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Model YPC Two-Stage Steam-Fired Absorption ... - Usair-eng.com

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FORM 155.19-EG3 (1108)Model YPC Two-Stage Steam-Fired Absorption ChillerStyle CModels YPC-ST-14SC through YPC-ST-19S300 through 675 Tons1050 through 2373 kW


Table of ContentsFORM 155.19-EG3 (1108) ..................................................................................................................................................................................... 1Introduction ........................................................................................................................................................................................................... 3How It Works ........................................................................................................................................................................................................ 4Ratings .................................................................................................................................................................................................................. 5MicroComputer Control Center ........................................................................................................................................................................... 6Mechanical Specifications ................................................................................................................................................................................... 8Optional Features ................................................................................................................................................................................................11Application Data ................................................................................................................................................................................................. 12Dimensions ......................................................................................................................................................................................................... 17Nozzle Arrangement 14SC ............................................................................................................................................................................... 18Nozzle Arrangement 16SL and Larger ............................................................................................................................................................ 19Guide Specifications .......................................................................................................................................................................................... 20NOMENCLATUREThe model number denotes the characteristic of the unitYPC – ST – 18S – 46 – C – A – CModelTubeCodeMod LevelHeat SourceSizeCodeElectricalCodeHeater Code (Always C)2 JOHNSON CONTROLS


IntroductionFORM 155.19-EG3 (1108)Model YPC Two-Stage Steam Absorption ChillersThe YORK YPC Two-Stage Absorption Steam Chiller represents the world’s most efficient commerciallyavailable absorption technology. The unique Two-Stage design requires a remarkably low steaminput rate of 9.8 Ibs. per ton-hour (1.26 kg per kW-hour), which equates to a COP of approximately1.19. With today’s energy and environmental considerations, the YORK YPC Two-Stage SteamAbsorption Chiller is the ideal choice for a wide range of applications.YPC Steam Chillers come equipped with the same sophisticated microprocessor controls foundthroughout YORK’s line of centrifugal chillers, making the YPC Steam Chiller the smartest and mostefficient absorber on the market today.With its high efficiency, “smart controls,” proven reliability and guaranteed quality, YPC units are theideal choice for today’s demanding specifications.JOHNSON CONTROLS3


How It WorksSTEAM MACHINESYPC Two-Stage Absorption’s remarkably efficient twostageabsorption refrigeration cycle uses water as therefrigerant and lithium-bromide as the absorbent. It is thestrong affinity these two substances have for each otherthat makes the cycle work. The entire process occurs inhermetic vessels in an almost complete vacuum.The large diagram above indicates the complete chillingcycle. The six steps are detailed below, with correspondingnumbers in the diagram to show where each steptakes place. YPC’s absorption chilling cycle is continuous;however, for the sake of clarity and simplicity, it is dividedinto six steps.1. Solution Pump/Heat ExchangersA dilute solution (58.3%) of lithium-bromide and waterdescends from the Absorber to the Solution Pump. Thisflow of dilute solution is split into two streams and pumpedthrough heat exchangers to the First-Stage Generator andto the Second-Stage Generator.YPC’s exclusive two-way split of solution flow virtuallyeliminates the possibility of crystallization (solidification)by allowing the unit to operate at much lower solution concentrationand temperatures than series flow systems.2. First-stage GeneratorAn outside steam source heats dilute lithium-bromide(58.3%) coming from the Solution Pump/Heat Exchangers.This produces hot refrigerant vapor which is sent tothe Second-Stage Generator, leaving a concentrated solution(63.8%) that is returned to the Heat Exchangers.3. Second-Stage GeneratorThe energy source for the production of refrigerant vaporin the Second-Stage Generator is the hot refrigerant vaporproduced by the First-Stage Generator.This is the heart of YORK’s remarkably efficient twostageabsorption effect. The refrigerant vapor producedin the first-stage Generator is increased by 40% – at noadditional expense of fuel. The result is much higher efficiencythan in conventional systems.This additional refrigerant vapor is produced whendilute solution from the Heat Exchanger is heated byrefrigerant vapor from the First-Stage Generator. Theadditional concentrated solution that results is returned tothe Exchanger. The refrigerant vapor from the first-stageGenerator condenses into liquid giving up its heat, andcontinues to the Condenser.4 JOHNSON CONTROLS


FORM 155.19-EG3 (1108)4. CondenserRefrigerant from two sources – (1) liquid resulting fromthe condensing of vapor produced in the First-StageGenerator and (2) vapor produced by the Second- StageGenerator enters the Condenser. As the liquid refrigerantenters the low pressure of the condenser, it flashes tovapor. The two sources of refrigerant vapor combine andcondense to liquid as they are cooled by the condenserwater. The liquid then flows down to the Evaporator.5. EvaporatorRefrigerant liquid from the Condenser passes through ametering valve and flows down to the Refrigerant Pump,where it is pumped up the the top of the Evaporator. Herethe liquid is sprayed out as a fine mist over the Evaporatortubes. Due to the extreme vacuum (6 mm Hg) in theEvaporator, some of the refrigerant liquid evaporator,creating the refrigerant effect. (This vacuum is createdby hygroscopic action-the strong affinity lithium-bromidehas for water-in the Absorber directly below.)The refrigerant effect cools the returning system chilledwater in the Evaporator tubes. The refrigerant liquid/vaporpicks up the heat of the returning chilled water, cooling itfrom 54°F (12.2°C) to 44°F (6.6°C). The chilled water isthen supplied back to the system.6. AbsorberAs the refrigerant liquid/vapor descends to the Absorberfrom the Evaporator, a concentrated solution comingfrom the Heat Exchanger is sprayed out into the flow ofdescending refrigerant. The hygroscopic action betweenlithium-bromide and water, and the related changes inconcentration and temperature, result in the creation ofan extreme vacuum in the Evaporator directly above.The dissolving of the lithium-bromide in water gives offheat, which is removed by condenser water entering fromthe cooling tower at 85°F (29.4°C) and leaving form theCondenser at 92°F (33.3°C). The resultant dilute lithiumbromidesolution collects in the bottom of the Absorber,where it flows down to the Solution Pump.The chilling cycle is now completed and begins again atStep 1.RatingsComputerized Performance RatingsEach chiller selection is custom-matched to meet the individual application requirements. It is not practical to providetabulated information for all possible combinations. Computerized performance ratings are available through each YORKsales office.Figure 1 details the high efficiency part load performance of the YPC Absorption Chiller. At both constant tower watertemperatures and ARI adjusted entering tower temperatures, the unique Two-Stage design delivers superior economyat low loads. Table 1 details the YPC machine’s superior IPLV according to ARI 560-92.TABLE 1 - IPLV ANALYSISFIG. 1 – ENERGY INPUT VS. OUTPUTShows the part load performance of the YPC Chiller. Thehighest efficiency is achieved between 50 and 100 percentchilling capacity. Valid for leaving chilled water temperature42°F-52°F (5.6°C-11.1°C).JOHNSON CONTROLS IPLV (expressed as a COP) = 1.295


MicroComputer Control CenterThe MicroComputer Control Center is designed for thevery best chiller protection and overall system efficiency.As standard equipment on all Millennium YPC Two-StageAbsorption chillers, the Control Center is a major developmentin absorption chiller technology, providing the mostprecise and reliable control available in the industry.INFORMATION DISPLAYVital chiller operating information can be shown on the 40character alphanumeric display. All information is in theEnglish language with numeric data provided in Englishor metric units. Information provided standard on all unitsincludes:• Chilled water temperatures, entering and leaving• Tower water temperatures, entering and leaving• First-stage generator pressure and temperature• Refrigerant temperature• Solution temperature• Operating hours• Number of starts• Number of purge cycles (last 7 days and lifetime total)• Steam valve position (in %)• Indication of each pump’s operationIn addition, all operating and setpoint information canbe transmitted to an optional remote printer through theRS232 port to obtain data logs:• At any time by pressing the PRINT button• At set time intervals by programming the panel• After a safety shutdown to list the cause of the shutdownand the operational parameters just prior toshutdown• For a complete history printout of the last four shutdownsand operational parameters just prior to shutdown.CAPACITY CONTROLWhen automatic capacity control is desired, the Micro-Computer Control Center automatically varies the steamflow rate to maintain the programmed leaving chilled watersetpoint for cooling loads ranging from 20% to 100% ofdesign.• Digital keypad entry of setpoint to 0.1°F (0.1°C)• Verify actual vs. setpoint temperature via alphanumericdisplay• Remote reset of setpoint (up to 20°F (or 11.1°C) range)with a 1 to 11 second PWM signal (optional 4-20mA,0-10VDC or contact closure).When automatic control is not desired, the input steamflow rate is also manually adjustable for the MicroComputerControl Center panel to any setting between minimumand maximum, provided steam input is not inhibited by aspecific operating condition (e.g. safety).STEAM LIMITING CONTROLS• Manual limiting available from 20% to 100% of capacity.• Programmable pull down demand limiting to auto-maticallylimit steam source loading at start-up.• Remote limiting of steam input form 30% to 100% witha 1 to 11 second PWM signal.SYSTEM CYCLING CONTROLS• Programmable seven day time clock for automaticstart/stop of chiller and chilled condenser waterpumps.• Separate schedule input strictly for holidays• Remote cycling contacts available for other field suppliedsignals• Multi-unit cycling contact input terminals for field suppliedsignals6 JOHNSON CONTROLS


FORM 155.19-EG3 (1108)WARNING CONDITIONS/INHIBITED UNIT LOADINGThe MicroComputer Control Center provides a warningannunciation and, when beneficial to the machine, willlimit heat input to 30% to 60% when operating conditionsindicate the unit is moving towards a safety shutdown.This gives the operator the opportunity to fix a problembefore it leads to a complete safety shutdown. Warningsinclude the following:• Low refrigerant temperature• High generator pressure or temperature• High or low entering condenser water temperature• Purge pump current overload• Faulty solution dilution temperature sensorSAFETY SHUTDOWN CONTROLSThe following conditions will lead to unit shutdown. Aftera shutdown, the reason for the shutdown is displayed inEnglish on the alphanumeric display. Each annunciationdetails the day, time, reason for shutdown and the typeof restart required.Cycling – those controls which automatically reset andpermit auto restart of the system.• Loss of condenser water flow• Low leaving chilled water temperature• Power failure (when automatic restart is selected)Safety – those controls which (when employed) requirea manual operation to restart the system.• Solution pump thermal or current overload• Refrigerant pump thermal or current overload• Low refrigerant temperature• First-stage generator high temperature• First-stage generator high pressure• Loss of chilled water flow• Power failure (when automatic restart not used)• Incomplete dilution cycle due to any of the following:• Power failure• Solution/refrigerant pump overloads• Low refrigerant temperature• Loss of chilled water flow• Auxiliary safety shutdown terminals for field suppliedsignalsCONCENTRATION CALCULATORThe micropanel monitors the first-stage generator concentrationto prevent operation at an unsafe concentration.Concentration is tied into both the Warning Conditions andSafety Shutdown systems discussed in this section. Alsoincluded is an operator interface concentration calculator.When in the PROGRAM mode, an operator can use theconcentration calculator to determine concentration byinputting set of conditions. The operator must input anytwo of three parameters (bromide solution temperature,saturation temperature, and pressure) and the micropanelwill display the concentration. The display will also indicateif the input are in the crystallization zone.CONTROL MODE SELECTIONThe Two-Stage Control Center includes secure programand servicing capabilities. There are three keys for theselection of the Control Center modes:• ACCESS CODE permits access to the Control CenterPROGRAM button when the proper password isgiven• PROGRAM permits operator to program the set-pointsand select desired MODE:• LOCAL allows manual unit start and purging.• REMOTE allows purging as well as remote start andstop of the unit and remote reset of the chilled watertemperature and steam limit.• SERVICE allows manual operation of the steam valve,including LOAD, UNLOAD, HOLD, and AUTO keys.Manual operation of all pumps is also included.ENERGY MANAGEMENT INTERFACEBy connecting with the YORK Integrated Systems Network,the MicroComputer Control Center can communicateall data accessible from the keypad (including alltemperatures, pressures, alarms and operating data)to a remote DDC processor through a single shieldedcable. In REMOTE mode, the DDC processor may issueall operating commands available at the keypad to theControl Center through the same shielded cable. Withan ISN translator panel, other BAS systems can receivethis same information.The MicroComputer Control Center also provides adirect hard wire interface capability with other buildingautomation systems using a 1-11 PWM standard signal(4-20mA, 0-10VCD or contact closure optional) includingthe following:• Remote unit start/stop• Remote chilled water temperature reset• Remote steam limit input• Remote read out of status including:• Unit ready to start• Unit operating• Unit safety shutdown• Unit cycling shutdownJOHNSON CONTROLS7


Mechanical SpecificationsGENERALThe YORK YPC Two-Stage Absorption Liquid Chiller iscompletely factory-packaged, including a first-stage (hightemperature) generator, solution heat exchangers, mainshell, hot water heater, microprocessor controls and allinterconnecting unit piping and wiring.All models are shipped as a single piece complete witha factory balanced lithium-bromide (LiBr) and refrigerantcharge inside of the unit to simplify and expedite start-up.The unit is also shipped with a nitrogen charge to eliminatethe possibility or air entering the machine during shipment.The burner and burner panel on each unit are factorymounted, wired and tested and shipped pre-installed asintegral components of the Chiller-Heater.The purchase price includes services of a JohnsonControls factory-trained, field service representative tosupervise the initial start-up of the machine.SOLUTION FLOWThe solution flow is divided into two parallel paths, oneleading to the first-stage generator and one to the secondstagegenerator. In this way, each stream is concentratedonly once, allowing for a more safe and efficient operation.The balance of flow between the two streams is factory-setduring the performance test to ensure maximum efficiencyfor any given application.MAIN SHELLThe main shell consists of four separate shell and tubeheat exchangers: the absorber, evaporator, condenserand second-stage (low temperature) generator, all housedin a single carbon steel shell divided into low pressureand intermediate pressure sections. The shell is fabricatedfrom formed carbon steel plates with fusion weldedseams. Carbon steel tube sheets, drilled and reamed toaccommodate the tubes, are welded to the end of theshell. Intermediate tube supports are fabricated of carbonsteel plates. Each tube is roller expanded into the tubesheets to provide a leak tight seal; each tube is individuallyreplaceable. The solution side of the shell is designed fora working pressure of 60 mm Hg absolute.The portion of the main shell opposite the generatorhouses the low pressure section of the machine whichincludes the evaporator and the absorber. Both the absorberand the evaporator are drip-type heat exchangerswith 5/8” (16 mm) OD, 0.025” (0.635 mm) wall, coppertubing for the 14SC and 3/4” (19 mm) OD, .028” (0.71mm) wall copper tubing for the 16SL and larger. Tubes areexternally enhanced where necessary to achieve desirecapacity. The absorber and evaporator are separated byfinned eliminator baffles designed to allow only water inthe vapor state to pass to the absorber.The side of the main shell closer to the generator containsthe intermediate pressure section of the machine consistingof the condenser and second-stage generator. Thesecond-stage generator is a drip-type heat exchangerwith 5/8” (16 mm), 0.025” (0.6 mm) wall, copper tubingfor the 14SC, and 3/4” (19 mm) OD, 0.028 (0.7 mm) wallfor the 16SL and larger. Generator and condenser areseparated by baffling which prevents liquid carryover tothe condenser. Condenser tubing is 5/8” (15.9 mm) 0.025”(0.6 mm) wall copper tubing for the 14SC, and 3/4” (19.05mm) OD, 0.028” (0.7 mm) wall for the 16SL and larger.The removable compact water boxes are fabricated ofsteel. The design working pressure is 150 PSIG (10.3 bar)and the boxes are tested at 225 PSIG (15.5 bar). Integralsteel water baffles are located and welded within the waterbox to provide the required pass arrangements. Stub-outwater nozzle connections with ANSI/AWWA C-606-stylegrooves are welded to the water boxes. These nozzlesare suitable for ANSI/AWWA C-606 couplings, welding orflanges, and are capped for shipment. Plugged vent anddrain connections and lifting lugs are provided on eachwater box.FIRST-STAGE GENERATORThe first-stage generator is a single flooded shell and tubeheat exchanger. The shell side is fabricated from carbonsteel plate with fusion welded seams, and is designed fora working pressure of 13.5 psia (0.9 bar) (the unit burstingdisk is designed to fail at 10 PSIG (0.7bar)). Carbon steeleliminator baffles laid out in a serpentine fashion preventsolution carryover over with the refrigerant vapor. Thegenerator has a single drilled and reamed carbon steeltube sheet and uses a “U” shaped tube bundle to minimizethermal stress. The “U” tubes are 5/8” (16 mm) OD, .035”(0.9 mm) wall, 70/30” cupro-nickel and are roller expandedinto the tube sheets. The tube side of the generator isdesigned for working pressures up to 150 PSIG (10.3 bar)and is ASME approved and stamped in accordance withASME Boiler and Pressure Vessel Code, Section VlII. Thehigh temperature generator contains a solution float valvewhich controls the level of solution in the generator. Thislimits the amount of sensible heating at part load conditions,resulting in much better performance.SOLUTION HEAT EXCHANGERThe solution heat exchanger is a shell and tube designwith geometrically-enhanced 5/8” (16 mm) OD for the14SC and 0.58” (14.7 mm) OD for the 16SL and larger,90/10 cupro-nickel tubing. The shell is formed from carbon8 JOHNSON CONTROLS


FORM 155.19-EG3 (1108)steel plate with fusion welded seams. Tubes are rollerexpanded into carbon steel tube sheets.DRAIN COOLERSYPC Absorption steam units come equipped with a condensatedrain cooler, eliminating the need for a separatecondensate cooler on the job site. Each drain cooler is ashell and tube heat exchanger with a tube side DWP of150 PSIG (10.3 bar) and a shell side DWP of 29 PSIG(2 bar). The drain cooler is fabricated from rolled carbonsteel plate with welded seams. Tubes are 5/8” (16 mm)OD, .030” (0.8 mm) wall, 90/10 cupro-nickel and are geometricallyenhanced to minimize heat stress. Each tubeis roller expanded into a drilled and reamed carbon steeltube sheet.PUMPSSolution and refrigerant pumps are hermetically sealed,self-lubricating, totally enclosed, liquid cooled, factory-mounted,wired and tested. Motor winding are notexposed to LiBr or water. The suction and dischargeconnections for each pump are fully welded to the jointpiping to minimize the opportunity for leaks. Suction anddischarge connections are also equipped with factoryinstalled isolation valves to permit quick and easy servicingof pumps. All YPC units include two solution pumpsand a refrigerant pump. Pumps are designed to operatefor a total of 55,000 operating hours between serviceinspections.VALVESAll valves used for adjusting the solution are fully weldedor brazed to prevent leakage of air into the unit. Valveoperators are covered with a seal cap to eliminate thepossibility of air leakage through the stem. Additionally, allconnections of valves to unit piping are fully welded.SOLUTION AND REFRIGERANTEach YPC unit is charged with lithium-bromide (LiBr)solution with non-toxic lithium molybdate as a corrosioninhibitor. Refrigerant is deionized water. A small amountof 2-ethyl hexanol is added as a heat and mass transferenhancer.PURGE SYSTEMThe purge system automatically and constantly removesnoncondensible vapors generated in the absorption processthorough the use of a eductor. Noncondensibles arethen stored in a purge chamber until they can be removedthrough the use of a purge pump. The purge pump is anoil, rotary, two-stage vacuum pump with a 1/4 HP, 3-Phase,ODP motor.The chiller control panel includes a SmartPurge systemthat will automatically sense the amount of non-condensiblesin the purge chamber and empty the tank whenevernecessary. The SmartPurge system eliminates the needfor an operator to ever manually empty the purge chamber.In addition, the control panel monitors the frequencyof purge cycles and alerts the chiller operator through aunique control panel warning message if the number ofpurges exceeds normal levels.CAPACITY CONTROLCapacity control is accomplished by modulating the steamvalve position. The YPC Steam-Fired unit is capable ofmodulating capacity from 20% to 100%.The YPC chiller design incorporates a float valve thatlimits solution flow to the generator as the cooling load decreases.This maintains optimum solution level throughoutthe operating range. In addition, manual control valves areused by YORK technicians in the factory and/or at start-upto fine tune solution and refrigerant flows to match the jobsite needs at peak efficiency.POWER PANELThe power panel enclosure includes the following: singlepoint wiring connection for the incoming power supply;non-fused disconnect switch; motor starters, completewith current and thermal-overload protection for solutionpump(s), refrigerant pump, and purge pump (currentoverloads only); 115VAC 50/60 Hz control power transformer.MICROCOMPUTER CONTROL CENTERThe microprocessor-based control center is factory-mounted,wired and tested. The electronic panel automaticallycontrols the operation of the unit in meeting system coolingrequirements while minimizing energy usage. Chilleroperating parameters are sensed by either thermistorsor transducers and displayed on the keypad. All pressuresare taken as absolute to alleviate typical gaugepressure inaccuracies. Temperatures and pressures canbe displayed in English (F, PSIA) or metric (C, KPa) unitsdepending on the application. Display of all informationis shown in the English language on a 40-character alphanumericdisplay.Available operating information includes return/leavingchilled water temperatures, return/leaving tower watertemperatures, first-stage generator pressure and temperature,refrigerant and solution temperatures, operatinghours, steam valve position and number of starts andpurges.JOHNSON CONTROLS9


Mechanical Specifications - continuedWarning Conditions – The MicroComputer ControlCenter provides a warning annunciation, when appropriate,limits heat input under the following conditions:low refrigerant temperature, high generator pressure ortemperature, high or low entering condenser water temperature,purge pump current overload, faulty solutiondilution temperature sensor.Safety Controls – The Control Center includes uniquesafety logic designed to protect the Two-Stage chiller fromdamaging malfunctions. Complete safety annunciationis displayed for each shutdown by pressing the statuskey. This information includes day, time and reason forshutdown. These include: solution – or refrigerant – pumpthermal or current overload, low refrigerant temperature,first-stage generator high pressure or temperature, loss ofchilled water flow, power failure, auxiliary safety shutdown,incomplete dilution cycle and power failure if manual restartafter power failure is selected.Operating Controls – Background messages aredisplayed while the unit is running to signal operatorof controlling conditions such as leaving chilled watertemperature control and noncritical sensor error. Systemcycling messages display day, time, cause of cyclingshutdown, and autostart indication. These include loss ofcondenser water (or hot water) flow, low-leaving chilledwater (or high leaving hot water) temperature, and powerfailure (when autostart is selected).Digital programming of operating setpoints from the keypadinclude leaving chilled water (or hot water) temperature,pulldown demand limiting, remote steam demandlimit, remote reset temperature range, and daily start/stopscheduling of chiller and water pumps with separate holidayschedule.Security access code is provided for operator to programsetpoints or to choose local, remote, or service modesof operation. Manual control of the steam valve positionand all pumps is provided through separate buttons in theservice mode of operation.the RS232 port in the control center to obtain data logs.This can be accomplished at any time by pressing the“Print” button on the control center, or automatically atpredetermined intervals by programming the panel’sdata logger. The printer will automatically record time andcause of any safety or cycling shutdown along with allchiller operating data monitored by the panel just prior toshutdown. A “History Print” button also allows the printoutof the last four causes of cycling or safety shutdowns plusoperating data for each shutdown.BAS Interface – The MicroComputer Control Center iscompatible with remote Building Automation Systems(BAS). The standard design allows remote start andstop; leaving chilled-water temperature reset and steamdemand limit through PWM signal; and “ready-to-start,”“unit running,” “safety” and “cycling” shutdown statuscontact. For designed-in features and reliability, YORKprovides a full line of BAS controls.FACTORY LEAK TESTEach YPC unit is subjected to a series of four rigorousleak tests, culminating in a vacuum leak test measuredby a mass spectrometer and conducted while the unit isimmersed in an atmosphere of low-density helium.CODES AND STANDARDS• ASME Boiler and Pressure Vessel Code - Section VIIIDivision 1• ARI 560-92• NEC – National Electrical Code• OSHA – Occupational Safety and Health ActPAINTExterior surfaces are protected by an initial coat of redoxide primer with a single finish coat of Caribbean-blueair-drying, high-solids, enamel machinery paint.Data Logging – All operating and setpoint informationcan be transmitted to a remote printer (by others) through10 JOHNSON CONTROLS


Optional FeaturesFORM 155.19-EG3 (1108)SPECIAL TUBE MATERIALS AND WALL THICK-NESSMillennium YPC Absorption units are designed for longlife with the standard tube materials and wall thicknessesin each heat exchanger. For special applications wheredifferent tube specifications are required, YORK offerscopper tubing with .028” (0.7 mm) (where .025” (0.6 mm)is standard) and .035” (0.9 mm) wall thicknesses. Also,90/10 cupro-nickel tubes are available for the absorber,evaporator, and condenser in both the standard and theabove-listed optional tubewall thickness.WATER FLANGES150 lb. ANSI raised-faced flanges for the evaporatorand/or absorber/condenser water connection are factorywelded to water nozzles. Companion flanges, bolts, mustand gaskets are not included.WATER FLOW SWITCHThis is a paddle-type, vapor-proof water flow switch suitablefor 150 PSIG (10.3 bar) DWP (300 PSIG (20.7bar)available) for the absorber/condenser water circuit(chilled-water flow switch is standard).FACTORY PERFORMANCE TESTAfter assembly, chillers can be individually performancetested at the conditions specified by the customer. Acomplete performance test report, signed by the residentengineer, is furnished to the customer and includes thefollowing:• Water flow rates and temperatures• Steam consumption rate• System operating temperatures and pressures• Absorber solution concentrations• All liquid levels in the sightglasses• Exact solution and refrigerant charge amountSPARE PUMPSA complete set of replacement solution and refrigerantpumps ships alongside the unit for local spare partsinventory.REMOTE RESET CONTROLSTwo optional boards allow for continuous reset of eitherleaving chiller-water temperature or remote steam limitusing a 4 to 20mA, 10 to 10Vdc, or contact closure as opposedto the standard 1 to 11 second PWM signal. Thesesignals may be wired directly to the panel terminal blockon the card file without any external interfacing.SHIP WITH SEPARATE CHARGEAll models ship with the LiBr refrigerant charge in theunit. For applications which require light rigging loads, thecharge can be removed and shipped alongside the unitfor recharging in the field.MARINE WATER BOXESMarine water boxes allow service access for cleaning ofthe heat exchanger tubes without the need to break thewater piping. Bolted-on covers are arranged for convenientaccess. ANSI/AWWA C-606 nozzle connections arestandard; flanges are optional. Marine water boxes areavailable for the evaporator or the absorber/condensercircuits. Marine water boxes are only available for circuitswith 150 PSIG (10.34 bar) working pressures.JOHNSON CONTROLS11


Application DataSHIPMENTProtective covering is furnished on the microprocessorcontrols, burner and other electric devices. Water nozzlesare capped prior to shipment.The following discussion is a user guide in the applicationand installation of YPC Absorption Steam Chillers toensure the reliable, trouble-free life for which this equipmentwas designed. While this guide is directed towardsnormal water-chilling applications, you local JohnsonControls sales representative can provide complete recommendationson other types of applications.LOCATIONYPC units make very little noise or vibration and maybe generally located at any level in a building where theconstruction will support the total system operating weight.The unit site should be a floor, mounting pad or foundationwhich is level and capable of supporting the operatingweight of the YPC chiller. The YPC unit will operate properlyand produce maximum output only if it is installed levelwithin 1/1000 of the unit length in the lengthwise directionand 1/1000 of unit width in the widthwise direction.Leave between 46 and 60 inches (1.17-1.52 meters) ofspace around the machine for servicing, reading instruments,and per forming tests. If there are flammable materialsnear the machine, leave at least 20 inches (0.5 m)of space above the machine and at least 40 inches (1.02m) above the first-stage generator. tube pull clearance isone unit length on either end with 60” (1.52 m) clearanceon the opposite end.Absorption chillers are not suitable for outdoor installation.The machine room must be enclosed, well lighted andproperly ventilated to keep its temperature no higher than104°F (40°C) and no lower and 35°F (1.7°C).WATER CIRCUITSFlow Rate – For normal water chilling duty, chilled andtower water flows are permitted at any velocity between4.9 and 10 fps (1.5 and 3.05 m/s). YPC chillers are designedfor constant flow systems. Applications involvingchilled and condenser water flow rates which vary by morethan +/- 10% from design will require special consideration.Contact your YORK representative.Temperature Ranges – For normal chilling duty, leavingchilled water temperatures may be selected between 42°Fand 60°F (5.55°C and 15.55°C) for water temperatureranges between 8°F and 20°F (4.4°C and 11.1°C).Water Quality – The practical and economical applicationof liquid chillers requires that the quality of the watersupply for the evaporator and the absorber/condenser beanalyzed by a water treatment specialist. Water qualitymay affect the performance of any chiller through corrosion,depositions of heat-resistant scale, sedimentation ororganic growth. These will hurt chiller performance andincrease operating and maintenance costs. Normally,performance may be maintained by corrective water treatmentand periodic cleaning of tubes. If water conditionsexist which cannot be corrected by proper water treatment,it may be necessary to provide a larger allowance for fouling,and/or specify special material of construction.General Water Piping – All chilled water and tower waterpiping should be designed and installed in accordancewith accepted piping practice. Chilled water and towerwater pumps should be located to discharge through theYPC unit to assure positive pressure and flow through theunit. Piping should include offsets to provide flexibility andshould be arranged to prevent drainage of water from thecooler and condenser when the pumps are shut down.Piping should be adequately supported and braced independentof the chiller to avoid imposition of strain on chillercomponents. Hangers must allow for alignment of thepipe. Isolators in the piping and in the hangers are highlydesirable in achieving sound and vibration control.Convenience Considerations – With a view to facilitatingthe performance of routine maintenance work, some orall of the following steps may be taken by the purchaser.Evaporator, absorber and condenser water boxes areequipped with plugged vent and drain connections. Ifdesired, vent and drain valves may be installed with orwithout piping to an open drain. Pressure gauges withstop cock, and stop valves, may be installed in the inletsand outlet of the tower and chilled water lines as closeas possible to the chiller. An overhead monorail or beammay be used to facilitate servicing.Connections – The standard YPC unit is designed for150 PSIG (10.3 bar) design working pressure in both thechilled and tower water circuits. The connections (waternozzles) to these circuits are furnished with grooves forANSI/AWWA C-606 couplings (ANSI flanges are optional).Piping should be arranged for ease of disassembly atthe unit for performance of such routine maintenance astube cleaning. A crossover pipe is shipped loose to routethe tower water from the absorber up into the condenser.All water piping should be thoroughly cleaned of all dirtand debris before final connections are made to the YPCmachine.Pump On/Off Control – Contacts are provided in theYORK MicroComputer Control Center to start/stop chilledand tower water pumps. The contacts can be used tosupply 115V power to a pump motor starter relay, or asdry contacts to signal a building automation system to12 JOHNSON CONTROLS


FORM 155.19-EG3 (1108)start/stop flow through the chiller. YORK recommends thatthese contacts be used for all installations whether theydirectly control the pumps or they are used as inputs thattell the building automation system when to supply flow.Absorption chillers require flow at shutdown to perform adilution cycle that will vary in length depending on operatingconditions at shutdown. Without flow, the dilution cyclewill terminate early, which can lead to crystallization.Chilled Water – The chilled water circuit should be designedfor constant flow. A flow switch, provided standardwith the unit, must be installed in the chilled water line ofevery unit. The switch must be located in the horizontalpiping close to the unit, where the straight horizontalruns on each side of the flow switch are at least five pipediameters in length. The switch must be electrically connectedto the chilled water interlock position in the unitcontrol center. A water strainer, of maximum 1/8” meshshould be field-installed in the chilled water inlet line asclose as possible to the chiller. If located close enoughto the chiller, the chilled water pump may be protectedby the same strainer. The flow switch and strainer assurechilled water flow during unit operation. The loss or severereduction of water flow could seriously impair the YPC unitperformance or even result in tube freeze-up.Condenser Water – Like the chilled water circuit, thetower water circuit requires a means of proving flow. Therecommended method of proving flow is a tower water flowswitch (not in standard supply scope, but available fromJohnson Controls) installed in the tower water piping in thesame manner as the chilled water flow switch (above).The YPC chiller is engineered for maximum efficiency atboth design and part load operation by taking advantageof the colder cooling tower water temperatures whichnaturally occur in the winter months. In its standard configuration,YPC absorbers can tolerate entering towerwater temperatures as low as 68°F (20°C). Because theunit flow rates must be maintained, the recommendedmethod of tower water temperature control is a three waymixing valve.At the initial startup, entering tower water temperature maybe as low as 59°F (15°C), provided the water temperaturerises to 68°F (20°C) within twenty minutes.LOW LEAVING CHILLED WATER ON/OFF CYCLINGOnce the chiller reaches its minimum operating load, if thecooling load decreases, the leaving chilled water temperaturewill fall below the setpoint. When the leaving chilledwater temperature falls 3°F (1.7°C) below the setpoint,the chiller will cycle off. During a cycling shutdown themicropanel continues to monitor the leaving chilled watertemperature; when that temperature rises 1°F (0.55°C)above the setpoint the chiller will cycle on. The on/offcycling band used causes no noticeable effect for mostcooling applications. To prevent wear damage associatedwith starting and stopping, it is recommended that installationsbe designed to prevent the two-stage absorptionchiller from cycling more than twice per hour.RUPTURE DISK PIPINGAll YPC chillers ship with a rupture disk(s) designed to failat 12 PSIG (0.83 bar). The purpose of the rupture disk isNOISE LEVELVIBRATION LEVELFIG. 2 – TYPICAL NOISE AND VIBRATION LEVELSJOHNSON CONTROLSLD0100413


Application Data - continuedto quickly relieve excess pressures as a precaution in theevent of an emergency such as a fire. All models have 4”(101.6 mm) rupture disks (large tonnage units may havemore than one rupture disk, refer to factory submittal).A CPVC or fiberglass discharge pipe should run from therupture disk to a drain. Steel is not recommended unlessextra care is taken to support piping and isolate any stressfrom the rupture disk. The discharge pipe must supportindependent of the Two-Stage unit.SOUND AND VIBRATION CONSIDERATIONSSince the YPC unit generates very little vibration, vibrationeliminating mounts are not usually required. However,when the machine is installed where even mild noise isa problem, mounts or pads should be used (see Fig. 2,p. 13). The use of anchoring bolts on the machine legs isnot normally necessary.THERMAL INSULATIONYPC units require thermal insulation (by others) on bothhot and cold surfaces in order to achieve maximum efficiencyand prevent sweating. Required insulation areais tabulated on page 17.STEAMGeneral – The YPC unit is nominally rated for dry steamwith minimal superheat, and a pressure of 115 PSIG (7.93bar) (at the steam valve). The inlet steam must not have atemperature higher than 363°F (183.9°C) and cannot havea saturation pressure higher than 128 PSIG (8.83 bar).Pressure – Since a lower steam saturation pressurecorresponds to a lower temperature in the generator, aYPC chiller’s available capacity varies with the steampressures at the steam valve. Fig. 3 on p. 14 graphicallydepicts the relationship between steam saturation pressureand available capacity.Piping – The steam piping must follow the diagram foundin Fig. 4 on p. 15. Beginning at the steam supply, the automaticshut off valve (by others) must be failsafe and isdesigned to protect the unit in case of a power failure. Asteam separator should be installed after the automaticshut off valve to ensure the unit receives only dry steam. Asteam trap below the separator will allow draining of onlycondensate. Beyond the separator, a #50 mesh strainerremoves foreign matter from the steam. A regulator isonly necessary if the steam supply pressure to the unitwill exceed 128 PSIG (8.8 bar). The pressure relief valveshould be set to open at 128 PSIG (8.83 bar). The JohnsonControls-supplied steam control valve must be no furtherthan 200 inches (5 m) from the first-stage generator steaminlet flange in order to minimize the pressure drop fromthe valve exit to the generator inlet.Dimension H1 is specified to prevent condensate backflowfrom the generator into the steam piping. DimensionH2 is specified to prevent excessive backpressure to thedrain cooler. During factory testing, the unit is calibrated toprovide design condensate flow to a condensate systemoperating at 15.0 PSIG (1 bar) (as measured immediatelydownstream of the Drain Solenoid Valve). To duplicate thiscondition in the field, an adjustable Condensate SystemBackpressure Valve (by others) must be installed suchthat:∆PH2 + ∆PPIPING + ∆PVALVE = 15.0 PSIG (1 bar)Where:∆PH2 = Pressure drop due to height, H2∆PPIPING = Pressure drop due to condensate piping,elbows, bends, etc.∆PVALVE = Pressure drop due to Condensate SystemBackpressure ValvePSIG 28.6 42.9 57.2 71.5 85.8 100 115bar 1.97 2.96 3.94 4.93 5.92 6.90 7.93STEAM INLET PRESSURELD01005FIG. 3 – CAPACITY VS. INLET STEAM PRESSUREAVAILABLEThe drain cooler installed on the unit effectively eliminatesthe need for an additional condensate cooler or a steamtrap. The drain solenoid valve is a factory installed deviceto insure zero steam flow through unit during shutdown.All steam piping should be adequately supported andbraced independent of the Two-Stage chiller. The supportsystem must account for the expansion and contractionof steam piping, avoiding the imposition of strain on thechiller components.Control Valve Sizing – Control valves are sized for eachjob based upon the available steam pressure, requiredsteam pressure at the unit, and the full load requiredsteam flow. During start-up, YORK technicians establishthe minimum load steam valve position (20%) and set the14 JOHNSON CONTROLS


FORM 155.19-EG3 (1108)limit switch accordingly, eliminating possible problems atstart up.ELECTRICAL DATATable 2 contains unit electrical data. Total kW includespower requirements for the system solution and refrigerantpumps. All models have one solution pump, one solutionspray header pump and one refrigerant pump.NOTES:1. H 1= 15 in. (381 mm) minimum to prevent condensate backflow.2. H 2= 32.8 ft. (10 m) maximum to prevent excessive back pressure.3. Condensate leaves drain cooler at approximately 15 PSIG (1 bar),180°F (82.2°C).4. Maximum inlet steam pressure 128 PSIG (8.83 bar).5. Automatic shutoff valve to be failsafe type.6. Both the steam supply and condensate drain pipes must be properlysized and pitched to prevent hammering.7. Steam control valve to be installed within 200 inches (5 m) of thefirst-stage generator steam inlet flange.FIG. 4 – PIPING LAYOUTJOHNSON CONTROLS15


Application Data - continuedTABLE 2 – ELECTRICAL DATA NOTES:1. Incoming wire to chiller must be copper only. Aluminum wiring is not permitted.2. Lugs in Power Panel will accept incoming wire range of #14 AWG through #1 AWG.3. Electrical system must be securely guarded.4. Field wiring must conform to NEC and all other applicable local codes.16 JOHNSON CONTROLS


DimensionsFORM 155.19-EG3 (1108)YORK International is committed to a policy of continuous product improvement. Dimensions subject to changewithout notice. Consult factory-submitted drawings. NOTES:1. Tube pull space for the main shell is equal to the unit length on either end of the machine. first-stage generator tube pull space is requiredon the end opposite the steam inlet.2. Steam inlet and condensate outlet are 150 PSIG raised face flanged.JOHNSON CONTROLS17


Nozzle Arrangement 14SCSTEAM INLETOPPOSITE ENDTOWER WATER NOZZLE ARRANGEMENTSEVAPORATOR NOZZLE ARRANGEMENTS NOZZLE SIZES *Number of passes refers to the number of absorber passes only. The condenser is always one pass with nozzle sizes that match the absorber.NOTES:1. Choose desired nozzle arrangement – water boxes are not interchangeable.2. Standard water nozzles are furnished as welding stub-outs with Victualic grooves, allowing the option of welding, flanges, or the use of Victualiccouplings. Factory installed, class 150 (ANSI B16.5, round slip on, forged carbon steel with 1/16” raised face), water flanged nozzles are optional.Companion flanges, nuts, bolts, and gaskets are not furnished.3. Connected piping should allow for removal of compact water box for tube access and cleaning.4. Tower water must enter the absorber first for proper performance.18 JOHNSON CONTROLS


Nozzle Arrangement 16SL and LargerFORM 155.19-EG3 (1108)STEAM INLETOPPOSITE ENDLD01008EVAPORATOR NOZZLE ARRANGEMENTSTOWER WATER NOZZLE ARRANGEMENTS NOZZLE SIZES *Number of passes refers to the number of absorber passes only. The condenser is always one pass with nozzle sizes that match the absorber.NOTES:1. Choose desired nozzle arrangement – water boxes are not interchangeable.2. Standard water nozzles are furnished as welding stub-outs with ANSI/AWWA C-606 grooves, allowing the option of welding, flanges, or the useof ANSI/AWWA C-606 couplings. Factory installed, class 150 (ANSI B16.5, round slip-on, forged carbon steel with 1/16” inch raised face), waterflanged nozzles are optional. Companion flanges, nuts, bolts, and gaskets are not furnished.3. Connected piping should allow for removal of compact water box for tube access and cleaning.4. Tower water must enter the absorber first for proper performance.JOHNSON CONTROLS19


Guide SpecificationsGENERALProvide YORK Millennium YPC Two-Stage AbsorptionSteam-Fired Chiller-Heater(s) capable of producingchilled water per the capacities shown on drawings andschedules.Each chiller shall be of hermetic design, leak tested, andfactory performance tested.Chiller-heater shall ship as a one-piece assembly readyfor connection to the building water, fuel, and electricalsystems. Purge pump, chilled-water flow switch and steamvalve shall be shipped loosed for filed installation.Chiller to ship complete with factory-balanced lithiumbromide(LiBr) and refrigerant precharged in unit in orderto simplify and expedite field start up. Unit shall ship witha nitrogen gas holding charge to eliminate the possibilityof air entering unit during transport and to permit theverification of a leak-tight unit upon delivery.Purchase price to include parts and labor warranty for aperiod of one year from start up or eighteen months fromdelivery, whichever occurs first.CONSTRUCTIONThe chiller-heater unit to consist of one first-stage (hightemperature) generator, solution heat exchangers, andmain shell. The main shell shall include the condenser,second-stage (low temperature) generator, evaporator,and absorber.Crossover routing cooling water from the absorber to thecondenser shall be shipped loose from the factory, eliminatingthe need for a customer supplied crossover pipe.The flow of solution shall be initiated by a hermetic solutionpump, located beneath the absorber, and shall be dividedinto two parallel paths, one leading to the first-stage generatorand the other to the second-stage generator. Thisparallel flow design shall permit each stream of solutionto be concentrated only once in order to limit the maximumconcentration of LiBr and thus minimize the risk ofcrystallization.TUBE MATERIALSThe first-stage generator tubes shall be 70/30 cupronickel,0.035 inch (0.89 mm) wall thickness and shall be“U-shaped” to minimize thermal stress, prolong tube life,and increase unit efficiency. The drain cooler tubes shallbe 90/10 cupro-nickel, .030” (0.76 mm) wall thickness.The second-stage generator evaporator, absorber, andcondenser shall be seamless copper 5/8” (15.875 mm),OD, 0.025” (0.635 mm) wall, copper tubing for the 14SC,and 3/4” (19.05 mm) OD, 0.028” (0.71 mm) wall for the16SL and larger, with enhanced surface as required tomeet given capacity.WATER BOXESWater boxes shall be removable to permit tube cleaningand replacement. Water-circuit tubing to be replaceablefrom either end of the chiller-heater unit. Stubout waterconnections having ANSI/AWWA C-606 grooves shallbe provided as standard (ANSI flanged connections areoptional). All water boxes and associated water-circuitnozzles and tube bundles shall be designed for 150 PSIG(10.3 bar) working pressure and shall be hydrostaticallytested to 225 PSIG (16 bar). Vent and drain connectionsshall be provided on each water box.SIGHT GLASSESUnit shall be equipped with no fewer than six (6) sightglasses to permit exact adjustment of solution and refrigerantlevels under full load conditions to ensure efficientand trouble free operation. Sight glasses to be located asfollows: upper evaporator, lower evaporator, first-stagegenerator, second-stage generator, absorber, oil trap.SPRAY DISTRIBUTIONSolution and refrigerant distribution shall be accomplishedby use of a drip apparatus which produces a fine, laminarfilm on the outside of the tube bundles.PUMPSSolution and refrigerant pumps shall be hermeticallysealed, self lubricating, totally enclosed, liquid-cooled,factory-mounted, wired and tested. Suction and dischargeconnections of solution and refrigerant pumps shall bewelded to chiller-heater unit piping. Flanged pump connectionsare not acceptable. Pumps shall be designed fora total of 55,000 hours between service inspections.ISOLATION VALVESSuction and discharge connections for the solution andrefrigerant pumps shall be equipped with factory weldedisolation valves to permit the servicing of hermetic pumpassemblies without any loss of solution or leakage of airinto the chiller-heater.SOLUTION VALVESValves used for adjusting solution flow shall be fullywelded or brazed to prevent leakage of air into unit. Valveoperator shall be covered with a seal cap to eliminate thepossibility of stem leakage. Fittings between valve bodyand unit piping to be welded. Threaded valve connectionsare not acceptable.20 JOHNSON CONTROLS


FORM 155.19-EG3 (1108)PURGING SYSTEMChiller-heater shall be equipped with a purge systemwhich will constantly remove noncondensible vaporsfrom the unit during operation using an eductor. Noncondensiblesshall be stored in a purge chamber until theycan be removed through the use of a purge pump.The Control Panel shall include a Smart-Purge system thatwill automatically sense the amount of non-condensiblesin the purge chamber and empty the tank whenever necessary.The SmartPurge system shall eliminate the need foran operator to ever manually empty the purge chamber.In addition, the control panel shall monitor the frequencyof purge cycles and alert the chiller operator, through aunique control panel warning message, if the number ofpurges exceeds normal levels.Purge systems that utilize a palladium cell (for venting hydrogen)on the purge chamber to prolong the time betweenemptying the purge chamber shall not be acceptable,since the vented hydrogen is the major byproduct of thecorrosion caused by a leak. If a system with a palladiumcell is offered, the purchase price must include a contractfor quarterly leak checking of the machine.The purge pump shall be of an oil, rotary, two-stage design.It shall be furnished complete with a 1/4 HP, 3 Phase,ODP motor, and all required accessories including base,pulleys, and belt guard. Purge pump shall be equippedwith stainless steel vanes.LITHIUM-BROMIDE AND REFRIGERANT CHARGELithium-bromide solution shall contain a corrosion inhibitoradditive, lithium-molybdate, to minimize the rateof copper and ferrous metal corrosion on the solutionside of the unit. The corrosion inhibitor, when applied atthe concentrations prescribed by the unit manufacturer,shall not cause the inhibited lithium-bromide solution tobe classified as a hazardous waste under the ResourceConservation and Recovery Act. Lithium-bromide solutionscontaining chromates or arsenites as corrosioninhibitors shall not be acceptable. If systems are bid thatinclude lithium-bromide solutions containing chromateor arsenate inhibitors, the purchase price shall include acontract supplying disposal services for removal of bromideas a result of regular service or when the machineis being taken out of commission.STEAM VALVEJOHNSON CONTROLSChiller-heater shall be furnished with a steam controlvalve, linkage, and actuator motor. This assembly shallbe shipped loose for installation by others. Valve/linkage/actuator motor assembly to be sized by the unit manufacturerin accordance with the specified steam pressureand flow requirements.The steam valve shall be a cage type valve incorporatinga carbon steel body and a teflon seat. Valve/linkage/actuatormotor assembly shall be capable of modulating steamflow in a linear fashion from 20% to 100% of maximumdesign chiller steam input. Valve shall be equipped with150 lb ANSI flanged connections.The actuator motor shall be 120V/1 Ph/60Hz, and shall bepowered from the chiller’s microcomputer control panel.Actuator motor position to be communicated to the MicroComputerControl Center through a 0 - 135 ohm feedback control signal.UNIT CONTROLSEach unit shall be furnished complete with a factorymounted and prewired control system. Unit controls tobe furnished shall include a total of two (2) enclosures:a Power Panel, and an MicroComputer Control CenterPanel.Power Panel – The Power Panel enclosure shall beNEMA 1 and shall house the following components:single-point wiring connection for incoming power supply;non-fused disconnect switch; motor starters, completewith current and thermal protection, for solution pump, refrigerantpump, and purge pump (current overloads only);and a 115VAC 50/60 Hz Control Power Transformer.MicroComputer Control Center Panel – The Micro-Computer Control Center enclosure shall be NEMA 1 andbe equipped with hinged access door with lock and key.All temperature sensors, pressure transducers, and othercontrol devices necessary to sense unit operating parametersto be factory-mounted and wired to panel. The ISNTwo-Stage Control Center Panel shall include a 40 characteralphanumeric display showing all system parametersin the English language with numeric data in English (ormetric) units (°F, PSIA or °C, KPa respectively).The 115V/1∅ control voltage will be supplied througha 1 KVA power transformer located in the Power Paneland will be factory wired to the MicroComputer ControlCenter Panel.Terminal blocks will be provided for all external safety andcontrol interlocks.The operating program shall be stored in non-volatilememory (EPROM) to eliminate chiller failure due to ACpower failure/battery discharge. In addition, programmedsetpoints shall be retained in lithium battery-backed RTCmemory for a minimum of 5 years.21


Guide Specifications - continuedAll wiring and control interlocks between the Micro-Computer Control Center Panel and the Burner ControlPanel shall be factory installed and tested prior to unitshipment.System Operating Information – During normal operationthe following operating parameters shall be accessiblevia the MicroComputer Control Center Panel:• Return and leaving chilled water temperatures• Return and leaving condenser water temperatures• first-stage generator pressure• Refrigerant temperature• Solution temperature• Indication of refrigerant/solution/purge pump operation• Operating hours• Number of starts• Number of Purge Cycles (last 7 days and total cumulative)• first-stage generator temperature• Steam valve actuator potentiometer position (in %)Capacity Control – The MicroComputer Control CenterPanel shall automatically control the input steam flow rateto maintain the programmed leaving chilled water setpointfor cooling loads ranging from 20% to 100% of design.The input steam flow rate shall also be adjustable manuallyfrom the MicroComputer Control Center Panel to anysetting between minimum and maximum when automaticoperation is not desired and when steam input is not beinginhibited by a specific operating condition.Safety Shutdowns – Panel shall be pre-programmed toshut the unit down and close “safety shutdown” contactsunder any of the following conditions:• Refrigerant or solution pump thermal or current overland• Low refrigerant temperature• first-stage generator high temperature or pressure• Loss of chilled water flow• Power failure (when “Automatic Restart after PowerFailure” option is not utilized)• Incomplete dilution cycle operation due to one of thefollowing conditions:• Power failure• Solution/refrigerant pump overloads• Low refrigerant temperature• Loss of chilled water flow• External auxiliary safety shutdownAll safety shutdowns will require unit to be manuallyrestarted.Whenever a safety shutdown occurs, the MillenniumControl Panel shall record the following information andstore it in memory (or communicate it to remote printer):day and time of shutdown; reason for shutdown; type ofrestart required (automatic restart is displayed, manualrestart is implied); all system operating information displayedjust prior to shutdown.Warning Conditions – MicroComputer Control CenterPanel shall close warning contacts and generate a uniquewarning message whenever one of the following operatingconditions is detected:• Low refrigerant temperature• High generator temperature or pressure• High or low entering condenser water temperature• Purge pump current overload• Faulty solution dilution temperature sensorCycling Shutdowns – Control Center Panel shall bepre-programmed to shut unit down whenever one of thefollowing conditions is detected:• Loss of condenser water flow• Low leaving chilled water temperature• Power failure (when “Automatic Restart after PowerFailure” option is selected)Cycling shutdowns shall permit unit to automatically restartwhen pre-programmed thresholds are reached. Followinga cycling shutdown, cycling shutdown contacts shallclose and cycling shutdown messages shall be displayedand recorded in a similar fashion as safety shutdownmessages.Programmable Setpoints – The following parametersshall be programmable directly from the key pad:• Leaving chilled water temperature in 0.1°F (0.1°C)increments• Remote reset chilled water temperature range (seedetail below)• 7 day schedule for unit start/stop (see detail below)• Holiday schedule for unit start/stop (see detail below)• Pull down demand (see detail on following page)• Time clock/calendar date22 JOHNSON CONTROLS


FORM 155.19-EG3 (1108)Remote reset signals for leaving chilled water temperaturesetpoint shall be 1 to 11 second pulse width modulated(PWM) as standard. An optional field installed card fileand card shall be available to permit the following resetsignals to be used in lieu of a 1 to 11 second PWM signal:4-20mA, DC, 0-10VDC, contact closure 7-day schedulingshall permit one unit start and stop to be made each dayat discrete times as desired over a seven day calendarbasis through the use of an integral timeclock. In addition,a separate holiday schedule shall be programmable upto one week in advance.All major system components such as chilled waterpumps and condenser water pumps shall be able to becontrolled from the control center panel to start and stopwith the chiller (except as required for safety shutdowns)to minimize system energy usage.The pull down demand feature shall permit ramp loading ofinput steam flow rate upon unit startup. Programmable inputsinclude initial input steam flow rate (30% to maximum)final input steam flow rate (30% to maximum), and durationof pull down demand period (0 to 255 minutes).Remote Steam Limit Input – The remote steam limitinput feature shall permit the limiting of input steam flowrate when the unit is operating in the remote mode at anytime from 30% to maximum based upon a remote 1 to 11second pulse width modulated (PWM) signal. An optionalfield installed card file and card shall be available to permitthe following remote pull down demand signals to beused in lieu of a 1 to 11 second PWM signal: 4-20mA DC;0-10VDC; contact closure.Concentration Calculator – The micropanel shallmonitor the first-stage generator concentration to preventoperation at an unsafe concentration. Concentrationshall be tied into both the Warning Conditions and SafetyShutdown systems. Also included shall be an operatorinterface concentration calculator. An operator shall beable to use the concentration calculator to determineconcentration by inputting a set of conditions. When anoperator inputs any two of three parameters (bromidesolution temperature, saturation temperature, and pressure),the micropanel shall display the concentration. Thedisplay shall also indicate if the input conditions are in thecrystallization zone.Data Logging – The MicroComputer Control CenterPanel shall contain an RS 232 port to enable the transmissionof all operating setpoint and shutdown informationto a remote printer (printer supplied by others). Thistransmission can occur as needed or automatically onpredetermined intervals (0.1 to 25.5 hrs). In the case of asafety or cycling shutdown, the RS-232 port shall transmitall operating data detected prior to the shutdown as wellas the time and cause of the shutdown to a remote printer(printer supplied by others). In addition, a history of thelast four safety or cycling shutdowns and operating data,with the exception of power failures, shall be retained inmemory and can be printed as well.Energy Management Interface – When connectedto an Integrated System Network provided by the chillermanufacturer, the MicroComputer Control Center Panelshall be able to communicate all data accessible from thekeypad to a remote integrated DDC processor througha single shielded cable. This information will include allunit temperatures, pressures, safety alarms, and statusreadouts for complete integrated plant control, data logging,and local/remote display of operator information. Thesingle shielded cable shall also allow the remote integratedDDC processor to issue operating commands to the controlcenter including, but not limited to, the following:• Remote unit start/stop• Remote chilled water temperature reset• Remote steam limit inputThe MicroComputer Control Center Panel shall alsoprovide a limited interface to other building automationsystems in order to permit the following operations:• Remote unit start/stop• Remote chilled water temperature reset• Remote steam limit input• Remote readout of status including• Unit ready to start• Unit operating• Unit safety shutdown• Unit cycling shutdownJOHNSON CONTROLS23


Printed on recycled paperForm 155.19-EG3 (1108) Supersedes: 155.19-EG3 (197)© 2008 Johnson Controls, Inc. P.O. Box 423, Milwaukee, WI 53201 Printed in USAwww.johnsoncontrols.com

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