately 0.03 gauge cold rolled steel withprepunched holes in the web 120 mm on centre to allow horizontal passage ofutility lines. Studs shall be spaced 1000 mm on centre with horizontal spacerchannels and framing materials.Glass panel framing shall be anodised aluminium with glazing recess. Glazing shallbe 6 mm clear sheet glass fitted with neoprene or vinyl gaskets.The Contractor shall submit samples of metal and drawings showing details ofconstructions for approval of the Board.18.6 Painting18.6.1 MaterialsAll paint distempers and other materials shall be of an approved brand or brandsand shall comply with JIS Standard or other, equivalent standard to be approvedby the Board. Paint for use on concrete or brickwork shall be of a type speciallyprepared for this purpose. Each coat shall be of a distinct colour from thepreceding one and all colours shall be approved by the Board. Mixed paint andsynthetic resin emulsion paint shall be applied based on the following method(unit: kg/sq.m)Mixed paint Synthetic resin emulsionMetal Wood Concrete BrickFirst paint(Rust inhibitive paint) 0.14 0.09 0.13Second paint 0.08 0.11 0.13Finishing paint 0.04 0.09 0.13Note: Rust inhibitive paint shall be either red lead or zinc rich lead type.For painting of structural steelwork, see Section of 18.5.1(7).18.6.2 Surface PreparationPrior to painting, the dust, grease, injurious adherent substance, rust shall beremoved from the surface to be painted. The planed grain, interlocked grain, fluffin wood shall be ridded with sandpaper and all cracks, manholes open; duct andother imperfection shall be made good with hard stoppings consisting of pastewhite lead and gold size stiffened with whiting. Cracks and holes on the concretesurface shall be flattended with cement paste, mortar, or cement filler.18.6.3 WorkmanshipAll painting and decoration shall be carried out by skilled workmen according tothe best current practice in accordance with manufacturer's instructions.All materials shall be applied by brush unless otherwise specified or approved.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)206

18.6.4 PrimingAll joinery, metal works to be painted shall be primed using appropriate andapproved primer before delivery assembly or fixing. No primer is required onsurfaces to be distempered or emulsion painted unless otherwise specified.18.6.5 Number Of CoatsUnless otherwise specified, the required finishes shall consist of the followingtreatments, in addition to preparation, priming etc:-a. Distempering Two coatsb. Emulsion painting Two coatsc. Oil painting Three coats on woodworkTwo coats on elsewhere18.6.6 StorageThe Contractor shall furnish an exclusive place for storing the combustible paints.The place for storage shall be fully ventilated. Adequate measures shall be takenagainst the ingress of dust and direct rays of the sun.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)207

Section 19Spare PartsGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)208

SPARE PARTSPage19.1 GeneralSpares during Warrantee PeriodSpares during LTSAGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)209

19. SPARE PARTS19.1 GENERALThe Contractor shall guarantee that the spare parts shall be available during thelife time of the plant.Spares during Warrantee periodThe Contractor shall submit a list of Essential spare parts with OEM Part No. andconsumables to be necessary for maintenance of the unit(s) and other plantequipment inclusive of emergency use that takes place in the course of operation(according to the Manufacture's recommendation and guideline) during theWarranty period (24 months). During the warranty period of 24 months, theContractor shall supply all necessary equipment, spare parts,materials/consumables etc. at his own cost and whether it is listed or not in theirlist. In preparation of the list the tenderer have to consider plant factor as 80%.Spares during Long Term Service agreement (LTSA)The Tenderer shall, in addition to essential spare parts and consumables forwarrantee period also submit a list of spares for LTSA period (next 4 years afterwarrantee period) which reflects the OEM's guidelines and Tenderer's experiencein the operation and maintenance of the type of equipment proposed. For LTSAperiod also the Contractor shall supply all necessary equipment, spare parts,materials/consumables etc. at his own cost and whether it is listed or not in theirlist. In preparation of the list the tenderer have to consider plant factor as 80%.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)210

LONG TERM SERVICE AGREEMENTGUIDE LINEForProvision for expert services and spare parts for smooth operation (includingall inspection/overhauling (CI, HGPI)/ major overhauling of GTG units andother BOPs for four (4) years after expiry of warrantee period under 'LongTerm Service Agreement (LTSA)' from the original equipment manufacturer(OEM) for Ghorasal 200MW to 300 MW gas turbine peaking power plantprojectGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)211

BACKGROUND INFORMATION:Bangladesh Power Development Board (BPDB) is in the process of implementation ofGhorasal 200MW to 300 MW gas turbine peaking power plant project in Ghorasal,Narashingdi.As part of the contract the contractor will be liable for providing all spares andconsumable and expertise service of schedule maintenances for smooth running of theplant during 2 years warrantee period. As a continuation of that process BPDB isconsidering Long Term Service Agreement for the plant for next four year (afterwarrantee period).The Operation & Day to Day Maintenance (O & M) is expected to be performed by BPDBpersonnel, but a O&M Contracting Firms may be engaged. But LTSA provider will beresponsible for all other scheduled and forced maintenance during the LTSA period.PLANT OPERATION PHILOSOPHY:Plant operation philosophy is based on the following salient points:-a) The units will run continuously as per requirement of load demand of thenational Grid system. For LTSA period services and spares & consumables thetenderer have to consider plant factor as 80%.b) BPDB staff or the O & M contractor responsible for operation and maintenanceof the peaking power plants will supervise the activities under LTSA. LTSAprovider shall provide the warranty of the spares (e.g; rotor, compressors,nozzles, buckets, hot section components etc. and all other parts for GT &axillaries, generator, DCS, electrical systems, control & protection systems andother BOPs), services and refurbished parts in order to meet the guaranteesunder the PPA.The manufacturer and EPC contractor of this peaking power plant will have the requisitepotential to furnish detailed technical & financial proposal for LTSA for the Power Plantscovering all major maintenances of GTG units and essential BOP equipment for a periodof 4 (four) years after the expiry of warranty period of the Generating units.2. SOURCE OF FUNDThe remuneration of expert services, the cost of spares and other expenditures under theLTSA shall be borne by BPDB3. SUBMISSION OF BIDThe bid shall be submitted as part of the tender for the project and shown underSchedule F, Volume 3 of 3.Scope of work of Expert Service required for overhauling (CI, HGPI and major)of GTG units and other essential auxiliaries of Ghorasal 200MW to 300MW gasturbine peaking power plant projectBefore starting minor, intermediate and major overhauling (CI, HGPI, MI etc) of GTGunits and other essential auxiliaries, all the parameters, Data of the control system andVibration, temperature, pressure etc., are to be noted and recorded. All defective partsGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)212

will be replaced by new spares under the supervision of the experts. As regards controlcircuit all testing calibration (if required) shall have to be done by the experts anddefective parts will be replaced under their supervision.A. Category of Experts required:-Mechanical Chief Supervisor-Electrical Chief Supervisor-Control System Specialist (DCS, Mark-VI & 1& C)-Blade fitter Supervisor-Re-commissioning Engineer- GBC specialist-Any other experts adjudged suitable by the OEM for the services / work.B. Scope of services:SCHEDULED OUTAGESScheduled maintenance outages shall be carried out at such time as set out in the tablebelow as per GTG manufacturer's guidelines.Timing of Schedule OutageInspectionAt 7000 Hr or Equivalent StartsType of InspectionCombustion Inspection (1 st CI within thewarranty period under the EPC contract)Scheduled maintenance services beyond the EPC contractor's warranty period tobe rendered under the LTSAAt 20000 Hr or Equivalent StartsAt 27000 Hr or Equivalent StartsAt 40000 Hr or Equivalent StartsAt 48000 Hr or Equivalent StartsHot Gas Path InspectionCombustion InspectionHot Gas Path InspectionMajor Inspection / OverhaulThe Experts proposed shall supervise and carry out the scheduled CI/HGPI /MI & overhauling, maintenances of essential BOP equipment, testing &commissioning work of the followings (indicative, but not limited to):- Disassemble of thermal block and combustion chamber (Reference measurementshave to be taken for coupling alignments, blade and labyrinth Clearances requiredfor re-assemble, as required).- Dismantling of upper casing of Gas Turbine and Compressor.- Removal of Gas Turbine and compressor rotors.- Cleaning work.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)213

- Overhauling of all electrical motors (including starting motor/exciter) andaccessories etc.- Leakage and functional inspection of regulating and control system and repair/replacement as required.- Visual control of the blading (compressor & turbine).- Inspection and change of gas turbine stator blading, if requires.- Inspection and change of gas turbine rotor blading, if requires.- Inspection and change of compressor stator blading if requires.- Inspection and repair of hot gas casing- Inspection of combustion chamber and burner and replacement of parts asnecessary- Inspection and replacement of GTG Bearings as required.- Major inspection of Generator/Generator rotor.- Checking of Generator stator / Generator rotor and windings and repair/replacement as required.- Inspection of electrical & control system and repair/ replacement as required.- Inspection of cooling water & lube oil system and repair/ replacement as required.- Balancing of the GT rotor, if necessary.- Re-assembling of the units.- Completion of any other works left due to oversight for successful overhauling &commissioning of the unit.- Re-commissioning of the Gas Turbine Generator units.- Major maintenance work relating to the essential BOP equipment (e.g; GBC units,etc.)C. Scope of supply of spares/equipment:Necessary spares required for the CI, HGPI, major inspection / overhauling work (e,g; 1st& 2nd stage Nozzles, Buckets, Shroud with hardware as per OEM guidelines) and all otherday to day maintenance spares of GTG units will be provided by the LTSA provider. Listof such spares with price offer shall be provided in the Proposal. Normal tools/tackles asavailable at the Power Station site will be provided.Special tools/tackles & Instruments required for the proposed services shall have to bearranged by the L TSA provider at their own arrangement.All necessary spares required for the Electrical protection system and Control system(DCS, such as Mark-VI) like relays, electronic cards, pick-ups, monitors, micro switches.sensors, switches, oil seals, etc., which shall be provided by the LTSA provider.All necessary spares required for the Electrical system/ equipment (HV/MV/LV) includingGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)214

transformers, switchgears etc., shall be provided by the LTSA providerAll necessary spares required for the maintenance work relating to the GBC units andother BOP equipment / machinery (fuel handling, cooling, lubricating system etc).REASSEMBLEY OF ABOVE MENTIONED OR ANY OTHER COMPONENTS AS PEROverhauling Guideline/Maintenance manual (In line with Operation &Maintenance Manual)After the CI, HGPI, major overhauling of Gas Turbine Generating units and properchecking of control system, testing, calibration of various equipment etc, the machineshould be commissioned and gradually loaded up to full capacity. During commissioning,note all the parameters, data and vibrations, temp, pressure and compare those with thedata noted before and after overhauling. If requires, subsequent correction measureshould be accomplished.A complete report shall be submitted; immediately after completion of the CI, HGPI,major overhauling of Gas Turbine units to the Plant Manager, Siddhirganj Peaking PowerPlant.After completion of CI / HGPI / overhauling work, the Experts (of LTSAprovider) shall be responsible for testing & commissioning and putting backthe GTG units into successful normal operation & guarantee the load outputand the other normal operation parameters of the GTG, Maximum load testshall be performed after commissioning of each unit. Uninterruptedcontinuous operation of 168 hours of each GTG unit shall have to be carriedout jointly by both O & M personnel and LTSA provider. If the unit trips for itsown troubles/ faults within this period, then the unit shall have to be startedafter necessary corrective measures and put the unit into operation for 168hours again. If the unit trips for external faults / troubles (e.g. Grid problem)within this period, then the balance running time will be added to the periodalready run by the unit.GENERAL CONDITIONS OF LTSA CONTRACT1. GENERAL1.1 The terms or conditions of Contract shall not be binding upon the LTSAprovider unless agreed and accepted in writing by the duly authorizedrepresentative of the LTSA provider.1.2 The governing language of the Contract shall be English2. SPECIFICATIONSServices and supply of spares shall be supplied in accordance with the conditionsand the specification set out in the Contract and both LTSA provider and the 0 &M contractor is responsible for satisfying itself to their suitability for the Procuringentity's application.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)215

3. BASIS OF PRICE3.1 Basis of price for this Contract shall be according to the actual service requiredduring a particular period, as mentioned in the scope of work and number ofSupervisors to be provided.3.2 Basis of price for this Contract shall be according to the actual supply of spares/equipment to be required against each service (inspection & overhaul) during aparticular period, as mentioned in the scope of work.3.3 Supervisory Service fee shall include base rate, holiday rate, traveling day rate,overtime rate, air fare, food and any other expenditure whatsoever necessaryshould be included in the man day rate of supervising service fee.3.4 Accommodation of Experts may be provided by the Manager of the Power Stationsite subject to the availability of the same. The rate of such accommodation shallhave to 'be paid by the LTSA provider as per BPDB rules applicable to LTSAprovider /consultant's personnel.4. PROCURING ENTITY'S GENERAL OBLIGATIONS4.1 The Procuring entity shall provide in time any approval, instruction, material, civilworks, access to site or other thing which may be required in relation to theperformance of the LTSA provider's obligations and which is not expressly statedto be the LTSA provider's responsibility.4.2 Procuring entity will assist the LTSA provider to obtain any authorization requiredby any authority in the country of installation to allow the LTSA provider toperform this Contract in due time.These authorizations include: application for import license, performance oftransport, performance of services, labor, temporary import license for tools orother equipment of LTSA provider necessary to perform the Contract or part ofthe contract.5. VARIATIONS5.1 Unless provided otherwise in the Contract, no variation to the Contract may bemade unless agreed in writing by the LTSA provider and the Procuring entity.5.2 If any variation of work increases or reduces the cost of the LTSA provider forperforming the work satisfactorily then the Contract price shall be adjustedaccordingly.5.3 The time for performance of the Contract shall be extended in order to take intoaccount the consequences of any variation.5.4 A variation will not be effective until an agreement on price and delivery isreached6. LTSA PROVIDER'S WARRANTY6.1 LTSA provider warrants to the Procuring entity that the services part of theContract will be performed in a competent manner (International standardpractice or appropriate maintenance guideline). If any failure to meet theGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)216

foregoing warranty appears within one (1) year counted from the date ofparticular work (inspection/overhauling) performed and subsequent issuance ofProvisional Acceptance Certificate (PAC) by a Committee to be constituted by theBPDB and if promptly notified in writing thereof, LTSA provider will re-perform theservice to the same extent as the original service or either (at its option) repairany damage part of the equipment or make available ex-works the repaired partor replacement for the part which was damaged as a result of the poorperformance of the service without any demand of payment .6.2 The liability of LTSA provider to the Procuring entity whether on warranty,contract or negligence and the repair or replacement of any damaged part of theequipment resulting from poor workmanship shall be re-performed by the LTSAprovider at their own responsibility. In such cases the liability regarding warrantyshall be extended by the both LTSA provider beyond one (1) year by proportionedweight of the reperformed service counted from the date of issuance of PAC.6.3 The provisions of this Clause shall not apply to any component parts orconsumable items or materials the nature and purpose of which is such that itwould be reasonable to expect their replacement or repair in carrying out routinemaintenance operations during the period of guarantee stated herein or wheresuch replacement or repair might reasonably be expected as a result of properuse, wear and tear during the said period.7. DRAWINGS AND DESCRIPTIVE DOCUMENTS7.1 BPDB shall retain the ownership of its studies, drawings, software models and anydocuments issued and communicated to Procuring entity, or of which Procuringentity may have had knowledge in fulfillment of the Contract. Such informationand documents may be used only by Procuring entity and exclusively forexecution of the Contract and operation, maintaining, adjusting and repairing ofthe works.These documents and information shall be treated as confidential and shall not bedistributed, published or generally communicated to any third parties without priorpermission of BPDB.8. LIMITATION OF LIABILITY8.1 The total liability of the Contract on all claims of any kind for any loss or damageresulting from performance or lack of performance by the LTSA provider underthe Contract shall be an amount up to the maximum of the Contract price.8.2.1 For the purpose of this clause the LTSA provider is or shall be deemed to beacting as agent or trustee on behalf of and for the benefit of all persons, firms orcompanies who are or may from time to time become Sub-LTSA provider'semployees or agents as aforesaid and to such extent all such persons firms orcompanies shall be, or be deemed to be parties to the LTSA provider9. LTSA PROVIDER'S LIABILITIES FOR FAILURE TO PERFORMIf the LTSA provider fails to meet the delivery date (Completion time) as specifiedin the Contract, then the LTSA provider shall pay to the Procuring entity liquidateddamages for that delay calculated on the Contract price of the delayed services ata rate of 0.5% per week of the respective service (inspection/overhauling) cost ofGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)217

the delayed services or such other rate as may be specified in the Contract.10. FORCE MAJEURE10.1 If performance of any obligation under the Contract (other than the obligation ofthe Procuring entity to make payment) is prevented, restricted or delayed by anyforce majeure event. The party whose performance is affected shall be executedfrom and shall not be liable for failure in performance to the extent of thatprevention, restriction or delay and the time for performance shall be extendedaccordingly.10.2 Force majeure shall be defined as any circumstances beyond the reasonablecontrol of the parties including but not limited to :Acts of god, earthquake, tempest, unusual adverse climatic conditions,Labor conflicts / industrials dispute,Fires and explosions,Action or failure to act of public services or government authorities,Acts of war, sabotage, embargoes,Insurrection, riots, breach of peace,Transportation interruptions or delays beyond LTSA provider's responsibility,General shortage of materials10.3 In case one party considers that an event shall be considered as force majeurecase and he shall inform the other party within a period of ten (10) working dayscounted from the date he was informed of the event.In case of force majeure case, the guaranteed delivery time shall be extended bythe delay time due to force majeure (including time to restart the work).10.4 Any reasonable additional costs due to a force majeure case incurred by the LTSAprovider to continue to perform his obligations under the Contract so far asreasonably practicable shall be certified and added to Contract value.10.5 If performance is delayed for more than 4 (four) months by any case referred toin the above sub-clause and the parties have not agreed upon a revised basis forcontinuing the work at the end of the delay, then either party may after thatperiod and while the cause of the non-performance still exists terminate thecontract by not less than 30 days notice in writing to the other party, in whichevent the provisions of the Termination Clause below shall apply.10.6 Payment on termination of force majeure:If the Contract is terminated under sub-clause 10.5 here above, the LTSAprovider shall be entitled to receive:10.6.1 The outstanding balance of the value of the services which havebeen delivered or performed.10.6.2 The costs incurred by the LTSA provider up to the date of notice oftermination in performing services which are not then in adeliverable state.Termination of the Contract in whole or in part however occasioned shall notaffect or prejudice the provisions of the clause, the Ownership and ConfidentialityGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)218

of Technical information Clause or Limitation of Liability Clause above or the Lawand Arbitration Clause.10.7 If as a consequence of force majeure and under the law governing the Contract,the LTSA provider is released to perform the Contract. The sum payable by theProcuring entity to the LTSA provider shall be as stated in 10.6.11. TERMINATION BY THE PROCURING ENTITY11.1 The Procuring entity may by giving 30 days notice be entitled to terminate thecontract for LTSA provider's default in the following cases:The LTSA provider repeatedly neglects to perform his Contractual obligations andfail to comply within a reasonable time with the Procuring entity notice to makegood such neglects, orThe LTSA provider becomes bankrupt, orThe LTSA provider assigns the whole of work of the Contract to sub-LTSAprovider s without the employer's consent.11.2 In case of termination (Art. 11.1) by the Procuring entity, the LTSA provider shallnot be paid further. The Contract value of the services which have already beendelivered or performed and the costs incurred by the LTSA provider up to the dateof notice of termination against which payment has been made by BPDB shall berealized / recovered.12. TERMINATION BY THE LTSA provider12.1 The LTSA provider may by giving 30 (Thirty) days notice be entitled to suspendand / or terminate the Contract when the Procuring entity is :- Failing to pay the LTSA provider in due time.- Failure to meet his contractual obligations.- Becoming bankrupt or insolvent.12.2 In case of termination by the LTSA provider. the Procuring entity shall pay to theLTSA provider an amulet calculated as below:The LTSA provider shall be entitled to receive12.2.1 The outstanding balance of the Contract value of the services which havebeen delivered or performed and those goods which have been shippedfor delivery, and12.2.2 The costs incurred by the LTSA provider up to the date of notice oftermination in performing services which are not then in a deliverablestate plus a reasonable margin to be agreed between the partiesTermination of the Contract in whole or in part however occasioned shall notaffect or prejudice the provisions of the clause, the Ownership and Confidentialityof Technical information Clause or Limitation of Liability Clause above or the Lawand Arbitration Clause.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)219

13. GENERAL CLAUSES CONCERNING TERMINATION13.1 Termination of the Contract in whole or in part however occasioned shall notaffect or prejudice the provisions of this Clause, the Ownership and Confidentialityof technical Information Clause or limitation of Limitation of liability Clause aboveor the Law and Arbitration Clause.13.2 In case of termination, the LTSA provider shall be entitled to remove immediatelyall equipment belonging to the LTSA provider, which is on site.14. ARBITRATIONAny dispute arising out of the interpretation of application of the terms of thisagreement shall unless mutually settled by direct negotiation between the partiesof the agreement, be resolved through arbitration in accordance with rules of'Arbitration Act'-200 I of Bangladesh. The venue shall be in Dhaka, Bangladesh.15. TERMS OF PAYMENTPayment of contract price for individual service / supply shall be made throughirrevocable letter of credit established in favor of the LTSA provider advised by theBOARD.All bank charges outside Bangladesh shall be borne by the LTSA provider andinside Bangladesh by BPDB.The LTSA provider shall have to bear all such charges inside and outsideBangladesh in case of extension of L/C if done at the request of the LTSAprovider.Unconditional & irrevocable Bank Guarantee against performance security [@10% of quoted price of the plant’s (including generating units and all other BOPs)scheduled maintenance along with supply of spares to be required immediatelyafter expiry of EPC contractor's warranty period] valid up to the contract durationof such scheduled maintenance, shall have to be submitted by the LTSA provider.Bank Guarantee against performance security shall be issued by a schedule Bankin Bangladesh on behalf of the LTSA provider in favor of the procuring entity.Payment against each service (inspection/overhauling of units/BOP)will be made as follows:-a) 10% payment of the relevant services (inspection/overhauling) may bemade to the LTSA provider as mobilization advance after contract effectivedate against an unconditional & irrevocable Bank Guarantee valid for aperiod of at least 1 (one) year. issued by a schedule Bank in Bangladeshon behalf of the LTSA provider.b) 80% payment of the relevant services ((inspection/overhauling)) may bemade to the LTSA provider after issuance of provisional acceptancecertificate (PAC). PAC will be issued after completion of the relevantservices ((inspection/overhauling work) and putting back the units intoGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)220

normal satisfactory operation, which will be witnessed and accepted by acompetent committee to be constituted by the BPDB.c) 10% payment of the relevant services (inspection/overhauling) may bemade to the LTSA provider after successful completion of at least 1 (one)year warranty period counted from provisional acceptance certificate(PAC). Final acceptance certificate (FAC) will be issued by a competentcommittee constituted by the BPDB.d) 10% performance security of the relevant services will be released afterthe issuance of FAC by a Committee to be constituted by the BPDB.Payment against supply of spares / equipment (inspection/overhauling)will be made as follows:-a) 90% payment of the submitted invoice of the respective supply shall bemade to the LTSA provider against submission of shipping document (Billof lading, packing list, manufacturer's test certificate, country of origin,etc.,) of the relevant supply of spares / equipment to the Power Plantauthority.b) 10% payment of the submitted invoice of the respective supply shall bemade to the LTSA provider after receipt and inspection (R & I) of thespares/ equipment at plant site by the Plant Manager.c) 10% performance security of the relevant supply will be released after theissuance of FAC by a Committee to be constituted by the BPDB.16. CONTRACT:a) Contract signing: Contract will be signed separately for each of theindividual services along with relevant supply of spares againstinspection/overhauling of units/BOP.b) Contract effectiveness: The contract shall come into force from the date ofreceiving confirmed unconditional & irrevocable Bank Guarantee againstpredominance security @ 10% of quoted price of the service and supply ofspares to be required for the units’/BOPs’ scheduled maintenanceimmediately after expiry of EPC contractor's warranty period.Subsequent Bank Guarantees against performance security for next scheduledmaintenances (inspection/overhauling of units and other BOP maintenanceservices) shall be cascaded accordingly in order to maintain the LTSA contract'seffectiveness and continuity during the whole period (4 years) of LTSA.LTSA provider's personnel shall be available in Dhaka, Bangladesh withinmaximum 1 (one) week from the date of receipt of request from the competentauthority of BPDB after the contract is made effective.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)221

17. INSURANCEThe insurance including all personal accident insurance for the expert will bearranged by the LTSA provider.18. INCOME TAX AND VATa) CD/VAT and other import related taxes against the importedspares/equipments will be paid by BPDBb) During payment of invoices by BPDB to the LTSA provider, IT and VAT (as perregulations and approved rates of National Board of Revenue during theperiod. of particular services) will be deducted at source from the contractprice. The LTSA provider shall indicate IT and VAT separately in the proposal.LTSA provider shall be well conversant with the prevailing rules of the Government ofBangladesh relating to income tax, VAT.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)222

Section 20Appendixes [Data/ drawings]Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)223

Appendixes20.1 Site Layout20.2 Grid Networks20.3 Sub-station Single Line Diagram20.4 Fuel Analysis20.5 Seismic Zone Map of Bangladesh20.6 Environmental StandardsGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)224