SPECICATION NO. ETI/PSI/144 (12/91) SPECIFICATION FOR ... - rdso

SPECIFICATION
FOR
SPECICATION NO. ETI/PSI/144 (12/91)
SUPERVISORY CONTROL AND DATA ACQUITION (SCADA)
SYSTEM FOR 2x25 kV A.T TRACTION
POWER SUPPLY
TRACTION INSTALLATION DIRECTORATE
RESEARCH DESIGNS AND STANDARDS ORGANISATION
MINISTRY OF RAILWAYS
GOVERNMENT OF INDIA
MANAK NAGAR, LUCKNOW – 226011
INDIA

Specification No. : ETI/PSI/144 (12/91)
SUPERVISORY CONTROL AND DATA ACQUISITION (SCADA) SYSTEM FOR
2x25 kV A.T. TRACTION POWER SUPPLY
1.0 Scope
1.1 This specification applies to the design, manufacture, supply, erection,
testing and commissioning of SCADA system to enable the Traction Power
Controller(TPC) or operator, to control from a central place called Remote Control Centre
(RCC), the switching operations of the equipments at traction sub-stations and switching
stations (hereinafter called "controlled stations"), to monitor the status of the equipments
and to collect and store information and data relating to the overall traction power supply
to the 2X25 kV overhead traction lines.
1.2 The SCADA equipment shall be based on the state-of-the-art technology.
The equipment at RCC, here after called as master station equipment, shall include dual
main mini-computer(s) system with sufficient semi-conductor RAM main memory, high
speed computer to computer communication link, system consoles, man-machine
interfaces through color VDUs and key-boards, front-end processors, modems, data
logging printers, watch dogs, floppy disks and hard disks along with their drives, switchover
unit for switching over from main to standby computer or vice-versa, mimic driver
and mimic diagram board (MDB), UPSs with battery, console desks and surge arresters.
1.2.1 As an alternative to the master station built around minicomputers, tenderer
shall also quote for a master station built around dual main micro-computers.
1.3 The SCADA equipment at controlled station, hereafter called as Remote
Terminal Unit (RTU), shall be micro-processor based and shall be compatib1e with the
master station equipment• It shall be complete in all respects including central processing
unit with watch dog, digital input/output modules, alarm input modules, analogue input
modules, transducers, memory, interposing relays, summation current transformers, power
supply units, surge arresters and modem.
1.4 The SCADA equipment at RCC and at controlled stations shall be complete
with all units, parts and accessories necessary for their efficient operation and all such
units, parts and accessories shall be deemed to be within the scope of this specification
whether specifically mentioned or not.
2.0 Service conditions
2.1 The SCADA equipment may be installed any where in India. The
equipment at RCC shall be installed indoors. Air-conditioning may be provided, if
convenient, or else filtered air will be blown through to cool the equipments.
2.2 The SCADA equipment at controlled stations shall be installed inside track
side cubicles and subjected to vibrations on account of running trains on the near-by
railway tracks. These cubicles will not be air-conditioned and are liable to exposure to
polluted atmosphere.

2.3 Atmospheric Conditions
Maximum average ambient temperature
Minimum ambient temperature
Relative humidity
… 45 deg C
… 0 deg C
... 100 %
The locations at which the equipment is to function shall be subjected to dust
storms in summer, and to heavy rains and lightning during monsoon.
2.4 The SCADA system is intended for use at altitude not exceeding 1000 metres.
2.5 Voltage and frequency
2.5.1 At RCC : 415 V, 3 phase 50 Hz supply from the State Electricity Board shall
be made available by the Railways. The voltage may vary between +10% and -15%, while
the frequency between +3% and -3% of the nominal values. The master station equipment
shall be suitable for satisfactory operation throughout these variations.
2.5.2.1 240V, single phase 50 Hz a.c.supply from the auxiliary transformers provided
at controlled stations shall be made available by the Railways. Due to variation in the
catenary voltage(25kV). The single phase voltage may vary between 180 V and 265 V.
The frequency may vary between +3% and -3% of the nominal value. The RTU equipment
shall normally operate off this a.c. supply and be suitable for satisfactory operation
throughout variations in voltage and frequency.
2.5.2.2 Operation (open/close) of circuit breakers, interruptors and other
equipments is carried out at 110 V d.c. For this purpose necessary battery charger shall
be provided by the railways.
2.5.2.3 In case of failure of a.c. supply at the controlled station, the RTU shall
automatically operate off the 110 V d.c. supply. The d.c. voltage may vary between +l0%
and -15% of the nominal value. The RTU shall be suitable for satisfactory operation
throughout this variation.
3.0 Governing specifications
3.1 The SCADA equipment and component thereof shall, unless otherwise
specified, conform generally to the latest editions of the Bureau of Indian Standards
specification mentioned below:
IS:590 Fixed paper dielectric capacitors.
IS:1554 PVC (Heavy duty) insulated electric cables.
IS:1652 Stationary cells and batteries, lead-acid type with plants positive plates.
IS:1765 Direct current Potentiometers.

IS:3700 Ratings and characteristics of semiconductors devices.
IS:3895 Monocrystalline semi-conductor rectifier cells and stacks.
IS:4007 Terminals for electronic equipment.
IS:5051 Relays for electronic and telecommunication equipment.
IS:5786 Fixed carbon resistors, general purpose, low power.
IS:8309 Compression type tubular terminal ends for Aluminium conductors of
insulated cables.
IS:9521 Metal clad base material for printed circuits for use in electronic and
telecommunication equipment.
IS:9638 Fixed polyester film dielectric capacitors for direct current.
IS:9891 Edge connectors for printed wiring board.
IS:10482 Connectors for printed wiring board.
3.2 The above specifications shall be applied in a manner altered amended or
supplemented by this specification and the latest Indian Electricity Rules wherever
applicable.
3.3 Any deviation from this specification proposed by the tendered,
calculated to improve upon the performance, utility and efficiency of the equipment, will
be given due consideration, provided full particulars of the deviation with justification
thereof are furnished. In such a case, the tendered shall quote according to this
specification and deviations, if, any, proposed by him shall be quoted as an alternative(s).
4.0 Description of the 2x25 kV A.T. system
4.1 The power for electric traction is supplied in a.c. 50 Hz, single phase
through 2x25kV A.T. feeding system, which has a feeding voltage (2x25kV) from the
traction sub-station (TSS) two times as high as the catenary voltage (25kV). This high
voltage power supplied from the sub-station through catenary wire and feeder wire in
stepped down to the catenary voltage by use of auto-transformer (ATs) installed about
every 13 to 17 km along the track at auto transformer Post (ATP), Sub-sectioning, and
Paralleling Post (SSP) and Sectioning, and Paralleling Post (SP) and then fed to the
locomotives. In other words, both the catenary voltage and the feeder voltage are 25kV
against the rail, although the sub-station feeding voltage between catenary and feeder
wires is 50kV. Therefore, the catenary voltage is the same as that of the conventional
25kV system.
Since the power is supplied in two times higher voltage, the 2x25kV AT
system is suitable for a large power supply and it has the following advantages as
compared with the conventional 25kV system.
(a) Less voltage drop in feeder circuit.
(b) Large spacing of traction substations.
(c) Less telecommunication interferences.
(d) Suitable for high speed operation.
The power is obtained from 220 or 132/2x25kV Scott-connected/single
phase transformer provided at the sub-station, which are normally spaced between 70 to
100km apart. The primary windings of the transformers are connected to two or three
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phases of the 220 or 132kV, three phase, effectively earthed transmission net work of the
State Electricity Board, in case of a single phase transformer or in case of two single
phase V-connected transformers/Scott connected transformer respectively. The Scottconnected
transformer and V-connected single phase transformers are effective in
reducing the voltage imbalance caused by the traction loads on the transmission net-work
of the Electricity Board.
One outer wide terminal of the secondary windings of traction transformer is
connected to the catenary, the other outer side terminal being connected to the feeder.
Two inner side terminals are, via series capacitors or directly, connected to each other,
and their joint is solidly earthed and connected to the running rails.
The load current from the sub-station flows through the catenary and returns to the
sub-station through the feeder. Between two adjacent ATs, the load current fed from the
catenary to the locomotive flows in the rail and is boosted up to the feeder through the
neutral tape of the two ATs.
Mid-way between two sub-stations, a SP is introduced. At the point of
TSS and SP, a dead zone known as neutral section is provided in the OHE to avoid wrong
phase coupling. The power to the catenary and feeder on each side of the TSS is fed by
one feeder circuit breakers, even if there exist two breakers for one side. The two
breakers are used as a stand-by for each other. For maintenance work and keeping the
voltage drop within limits, one or more SSPs are introduced between the TSS and SP. On
a double track section, a SSP normally has four sectioning interruptors and one
paralleling interruptor, and a SP has two paralleling interruptors and two bridging circuit
breakers. In case of fault on the OHE, the corresponding feeder circuit breaker of the substation
trips and isolates it.
A figure showing the principles of AT feeding system and a typical power
supply diagram showing this general feeding arrangement at a traction sub-station and
sections of the OHE are given in the sketch at Appendix-I.
4.2.1 Protection System at traction sub-station:
transformers:
Following relays are provided for the protection of traction sub-station
(a) Differentials relay.
(b) Over current relay on receiving side.
(c) Earth fault relay on receiving side.
(d) Instantaneous over-current relay on receiving side.
(e) Phase failure relay (to detect malfunction of feeder circuit breaker).
(f) Auxiliary relays for transformer faults i.e. Buchholz, excessive winding
and oil temperature strip and alarm, pressure relief device trip and alarm
and low oil level alarm.
(g) Over-current relay on 2x25 kV side as back-up to feeder protective relays.
4.2.2. Following relays are provided for the protection of OHE:
(a) Distance relay (with a parallelogram protection characteristics)
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(b) Delta-I type fault selective relay.
(c) Instantaneous over-current relay
(d) Under-voltage relay to avoid wrong phase coupling
4.3 Auto reclosing of feeder circuit breaker:
A single shot auto-reclosing scheme for the feeder circuit breaker at
traction sub-station has been adopted to facilitate reclosing of the breaker automatically
once, after a pre-set time delay after tripping of the breaker on OHE fault. This feature
will help in quick restoration of traction power supply to OHE if the fault is of a transient
nature.
4.4 All traction substations and switching stations are normally unattended and
off circuit tap changer of the transformer, circuit breakers, interruptors, and motor
operated remotely from the RCC through the SCADA equipment.
4.5 The off circuit tapchanger of the transformer, circuit breakers, interruptors
and motor operated isolators could also be operated locally as well as manually at the
TSS, SP and SSP as the case may be. At the TSS, a local/remote changeover switch is
provided on the control panel, as well as in the mechanism box of the circuit breaker,
interruptor and motor operated isolator. No control panel exists for the interruptors
/circuit breakers at the SP and SSP and therefore the local/remote changeover switch is
provided on the mechanism box of the interruptor/circuit breaker.
5.0 General Information
5.1 Remote Control Centre
5.1.1 The building, provided by the Railways for housing the RCC, shall include
the main control room, equipment room, UPS room,RC laboratory and battery room. The
layout of the RCC and the equipments therein will be decided by the `Railways‘.
5.1.2. The RCC will be suitably illuminated, and the equipment room, control
room and RC laboratory may be air-conditioned, if convenient, or else filtered air will be
blown through to cool the equipments, by the Railways. The SCADA equipment shall be
designed to give satisfactory Service without air-conditioned.
5.1.3. Necessary cable trenches will be provided by the Railways.
5.1.4. The computer furniture for operator workstation shall be supplied by the
successful tenderer. It shall include:
(i) One table and one chair for each workstation.
(ii) Two tables, one for each data logger, and
(iii) One table and one chair for the Engineer‘s workstation.
The furniture shall be procured from M/s Godrej or other reputed manufacturer as
per the basic design enclosed a Appendix 2 to this specification.
5.2 Control room building at controlled station:
5.2.1. A control room building will be provided by the Railways at each TSS,
having an equipment room and also a battery room. This equipment room will house the
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main control and relay panel, 240V a.c. and 110V d.c. distribution board, 110V battery
chargers, telephone apparatus as well as RTU(S). The battery room will house the 110V
and telephone batteries. A Typical layout of the control room building is indicated in Drg.
No.ETI/PSI/0238. Mod.B at Appendix.3.
5.2.2 A small masonary building will be provided by the Railways at each SP,
SSP and ATP, having an equipment room and a battery room. The equipment room will
house RTU, battery charger, terminal board, 240V a.c. distribution board and telephone
apparatus. The battery room will house 110V and telephone batteries. A typical layout is
indicated in Drg. No.ETI/PSI/0010, Mod.D Appendix 4.
5.2.3 The buildings at controlled stations are not air- conditioned. Suitable
illumination inside the rooms shall be provided by the Railways.
5.3 Operation of circuit breakers, interruptors and motor operated isolators at
controlled stations
5.3.1 The closing and tripping circuits of the circuit breakers, interruptors and
motor-operated isolators are designed to operate off 110V battery supply, the batteries
being provided by the Railways.
5.3.2 Interposing contractors, for operating the closing and tripping circuits from
RCC shall form part of the SCADA equipment. The contractor shall be suitable for 110V
d.c. supply varying from +10% to -15%. The contacts of contractors shall have a
continuous current carrying capacity of 10A, making capacity of 20A and breaking
capacity of 2A inductive load. The contacts are liable to damage due to breaking of
inductive current in the trip/closing coil circuits and therefore an arrangement for spark
quenching, if necessary, shall be provided. Besides, the interposing contractors shall be
so designed that it remains energised for a period adjustable between 500ms and 2s,
arrangement for which shall be provided on the control output card in the RTU. These
measures are required to prevent damage to the contacts.
5.4 Monitoring of the state of catenary
Outdoor type 27.5kV/110V, 100VA potential transformers are installed at
the controlled stations by the Railways for monitoring the state of sub-sectors of the
catenary i.c. Whether energized or not and for under-voltage relay operation at the SPs.
The catenary voltage sensing shall be done through rectifier and solid-state comparator
circuits so designed that the de-energised indication on the MDB/VDU appears at a
voltage selectable between 50% and 70% and disappears between 60% and 80% of the
rated voltage viz 110V a.c.
5.5 Telesignals and their monitoring
5.5.1 The various telesignale from typical TSS, SSP, SP and ATP in a double line
section to the master station are as under:
I. From each TSS
(a) Name of telesignal
1. 110V d.c. low.
2. 240V a.c. fail.
3. Catenary-1 fail/feeder-1 P.T. fuse fail.*
4. Catenary-2 fail/feeder-1 P.T. fuse fail.*
5. Catenary-3 fail/feeder-2 P.T. fuse fail.*
6. Catenary-4 fail/feeder-2 P.T. fuse fail.*
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7. 220/132/110/66kV transmission line circuit-1 P.T. fuse fail
(wherever required).
8. 220/132/110/66kV transmission line circuit-2 P.T. fuse fail
(wherever required).
* There is no separate telesignal for PT fuse fail indication. The
annunciation for PT fuse fail indication shall be done in case of any inconsistency
between the status of feeder circuit breaker/paralleling interruptor and the catenary
indications. (Feeder circuit breaker/paralleling interruptor when under power block is to
be treated as ‗open‘ for this purpose.)
(b) For each Scott-connected/single phase Traction Power Transformer, Auto
transformer and associated switchgear
(i) From transformer-1
*9. TR-1 Alarm.
**10. TR-1 Fault
***11. TR-1 Trip circuit 110V dc fail
12. TR-1 220/132/110/60 LV circuit breaker ―Locked –out‖ due
to low gas/air pressure.
13 TR-1 25kv CD-1 ―Locked out‖ due to low gas/air pressure
14-19 TR-1 tap 1 to 6 position
20 TR-1 Blower fans working
21 TR-1 25kV CB-2 ―Locked-out‖ due to low gas/air pressure
(In case of Scott-connected transformer only).
* TR-1 Alarm: This has to come whenever any alarm viz. Buchholz Alarm,
pressure relief device alarm, oil/winding temperature my high alarm and low oil level
alarm occurs.
** TR-1 fault: This has to come whenever the inter-trip relay (which trips both
HV and LV breakers of the transformer) operates.
*** TR-1 trip-circuit fail: Whenever the 110V dc supply to the control circuits
fails or any of the trip circuits of 220/132/110/66kV or 25kV transformer circuit breakers
fails.
Necessary auxiliary contacts of various relays/indicators suitably wired up
and terminated on the control and relay board at traction sub-station shall be provided by
the Railways. Suitable relays or circuits required in the RTU at TSS for the telesignal
shall be provided by the successful tenderer.
(ii) From Transformer-2
22 to 34-as for TR-1
(iii) From Transformer-2(as required)
35 to 47-as for TR-1
(iv) From Auto Transformer-1
*48. AT-1 Alarm
**49. AT-1 Fault
* AT-1 alarm: This has to come whenever any alarm viz. Suchholz
alarm, pressure relief device alarm, oil/winding temperature high alarm and low
oil level alarm occurs.
** AT-1 fault: This has to come whenever any fault in the transformer is
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indicated by operation of Buchholz relay, pressure, relief device, winding
temperature indicator and oil temperature indicator.
Necessary auxiliary contacts of various relays/indicators suitably wired
up and terminated on the control and relay board/terminal board shall be provided
by the Railways. Suitable relays or circuits required in the RTU for the telesignal
shall be provided by the successful tenderer.
5 From AT-4
(v) From AT-2
(vi) From AT-3
50-51-as for AT-1
52-53-as for AT-1
54-55-as for AT-1
(c) Common telesignals for TR-1 to TR-3 and AT1 to AT4
56. 110V dc supply for alarm circuits fail.
(d) For each feeder circuit breaker
(i) For feeder-1
(ii) For feeder CB-2
57. Feeder CB-1 DPR operated.
58. Feeder CB-1 instantaneous OCR operated.
59. Feeder CB-1 Delta-I relay operated.
60. Feeder CB-1 ―Locked out‖ due to low gas/air pressure
61. Auto-recloser for CB-1 ―Locked-out‖.
62 to 66-as for feeder CB-1
(iii) For feeder CB-3
67 to 71-as for feeder CB-1
(iv) For feeder CB-4
72 to 76-as for feeder CB-1
(c) For shunt capacitor bank control (as required)
(i) Bank-1
(ii) Bank-2
77. CB ―Lockedout‖ due to low gas/air pressure.
78. PT fuse fail
79. Shunt capacitor bank fail
80 to 82-as for bank-1
* The shunt capacitor bank may be provided with a potential free 11/0 contact
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which closes in case of my internal fault(s) in the shunt capacitor bank.
II. From each SP
1. 110V dc low..
2. 240V ac fail
3. Catenary-1 fail
4. Catenary-2 fail
5. Catenary-3 fail
6. Catebary-4 fail
7. AT-1 Alarm
8. AT-1 Fault
9. AT-2 Alarm
10. T-2 Fault
11. At-3 Alarm
12. AT-3 Fault
13. AT-4 Alarm
14. AT-4 Fault
15. CB.1 ―Locked out‖ due to low gas/air pressure.
16. CB.2 ―Locked out‖ due to low gas/air pressure.
For details of AT-1 to 4 Alarms and At-1 to 4 Faults, explanation given in clause No.
5.5.1.I.b (iv) may be seen.
III. From each SSP
1. 110V dc low
2. 240V ac fail
3. Catenary-1 fail (wherever required)
4. Catenary-2 fail (wherever required)
5. AT-1 Alarm
6. AT-1 Fault
7. AT-2 Alarm
8. AT-2 Fault
For details of AT-1 to 2 Alarms and At-1 to 2 Faults, explanation given in clause No.
5.5.1.I.b (iv) may be soon.
IV. From each ATP
1. AT-1 Alarm
2. AT-1 Fault
3. AT-2 Alarm
4. AT-2 Fault
5. 240V ac fail
6. 110V dc low
For details of AT-1 to 2 Alarms and At-1 to 2 Faults, explanation given in clause No.
5.5.1.I.b (iv) may be seen.
5.5.2 The protective relays viz. OCR, DPR and delta-I relay reset themselves
immediately after operation.
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5.5.3 Amongst the above tele-signals, the monitoring of ―dc low‖
Indications shall be through solid-state comparator circuits, while that of ―a.c. fail‖ and

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―PT fuse fail‖ indication through rectifier and no-volt relays, and that of ―catenary
supply‖ indications through rectifier and solid-state comparator circuits. Monitoring of
the balance indications shall be through 110V dc interposing relays. The rectifier,
comparator circuits, no-volt relays and interposing relays shall form part of the RTUs.
5.6 Tap-changer control of traction power transformers
5.6.1 The traction power transformer at s TSS may be provided with motor operated
off-circuit tap changer with 110V dc control circuit. For remote control of the tapchanger
from the RCC, progression/regression telecommand shall be provided. The tap
position shall be telesignalled to the RCC in confirmation of the telecommand.
5.6.2 The tap changer switch has six tap positions. For each tap position one NO
type contact is provided. At any tap position, only the corresponding NO contact will
remain closed and the remaining contacts will remain open.
5.6.3 Each telecommand for the tap changer shall include progression/regression
telecommand and the back telesignal from the TSS of the tap position.
5.7 The terminal required for interfacing the controlled station with RTU at TSS
shall be provided by the railways in the control and relay panel at TSS. The terminal at
SP/SSP/ATP shall be provided on a terminal board mounted on the wall inside the
masonry building at SP/SSP/ATP. The supply of cable and wiring between the control
and relay panel/terminal board and RTU shall be done by the successful tendered. The
cable shall conform to IS:1554.
5.8 Underground trunk cable
5.8.1 Underground telecommunication trunk cable is provided by the railway
alongside the railway track. Three part of conductors (one pair for ―Send‖, one pair for
―Receive‖ and third pair as spare) from this cable shall be made available for remote
control purposes.
5.8.2 The cable shall conform to railways specification No.TC-14/75. The salient
technical particulars of the star quads Of the cable circuits made available for remote
control operation are as under:
(a) Dia of copper conductor 0.9mm
(b) Type of insulation Paper
(c) Nominal loop resistance at 55.2 ohms/km
20 degree c.
(d) Resistance unbalance between Not more than 1%
Two conductors of a pair of nominal loop.
(e) Nominal mutual capacitance of 0.041 microfarad/km.
The pairs of paper insulated
VF quads
(f) Capacitance unbalance after
Balancing of full loading
section of 1.83km.
(i) Between pairs (same quad) Less than 40pF

(ii) Between pairs (adjacent quads) Less than 40pF Quads)
(g) Characteristic impedance of 1120 ohms
Paper insulated pairs at 300Hz
when loaded
(h) Insulation resistance when Not less than 10,000
measured at 500V meg. Ohms/km
(i) Loading at intervals of 33 milli Henries
1.33km
(j) Attenuation at 800Hz 0.25dB/km
when loaded
5.8.3 The characteristics of tapping, terminating and sectionalisting transformer
for voice frequency circuits are as under:
(a) Impedance ratio 1120:1120+2%
(b) Insertion loss from 300Hz Less than 0.9 dB
to 2500Hz
(c) Bridging loss with secondary Less than 0.015dB
open from 300Hz to 2500Hz
(d) Attenuation distortion from Less than +0.1dB
300Hz to 2500Hz
(e) Dielectric strength 2000V ac (rms) for
1 Minute
(f) Return loss in frequency More than 20 dB
range of 300 Hz to 2500 Hz
5.8.4 Isolating transformers will be installed at every 10 to 20 kms by the railways
to limit the induced voltage.
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5.8.5. Voice frequency repeaters will be provided by the Railways at intervals of
40 to 50 km to boost the signal level. The amplifier gain at the repeater station will be
about 20dB with an equaliser incorporated to compensate up to 0.02dB/kc/km. The
SCADA equipment shall, however, incorporate an amplifier having a minimum gain of
30 dB to compensate for any signal level variation at difficult points in the system.
5.8.6. The repeater section far and cross talk attenuation (equal level cross talk)
between any two voice frequency pairs at a frequency of 800Hz will be not less than
65dB and that at the near-end not less than 61dB.
5.8.7. The underground trunk cable being normally laid close to the railway track,
the lead from tapping transformers to the remote control or control building would be
small.

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5.8.8. The Railways will tap the main underground cable and terminate three pairs
(including one spare pair) of conductors on a terminal board at the RCC and at each
controlled station. At the point of tapping from the main underground trunk cable,
isolating transformer with impedance ratio of 1120/1120 ohms will be provided by the
Railways. Any other matching transformers considered necessary for satisfactory
operation of the SCADA equipment shall be provided by the successful tenderer.
5.8.9. Surge arrestor assemblies for protection of remote control equipment against
induced voltage in the telecommunication cable shall be provided on all the 3 pairs of
conductors at RCC as wail as at all the controlled stations by the successful tenderer.
5.8.10 The tendcrer shall carefully study and understand the specifications of the
to1ecommunication cable and associated equipments given above end confirm that the
SCADA equipment offered shall work satisfactorily. Any additional equipment/
accessories in the cable circuits required to ensure satisfactory working shall be provided
by the successful tendered.
5.9 Microwave communication
In. some of the sections on Indian railways dedicated Micro wave channel at
carrier frequency of 18 Ghz has been provided for the purpose of communication.
5.10 Optical fibre cable
Optical fiber cab1e is now being introduced for communication in acc of the
sections on Indian Railways. The interface between the optical fiber cable and the RTUs
to be supplied by the manufacturer shall b3 provided by the railways, The salient
technical particulars of optical fiber cable and optical line terminating equipment are as
under:
(I.) Optical fibre cable
a) The cable consists of six/eight mode fibres.
b) Mono mode fibre: As poor CCIET recommendation
No.G652.
c) Optimised wave length 1300nm +/— 0.25nm.
band
d) Nominal mode-field 0 to 10 micrometer +/—10%.
Diameter
e) Nominal cladding diameter 125 microns +/— 2.4%.

f) Cut—off wave length 1120 to 1280 nm
g) Attenuation Less than 0.5 dB/m at
1300mm band measured at
the worst wave length.
h) Total dispersion Less han7.0ps/nm/Icn
(Fibre 0ptimised for 1300nm
band)
i) Splicing loss including Less than 0.15 dB/joint.
splicing protection.
(II) Optical Line terminating equipment
(i) Electrical interfaces:—
a) Line bit rate 2048 kB/s.
b) Line code : HDB-3
c) Line Impedance 75ohms unbalanced or 120 ohm balanced
CCITT. Rec. G703
(ii) Optical interfaces: LED for transmission & SI-APD reception
a) Line Bit Rate 2048 kB/s
b) Line code CMI (Coded mark Inversion)
c) Modulation Im (Intensity modulation)
6.0 GENERAL DESIGN FEATURE OF THE SCADA SYSTEM
6.1 Master Station Equipment
6.1.1 Hardware configuration
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(i) There shall be dual main mini-computer(s) system, one main and
the other as hot standby, each system interfacing with its front and processor (s) and
modem (s) for communication with the RTU‘s and with the man machine interface
equipment to provide upto-date network data and to accept commands. Each system shall
have its own system console and hard and floppy disks along with their drives, and watch
dogs for monitoring the healthiness of the system.

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(ii) There shall be two data-logging printers one on-line and the other as
standby. Both the printers shall be connected to the same on-line computer system. In
case of one printer, the other printer shall automatically take over.
(iii) In case of failure of one computer system, the switchover to the other
computer system shall be through an automatic switchover system. However, provision
for manual changeover between the computers shall be provided by the manufacturer.
6.1.2 Man Machine Interface
6.1.2.1 Workstations
6.1.2.1.1 There shall be two work-stations, one for each of two operators, each
consisting of two semigraphic colour VDU‘s and their keyboards. The keyboard shall
contain both functional keys for operations that are repeated frequently, and alphanumeric
keys for inputting numerical data and text. The key-board shall be interactive
with the displays on the VDUs, which allows parameter changes and device control by
identification of the object to be addressed by device or position reference input or via the
function and alphanumeric keys, or by the positioning of a cursor. The interaction
between the operator and the computer to select displays, to between the operator and the
computer system to select displays, to give commands, and to input data for limits,
calculation parameters and other items shall be of a simple dialogue nature. Text, for
tagging or recording or sanctions. May be temporarily added to the displays when entered
via the keyboard.
6.1.2.1.2 Both the workstation shall be connected to the same online computer and
shall meet the following requirements:
(i) Each workstation shall normally control pre-defined, physically demarcated
sections.
(ii) In case of complete outage of one workstation, all its functions shall be
transferred to the healthy workstation so that normal operations continue.
(iii) Normally one VDU will be online and the other VDU as standby at each of
the workstations. However, if desired by the operator, it shall be possible to have online
both the VDUs for viewing station diagram for tele control purpose and the other VDU
for viewing alarms, on-demand trend curves, histograms and other data.
Note:- Two workstations as mentioned above are for controlling upto 30
RTUs. However, if the number of RTU‘s in the system are less than or equal to 15 then
only one workstation shall be provided. On the other hand, if the number of RTUs in the
system are more than 30, then for each 15(or less) additional RTUs one more workstation
shall be provided.

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6.1.2.2.4 Modes of operation
The modes of operation shall include the supervisory mode, control mode,
edit mode and programming mode.
6.1.2.1.4. Security
To ensure a high degree of system security and to prevent unauthorized
operations, the following levels of access shall be provide.
(i) Operator‘s level
This level is for interaction of the TPC with the computer for his
day-to –day working.
(ii) Supervisory level
This level is meant only for getting information from the computer.
Control operation of electric switchgear shall not be this level.
(iii) Programmer‘s level
This level is for compilation purposes only.
(iv) Engineer‘s levels
This level shall have total access to all the programmers stored in
the system and shall normally be retained by the manufacturer till specifically asked for
the railways.
6.1.2.1.5 The operators‘ console desk and separate stand(s) for VDUs (if any) shall
form part of the SCADA equipment.
6.1.2.2 VDUs
The size of VDUs at the operator‘s work-stations shall be a minimum of
48cm (19‖) diagonally. It shall support 8 foreground and 8 background colours, have
high resolution and provide a 80 columns X32 rows display. The character set shall
include full standard ASCII characters and user-generated symbols, so as to generate
tabular displays and semi-graphic displays of the traction power supply system.
6.1.2.3 Engineer’s workstation
A separate plug-in Engineers‘ workstation shall be provided incorporating a
QWERTY key Board including special function keys and special characters and cursor
control keys. Engineers‘ workstation shall include a 35 cm (14‘,) 80 columns x 32 rows
monochrome VDU with a console capable of housing all equipments. The console shall
be so designed that its installation in the equipment room is conveniently possible
through plugs and sockets. Unauthorised use of key boards shall be prevented by use of a
key lock switch and by entry of a security code.

6.1.3. Mimic diagram board (MDB)
- 17 -
6.1.3.1 A mimic diagram board and its associated mimic driver shall be provided
at the RCC. The MDB shall depict the traction power supply diagram, indicating the
energised/ de-energised condition of sub-sectors of catenary, status of interruptors and
feeder circuit breakers at TSS & FP, SSP and SP.
6.1.3.2 Since all control operations are to be carried out from the key board (s)
provided at the workstation (s), the MDB‘s sole purpose is to give an overall view of the
traction power supply system to the operator. In view of this limited function, the overall
size of the MDB shall be restricted to 3500mm x 750mm x 200mm for depicting 30
controlled stations.
6.1.3.3 Annunciation for controlled stations
For each controlled station an annunciation ―Remote station defective‖
shall be provided on the MDB using an LED.
6.1.3.4 Annunciations for master station equipment
The following annunciations by LEDs shall be provided the MDB:
i) Main system ON
ii) Stand by system ON
iii) Main system defective
iv) Stand by system defective
v) Main UPS sail
vi) Stand by UPS fail
vii) UPS battery low: This shall show up when the UPS
battery voltage falls below 90% of the nominal voltage.
Necessary relays/circuits for this purpose shall form part
of the contract.
viii) 415 V 3-phase ac to UPS fail
6.1.3.5 Other facilities on the MDB
The following facilities shall be provided on the MDB:

- 18 -
i) Alarm indication pilot LED: A yellow alarm indication LED of
10mm diameter shall be provided for each remote station. The LED shall light up when
any alarm is received from the RTU.
ii) A LEDs test push button(s) shall be provided to test the healthiness
of LEDs on the MDB. Alternatively, the tender may carry out this function by software
programme to be initiated from the workstation.
6.1.3.6. No standby is required for the mimic drivers. Now ever, the arrangement
shall be such that failure of any module shall not affect more than one RTU display on
the MDB. However, there is no necessity to provide individual CPU for each controlled
station on the MDB. The renderer may offer a system in which one CPU designated as
―main‖ controls a maximum of ten stations along with its ―stand by ― CPU which shall
take over functions automatically in the event of failure of main CPU.
6.1.4 General requirements of Software
6.1.4.1 The operating system used shall be suitable for multi-user, multi-tasking,
networking and real time applications.
6.1.4.2 The software shall include compilers for high level languages viz.
FORTRAN, BASIC and COBOL.
6.1.4.3 The software shall support local area network facility.
6.1.4.4 SCADA software
6.1.4.4.1 The system shall be modular in structure and user friendly.
6.1.4.4.2 VDU displays
The software shall support the following VDU displays.
(i) Station diagrams:
(a) Semigraphic, coloured displays of any three adjacent controlled
stations shall be provided. The display shall include both fixed and variable data, namely
ON/OFF status of equipments, catenaries, alarms, measurands and names of the
controlled stations.
(b) Symbols: The symbols for various equipments shall be as per
international standard.
(c) The display shall permit transmission of telecommands to circuit
breakers, interruptors and other equipments, by simple key-board operations by the
operator. Facility for marking (manual input) shall be provided for any alarms,

equipments status including manually operated isolators, measurands and limit-settings,
by simple key-board operations by the operator.
(ii) Tabular displays: Tabular display of data of a controlled station
shall be provided. The data shall include equipment status, alarms and measurands.
- 19 -
(iii) Alarm list: Display of the alarm list in a chronological order
starting from any given time shall be provided. It shall include both current and historical
alarm list. The current alarm list shall have 400 entries.
(iv) Event list: Display of the event list, which includes commanded
and uncommanded changes in equipment status, starting from any given time shall be
provided. It shall include both current and historical event list. The current event list shall
have 400 entries.
(v) System clarms: The alarms generated by the SCADA equipment,
and not by the traction power supply system, shall be displayed here.
(vi) Trend diagrams: The time version value plot of upto four
measurands shall be displayed in a trend diagram. Each measurand shall be displayed in a
separate colour. The trending shall include both historical trending and dynamic trending
of the current data.
(viii) Histograms: For both current and historical data the time versus
value plot of any measurand by histogram shall be provided.
(viiii) Bargraphs: Display of the current values of upto four measurands
by bargraphs-each bar having a different colour-shall be provided.
(ix) Message pad: One page shall be provided for the operator to record
important messages.
Calling any of the VDU displays shall be by simple keyboard
operations by the operator. NEXT/PREVIOUS or PAGE UP/DOWN option shall be
made available.
6.1.4.4.3 Update, process and alarm inhibit, equipment and RTU block/deblock and
portability and upgradability feature
(i) The software for the SCADA equipment shall be designed to cater
for updating for adding or deleting controlled stations or individual parameters such as
telecommand, telesignal or measurand at any of the existing controlled stations. The
method employed to achieve this feature shall be clearly explained by the tenderer in his
offer. The system shall be supplied alongwith high level language compiler (s) to enable

an authorized person without any previous knowledge of programming language to carry
out the necessary amendments.
(ii) Facilities shall be provided for the operator, through simple
keyboard commands to:
-take out of scan and control (process inhibit) any alarm
point/control point/measured or a complete RTU.
- 20 -
-block/de-block a complete RTU as well as any control point
(circuit breaker, interruptor and other equipments at the controlled station) which
disables/enables control operations from the RCC. The blocked condition of any
equipment shall be suitably indicated on the VDU, for example by a change in colour of
the corresponding equipment display.
-inhibit any alarm point which shall discontinue processing of the
alarm point at the RCC.
(iii) The software shall be designed for maximum portability and
upgradability, so that it is generally machine independent and upgradable to meet with
the developments in the computer hardware/technology.
6.1.4.4.4 The software should support BROADCAST control, i.e. sequential
commands to a group of equipments like circuit breakers, interruptors.
6.1.4.4.5 Transmission and coding system
The master station equipment shall normally scan continuosly all the
RTUs in a pre-defined cyclic sequence, to update the equipment status, alarms, events
and measurands. Exchange of information between the master station and the RTUs shall
be on interrogation by the master followed by the reply from the RTU. The
communication technique shall be based on Digital Address Time Division Multiplexing.
Every data-exchange shall be based on a well defined transmission protocol based on
International Standard for data transmission. Each transmitted information shall contain
sufficient parity check bits so as to allow an effective error detection code to detect
different combination of transmission errors. The error checking system shall have a
minimum Hamming distance of four i.e. all three bit errors shall be detected one hundred
percent.
6.1.4.4.6 Communication pr optical
The communication protocol employed in the system, including transmission security
and computation of reliability factor, shall be clearly explained in the offer. The tenderer

shall confirm in the offer that the protocol employed will not allow false indications and
invalid transmissions.
6.1.4.4.7 Issue/cancellation of power Block
- 21 -
(i) Power block is generally given for maintenance of any equipment
like transformer, circuit breaker, interruptor, section of OHE or any other equipment by
de-energising the equipment/section of OHE. Provision shall be made for entering into
the computer necessary private numbers and messaged exchanged between the field staff
at site and the operator at RCC in connection with the requisition for issue/cancellation of
the power block and the time duration for which the power block is given. If a power
block is not cancelled at the end of the permitted duration, a message ―Power Block Time
exceeded‖ shall appear on the VDU along with the equipment/section reference and time,
with an audible alarm to attract the attention of the operator.
(ii) When an equipment is under power block, it shall not be possible
to operate that equipment unless the power block is first cancelled from the RCC. In
case the telecommand for operating that equipment is attempted, a message "Equipment
under power block" shall appear on the VDU.
6.1.4.4.8 Indication for complementary faults
The status of any bi-state device like circuit breaker, interruptor is
monitored through two auxiliary contacts of the device, the status (open/ close) of the two
contacts being normally complement(opposite) of each other, in the ON/ OFF condition
of the device. However, when both the auxiliary contacts are either in open or in closed
condition, such faults shall be detected and identified as complementary faults. The event
shall be logged and suitable indication shall appear on the MDB and VDU.
6.1.4.4.9. Alarm processing
(i) Any and every change in the state of telesignals, uncommended
change in the status of equipments like circuit breaker, interruptors, and limit violation of
telemetered parameters (measurands) shall he processed as alarms.
(ii) Each and every alarm shall attract the attention of the operator by
an audible hooter and by a change in this display of the equipment status or change in
colour of display of the telemetered parameter or change in colour of display of the alarm
(telesignals) point as applicable, and the display shall start blinking (flashing). Upon
acknowledgement by the operator, the audible, alarm shall cease and the display on VDU
become steady.
(iii) Each and every alarm that appears on any VDU display, operation.

6.1.4.4.10 Historical data storage
- 22 -
(a) The SCADA equipment at RCC shall be designed to cater for historical data
storage of the traction power supply system data for a period of one year. This shall
include:
(i) All alarms/events/measurands of the controlled stations and all
system alarms.
(ii) Day-wise storage of average feeder current and voltage during the
day, maximum demand, maximum and minimum feeder voltage, total number of
operations of feeder protective relays viz OCR, DPR and WPC relays, and maximum and
minimum OHE voltage at SP on both sides of the neutral section or phase break.
A memory capacity of 80 MB shall be provided for this purpose in the hard
disk. This required memory shall be capable of being expanded a required later. The
tendrer shall indicate the details for this feature in this offer.
(b) A facility shall be provided for accessing any data from the SCADA database
from any other remote computer terminal/ RCC or from a centralised computer
located at the zonal railway headquarters.
6.1.5 UPS and batteries at RCC
The tenderer shall quote for dual stand alone UPS systems of adequate
capacity for supplying stabilised 240V ac, 50 Hz, single phase supply to various
equipments of the SCADA system at master station. Input supply to the UPSs shall be at
415V ac, 50 Hz, 3 phase with a permissible variation between +10 and -15% for the
voltage and +3% and -3% for the frequency. Both the UPSs shall work in parallel to
share the load of the system. However, the capacity (VA rating) of each UPS shall be
designed to meet with the entire load of the system in the eventuality of the failure of the
other. The taking over the load by the healthy UPS shall be automatic without effecting
the normal working of the system. The failed UPS shall also disconnect it form the circuit
automatically. The UPSs shall provide for trickle/normal/boost/auto charging of the
battery in addition to supplying normal load to the various equipments. The UPS shall
conform to relevant international standard and be suitable for operation with computerbased
equipment. Alarm and mimic facilities shall be provided on the facia of the UPS
for ease of operation and maintenance. The acoustic noise level generated by UPS shall
be as low as possible and shall not be exceed 50 dB when working alone.
A single set of storage battery of Nickel-Cadmium type shall be provided with
both the UPSs. The battery shall have adequate Ah capacity to provide two hours of
supply to various equipments in case of failure of input 415V a.c. supply.

6.1.6 Data-logging printers
- 23 -
6.1.6.1 Two alphanumeric dot-matrix printers with a printing speed or 189
characters per second shall be provided. The printer shall have 132 columns with facility
for friction roller and tractor paper feed. It shall be robust and noiseless.
6.16.2 Data-logging
a) Alarm/Event logging
Logging shall be done of the following:
All events such as signals and alarms, commanded and uncommanded
changes and limit violations of telemetered parameters shall be printed automatically by
the data-logger with date (year, month and day) and time of occurance (hours, minutes,
seconds and milli-seconds) stamp.
b) Diagnostics
The system shall provide diagnostic checks for faults in
(i) The SCADA equipment at the RCC,
(ii) In the communication lines and
(iii) at the controlled stations
These faults shall be printed out with details such as name of controlled
station, card number with date and time stamp.
c) On-demand facility
The facility shall be provided for the operator to obtain reports on-demand
through the keyboard. Such reports may include current status of bistate devices, signals
and alarms at the remote stations, communication failures, telemetry printout and other
information required.
d) Periodic printouts
The dataloggar shall give periodic printouts, whenever required by the
operator, as under:
(i) 15/30 minutes printout giving average values of all the analogue
parameters at TSSs and SPs during the last 15/30 minute period.

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(ii) 8 hourly printouts giving summary of all important events that
occurred during the immediately proceeding 8 hours. It shall be possible to alter the
format of such printouts from time to time based on changed requirements.
Events that occurred during the periods when the datalogger is printing
‗periodic‘ or ‗on-demand‘ reports shall not be lost but printed out thereafter with their
time of occurrence stamp.
6.2 Remote Terminal Unit (RTU)
6.2.1 Hardware
The RTU shall be microprocessor based. It shall include its associated
digital input/output modules, alarm input modules, analogue Input modules, watchdog
transducers, memory, modems, interposing contactors, summation current transformers,
power supply unit(s) and surge arresters and other items necessary for its proper
functioning. A suitably designed circuit for giving initialization pulse to the CPU at
predefined interval of time, which itself shall be user selectable, shall also be provided in
the RTU, so that the CPU gets initialized automatically in case it halts due to any reason.
6.2.2 Reporting of events and alarms
(i) All the changes (one or more) in the status of the circuit breakers*
interruptors/motor-operated isolators and alarms that may occur between consecutive
pollings shall be stored by the RTU until the are reported to the master station along with
their time of occurrence. In other words, no event shall be lost without being reported to
the master station. This feature is essential in view of the fact that the normal polling may
get suspended due to failure of communication channel or other reasons.
(ii) The storage capacity, in terms of number of events and alarms that
the RTU can store, shall be clearly indicated in the offer.
6.2.3 Power Supply Units
6.2.3.1 The RTU shall normally operate off 240 V a.c., 50 Hz, single phase supply
from the auxiliary transformer provided at the controlled station. This voltage may vary
from 180V to 265V due to variation in the catenary voltage(25kV). In case of failure of
a.c. supply, the RTU shall operate off the 110V battery. The load of the RTU shall be as
low as possible and in any case shall not exceed 1 Amp at 110V d.c. power supply units
required for conversion from the ac/dc supply to any other internally required voltages
shall form part of the RTU.

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6.2.3.2 The ac supply will have voltage surges and spikes due to the switching
ON/OFF of the traction loads. Hence the power supply units shall include suitable surge
suppressors to effectively suppress the voltage surges, spikes and the electrical noise in
the incoming a.c. supply.
6.2.4 Parameters to telemetered/computed (measurands)
6.2.4.1 The RTUs shall be designed to telemetere two feeder currents and two OHE
voltages from each TSS, and two OHE voltages from each SP. The arrangement for
telemetry shall be as under:
(a) From TSS
i) Feeder currents: Two current transducers shall be provided, one
each for either side of the TSS, taking reference from the two feeder CTs of that side
through a summation CT. The summation CTs shall form part of the RTU.
ii) Feeder voltages: Two voltage transducers shall be provided, one
each for either side of the TSS, taking reference from the two OHE PTs of that side
through a suitable change-over device. In the event of supply failure in any of the PTs,
The change-over device shall automatically connect the live PT to the transducer. The
change-over devices shall form part of the RTU.
b) From SP
Voltage of the OHE on either side: Two voltage transducers shall be
provided, taking reference either from the UP or DOWN line PT through a suitable
change-over device which shall form part of the RTU.
6.2.5 Transducers
6.2.5.1 Transducers provided at the controlled stations (TTS and SP) shall be
Auxiliary-powered and of quick response type with a response time not greater than 1
second. They shall have linear characteristic over the entire range with accuracy of +/-
0.5%. Transducers shall give an output proportional to the input from current
transformers and potential transformers at the TSS and at the SP as the case may be.
6.2.5.2 The salient features of CTs and PTs provided at the TTS. SSPs, SPs are at
Annuxure-3.

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6.2.5.3 The voltage at TSS and SP may rise to 30kV for short durations and the
apparent power of the traction power transformer may go upto 200% for 5 minutes
intermittently.
6.2.5.4 Current transducers shall be rated for a 100% overload for 5 minutes and
short time current rating of 50 Amps for 5 second. The burden of voltage and current
shall not normally be more than 4 VA.
6.2.5.5 Since the current transducers shell be connected in series with the
operating coils of protective relays, it is, therefore, essential that loose connections or
open circuiting shall be avoided so as to prevent damage to the CTs and render the
protective system at the TSS ineffective. It shall, therefore, be ensured that:
i) The transducer case is so designed that the current coil terminals
are automatically short circuited in case the transducer is taken out. Labels shall be
provided to notify this aspect prominently.
ii) All terminal connections are rigid.
iii) Wiring to the current coil of transducer is done with PVC insulated
copper cable of cross section not less than 4 sq mm.
6.3 System alarms
The system alarm that shall be provided include at least:
i) Remote station defective
In the event of partial or complete failure of the RTU to communicate with the
master station due to failure of RTU, or on failure of individual I/O modules and other
modules in the RTU, this alarm shall appear. The exact nature of fault shall be indicated
on the VDU.
ii) Master Station defective
In the event of failure of any equipment at master station such as modem,
CPU, bus driver, computer, mimic driving modules or any other items, this alarm shall
appear. The exact nature of fault shall be indicated by LEDs on an indication panel or the
individual module inside the equipment cabinet.
iii) MDB panel fuse fail
In the event of failure of the fuse provided inside the mimic panel for
controlling the supply to various indication lamps/LEDs on the MDB, this shall appear.

6.4 Equipment capacity
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6.4.1 Number of controlled stations
The number of controlled stations to be commissioned initially is indicated
in the particular specification referred to in clauses 10 beroof. However, the SCADA
equipment at RCC shall be designed and engineered to control about 120% of the number
of stations to be commissioned initially. The extra capacity shall be available for
expanding the system in future. It shall be possible to realize the extra capacity simply by
adding the required functional modules in the spare sub racks of the mimic driver and
incorporating. Necessary changes in the software and MDB at RCC, without affecting the
existing system either physically or operationally.
6.4.2 Number of telecommands, telesignals and telemetered parameters
(measurands)
6.4.2.1 The SCADA equipment shall be designed for the following capacity of
telecommands, telesignals and telemetered parameters for a typical TSS, SSP, SP and
ATP of a double line section.
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
S. No. Controlled Telecommands Telesignals Measurands
station
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
1 TSS 24* 88 8
2 SP 8* 20 4
3 SSP 8 12 -
4 ATP - 8 -
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
* No of telecommands for faultlocator is not included, it is to be added where applicable.
6.4.2.2 The above figures may vary depending on the layout of TSS, SP, SSP and
ATP in a particular section, which could have three or more tracks, the details of which
will be contained in the particular specification referred to in clause-10 hereof.
6.4.2.3 The number of parameters to be commissioned initially may be less than the
above figures and the balance designed capacity shall be available for future use. A
typical requirement of telecommands, telesignals and telemetered parameters on a double
line section is at Annexure-I.

6.4.2.4 In order to cater for the above requirements the SCADA equipment shall be
designed such that:
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(i) (a) The equipment at the various controlled stations is complete in all
respects for the total number of telecommands, telesignals and telemetered parameters to
be utilised initially.
(b) For the balance designed capacity of these parameters, the
equipment is complete in all respects except for the provision of realisable simply by
inserting the interposing contactors/relays/transducers in position as and when required.
For this purpose the wiring shall be terminated at the exact location where the
contactor/relay/transducer is to be provided, in suitable relay bases/terminal blocks.
(ii) The equipment at the RCC shall be designed, engineered and wired
for the designed capacity of telecommands, telesignals and measurands such that the
balance designed capacity can be embedded in the software by making necessary
modification and by inserting necessarily input/output modules in the sub-rack of the
mimic driver.
6.4.2.5 Each telecommand shall include transmission of both ―ON‖ and ―OFF‖
control commands for a circuit breaker/interruptor/motor operated isolator or any other
bi-state device and shall also include corresponding ―ON‖ and ―OFF‖ status telesignals of
the device concerned, confirming execution of the telecommand at the controlled station.
6.4.2.6 The number of telesignals stipulated for each controlled station shall be for
the exclusive use of the railways and shall not include telesignals required for reporting
defects in the RTU.
6.4 Speed of transmission and update time
6.5.1 The communication between the master station and the RTUs shall be at a
suitable transmission speed not exceeding 600 baud, in the case of the trunk cable
specified in clause-5.8 hereof. The normal polling time for updating of status, alarms and
measurands for the designed capacity of controlled stations and for the design capacity of
telecommands, telesignals and measurands shall be not more than 4 seconds for 20
controlled stations and not more than 6 seconds for 30 or more controlled stations.

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6.5.2 Whenever the number of controlled stations is more than 30 and the RCC
is located somewhere in the middle of the section, the controlled stations on one side of
the RCC shall be polled simultaneously in parallel with the controlled stations on the
other side RCC, so that the cyclic update time is kept to the barest minimum. The master
station equipment configuration shall be suitable for such simultaneous polling.
6.6 Priority of data exchange between master station and RTUs
While the master station shall normally be polling the RTUs cyclically, the
telecommands shall receive the highest priority. The normal polling shall get interrupted
for sending the telecommand and for receiving the telesignal from the RTU for change of
status resulting from execution of telecommand before normal polling restarts.
6.7 Priority of data exchange between RTUs and Master Station
During polling, the RTU shall transmit data to the master station in the
order of importance. Any tripping of feeder circuit breaker on fault (relay operation) shall
get the highest priority.
6.8 Modems
(i) The modems provided for communication between the master
station and the RTUs shall utilize frequency shift keying (FSK) modulation and include.
Receive and timing functions. The send and receive functions shall be independently
programmed as required. The modem shall work satisfactorily up to an input signal level
of -45dbm. It shall also perform a watch dog role and turn the transmitter off in the event
of any fault occurring within the equipment.
(ii) The modem shall also incorporate necessary amplifiers having a
minimum gain of 30 db to compensate for any signal variation at different point of the
system. Suitable attenuation pads shall be provided within the amplifiers to adjust the
level through trimpot/rotary switch. It shall have an output signal level adjustment
between 0 and 30 dbm in steps of 1 dbm.
(iii) A test switch on the modem shall allow a square wave data pattern
to be transmitted continuously at maximum band rate to allow receiver levels and bias
distortion to be set.

6.9 Construction of the SCADA equipment
6.9.1 The word ―equipment‖ in this clause refers to both master station
equipment and RTUs.
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6.9.2 The equipment shall be housed in dust and vermin proof steel cabinets
with doors in the front and rear. The doors shall have proper looking arrangement. The
cabinets shall have facility for bottom entry of incoming/outgoing cables for operation of
the equipment. The steel sheet used for making the cabinets shall be of thickness not less
than 1.6mm and shall be reinforced wherever required. The sheet steel as well as other
iron/steel work shall be properly treated and then applied an under-coat suitable to serve
as base and binder for the finishing coat. The exterior and interior surfaces and the base
frame of the cabinets shall be epoxy power coated in shade to be mutually decided later
between the supplier and the purchaser.
6.9.2.1 The dimensions of the RTU cabinets at TSS and SP/SSP shall not exceed
1750 mm x 800 mm x 650 mm and 1450 mm x 800 mm x 650 mm respectively. At ATP
the RTU cabinet shall preferably be wall mounted type. Every endeavour shall be made
by the manufacturer to offer as small a cabinet as possible. It may be noted that all the
SCADA equipment at RTUs shall be housed inside the cabinet. Provision of subcabinet(s)
and/or wall mounted relay/transducer cabinet(s) shall not be permitted.
6.9.3 Integrated circuits (ICs) shall be used to the maximum extent and discrete
components avoided. All semi-conductor components including TCs shall be burnt in
accordance with relevant specification to minimize infant mortality failures. Use of
potentiometers and electro-mechanical devices like relays shall be kept to the absolute
minimum. The number of makes and type of components used shall also be kept to the
minimum. The components shall be from reputed manufacturer, of best quality and wallproved
in services.
6.9.4 The manufacture of the equipment shall be based on modern practice with
up-to-date technique in order to achieve a robust, versatile and economical construction.
The entire equipment shall be so designed that components/parts of similar equipment
shall be conveniently interchangeable. The entire equipment shall be divided and wired
up in easily removable compact units to facilitate quick attention or replacement by
similar units, without necessitating any soldering or similar messy process. Modular type
of construction shall be adopted to facilitate unit replacement of devices where required.
The solid state components shall be laid out, assembled and arranged in form of printed
cards. Standard plug-in and connector arrangement shall be made for the printed cards so
that contacts and good and firm and arc not affected due to vibrations. Facility of guide

- 31 -
channels and other such aids shall also be incorporated liberally to ensure that printed
cards are properly inserted. The printed circuit cards shall be assembled vertically in
standard 40cm (19‖) sub-racks which are fixed on the main frame of the cabinets.
Suitable check points/diagnostic indications shall be provided on the card for monitoring
its healthiness.
6. 9.5 All the sub-systems and system including modules shall be burnt in for at
least 72 hours at the works of the manufacturer to prove the quality and workmanship.
6.9.6 Suitable labels of approved design shall be provided on all the equipment.
These labels shall contain information related to identification of the equipment and
safety instruction if any.
6.9.7 The equipment and the circuitry shall be such as to provide affective
means to check for correct generation, transmission as well as reception of all signals and
that failure due to internal defects of the equipment or to external disturbances on
transmission circuits shall not cause mal-operation.
6.9.8 The equipment shall be designed and mounted in such a manner that
inspection, cleaning, testing, repairs and renewals, if any, can be carried out conveniently
and expeditiously. Facility for expedition checking of operation of equipment under
working condition shall be provided.
6.9.9 The equipment shall be wired with PVC insulated copper conductors of
adequate size, screened wherever necessary. All wiring shall be suitably colour coded for
easy identification. The bunches of wires shall be neatly dressed and cleated/supported
suitably. Separate wire bunches shall be run for AC & DC power circuits, control and
signal circuits.
6.9.10 All soldering shall be done with good quality solder at proper temperature
to avoid dry soldering.
6.9.11 All the cables which are laid in the cable trenches for the purpose of
interconnecting various equipment shall be rodent proof.
6.9.12 Each type of input/output module employed in the equipment shall be
designed for handling not more than 8 telecomands, 16 status inputs (5 ON+8 OFF), 16
telesignals/alarms or 8 measurands.

- 32 -
6.9.13 All the equipments viz. computer, VDUs, key-boards, date logging
printers etc. and components used in the SCADA system shall be of industrial grade. A
certificate to this effect shall be furnished by the tederer.
6.9.14 The micro-computers used, If any, shall be IBM compatible.
6.9.15 The mimic-driver cabinets and the layout of the traction power supply
diagrams on the MDB shall be so designed as to convert any SP to TSS, if required, by
simply adding the required modules in the mimic driver and making minimum changes in
the MDB.
6.9.16 Construction of MDB
(i) The MDB shall normally be not more than 3.5 m in length for 30
controlled stations, 0.75 m in height and 0.2 m in width, and shall be desk-top/pedestal
mounted close to the operator.
(ii) The MDB shall be made of steel of thickness of 1.6 mm, reinforced
wherever necessary. To prevent corrosion the steel work shall be properly treated and
then given a primary coat of zinc chromate, both on the interior and exterior surfaces
followed by two coats of finishing enamel paint. The inner side shall be finished with
stoved enamel white paint. The external surface shall be finished with stoved enamel
paint of opaline green shade number 275 as per IS:5 or any other colour decided by the
railways, evenly sprayed to present a smooth and pleasing appearance.
(iii) Mimic display of catenary shall be by means of LEDs and metal strips. The
tederer may however offer any other state-of-the-art technique for consideration as an
alternative offer.
(iv) Each circuit breaker & interruptor shall be depicted with the help of a 3
legged LED on the MDB. The LED shall emit red/green colour to indicate
CLOSE/OPEN status respectively. The complementary fault shall be indicated by yellow
colour or dark state of the LED.
(v) Whenever any of the sub-sectors of OHE gets de-energised, the
corresponding portion shall be lit up and start flashing until acknowledged by the
operator.
(vi) The scheme of connections, identification numbers for circuit breakers,
interruptors and motor operated isolators, if any, and other indications on the MDB shall

e so engineered that they are clearly and distinctly visible from a distance of four
meters.
- 33 -
(vii) The MDB shall be wired with PVC insulated copper conductors of adequate
size, screened wherever necessary. All wiring shall be suitably colour coded for easy
identification, neatly arranged and adequately supported. The wiring shall be kept to the
barest minimum and undue losses therein avoided.
6.10 Fuses & Fuse holders
The fuses and holders used for various circuits at the RCC as well as at the
controlled stations shall be of approved quality non-deteriorating cartridge type.
Rewirable type fuses shall not be used unless specific prior approval has been obtained
form the purchaser.
6.11 Cables
Cables of different colours shall be used ac and dc supplies of various
voltage at the RCC as well as at the controlled stations for easy identifications. The 240
V ac cable shall be routed separately for easy identification by the maintenance staff .
Caution plated should also be provided near the terminal connections.
6.12 Special requirements of SCADA equipment
6.12.1 Tripping of bridging circuit breakers on undervoltage at SP
i) Instantaneous type under voltage circuits shall be provided at the SPs,
operated off 27500/110V potential transformers and designed to trip the bridging circuit
breakers if the catenary voltage drops below a preset limit. The operating range for the
circuit shall be adjustable between 15,000V and 20,000V continuously, in steps of
1,000V.
ii) The arrangement shall be such that the bridging circuit breakers can be
closed only when the section on one side of neutral section is dead and the undervoltage
circuit shall become operative only after the bridging circuit breakers is closed.
6.12.2 Interlock release-request facility for circuit breakers/interruptors
control at boundary post

- 34 -
When a controlled station separates the zones controlled by two adjacent
RCCs, control of breakers/interruptors at this controlled station shall be so arranged that
the breakers/interruptors can be operated from one RCC only when an interlock is
released from the other RCC.
6.12.3 Auto reclosing scheme for feeder circuit breaking at TSS
(i) In case of tripping of the feeder circuit breaker on fault at TSS, a
single-shot auto-reclosing scheme recloses that breaker automatically only once, after a
pre-set time delay.
(ii) In the event of any fault on OHE persisting, the feeder circuit
breaker trips again and the auto-reclosing scheme gets automatically ― locked-out ‖ to
prevent reclosing of the breaker a second time. The locked-out condition shall be
telesignalled to RCC. The ―locked-out‖ condition shall be released by the operator when
a telecommand is initiated through the key board console.
(iv) Drawing No.ETI/FSI/0231-1, at appendix-5, indicates the autoreclosing
scheme. While the relays of the auto-reclosing scheme are provided be the
Railways along with other protective relays panel at TSS. The wiring between
autoreclosing scheme and SCADA equipment at TSS shall be supplied and installed by
the successful tederer.
6.12.4 Automatic localisation of OHE faults
6.12.4..1 This feature of automatic fault localization of OHE faults by the SCADA
system is required in cases where the fault locators described in clause 6.12.5 are not
provided.
6.12.4.2 The system shall be designed for automatic localisation of faults in OHE,
segregation of faulty sub-sector/broken sub-sector and restoration of 25 kV power to
healthy sections of OHE, through a suitable software package incorporated in the
SCADA system. The fault localisation process shall be initiated by the operator through
the key board console.
6.12.4.3 In general, the fault localisation process shall employ the technique of
energising all the sub-sectors/broken sub-sectors that were live prior to the fault one after
the other until it identifies the faulty sub-sector/broken sub-sector by the tripping of the
feeder circuit breaker.

6.12.4.4 The system shall also take following into account while localising the fault
automatically:
- 35 -
(i) Power block(s) imposed on an interruptor:
Whenever power block is imposed on any interruptor, no further control
on that interruptor shall be possible from the master station. For the purpose
of fault localisation, such interruptors shall be assumed as ―open‖.
(ii) Discontinuity caused in any sub-sector due to imposition of power
block on an elementary section of that sub-sector.
6.12.4.5 The software adopted for the fault localisation and isolation process shall:
(i) Take into account the inputs entered by the operator as described
above.
(ii) Ensure that no interruptor that was open prior to the occurrance of
fault by is closed during the fault localization process.
(iii) Segregate the fault by opening minimum number of interruptors.
6.12.5 AT Neutral current ratio type fault Locator.
6.12.5 A special equipment, called AT neutral current ratio type fault locator
(hereinafter referred to as fault locator), may be provided by Railways at the Traction
Sub-stations, Switching Stations (SSP/SP) and at Auto Transformer Posts (ATPs) for
locating catenary/feeder to earth fault on the OHE. The term ― Neutral current ‖ refers to
the current that flows in the connections between the midpoints of the auto-transformers
(ATs)/secondary winding of traction transformer and earth. For the descriptions which
follow reference may be made to the relevant diagrams in Appendix 6.
6.12.5.2 Principle of working of fault locator:
6.12.5.2.1 Measurement of neutral currents.
Whenever a catenary/feeder to earth fault occurs on the OHE, the
corresponding feeder protective relay(s) operates causing the master trip relay to operate
and trip the concerned feeder circuit breaker. One contact of the master trip relay is used
for sending a trip signal to the feeder circuit breaker while another contact is used for
sending an initiate‘ command to the fault locator at the TSS. On receipt of the initiate

- 36 -
command, the fault locator at the TSS starts measuring the neutral current of the autotransformers/traction
power transformer at the TSS, and sends a ―Fault Start‖ signal to
the other fault locators at the switching stations/ATPs upto and including the SP In case
of normal feeding condition, and upto and including the adjacent TSS in case of extended
feeding condition through the telecommunication cable. On receipt of the fault-start
signal, the fault locators start measuring the neutral currents of the auto-transformers. The
measurement takes about 40 ms from the instant the master trip relay at the TSS has
operated. The neutral currents measured are stored in the fault locators in Binary Coded
Decimal (BCD) form in two digits (8 bits).
6.12.5.2.2 Transmission of neutral currents data to RCC.
After a neutral current measurement, the fault locator transmits a ―RTUstart‖
signal to the remote terminal unit (RTU) by closing a normally open contact. On
receipt of the RTU-start signal, the RTU will receive and store the neutral current data
(which is in 11 bits-8 bits for neutral current and 3 bits for AT number) and send a ‗Reset‘
signal to the fault locator to re-set the fault locator for further operation. The neutral
current data so received shall be transmitted to the master station equipment by the RTU
during the normal scanning.
6.12.5.2.3 Calculation of the kilometerage of the fault point.
After receiving the neutral current data from all the RTU‘s in the zone fed
by the feeder circuit breaker which tripped under fault, the kilometerage of the fault point
shall be calculated by the master station equipment in accordance with the procedure
given below:-
(i) Pick up the two neighbouring auto-transformers which recorded the highest
and second highest neutral currents.
(ii) Calculate the kilometerage of the fault point by using the following
equation:
Ln+1 – Ln In+1
L = Ln+ x (100 x - Q1)
100-Q1-Q2 In + In+1

where,
Ln, Ln+l = kilometerage of the ATs which recorded the highest/second highest
neutral currents.
In, In+1 = The neutral currents recorded by the ATs at the location Ln, Ln+1
respectively.
Q1, Q2 = Constants for the ATs concerned (varying between 5 and 15).
L = kilometerage of the fault point.
- 37 -
6.12.5.2.4 After calculating the kiloneterage of the fault point, a suitable message
shall appear on the VDU, giving the kilometerage of the fault point, TSS/SSP/SP/ATPs
concerned. The massage shall also be printed by the data-logger.
6.12.5.2.5 For the purpose of calculating the kilometerage of the fault point, the
master station equipment shall have the kilometerage of the ATs and the constants for all
the ATs required for the calculation stored in the data-base of the SCADA software. It
shall be possible to store two different kilometerage for an AT (i.e. one kilometerage for
each of the two directions) to cater for situations where the reference point for the
kilometerage may change the kilometerage/constants in the data-base by simple
operations by the operator as and when necessary.
6.12.5.3 Number of neutral currants at TSS/SP/SSP/ATP.
The interfacing between the fault locator and the RTU shall be for two
neutral currents in case of a TSS/SP (one neutral current for each of the two directions),
and one neutral current in case of a SSP/ATP. However, where a TSS feeds only one
direction, the interfacing at the TSS is required only for one neutral current.
6.12.5.4 Call-start tele-command for TSS
Provision exists in the fault locator at the TSS for checking the functioning
of the fault locators by sending a ―Call-start‖ signal to he fault locator at the TSS. For this
purpose two call-start tele-commands shall be provided in the SCADA system for each
TSS, one tele-command for each of the two directions from the TSS. However, where a
TSS feeds only in one direction, only one call-start tele-command is required.
6.12.5.5 Feed extend/Food normal tele-command for SP.
Whenever feed is extended from one TSS to the adjacent TSS, it is
necessary to send a ‗feed-extend‘ tele-command‘ to the fault locator at the SP between
the two TSSs. Similarly, whenever the feed is restored to the normal condition, it is
necessary to send a ‗feed-normal‘ tele-command to the fault locator at the SP. For this
purpose two tele-commands shall be provided shall be provided in the SCADA system

- 38 -
for each SP one tele-command will make a potential-free normally open contact in the
RTU ―Closed‖(for extended feed condition), the other tele-command will make the
normally open contact ―Open‖ (For normal feed condition).
6.12.5.6 Strong and VDU display of neutral currents.
Whenever neutral currents are received at the master station from the
RTUs in the feeding zone of a TSS, the neutral currents data shall be stored in memory.
The SCADA software shall support VDU display of the neutral current in the tabular
form to indicate date/time, dispatch station, data received and neutral current value. It
shall be possible to have a print out of the same on the data-logger.
6.12.5.7 Wiring.
The supply of cables and wiring between the fault locator and the RTU
shall be done by the successful tenderer.
6.12.5.8 The telecommands for the fault locator at TSS/SP and telemetry of neutral
currents data have not been catered for in the equipment capacity specified in clause
6.4.2. The requirements given in clauses 6.12.5.1 to 6.12.5.7 above shall be catered for in
the SCADA system in addition to that stipulated in clause 6.4.
6.13 Tripping of feeder circuit breaker in case of PT fuse failure
The SCADA system shall cause the feeder circuit breaker to trip in case
the fuse of the associated potential transformer fails.
7.0 Instruments, Testing Equipment and Tools
7.1 The tenderer shall quote for the following giving unit prices of individual
items:
(i) Instruments including two level meters, two portable dual trace
oscilloscope (0-25 MHz) and four digital multimeters required for the maintenance and
xxxx of the equipment offered, pamphlets giving full technical and other details of the
instruments shall be furnished along with the offer.
(ii) Diagnostic kit and logic probes for ―on-line‖ and ―off-line‖
trouble-shooting and repairs. The diagnostic kit shall be comprehensive and capable of
testing all types of modules employed in the SCDA equipment for their normal
functioning and to identify the faulty zone.
(iii) Any other standard or special testing and diagnostic equipment
necessary for preventive as well as corrective maintenance of the various
parts/components of the SCADA equipment.
equipment.
(iv) Complete set of tools required for maintenance of the SCADA

7.2 The required quantity of instruments, test equipments and tools shall be
indicated to the successful tenderer at the time of issue of the contract.
8.0 Spares
8.1 The tenderer shall quote for spares as indicated below for the SCADA
equipment:
- 39 -
i) Modules of various types (including 10% of each type
power supply units) used at RCC.
ii) Modules of various types (including 10% of each type
power supply units) used at controlled stations.
iii) Spare transducers and summation CTs One of each type
iv) Interposing relays 10% of each type
v) Components such as critical ICs 20% of each type
vi) Read relays 20% of each type
vii) Various types of lamps/LEDs used 10% of each type
on MDB
viii) Spares for individual items As considered
such as printer etc necessary for
a period of
2 years.
ix) Spare keyboard for VDU one
8.2 The tenderer shall confirm in his offer the availability of spares for a
period of 15 years after commissioning of the equipment.
9.0 Technical deviations
The tenderer shall specifically indicate in a statement attached with his
offer, his compliance with each clause and sub clause of this specification. A separate
statement shall be attached with the offer indicating reference to the clauses where the
tenderer deviates therefrom together with detailed remarks/justification. If either the

statement of compliance or statement of deviations is not attached with the offer, it is not
likely to be considered. If there are no deviations, a ‗NIL‘ statement shall be attached.
10.0 Particular specification
- 40 -
Particular specification giving details of the location of RCC, repeater
the purchaser. stations, stations to be controlled, number of telecommands, telesignals
and telemetered parameters at each on the controlled stations and other detail will be
furnished separately by the purchaser.
11.0 Type Tests
11.1 The type tests shall be carried out in the presence of the purchaser‘s
representative at the manufacturer‘s works on a complete set of equipment (sending end
and receiving end) to prove the quality of the design and workmanship and there
conformity with the specification. If any of the type tests on components have already
been successfully carried out, repetition of such tests may be waived, provided photostat
copies of the type tests certificates and other particulars are submitted and got approved
by the purchaser.
11.2 Before giving the call to RDSO/the Chief Electrical Engineer for
inspection and testing of the prototype of the system, the manufacturer shall submit a
detailed test schedule consisting of schematic circuit diagrams for each of the tests and
nature of the test, venue of the test and the duration of each test and the total number of
days required to completer the test at one stretch. Once the schedule is approves, the test
shall invariably be done accordingly. However, during the process of type testing or even
later, RDSO representative reserves the right to conduct any additional test(s) besides
those specified herein, on any equipment/sub-system or system so as to test the system to
his satisfaction or for gaining additional information and knowledge. In case any dispute
or disagreement arises between the manufacture and RDSO/the Chief electrical Engineer
during the process of testing as regards the type tests and/or the interpretation and
acceptability of the type test results, it shall be brought to the notice of the Director
General(Traction Installations), RDSO/the Chief Electrical Engineer as the case any be,
whose decision shall be final and binding.
11.3 The type tests shall include visual inspection, insulation resistance test,
power frequency high voltage withstand test, functional tests, operational tests and test on
major components. The detail of tests to be carried out shall be finalized by mutual
consultation between the purchaser the successful tederer.

- 41 -
11.4 Only after clear written approval of the result of the tests on the prototype
unit is communicated by RDSO/Purchaser to the manufacturer, shall be take up bulk
manufacture of the ordered equipment which shall be strictly with the same materials and
processed adopted for prototype unit. In no circumstances shall the material, other the
those approved in the design/drawings and/or prototype.
11.5 The successful tenderer shall be required to supply 3 sets of type test
reports to the purchaser.
12.0 Erection and Commissioning tests
The creation and commissioning of SCADA equipment shall be done bye
the successful tenderer who will arrange all tools, plants, instruments and other materials
required for the purpose at his own cost. Tests shall be carried out during creation/
commissioning of the equipment at site. The successful tenderer shall be required to
submit to the purchaser the details of the checks and tests to be carried out during
erection and commissioning.
13.0 Tests after installation and commissioning of the equipments
Tests shall be carried out on the complete equipment in the presence of the
purchaser representative to check the erection and commissioning of the equipment. This
shall include functional tests, checking of adjustment of transducers, limit settings of
measurands, cyclic update time, telecommand execution time, signal levels both on the
send and receive side of the various modems for satisfactory operation of the equipment,
and others. Three sets of the test report shall be supplied to the purchaser for record.
14.0 Technical data, Drawings and Information
14.1 The tenderer shall furnish guaranteed performance data, technical an other
particulars of the equipment offered in the proforma at annexure -2.
14.2 The information furnished in schedule of guaranteed performance data,
technical and other particular (Annexure-2) shall be complete in all respects. If there is
any entry like shall be furnished later or blanks are left against any item, the tender is not
likely to we considered as such omissions causes dele in finalising the tender.
14.3 The tenderer shall submit alongwith his offer the following:

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a) System diagram of the SCADA equipment showing general layout of
RTUs and and there connection with waster station equipment through
communication cables.
b) Hardware configuration of master station equipment.
c) Hardware configuration of RTUs (TSS, SSP, SP and ATP).
d) Software configuration of mater station equipment.
e) Software configuration of RTUs.
f) A write-up explaining the principle of operation of the equipment.
g) The General arrangement drawing of the HDB at RCC, indicating the
catenary indications, equipment status indications, aanunciations and lettering for
controlled station.
h) The General arrangement drawing of waster station equipment cabinet,
showing module layout.
i) The General arrangement drawing of RTU cabinet (TSS,SSP,SP and ATP)
showing module layout, transducers and interposing relays.
j) A detailed write-up giving the details of SCADA software including the
communication protocol and transmission security.
k) Any other detail considered necessary for the proper the understanding of
the system.
NOTE: The general arrangement drawing should also indicate the overall
dimensions as well as mounting details.
14.4 The successful tenderer shall be required to submit the following:
a) Detail drawings for approval of the purchaser in Railways standard
sizes of 210mm x 297mm or any internal multiple thereof. These drawings shall cover
schematic circuit diagrams, block diagrams, layout of equipment at RCC and at
controlled stations, constructional details of various equipment at RCC and at controlled
stations, layout of various modules in equipment cabinets at RCC and at controlled
stations, interconnection diagram between Railways power equipment and remote control
equipment, and wirings diagrams. The manufacture of the equipment shall be taken up by
the successful tenderer, only after approval of the drawings by the purchaser.
equipment.
b) Circuit schematic and explanation with full technical details of the

- 43 -
c) Detailed step by step procedure for operation, maintenances and
repairs of the system and individual equipments, indicating procedure for troubleshooting,
measurement of various signals at different points and diagnostic check to be
adopted for repairs at site.
d) Details of various RCC modules indicating rating and modification
number and layout of equipment.
10 Details of SCADA software, including operating instructions.
14.5 Only after all the designer and drawings have been approved and
clearance given by RDSO to this xxxx the manufacturer shall take up manufacturer of the
prototype unit for RDSO inspection. It is so clearly understood that any change required
to be done in the prototype unit as required RDSO shall be done expeditiously.
14.5 The successful tenderer shall be required to supply 3 prints of the final
approved drawings and 3 dates of reproducible tracings.
14.6 The successful tenderer shall supply 10 copies of technical booklets giving
detailed description of the equipment, constructional features, ratings and characteristics
and instruction for operation and maintenance of the system as well as of individual
equipment.
15. Training of Railway staff
The offer shall include the training of two Engineers and six Supervisors
of the Indian Railways free of cost at the manufacturers in India and abroad. The total
duration of training shall be 12 weeks, of which approximately six weeks will be at
manufacturers works and six weeks on a railway system or 0ther pubic utility. The cost of
travel to the country of manufacture and back will be borne by the Indian Railways.
Other details shall be settled at the time of finalising the contract or purchase order.
The training shall cover the following aspects:
a) Study of system engineering and trouble shooting of all modules
and system faults.
b) Training in operation of SCADA equipment and Man-Machine
interaction.
c) Erection, testing, commissioning and adjustments required in
service of the equipment.
16. Warranty
16.1 The SCADA equipment supplied against a purchase order/contract in which
this specification is quoted, irrespective of origin of individual equipment
(imported/indigenous), shall be guaranteed for trouble-free and satisfactory performance
for a period of 18 months from the date of supply or 12 months from the date of

- 44 -
commissioning, whichever period is shorter. Details of warranty clause, the extent of
responsibility and other relevant aspects shall be included in the purchase order or
contract. The tenderer shall furnish detailed terms and conditions in this regard in his
offer.
16.2 The successful tenderer shall make necessary arrangements for closely
monitoring the performance of the SCADA equipment through periodical (preferably
once in two months during the warranty period) visits to the RCC and the various
controlled stations for on the spot detailed observations. Arrangements shall also be made
for spare parts, modules and other items to be kept readily available with the
manufacturer/supplier/successful tenderer to meet exigencies warranting replacement, so
as to put back the SCADA equipment in service without unduly affecting the operations
of the Traction Power Controller.

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ANNEXURE-I
TYPICAL REQUIREMENT OF TELECOMMANDS, TELESIGNALS
AND TELEMETERED PARAMETERS IN A DOUBLE LINE SECTION AT TSS,
SP, SSP AND ATP
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
DESCRIPTION TSS SP SSP ATP
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
A. Telecommands
1. 220/132/110/66 kV 2 (3)* - - -
circuit breakers
2. 25 kV circuit breakers 10 (9) 2 - -
3. 25 kV Interrruptors 2 2 5 -
4. Auto-recloser ―Release‖ 4 - - -
With locked out indication
5. Transformer tap changer 2 (3) - - -
6. Interlock release request (as applicable) - - -
at boundary post
7. Spares (for locoshed feeders 4 (3) 4 3 -
motorized isolators, etc.
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Total: 24** 8** 8 -
- - - - - - - -- - - - - - - - - - - - - - - - - - - - - - - - - - - -
* The figures given in the brackets are for traction substation having three
single phase (V-connected) transformers.
The figures given outside the brackets are for traction substation having two
scott-connected transformers.
** No. of telecommands required for fault locator as per C1.6.12.5 is to be
added where applicable as the same has not been included.

B. Telesignals
For details of telesignals actually required, clause 5.5.1 may by refered to.
C. Telemetered parameters
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
DESCRIPTION TSS SP SSP ATP
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
1. 25 kV Bus/OHE voltage 2 2 - -
2. Feeder current 2 - - -
Spares 4 2 - -
- 46 -
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Total: 8*** 4*** - -
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
*** Telemetered parameters required for fault locator have not been included in
the above table. The same are received from fault locator in digital form.

- 47 -
ANNEXURE-2
SCHEDULE OF GURANTEED PERFORMANCE DATA, TECHNICAL DATA,
TECHNICAL AND OTHER PARTICULARS
1. Maker‘s name and country of origin.
2. Manufacturer‘s type destination.
3. Details of mini/micro-computers at RCC
i) Make & type
ii) Power supply required for operation.
iii) Permissible variation in power supply voltage and frequency
iv) Main semi-conductor RAM memory size
v) Other detailed particulars along with technical pamphlets.
4. Name of equipment for which 100% standby is provided at RCC.
5. Arrangement of changeover from on line to standby system
(manual/automatic, electronic, electrical).
6. Hard disk memory capacity of each computer system (main/standby).
7. Hard disk memory capacity of each computer system (main/standby).
8. Colour VDUs
i) Make & type
ii) Size of screen
iii) Whether fully graphic or semi-graphic
iv) Number of background and foreground colours
v) Does it conform to clause-6.1.2.2.?
vi) Other detailed particulars along with technical pamphlets.
9. Key-boards for VDUs
i) Make & type
ii) Whether functional keys and alpha-numeric keys are provided on
separate keyboards or integrated in one ?.
iii) Other detailed particulars along with technical pamphlets.

10. Data-logging printers
i) Make & type
ii) Speed in characters per second
iii) Number of characters per line
iv) Power supply required for operation
v) Other detailed particulars along with technical pamphlets.
11. Mimic diagram board
- 48 -
i) Indication LEDs/magnetic semaphore indicators for circuit
breaker/interruptor/motor operated isolator-type, voltage rating and
wattage.
ii) Hooter voltage rating and wattage
iii) Annunciation window LEDs-voltage rating and wattage.
iv) Does it conform to clause-6.1.3?
12. UPS at RCC
i) Makes & type
ii) Ratings
iii) Input power supply
iv) Permissible variation in input power supply voltage and frequency.
v) Inverter output voltage and frequency
vi) Variation in inverter output voltage from no-load to full load
vii) Permissible variation in battery voltage for satisfactory operation
of inverter
viii) Rectifier ratings
ix) Inverter ratings
x) Efficiency of rectifier at rated output
xi) Efficiency of inverter at rated output
xii) Does it conform to clause-6.1.5?
xiii) Is automatic changeover switch provided as per clause-6.1.5.?
xiv) Acoustic noise level
xv) Are equipment earthling terminals provided as per relevant
standards?
xvi) Maximum temperature inside the cabinet of the UPS, under normal
working conditions.
xvii) Other detailed particulars along with technical pamphlets.
13. Battery for UPS
i) Make & type

- 49 -
ii) Battery voltage and ampere-hour capacity
iii) Is the battery rated to provide 2 hours standby, in case of input a.c.
supply failure to the UPS?
14. Load at nominal inverter output voltage
i) Load at nominal inverter output voltage.
ii) Load on battery in case of input a.c. supply failure to the UPS.
15. Software details
i) Operating system used at RCC
ii) High level language compliers provided in the system at RCC.
iii) Does the software meet the requirement of clause-6.1.4 ?
iv) Is the communication protocol with complete details enclosed?
v) Hamming distance of the error checking system used for detecting
errors in transmission.
vi) Are the SCADA software and operating system details enclosed?
vii) Are the limit settings of measurands selectable through software as
per clause 6.2.4.2 ?
16. Cyclic update time for updating of designed capacity of statue, alarm and
measurand for:
i) Total number of RTUs to be commissioned initially.
ii) Total number of RTUs as per designed capacity.
iii) Are calculations for the update time enclosed?
17. Maximum time taken for execution of any control command including
confirmation of back indication.
18. Modems
i) Make & type
ii) Operating speed range (in bauds)
iii) Actual transmission speed from master station to RTUs and carrier
frequency adopted.
iv) Actual transmission speed from RTUs to master station and carrier
frequency adopted.
v) Half duplex/full duplex
vi) Type of modulation

- 50 -
vii) Output signal level on send side:
Nominal ……….
Maximum ……….
Minimum ……….
viii) Threshold values of input signal on receive side
Maximum ……….
Minimum ……….
ix) Dynamic range
x) Maximum gain provided in the amplifier
xi) Indications provided for fault diagnostics
xii) Are the modems and the transmission speed suitable for the
communication mediums specified in clause 5.8, 5.9 & 5.10 ?
19. Power Supply for RTUs
i) Power supply required for operation of RTU
ii) Permissible variation in power supply voltage and frequency
iii) Is the RTU designed for Operating from both ac & dc supply, as
per clause-6.2.3 ?
iv) Load of the RTU for designed capacity of parameters as per clause
6.2.3 at 240V ac single phase vis-a-vis 110V d.c :
- At TSS
- At SP
- At SSP
- At ATP
240V a.c. 110V d.c.
20. Are events and alarm stored in the RTU, as per Clause-6.2.2 ?
21. Do the RTUs meet the requirements of Clause-6.2 ?
22. Catenary voltage indication circuits in RTU
i) Voltage at which the catenary voltage indication circuit work.
ii) Pick up voltage of the circuit ( please indicate range)
iii) Drop off voltage of the circuit ( please indicate range)
23. Catenary under voltage circuit in the ETU at SP
i) Voltage at which the catenary under voltage circuit at sectioning and
paralleling post (SP) works.

- 51 -
ii) Limits (field settable) within which the catenary under voltage
circuit can be set to trip the bridging interruptor.
24. PT fuse fail circuits in the RTU at TSS
i) Voltage at which the PT fuse fail circuit works.
ii) Minimum pick up voltage of the circuit
iii) Drop off voltage of the circuit.
25. Interposing contactors/relays in the RTUs
a) Telecommands
b) Alarms
i) On command
ii) Off command
iii) On status
iv) Off status
Type & make Operating voltage Current carrying
capacity of
contacts.
i) Alarm relays ( Suitable for 110 v d. c. operation)
26. Range of setting provided in the solid state comparator circuit in the RTU
for 110V d.c. low indication.
27. Are the telesignals at the controlled stations monitored as per clause 5.5.3. ?
28. Furnish details of the no-volt relays used for ―ac fall‖ and ―PT fues fail‖
indications.
29. Details of transducers
a) Voltage transducers
i) Make and type
ii) Range
iii) Input
iv) Output

v) Characteristics
vi) Response time
vii) Accuracy
viii) Burden in VA
ix) Self powered/auxiliary powered
b) Current transducers
i) Make and type
ii) Range
iii) Input
iv) Output
v) Characteristics
vi) Response time
vii) Accuracy
viii) Burden in VA
ix) Self powered/auxiliary powered
30. Are the special requirement of the SCADA equipment specified in clause
6.12, met with?
31. Time taken to complete inter-tripping process from the instance of operation
of W. P. C. relay at TSS.
32. Equipment capacity at the RCC
a) Maximum number of controlled stations,
telecommands, telesignals and measurands that
can be accommodated in the system offered
i) Controlled stations
ii) Telecommands
iii) Telesignals
iv) Measurands
b) Number of controlled stations for which the
equipment offered is complete in all respects and
which are to be commissioned initioally:
i) TSS
ii) SP
iii) SSP
iv) ATP
- 52 -

c) Number of controlled stations that can be added
in figure by simply adding functional modules in
the mimic driver for states/alarm out puts and
incorporating, necessary changes in the software
and the HDD, without effecting the existing
system either physically or operationally.
d) Number of telecommands, telesigmnals and
measurands per controlled station for which the
equipment is complete in all respects including
functional modules.
i) Telecommand
ii) Telesignals
iii) Measurands
33. Equipment capacity at the RTUs
a) Number of telecommands, telesignals and
measurands, per controlled station for which the
equipment has been designed, engineeredand
wired up except for end stage interposing relays
and transducers.
i) Telecommands
ii) Telesignals
iii) Measurands
b) Number of telecommands, telesignals and
measurands per controlled station for which the
equipment is complete in all respects including
end stage interposing relays, tranducers andeither
items.
- 53 -
TSS SP SSP ATP
TSS SP SSP ATP
TSS SP SSP ATP

i) Telecommands
ii) Telesignals
iii) Measurands
34. Number of devices / alarms / measurands controlled by each module is
RTU.
i) Control and status module
ii) Alarm module
iii) Analogue module
35. Number of devices / alarms controlled by each module in this mimic
driver at RCC.
i) Status module
ii) Alarm module
36. Are all the equipment used in the SCADA system of industrial grade, as
per Clause 6.9.13?
37. Diagnostic kit
i) Make and Type
ii) Give detailed particulars
iii) Does the kit conform to clause 7.1(ii) ?
38. Oscilloscope
39. Multimeter
i) Make and type
ii) Other detailed particulars along with technical pamphlets.
i) Make and type
ii) Other detailed particulars along with technical pamphlets.
- 54 -

40. Level meters ( dB Meter)
i) Make and type
ii) Other detailed particulars along with technical pamphlets.
41. Dimensions
Overall dimensions of –
i) Mimic panel.
ii) Equipment cabinate at remote control centers.
iii) Equipment cabinate at controlled stations:
a) TSS
b) SP
c) SSP
d) ATP
42. Are the enclosures, specified in clause- 14.3. enclosed along with the
offer?
- 55 -

- 56 -
ANUEXURE= 3
SALIENT FEAATURES OF 25KV CURRENT AND POTENTIAL
TRANSFORMERS
A) Current Transformers
i) Type Low reactance, single phase, oil filled,
ii) a) National system voltage 27 kV
b) highest equipment voltage 52 kV
iii) Frequency 50 Hz
iv) Rated primary current 1000/500 A
v) Rated secondary current 5 A.
vi) Rated transformation ratio 1000-500/5
vii) Rated burden 60 VA
viii)Accuracy class 5P
self-cooled scaled outdoor types.

ix) Rated accuracy limit factor 15
x) Rated short-time thermal current 25 kA (r.m.s.) for 1sec.
xi) Rated dynamic current 62.5 kA (peck)
B) Potential transformers, Type III
i) Type Oil- immersed, self-cooled, core / shell
type, suitable for outdoor use.
ii) Rated system voltage 25kV nominal subject to variation from 19 kV
. to 30 kV.
iii) Frequency 50 Hz
iv) type of connection Between Phase and earth
c) Potential Transformers, Type-III ( Cont.)
v) Rated primary voltage 27.5 kV
vi) Rated secondary voltage 110 VA
vii) Rated burden 100 VA
viii) Class of insulation ‗A‘ class
ix) Rated voltage factor 1.1 (Continuous)
-----------------
- 57 -

- 58 -

- 59 -

- 60 -

SS -TRACTION SUBSTAION.
TP -AUTO TRANSFORMER POST.
SP SUB-SECTIONING AND PARALLELING POST.
P -SECTIONING POST.
B -CIRCUIT BREAKER.
-RY1, P-RY2 -CONTACTS OF PROTECTIVE RELAYS FOR CIRCUIT-
-RY-3 BREAKERS CB1, CB2, CB3 RESPECTIVELY.
-FAULT LOCATOR.
DM -MODEM.
TU -REMOTE TERMINAL UNIT.
-ST1, CST2, -CALL-START TELE COMMAND FOR CB-1, CB-2, AND
-ST3 CB-3 RESPECTIVELY,
ED -N/O CONTACT OF RTU FOR FEED EXTENDING
PURPOSE. [THIS CONTACT SHALL REMAIN OPEN IN
NORMAL FEED CONDITION AND REMAIN CLOSED
- 61 -

IN EXTENDED FEED CONDITION]
-INT -DATA INTERFACE
Note:-
In case of underground telecommunication trunk cable, no modems (MDM)
are required. The fault locators from TSS to SP shall be directly connected through one
pair (two wire) of metal conductors of the trunk cable. No isolating transformer shall be
provided in the trunk cable.
- 62 -

- 63 -