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Bulletin No. IM 127 Rev. November 1973 INSTALLATION AND MAINTENANCE DATA WHC CENTRIFUGAL WATER CHILLER 145 THRU 362 TONS l McQUAY-PERFEX INC. l 13600 INDUSTRIAL PARK BLVD., P.O. BOX 1551 MINNEAPOLIS, MINNESOTA 55440 l PHONE: (612) 545-2892

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  • Bulletin No. IM 127Rev. November 1973

    INSTALLATION ANDMAINTENANCE DATA

    WHCCENTRIFUGAL WATER CHILLER

    145 THRU 362 TONS

    l McQUAY-PERFEX INC. l 13600 INDUSTRIAL PARK BLVD., P.O. BOX 1551MINNEAPOLIS, MINNESOTA 55440 l PHONE: (612) 545-2892

  • TABLE OF CONTENTS

    Controls ............................................... ..12Sequence of Operation...................................1 5Set Points ........................................... ..l 6

    Wiring Diagram ...................................... 26,27Charging ................................................. 37

    Dimensional Data ......................................... 5

    Electrical ............................................. ..ll

    Auxiliary Interlocks .............................. ..13.14Motor Data ........................................... ..4 5

    Power Wiring ......................................... ..llElectronic Control ....................................... 34

    Operation ............................................ ..3 4Calibration ............................................ 40

    Evacuation ................................ .._............3 6Leak Tests .............................................. .3 6Liquid Flow Control ...................................... 32

    Location ................................................. 3

    Motor Cooling .......................................... ..3 4Moving and Mounting ...................................... 4

    Oil System ............................................. ..2 4Physical Data .......................................... ..4 6Pre-Installation ................................... ..ti ... 3

    Pre-Startup ............................................ ..19

    Pressure Drop-Evaporator ............................... ..4 3Pressure Drop-Condenser ................................ ..4 4Shutdown ............................................... ..3 7

    Startup ................................................ ..2 3Trouble Shooting ......................................... 48Vane Control .......................................... ...2 9

    Warranty Information ..................................... 47Water Piping ............................................. 6

    Chilled Water .......................................... 9

    Condenser Water ........................................ 9

    Oil Cooler ............................................ .lO

    System Schematic ....................................... 7

    0 1 9 7 2 McQuay Div is ion, McQuay - Perfex Inc.

    “McQUAY” a n d “ S E A S O N P A K ” are registered trademarks of McQuay D iv is ion , M inneapo l is , M innesota .

    NOMENCLATURENominal Capacity (Tons)

    WHC _ 228A _ A t R . H . C O N D E N S E R , R H . E V A P O R A T O R

    - 6 k R .H . CONDENSER, L .H . EVAPORATOR

    - c k L .H . CONDENSER, R .H . EVAPORATOR

    - D t L .H . CONDENSER, L .H . EVAPORATOR

    Page 2

  • INTRODUCTION

    McQuay WHC Seasonpak centrifugal water chillers are completelyindependent, automatic refrigeration systems, designed to chillwater. The WHC Seasonpak centrifugal chillers are factoryassembled as a complete packaged unit, piped, wired, evacuated,charged with refrigerant and oil, and performance tested, readyfor installation. Each unit consists of: a flooded refrigerantshell and water thru-tube condenser: a single stage gear drivencentrifugal compressor with a liquid cooled hermetic motor,and an independent oil pump with reservoir system. Alsoincluded are manual liquid line shut-off valves, liquid linetrimming valve, liquid line orifice and discharge line checkvalve.

    The 115 volt control center supplies power to the oil pump, oilheaters, and all safety and operating controls for completeautomatic operation of the centrifugal chiller. Terminals areprovided for all necessary field interlock wiring betweencontrol panel and unit starter, condenser pump relay, chillerpump starter, flow switch and oil cooler solenoid.

    PRE-INSTALLATION

    I. GENERAL - Equipment such as this is intended forinstallation by qualified personnel only. As a conditionof the warranty, the equipment start up must be performedunder the supervison of a McQuay Service Representative.Failure to do so voids the warranty.

    II.

    1

    INSPECTION - Upon receipt of equipment all items shouldbe carefully checked against the Bill of Lading to be sureall crates and cartons have been received. All unitsshould be carefully inspected for damage when received.Shipping damage may cause loss of refrigerant charge andcontamination of system. If any damage is found itshould be reported to the carrier immediately and a claimfiled for damage. McQuay, will not be responsible forany damage incurred in shipment.

    LOCATION

    A. This unit is designed for indoor application and must belocated in an area where the surrounding ambienttemperature is 40 F. or above. A good rule of thumb isto place units where ambients are at least 5 degreesabove the leaving water temperature.

    Page 3

  • L OC ATION (CONTINUED)

    B.

    C.

    D.

    I.

    Because of the electric control devices, the units shouldnot be exposed to the weather. A plastic cover over thecontrol box is supplied as temporary protection duringtransit.

    An adequately strong foundation or base must be providedfor mounting the concentrated load of the unit. Ifnecessary, additional structural members should be providedto transfer the weight of the unit to the nearest beams.Surfaces must be reasonably level.

    Adequate free area must be provided around the installedunit for connections and service. Allow 14 feet for tuberemoval and at least 3 feet around the remainder of theunit for servicing compressor, oil pump, and controls.

    MOVING AND MOUNTING UNIT

    MOVING THE UNIT

    A.

    B.

    C.

    D.

    The McQuay Seasonpak centrifugal chiller is mounted onheavy wooden skids to protect the unit from accidentaldamage and to permit easy handling and moving. SeeFig. 1 for physical and mounting information.

    It is recommended that all moving and handling beperformed with the skids under the unit and that theskids not be removed until the unit is in the finallocation.

    When moving the unit, dollies or simple rollers can beused under the skids. In moving always apply pressureto the base on skids only and not to the piping orshells. A long bar helps move the unit easily.Always avoid dropping the unit.

    When rigging the unit attach slings thru holesprovided in the base and always use spreader bars toprotect the control panel, piping and insulation fromdamage.

    Do not attach slings to piping or equipment. Move unitin the upright horizontal position at all times. Letunit down gently when lowering from the trucks orrollers.

    Page 4

  • II. HANDLING

    A. Every model WHC Seasonpak centrifugal chiller issupplied with a full refrigerant charge. For

    shipment, the charge is contained in the condenserand is isolated by the manual condenser liquid linevalves and discharge line check valve.

    B. Should the unit be damaged allowing the refrigerantto escape, there may be danger of suffocation in theequipment area since the refrigerant will displacethe air. Avoid exposing an open flame to refrigerant.Care should be taken to avoid rough handling or shockdue to dropping the unit. NEVER LIFT, PUSH OR PULLUNIT FROM ANYTHING OTHER THAN THE BASE.

    III. MOUNTING THE UNIT

    A. The negligible vibration normally encountered withthe Seasonpak centrifugal chiller makes this unitparticularily desirable for basement or ground floorinstallations where the unit can be bolted directlyto the floor if desired. The floor constructionshould be such that the unit will not affect thebuilding structure, or transmit noise and vibrationinto the structure.

    B. Mount the unit on the rubber isolation pads providedfor use under each corner of the base. On a.11 upperlevel installations or areas in which vibrationtransmission is an important consideration, optionalrubber-in-shear or spring-type isolators arerecommended for maximum vibration isolation from thebuilding structure. Use steel shims if necessary tolevel unit.

    WATER PIPING

    I. GENERAL CHILLER AND CONDENSER PIPING (See Fig. 2)

    A. When installing water piping follow established practicesand comply with local building and safety codes.

    B. Shut-off valves should be provided at the unit so thatnormal servicing of the unit can be accomplished with-out draining the entire system.

    Page 6

  • WATER PIPING (CONTINUED) GENERAL

    C.

    D.

    E.

    F.

    G.

    H.

    I.

    J.

    K.

    All piping should be installed and supported toprevent the unit connections from bearing any strainor weight of the system piping.

    Vibration eliminators in all water piping connected tothe unit are recommended to avoid straining the pipingand transmitting pump noise and vibration to thebuilding structure.

    It is recommended that temperature and pressureindicators be installed within 3 feet of the inletand outlet of the shells to aid in the normal checkingand servicing of the unit.

    A cleanable-type wire mesh strainer is recommended atthe condenser pump suction and must be provided atthe evaporator pump suction to protect the pump andshell from foreign matter. Freeze up can result ifforeign matter is allowed to block evaporator tubes.

    Design the water piping so that it has a minimumnumber of changes in elevation. Include manual orautomatic vent valves at the high points of the waterpiping, so that air can be vented from the watercircuit. System pressures can be maintained by usingan expansion tank or a combination pressure reliefand reducing valve.

    A preliminary leak check of the water piping should bemade before filling the system.

    The water connections are of the grooved Victaulictype for use with Victaulic couplings. Matched fittingsmust be field provided for the inlet and outletconnections. The water inlet is the bottom connectionand the water outlet the top connection on bothevaporator and condenser for all 2 and 3 pass units.See Table I for chiller and condenser connection sizes.

    If the shells must be drained for winter shut-down itis recommended that an anti-freeze solution be circulatedand drained for positive freeze protection.

    All supply and return water boxes for the evaporatorand condenser are provided with two pipe plugs whichcan be removed for venting and draining the shells.

    Page 8

  • II. CHILLED WATER PIPING

    A. All chilled water piping should be insulated toprevent condensation on the lines. If insulation isnot of the self-contained vapor barrier type, itshould be covered with a vapor seal. Piping shouldnot be insulated until completely leak tested. Ventand drain connections must extend beyond proposedinsulation thickness for accessability.

    B. The system cycling thermostat, TC(W) and electronicvane control EVC are mounted inside the controlconsole with the sensors mounted in the evaporatorleaving water connection. The low water temp safetyTS(LW), sensing bulb is located in the chiller tubesheet. Care should be taken not to kink or break thecharged capillary tubing when working around theunit. It is also advisable to check the cap tubebefore running the unit to be sure that it is firmlyanchored and not rubbing on the frame or any othercomponent.

    C. The evaporator water boxes can be interchanged endfor end so that the water connections can be made ateither end of the unit. If this is done the 3sensors discussed above must be moved to sense theleaving water temperature from the unit. New headgaskets must be used if a change is made. Gasketsmust be trimmed to conform to block-off bafflearrangements in the water boxes which vary with thenumber of passes in the shell.

    III. CONDENSER - WATER PIPING

    A.

    B.

    C.

    Water cooled condensers may be piped for well waterapplications, or for use in conjunction with acooling tower. Cooling tower applications shouldinclude a small amount of waste circulating waterand adequate water treatment provided to preventbuild-up of contaminants and scale in condenser tubesand tower basin.

    The condenser water boxes can be interchanged endfor end so that the water connections can be made ateither end of the unit. New head gaskets must betrimmed and used if a change is made.

    The minimum entering water temperature to thecondenser is 65 F. This can be accomplished by acooling tower or condenser bypass or by thermostaticcontrol of the cooling tower fans,

    Page 9

  • CONDENSER WATER PIPING (CONTINUED)

    D. A condenser flow switch is not required and cannotbe wired directly into the interlock circuit. Ifused, a normally closed timer must be used to bypassthe condenser flow switch on start up.

    IV. OIL COOLER WATER PIPING

    A.

    B.

    C.

    A minimum of 8 GPM of water at 85 F. or lowertemperature must be provided to the oil cooler tomaintain the oil temperature leaving the cooler ata maximum of 110 F. The bottom 1"" NPT connection isthe inlet and the top 1"" NPT connection is the outlet.

    If condensing water is used it is imperative that thewater temperature be kept within design limits to keepoil temperature supply below 110 F. There is also apotential problem due to fouling which reduceseffectiveness. This problem must be recognized andfrequent tube cleaning may be required.

    When chilled water is used as the source of water forthe oil cooler it should be piped across the chillerpump directly to assure full pump pressure across theoil cooler. See Figure below.

    Preferred Oil Cooler Piping

    AA

    CHILLED WATERPUMP

    EVAPORATOR

    t’

    DRAINVALVE WITHLN3 F T O F

    COOLER

    Page 1 0

  • D.

    E.

    F.

    A.

    I. POWER WIRING

    If it is necessary to connect the oil cooler inparallel with either shell, it is essential thatthe pressure drop in the line be kept down to assureadequate flow to the oil cooler. The oil coolerwater pressure drop is 3.5 feet of water at 8 GPM.

    City water can also be used as the source of supply.A flow balance valve should be provided and thedrain line should be trapped to prevent the oilcooler from draining on the off cycle.

    In a.11 cases a strainer with a maximum l/4" meshshould be provided at the oil cooler inlet and anormally closed 115V. solenoid valve (water duty)must be provided and wired as shown on the unitwiring diagram.

    REFRIGERANT VENT PIPING

    Both the evaporator and the condenser shells havepressure relief valves to vent out refrigerant gasif an unsafe pressure should build up in the shell.It is recommended that these valves be vented tothe outside to meet local codes. For proper ventpiping procedure follow ASA B9-Sec. 12, ASME andlocal codes.

    ELECTRICAL

    The WHC Seasonpak centrifugal chiller is designed to beused in conjunction with a separately supplied starter ofthe across-the-line, star-delta or auto-transformer type.The starter and overloads are specifically selected forapplication with a specific size Seasonpak centrifugalchiller. Standard NEMA motor starters are not acceptable.

    A. All field wiring must comply with local, state andNational Electrical Codes.

    B. All fuses and wiring between disconnect, starter, andmotor must be in accordance with the National ElectricalCode.

    c. The compressor motor is supplied with 6 terminals foruse with across the line, star-delta, or auto-transformerstarters. When across-the-line or auto-transformerstarters are used terminals l-6, 2-4 and 3-5 must bejumpered together with terminal straps.

    Page 11

  • E L E C T R IC AL POW ER WIRING ( CO N T I N UE D)

    D. CARE must be used in wiring leads to compressor motorterminals to assure that proper phase relationship iscarried through starter to motor. NOTE: FINALCONNECTIONS TO THE COMPRESSOR ARE NOT TO BE MADE UNTILPOWER WIRING HAS BEEN CHECKED AND APPROVED AY ANAUTHORIZED McQUAY FIELD SERVICE REPRESENTATIVE.CAUTION: DO NOT TURN MOTOR TERMINAL STUDS WHEN MAKINGPOWER CONNECTIONS. THIS COULD LOOSEN STUD NUTS ANDCAUSE REFRIGERANT LEAKAGE.

    E. The power wiring to the compressor must be in theproper phase sequence for correct motor rotation.With phase sequence of l-2-3 and Ll connected toTl-T6, L2 connected to T2-T4 and L3 connected to T3-T5the motor will rotate in the proper direction (clock-wise when checking in motor sight glass). Label Ll,

    L2, and L3 lines at compressor motor junction box.

    F. EXTENSIVE DAMAGE CAN RESULT IF MACHINE IS ALLOWED TORUN IN WRONG DIRECTION. McQUAY IS NOT RESPONSIBLEFOR MACHINE DAMAGE CAUSED BY REVERSAL OF POWER PHASEBY POWER COMPANIES, ELECTRICIANS OR OTHERS.

    II. CONTROL WIRING

    A separate source of 115 volt, 60 cycle power is requiredfor the Seasonpak centrifugal chiller control circuit.This circuit is to be fused at 15 amps to protect thecontrol circuit from overload.

    A.

    B.

    IMPORTANT - THE DISCONNECT TO THIS CIRCUIT MUST REMAINON AT ALL TIMES TO MAINTAIN PROPER OIL TEMPERATURE INTHE SEASONPAK CENTRIFUGAL CHILLER TO PREVENTREFRIGERANT FROM ACCUMULATING IN THE OIL.

    ATTACH A LABEL WITH THE ABOVE NOTE TO THE CONTROLCIRCUIT DISCONNECT SWITCH.

    The source of power for the control circuit can be atransformer, if provided, in the unit starter. Thetransformer must be rated at 3 KVA with an inrushrating of 18 KVA. If the transformer is used as asource of power the unit disconnect should also bemarked with the label shown above in Paragraph A.

    Page 12

  • III. AUXILIARY WIRING

    In addition to the power wiring supplied to the unitcontrol center, additional interlock wiring is requiredand is to be wired directly to terminals provided inthe control center. Wire Gauge #14 THW is of sufficientsize for the amp capacity of the circuit. Consult theauxiliary interlock wiring diagram (Diagram 1) fordetailed wiring information.

    A.

    B.

    C.

    D.

    E.

    F.

    G.

    H.

    Wire the two sets of normally closed contacts (inunit starter) to terminals 26, 27, and 33, 34 in thecontrol center.

    Add wires from the current transformer provided in,the unit starter to terminals 37, 38 in the controlcenter.

    Provide a chiller pump interlock to prevent thecompressor from starting until chiller water flow hasbeen established. A set of normally open contactson the chiller pump starter is required inconjunction with a flow switch to be wired toterminals 29, 40, and 30.

    Provide a condenser pump relay with 2 sets ofnormally open contacts (115 v. coil max. 100 VArating), to start the condenser water pump at thetime the compressor is ready to start and cycle thecondenser pump with the compressor. Wire coil tocontrol center terminals 24, 28 with a set of normallyopen contacts wired to terminals 24, 25 and thesecond set of normally open contacts to start thecondenser water pump.

    Wire in the leads from the oil cooler water solenoid(115 V. coil) to terminals 8 and 6 in the controlcenter.

    Add interlock wiring between the control centerterminals 25 and 28 and the m&r starter relay inthe unit starter.

    Terminals 35 and 36 in the control center can bewired into a customer supplied and powered alarmcircuit if desired.

    Terminal 39 is a ground terminal for the controlpanel and should be wired to a suitable ground iflocal codes permit.

    Page 13

  • The necessary operational and safety controls for the McQuaySeasonpak centrifugal chiller are mounted in the control centeror incorporated in the system. With the interlock wiringbetween the starter, pumps, and unit: the control circuit is completeand the system will operate automatically.

    A description of the controls, control function and set point isshown in Table II.

    A schematic wiring diagram incorporating wire numbers is shown onP 26 & 27. The numbers on the left of the diagram designate theline numbers as an aid in following the sequence of operation.With 115 V. power to the control circuit, the system switch Sl"Off" and the unit calling for cooling the following sequenceof operation applies.

    I SEQUENCE OF OPERATION (Note: A simplified Sequence Appearsin Catalog 920)

    A. Power is fed thru the normally closed contacts of TD(P) andenergizes the oil sump heater and compressor heater (L. 65).

    B. Power is also fed to transformer, Tl, (L.85) energizing the24V. circuit controlling the vanes and energizing the D.C. motorrelay (L. 82) closing R (T) contacts l-2(L.52).

    C. Providing all safeties PS(HR), PS(LR), TS(HR), TS(HO), TS(LW);PS(L0) and R(T) are made, reset switches 2-8 can be pushed energizingrelays R4-R10 and de-energizing lights LTl-LT7.

    D. With the l-3 contacts of R4-R9 closed, R3 is energized closingits contacts 4-6 in the compressor starter circuit (L.25).

    E. If 40 minutes have elapsed since the machine has last started,Rll will be de-energized and Rll contacts 1-2 closed (L-21).

    F. By switching Sl to the "on" position, power is now fed thruTD(L) normally closed-timed open contacts if all interlocks areclosed and above conditions have been met.

    G . The TD(P) clutch coil is energized closing TD(P) normallyclosed - timed open contacts which energizes Ml contactor and TD(P)motor, providing oil pump overload, OL is closed (L.13).

    H. All Ml contacts of the oil pump starter close, starting theoil pump and energizing the field wired oil cooler solenoid.Closed vane indicator control, PC(V), will close at 30 PSIG oilpressure differential (only if vanes are closed).

    Page 15

  • I. As the oil pressure builds up the closed vane indicator control,PC(V), will close at 30 PSIG oil pressure differential (only ifvanes are closed). As the oil pressure builds up to 60 PSIG abovesuction pressure, PS(L0) contacts close energizing Rl and the fieldwired condenser pump relay, R(CP) (L-27).

    J. With the closing of Rl contacts 4-6 (L.59) the TD(N) clutch isenergized along with the TD(N) motor and Rll thru the normallyclosed-timed open contact of TD(N). This non recycle timer preventsthe machine from starting again for 40 minutes by keeping Rllenergized and Rll contact 1-2 open.

    K- When R(CP) is energized, R(CP) contacts close energizing R2 andthe motor starter relay, R(MS) (L.27).L. The R(MS) normally open contact in the starter energizes the circuitto the starter, providing power to the compressor motor. Thecompressor will now start.

    M. The unit will have started on low load with the vanes closed sincenormally closed starter interlock (Terminals 33, 34) will haveenergized fast close solenoid SV(FC). The normally closed interlocknow opens permitting the EVC to control the vanes.

    N. Compressor starter normally closed interlock (Terminals 26, 27)(L.17) also opens de-energizing TD(L) and preventing TD(L) fromopening the circuit. If for some reason the oil pump does not buildup pressure in 60 seconds, TD(L) will open up the compressor circuitand stop the oil pump.

    0. The electronic vane control (EVC) utilizes an electronic sensorlocated in the chiller leaving water to control the compressorinlet guide vanes. On temperature increase SV(0) is energized,causing the vanes to open and on temp. decrease SV(C) is energizedslowly closing the vanes and thereby limiting the volume of gas thecompressor handles.

    P. The electronic vane control (EVC) also receives a signal from acurrent transformer, CT, located in the unit starter. If thecurrent reaches 100% of the control set point, the current controlcircuit in the EVC overides the temperature control circuit andprevents the vanes from opening further. If motor current continuesto increase to 105% of the set point the current control energizesSV(FC)and SV(C). These solenoids direct oil flow to swiftly closethe vanes and thereby limit the unit power.

    Q . The low refrigerant pressure vane control PC(LR), (L.78) canalso override the EVC and put the vanes in fast close as above ifthe suction pressure drops to an undesirable low point.

    Page 17

  • R. The above control sequence described in 0, P, and Q will keepthe machine on the line and provide automatic operation down to a10% load. If leaving water temperature drops below the set pointof TC(W) (L.25), it will open , de-energize the circuit to R(MS)and stop the compressor. The TD(P) clutch will also be de-energizedwhich starts the timing of the TD(P) motor. The oil pump will continueto run for 30 seconds however until TD(P) contacts time open.

    S . The compressor can also be stopped similar to R above by any oneof the six safety controls: PS(HR), PS(LR), TS(HR), TS(H0) TS(LW),or PS(L0).

    If for example, PS(HR) opens R4 (L.35) is de-energized openingcontacts R4, l-3 and 4-6 and closing R4, 4-5. This lights warninglight LTl, de-energes R3 opens R3 contacts 4-6 and closes R3 contact1-2. The R3, 1-2 contacts will energize a circuit to a fieldsupplied alarm bell if used. Although PS(HR) automatically resetsupon pressure reduction, R4 cannot be energized until S2 is reset,energizing R4 and consequently R3. Operation of other safety controlsis similar.

    T. If the oil pressure drops below 50 PSIG differential duringoperation, PS(L0) contacts (L.25) open stopping the compressor,de-energizing R-10 and lighting LT7. S8 must be reset after PS (LO)

    resets to energize R10 (L.55). On unit shut down or onoperation of safeties in 2 above R2 normally closed contacts 1-2keep RlO energized after PS(LO)opens and reset of S8 is not required.For detailed control operation see control operation and calibrationP. 16 .)

    As described above, an opening of a system safety control will stopthe machine and the light will indicate the malfunction. Beforeresetting the corresponding reset button the cause of tie malfunc-tion must be located and corrected. Failure to do so will causerepeated malfunction and machine damage.

    Repeated tripping of a safety should be reported to the McQuayService Department and immediately investigated by a qualifiedrefrigeration service engineer.

    PRECHECK FOR INITIAL START UP

    After all of the piping and interlock wiring to the unit has beencompleted, and all auxiliary components installed a pre-startup check is to be made per Items A - K below. See Appendix B forlist of instruments and tools suggested for unit check out andoperation. At this point the McQuay Seasonpak Centrifugal Pre-StartCheck List (Form 240284A) must be completed and returned to theMcQuay Service Dept.

    Page 18

  • NOTE: The completed form must be received by the McQuay ServiceDepartment at least two weeks before a McQuay Service Representativewill be sent to the job site for start up.

    c'NOTE: THE INITIAL UNIT START UP MUST BE PERFORMED IN THE PRESENCEOF AN AUTHORIZED McQUAY SERVICE REPRESENTATIVE TO VALIDATE WARRANTY.

    *

    I PRE-START UP

    A. With main disconnect open manually close and open main startercontactor to make sure it operates freely. All shipping wedgesand clamps must be removed from relays and contactors. Manuallyoperate relays, contacts and interlocks to see that they workfreely. Check current carrying contacts and terminals forcompatibility of materials, dirt, and rust and change or clean ifnecessary. Check the 3 overload relays to make sure they are ratedat 105% of compressor FLA. Check dashpot and piston assembliesfor cleanness and add dashpot fluid per manufactures overloadinstructions.

    B. Check all electrical connections in control panel and starterto be sure they are tight ardprovide qood electrical contact.Although connections are tightened at the factory they may haveloosened enough in shipment to cause a malfunction.

    C. Check and inspect all water piping. Make sure flow directionis correct and piping is made to correct connection on evaporator,condenser and oil cooler.

    D. Open all water flow valves to the condenser and evaporator.

    E. Flush the cooling tower and system piping. Start evaporatorpump and manually start condenser pump and cooling tower. Checkall piping for leaks. Vent the air from the evaporatorand condenser water circuit as well as from the entire water system.

    F. Check pressure drop across evaporator, condenser, oil coolerand see that water flow is correct per the design flow rates.

    G. Check the actual line voltage to the unit to make sure it isthe same as called for on the compressor nameplate within 210%and that phase voltage unbalance does not exceed 2%. Verify thatadequate power supply and capacity is available to handle load.

    H. Make sure all wiring and fuses are of the proper size. Alsomake sure all interlock wiring is completed per McQuay diagrams.

    I. Verify that all mechanical and electrical inspections by codeauthorities have been completed.

    J. Make sure all auxiliary load and control equipment is operative

    and that an adequate cooling load is available for initial start up.

    Page 19

  • K. Arrange to have qualified maintenance personnel (who will bein charge of operation of equipment) present at initial start upfor operating instructions.

    Upon completion of the above checks, return the Pre-Start checklist (Form 240284A) to the McQuay Service Dept.

    After the above checks have been completed, the unit is ready forleak testing and control circuit checking before actual start up.THESE TESTS MUST BE DONE IN THE PRESENCE OF AN AUTHORIZED McQUAYSERVICE REPRESENTATIVE.

    II LEAK TESTING

    Although the unit underwent two extensive refrigerant leak testsat the factory and was free of leaks when shipped, leaks coulddevelop if damaged or mishandled in shipping. A leak test mustbe performed by the start up contractor under supervision of aMcQuay Service Representative. See Appendix A for details on leaktesting.

    III CONTROL CIRCUIT CHECKS

    Upon completion of above pre-start up check the control panel mustbe checked. Although the unit was completely checked at the McQuayfactory before being shipped, control settings may change duringshipping and field interlock wiring circuits, if incorrect, couldcause system malfunction.

    NOTE: Before control circuit is energized oil pump valves must beopen. Open fully all three shut off valves (#3, 4, and 5) on topof oil pump and close the right hand pump return valve (#4) 1 l/2turns from full back-seat position to allow oil drainage from vanesystems. Open oil shut off valve (#6) at oil filter. (Check thatoil level is in top l/4 of sight glass).

    The oil pump can be run during control circuit test for a shortperiod of a time, but the compressor must not be started.

    T THIS TIME.

    With the control circuit only energized and the unit disconnectopen, correct unit operation can be determined by observing themotor starter relay in the unit starter.

    For initial part of test, temporarily remove 2 wires fromterminals W and R on oil pump and tape individually to preventpossible dead shorting.

    Add (2) - 115V lights in parallel with oil cooler solenoid andto observe simulated oil pump and compressor operation.

    Page 20

    R (MS)

  • Clamp ampmeter across heater circuits to check their operation.

    A. With system switch Sl "off" lights 1-7 and alarm will beenergized when 115 V. power is applied to the control circuit.Reset all safeties - alarm should stay on until last light isreset.

    B. Warm bulb of TC(W) above 45 deg.

    C . Switch Sl to "on".

    D. TD(P) clutch should start, closing TD(P) contacts. TD(L)should start timing. Heaters should de-energize.

    E. TD(P) motor should start. Ml contactor should pull in and theoil cooler solenoid should energize.

    F. Temporarily jumper Ll, Ml and L2, M2 on oil pressure controlPS(L0) and Ll, Ml on PC(V).

    G . Rl and R(CP) should then energize, close contact R (CP)and start the condenser pump.

    H. R2 and R(MS) should then energize and TD(L) should quit timing.

    On star-delta starters there will be approximately an 8 seconddelay between starting and running contactors.

    I. TD(N) should time for 40 minutes. After initially startingTD(N) should continue to time independent of status of rest ofcircuit.

    J. Warm electronic sensor bulb. EVC should simulate vane openingby lighting load light on EVC.

    K. Cool electronic sensor bulb. EVC should simulate vane closingby lighting unload light on EVC.

    L. Drop pressure to suction control line by closing servicevalve (#l) on top of evaporator and slowly relieving pressurefrom control line by loosening flare nut. At 30.3 PSIG, PC(LR)contact should close and simulate vane fast closing by lightingunload light on EVC.

    M. Drop suction control line pressure further. At 28.3 PSIGPS(LR) should open, drop out R5 and R3 and de-energize relaysR(MS) and R(CP). LT5 should light, along with the alarm circuit.The oil cooler solenoid and oil pump contactor should remainenergized for 30 sec. Retighten flare nut on suction control lineand valve (#l) and open valve slowly to raise line pressure.

    Page 21

  • At 31.3 PSIG PS(LR) control should reset. It is now possible toreset PS(LR) with S3. LT2 should energize, and pull in R(MS)and R(CP).

    N. Raise suction control line pressure to 33.3 PSIG and PC(LR)should open.

    0 . Operate EVC on manual switches and verify operation is correct.

    P. Check additional controls similar to Item L. To check TS(LW)put sensor in ice water. TS(LW) should open on temp. drop at36 F. and close at 39% F.

    Q. For control circuit check of PS(HR), TS(HR), TS(H0) and R(T)temporarily remove lead from control and reconnect. Correspondinglight should light and reset switch should function as in Item L.

    R. Remove jumpers from PS(L0). LT7 should light and R(MS) shoulddrop out. Ml contactor and oil cooler solenoid should remain energizedfor 30 seconds.

    S . Shut off chiller water pump. This should open the starter circuitto R(MS). NOTE: IMPORTANT After all above tests have been completedsatisfactorily, turn off power and remove all jumper wires usedfor above test and re-wire oil pump to correct terminals. Leave115 V. lights connected for oil pump operational check.

    IV OIL PUMP OPERATIONAL CHECK

    A. Make sure all oil pump valves are open - See P. 20 .

    B. With system switch "off" compressor motor leads disconnected,and/or compressor power disconnect "off", energize the unit controlcircuit to provide power to heaters in oil pump and compressor.

    NOTE: HEATERS MUST BE ENERGIZED 24 HOURS BEFORE OIL PUMP ISSTARTED TO ASSURE ALL REFRIGERANT HAS BEEN DRIVEN FROM THE OIL.OIL SHOULD BE HOT (APPROXIMATELY 130 F.) BEFORE TESTING AND

    C . Reset safeties as necessary.

    D. Switch control circuit switch Sl, to "on" (TD(W) bulb mustbe in an ambient temperature above set point).

    E. Oil pump should start per sequence of operation and buildup pressure to llO# above suction. (Adjust relief valve (#12)on pump if necessary - clockwise raises pressure).

    F. PC(V) switch should close at 30 PSI above suction pressure.

    Page 22

  • G.

    H.

    I.

    J.

    K.

    PS(L0) switch should close at 50 PSI above suction pressure.

    Unload light should be on until PS(L0) and PC(V) are made.

    Set EVC to "load" vanes should open (load light on).

    Set EVC to unload - vanes should close. (Unload light on)..

    Switch Sl to "off" - oil pump should run for 30 seconds beforeTD(P) turns it off.

    V INITIAL UNIT START

    After the above steps have been completed continue with thefollowing:

    A. Establish correct water flow to evaporator.

    B. Open up suction, discharge and oil pressureline valves. (#l, 2 and 6).

    gauge and control

    C . Open up refrigerant liquid line valve (#7) for compressormotor cooling.

    D. Open all liquid line valves (#8-10) between evaporator andcondenser.

    E. Check that all oil line valves (#3, 4, 5 and 6) are open, andthat an adequate supply of hot oil is available.

    F. Check all auxiliary equipment (cooling tower cooling-load,pumps, fans and air handlers) to be sure it is operative.

    G. Set EVC at"unload" for assured closed vane start.

    H. Open oil cooler water valves.

    I. Connect up power leads at compressor motor junction box perdiagram in cover. BE SURE PHASE IS CORRECT. SEE P. 12 .

    J. JOG MACHINE - momentarily switch Sl to "on" long enough foroil pressure to build up oil and start compressor. Switch Sl to"Off" and check compressor rotation thru bulls eyes in compressor.Rotation must be clockwise from motor end. Turn off power andchange phase wiring if rotation is incorrect. Repeat ifnecessary.

    Page 23

  • K. After correct rotation has been established and the TD(N)control has timed thru its 40 minute cycle the machine canbe restarted by switching Sl to "on".

    CAUTION: Manually shut down unit if any malfunction is noted.

    VI . INITIAL UNIT OPERATION

    When initial start is satisfactory observe the following duringthe

    A.

    B.

    first few minutes of operation.

    Adequate oil pressure - 110 PSI above suction.

    Liquid refrigerant to motor for cooling. Sense temperaturedrop across motor cooling orifice plate.

    C . Water flow to oil cooler is sufficient and oil temp. tobearings remains below 110 F. at outlet of oi l cooler.

    D. Oil level - top l/2 of sight glass.

    E. No unusual noise or vibration.

    F. With EVC current control set at 100% set manual switch at"Auto " and observe loading of machine. If vanes open toofast, adjust vane speed needle valve (See Control Operation andCalibration (P. 40 ).

    G . When machine is fully loaded check to be sure the temperaturesentering and leaving the evaporator and condenser are withindesign limits, and that amperage and voltage are correct per load.

    H. Adjust EVC as needed per procedure outlined in Control Operationand Calibration (P. 40 ).

    I. After the machine has been jogged and correct rotation determined,the motor terminals and exposed bare wire must be thermally insulatedwith insulating tape provided with the unit. This is necessary toprevent moisture from condensing on the terminals during operationwhich could cause current leakage and in severe cases a direct short.IT IS EXTREMELY IMPORTANT THAT TERMINALS ARE PROPERLY INSULATED BEFORETHE UNIT IS PUT INTO OPERATION.

    SYSTEM OPERATION

    I OIL SYSTEM

    The oil system for this unit is designed with a dual function; toprovide lubrication to the compressor bearings and provide oilfor the hydraulic vane control system. Figure 3 shows the completeoil system with figures 4A and 4B and 5 showing in detail thevane control system.

    Page 24

  • A. LUBRICATION SYSTEM

    1. Oil Pump a n d Reservoir Assembly.

    The major component of the oil system is an oil pump andmotor assembly operating at 115 V. The direct coupledoil pump located in the oil reservoir also drives a centrifugaloil separator which removes the refrigerant vapor from the oiland returns it thru a service valve (#5) to the compressor.The oil differential pressure, above suction, can be controlledby adjusting the relief valve (#12) on top of the oil pumpassembly. By using a l/4" Allen head wrench the pressure canbe adjusted upward by clockwise rotation. During normaloperation pressure should be 110 PSIG above suction. An oilheater located in the bottom of the oil reservoir is energizedduring the compressor off cycle and is used to provide warm(135 F) refrigerant free oil on unit start up. The oil heatermust be enegized 24 hours before start up to adequately heatthe oil.

    2. Oil Cooler

    The oil is pumped thru a service valve (#3) in the oil pumpto a water cooled oil cooler located on the unit. Here theoil temperature is lowered sufficiently to provide oil ofthe proper temperature (90 - 110 F) to the bearings.

    3. Oil Filter

    The oil is then pumped to the oil filter which is an integralpart of the compressor housing. The filter contains a 10micron cartridge that should be changed when the differencebetween oil pressure and suction pressure (oil gauge reading)drops to 60 PSIG.

    To change the oil filter, front seat the outlet valve (#3)on the oil reservoir cover and close the l/4" shut off valve(#6) on the oil filter. Purge the oil supply lines slowlybefore removing cover and replacing core. (A check valve onfilter outlet prevents losing pressure from compressor.)After assembly vent air from oil lines before restartingmachine.

    From the oil filter, oil is supplied to the safety spindownoil reservoir as well as the 2 low speed and 3 high speedbearings thru internally drilled passages in the compressorhousing. The spring loaded piston in the spindown reservoirsupplies adequate lubrication for 3 times the spindown timeduring normal operation and in the event of oil pressure lossdue to power failure, oil pump overload or oil pump failure.

    Page 28

  • B.

    4. Gear Lubrication

    The oil drains from the bearingsinto the gear housing and is returned to the oil pumpthru a full flow return line. A shut off valve (#4)is in this line, at the oil pump reservoir and withvalves #3 and 5 permit complete isolation of the oilpump and reservoir. When the high pressure oil drainsfrom the bearings into the low pressure gear cavity itimmediately flashes into a fine oil mist, and releasesany refrigerant which may have been entrained in theoil. This fine oil mist provides the lubrication forthe gears. A gear case heater is provided in thecompressor housing to prevent refrigerant collectionin the oil on the off cycle.

    5. Oil Charging

    The oil level during operation should always be visiblein the sight glass (normally at l/2 level). If necessaryto add oil use only McQuay oilNo. 921-238031X (Suniso 4G S) and charge with an oilcharging pump at valve (#13) on the bottom of the oilreservoir.

    VANE

    0 OTHER OIL IS SUITABLE/

    NOTE: Fill only to top l/4 of sight glass onOver charging can cause oil loss to the refrigerant system.

    CONTROL SYSTEM

    The capacity of the unit is controlled by inlet guide vaneslocated at the impellor eye. The vanes are positioned by apiston (Figures 4A and 4B) which moves to open or close thevanes, depending on which side of the vane control pistonoil is supplied. The oil flow to the piston is controlled bythe operation of a 4-way normally open solenoid valve (coilsSV(S) and SV(0)) and a 2-way normally closed solenoid valve,coil SV(FC).

    When a coil in the 4-way solenoid valve is energized, the flowis from the port, thru the adjustable orifice and to theoutlet. When a coil is de-energized the flow is from theinlet, thru the solenoid valve and thru the port.(See Fig. 4A and 4B).

    Page 29

  • When the electronic controls call for vane opening andincreased capacity the oil flow is as shown in Figure 4A(with SV(O) energized SV(S) and SV(FC) de-energized). Whenthe electronic controls call for vane closing and reducedcapacity the oil flow is as shown in Fig. 4B (with SV(C)energized and SV(0) and SV(FC) de-energized).

    When the electronic sensor indicates leaving chilled watertemperature has reached design conditions, all solenoidswill be de-energized, full oil pressure is supplied to bothsides of the piston and the vanes will hold.

    If the control circuit calls for fast vane closing as describedin the sequence of operation SV(C) and SV(FC) will be energized,SV(0) will be de-energized and oil flow will be as shown inFig. 5. Under this condition the metering valves A and B areby-passed speeding the oil flow and closing the vanes inapproximately 15 seconds.

    When the vanes are completely closed, the vane closed switchport is uncovered and with positive oil pressure the PC(V)differential switch closes. This assures a vane closed start.

    The speed of the vanes is controlled during normal openingand closing by two needle metering valves (adjustable orificesA and B) in the oil drain line (See Figs. 4A and 4B). Theseneedle valves are factory set to provide a minimum of 1 minutefrom full closed to full open vanes.

    Closing the needle valves slightly slows the vanes down.The correct speed should be slow enough to prevent huntingand over controlling. These needle metering valves are notin the system during fast close and do not affect the fastcbse speed.

    II LIQUID FLOW CONTROL

    The sub-cooled liquid refrigerant leaving the condenser isexpanded thru a liquid line orifice and equalizer systemand enters the distributor in the evaporator. Thedistributor assures uniform refrigerant distribution thruout the full length of the evaporator. The correctrefrigerant flow to the evaporator is maintained under allconditions of operation by an automatic trimming valve (#ll).The automatic trimming valve is factory preset to maintainthe correct level of refrigerant in the evaporator and doesnot require field adjustment.

    Page 32

  • Shut off valves (#8-10) are provided in the liquid line to enableisolation of condenser for pumpdown of the unit.

    III MOTOR COOLING SYSTEM

    The hermetic motor is cooled by liquid refrigerant from thecondenser outlet. The sub-cooled liquid passed thru a shut offvalve (#7), check valve, and filter drier up to an orifice platemounted on the compressor housing.

    Upon flashing into the motor housing, the refrigerant cools therotor and stator. The gas and excess liquid is drained backinto the evaporator thru separate drains in compressor housing.

    IV ELECTRONIC CONTROL OPERATION

    A solid state combination electronic temperature control and motorload control (EVC) is used to regulate the cooler leaving watertemperature and control the current draw of the motor.

    A. ELECTRONIC TEMPERATURE CONTROL

    An electronic sensor located in the leaving chilled water changesresistance with water temperature and sends a signal to a bridgecircuit in the electronic temperature control. This signal isamplified by the control module and is used to actuate the solidstate switches. The solid state switches operate the coils ofthe 4 way oil solenoid to open and close the vanes as describedunder Vane Control.

    The electronic temperature control contains a selector switch whichpermits manual operation of the inlet guide vanes and overridesthe signal circuit. During normal operation switch should be in"Auto". To manually close vanes switch to "unload" (lower load)and to manually open vanes switch to "load" (higher load).There is also a "hold" position which holds vanes in existingposition. This switch should be set at "Auto" except when usedto manually control vanes when servicing unit.

    The electronic temperature control utilizes integral action toprovide a very precise control of leaving chilled water temperature.It eliminates the throttling range and feedback circuits usuallyneeded with this type of control. With integral action the "on"time of the load or unload switch is dependent upon the differencebetween the set point and the leaving chilled water temperature.As the difference between the set point and the control pointdecreases, the on time (either load or unload) becomes shorter.The load status is shown by a red indicator light and the unloadstatus by a green indicator light for ease of service.

    Page 34

  • The solid state electronic temperature control is calibratedat the factory but it should be checked for recalibration.See Appendix C for calibration and adjustment.

    B. MOTOR LOAD CONTROL

    The function of the motor load control circuit in the EVC is toprevent the machine from operating at a higher amp rating thandesign. The motor load control is a two stage override protectionsystem for the compressor motor which limits the current to themotor at any selected valve from 40% to 100% of full load.

    A window type current transformer (CT) is located on one of themotor leads in the starter and gives a secondary current whichvaries with load. A resistance load is added to the currenttransformer secondary to produce a voltage signal proportionalto load, which operates the motor load control. At full loadthe voltage signal should be between .45 and .55 volts.

    This voltage signal is used to activate solid state switchesin the EVC. When the motor current reaches 100% a switch putsthe vanes in a "hold" position. If the motor current continuesto increase to 105%, another switch will close and the vaneswill go into fast close to prevent a further power increase.If either the 100% or 105% switch is activated a "current control"light is energized to indicate that the override control is inoperation.

    The motor load control remains in control of the machine onlyas long as the compressor attempts to deliver more than 100%of full load. It will override the electronic temperature controlunder any condition when needed.the position of the vane selector"Load", etc.

    The motor load control contains a

    It operates independently ofswitch, whether, "Auto", "Hold",

    percent current limit switchwith a range of 40% to 100%. This permits setting the maximumpower input of the machine at any point between 40 and lOO%,thus limiting demand charges.

    If, for example, this switch is set at 60% and the chiller fullload amp (FLA) rating is 265 amps, the unit will go into "hold"at 159 amps (.60 x 1.0 x 265) and "fast close" at 167 amps(.60 x 1.05 x 265).

    To calibrate the motor load control see Appendix C.

    Page 35

  • APPENDIX A

    I. LEAK TESTING

    A. The unitstart up, to

    should be completely leak tested before initialcheck for leaks which may have resulted from

    shipping damage. The presence of refrigerant oil on ornear the unit may indicate a leak and adjacent areas shouldbe carefully checked.

    B. The refrigerant charge shipped with the unit will providea positive pressure for this test. During shipment the chargeis isolated in the condenser. Crack one condenser shut offvalve and allow enough. refrigerant to enter the evaporatorto build up pressure to approximately 60 psig. and immediatelyclose valve.As a general rule of thumb this pressure shouldbe approximately 10 PSIG below the corresponding saturationpressure at ambient temperature.

    C. With an electronic leak detector carefully check allbrazed joints, pipe connections, "Victaulic" connections andcontrol line flare connections for leaks.

    D. If leaks are found they must be repaired. Leaks in theevaporator circuit, liquid lines, control lines, etc., canbe easily repaired without removing charge since the unitis shipped pumped down with charge isolated in the condenser.

    E. After any leak is repaired retest by building up pressurein the circuit by bleeding a slight amount of refrigerantfrom the condenser as in Item B above. If no leaks are foundon recheck, unit is ready for evacuation.

    II. EVACUATION

    To evacuate evaporator circuit keep valves at condenser(#7, 8 and 9) and oil pump (#3, 4, and 5) closed. Valveat evaporator (#l0) and gauge line valves on top of evaporatorand condenser (#l and 2) should be open.

    Remove existing cores in filter drier in liquid line andinstall new cores.

    Evacuate by attaching one or more lines from vacuum pump tovalves on bottom of evaporator and to l/4" fittings onevaporator liquid line valve (#l0).

    Page 36

  • Continue evacuation until a reading of 1000 microns (1 millimeter)or less is obtained and maintained for a minimum of 15 minutesafter the vacuum line is closed. An electronic or micron gaugeshould be connected at the unit to accurately determine thecorrect unit vacuum.

    If the vacuum pump is incapable of pulling down to 1 millimeter,a triple evacuation can be used. Pull down to approximately 29inches of mercury vacuum, add a small amount of refrigerant 12vapor to build up to a positive pressure and pull down to 29inches. Repeat 3 times.

    Charging

    After evacuation, refrigerant - 12 charge is to be added. Open upliquid line, shut off valves at condenser and allow pressure toequalize in evaporator and condenser.

    If some charge has been lost due to a leak it will be necessaryto trim charge with unit running.

    Note

    This additional charge should not be added at this time. Completepreliminary pre-start up checks (P ) before charging cancontinue.

    After machine has been initially jogged and started per sequenceoutlined and additional charge can be added. THE UNIT MUST BEOPERATING NORMALLY WITH OIL PUMP RUNNING, WATER FLOW TO CHILLERAND CONDENSER, AMPS AND VOLTS NORMAL, AND LEAVING CHILLED WATERTEMPERATURE AND SUCTION PRESSURE ABOVE FREEZING .

    CAUTION

    DO NOT LIQUID CHARGE OR RUN UNIT (UNDER ANY CONDITION)IF SYSTEMPRESSURE IS LOWER THAN 30 PSIG.

    Connect the refrigerant charging line to the service valve onbottom of evaporator and charge with R-12 vapor. The unit isadequately charged when suction superheat is 2-4 degrees atfull load operation.

    UNIT SHUTDOWN

    During winter or extended shutdown special precaution should betaken to prevent possible unit damage.

    Page 37

  • A. If the machine will be exposed to freezing conditions allwater in the chiller, condenser and oil cooler circuits must bedrained. This can best be done by disconnecting Victaulicconnection at water boxes and opening vent and drain connectionon water boxes.

    CAUTION - since it is possible that water could hang up in thetubes, the only sure way of removing all water and avoidingfreeze up is to circulate anti-freeze solution thru the tubes,as well as oil cooler.

    Leave drains and vents open until system is refilled.

    B. To prevent accidental start-up of unit during shutdowncycle open compressor disconnect and remove fuses from disconnect.

    NOTE: If control circuit power is provided by transformer instarter, the disconnect must be left on to provide power to oilheaters. It is important to keep the oil heater energized toprevent absorption of refrigerant by the oil. In this case, toprevent accidental start up, position system switch Sl to "off"and remove R-3 relay.

    PUMPDOWN

    It is possible to make repairs or replacements on compressors,controls, liquid lines, etc. if necessary without losing therefrigerant charge by pumping the unit down and isolating thecharge in the condenser. If it is necessary to pump the systemdown use extreme caution to prevent freeze up of the chiller.

    CAUTION: Be sure that full water flow is maintained thru thechiller while unit is in pumpdown cycle. Use the followingprocedure to pumpdown:

    1. Close liquid line valves at condenser (#7, 8 and 9).

    2. Jumper PS(LR) control and temporarily disconnect wire #150from PC(LR).

    3. With water flow thru the chiller and condenser, startcompressor.

    4. Operate unit until suction pressure stabilizes atapproximately 20-25 PSIG.

    5. Operate unit at this point for approximately 2 minutes andthen turn off.

    Page 38

  • The discharge line check valve along with the condenser liquidline valves will isolate the major portion of the charge in thecondenser. Purge remaining gas pressure from evaporator circuitbefore working on system. Approximately 40-60 lbs. of refrigerant12 will be lost depending on the completeness of the pumpdown.

    APPENDIX B

    TOOLS AND EQUIPMENT

    The following tools, equipment and instruments are useful inservicing and checking the unit.

    1. Electronic leak detector (preferred) or halide torch.

    2. Portable high vacuum pump (capacity at least 3 CFM recommended).

    3. Refrigerant charging lines and equipment (gauges, scale,Refrigerant - 12 etc.).

    4. Refrigeration servicemans hand tools (wrenches, screwdriver,

    5.

    etc.).

    Volt - ohmeter (voltage scale

    Vacuum tube voltmeter (VTVM).

    to 480 volts).

    6.

    7.

    8.

    9.

    10.

    11.

    Clamp on ammeter (up to 750 amp scale).

    Thermometers (4 - minimum of 2) (2 deg. increments).

    Water pressure gauges or manometer.

    Oil charging pump suitable to pump against 70 psi pressure.

    Phase sequence meter.

    Page 39

  • APPENDIX C

    I. SOLID STATE COMBINATION ELECTRONIC TEMPERATURE AND MOTORLOAD CONTROL CALIBRATION (EVC).

    The following procedure applies to the Honeywell CentrifugalChiller Control W901A only.

    A. GENERAL

    While the basic function of the Centrigual Chiller Control isto maintain the temperature of the chilled water at thecontrol point setting by modulating the compressor vanes,its protective function of limiting excessive current drawby the compressor drive motor is very important. Therefore,current calibration must be done first to provide protectionduring temperature calibration or other testings.

    CAUTION: Adjustment and Calibration of the control must bemade while the machine is running.

    Set control switches as shown in the startup column ofTable 1.

    I NORMALSTARTUP RUNNING POSITIONManual Position Switch Close (Unload) Auto% Current Control 100% Desired Percentage

    (100% or less)Control Point Center of Travel Desired Chilled

    (Vertical) Water TemperatureCurrent Calibration Full Clockwise Leave at Position

    Determined atStart-Up

    Temperature Calibration Center of Rotation Leave at PositionDetermined atCalibration

    Page 40

  • B. CALIBRATE FOR CURRENT

    This calibration procedure adjusts the current control sectionof the control to the current input signal at terminals A-B.This signal must be .50 2 .20 VAC when motor load is 100% ofrated current.

    When the above signal has been provided, adjust the CURRENTCALIBRATION control ccw until current control light just comeson.

    NOTE: Calibration at 100% automatically calibrates for currentcontrol action at 105%.

    C U RR ENT INPUT SIGNAL TO T E R MI N A LS A- B (MOTOR LOAD AT 1 0 0 % OFRATED CURRENT.)

    This signal comes from a current transformer and shunt resistornormally supplied as part of the compressor motor starter. Thetransformer and resistor must be sized, along with a specifiedsize and length of two-wire lead, to provide a nominal 0.5 voltsrms to terminals A-B of the control.

    CAUTION: Maximum allowable voltage to terminals A-B is5 volts ac.

    GROUNDING NOTE: Ground at current transformer only, NOT atterminals A-B.

    CURRENT CONTROL SYSTEM OPERATES AS FOLLOWS:

    a. When the compressor drive motor current rises to 100%of its rated value,the current control system preventsfurther opening of the vanes.

    b. If compressor motor current reaches 105% (+O, -2) thevanes drive toward the closed position until the currentdrops to 100% +l. (The vanes can still be driven closedby the temperature control.)

    C . When the compressor current falls to 95% (+2, -0) ofits full value, the device returns to full temperaturecontrol.

    Check the preceeding by using the manual position switch tochange compressor load, then look for proper vane action.After checking, return the selector switch to AUTO. Thedevice is now calibrated for current.

    Page 41

  • C . CALIBRATE FOR TEMPERATURE

    1.

    2.

    3.

    4.

    5.

    Set the manual switch in the AUTO position.

    Operate the system until the chilled water temperaturereaches 45 deg. F. For accurate control calibrationthe temperature sensing bulb must be maintained at aconstant temperature which can be accurately measured.

    Set the control point to mid position (pointer vertical).

    Adjust the temperature calibration potentiometer toachieve a null condition (no vane movement) . NOTE:Because of the "pecking" action of the temperaturecontrol section, (integral action control) the device isin a null condition only after a minimum of 45 secondswith no signal to either load or unload.

    The device is now calibrated for 45 deg. F. + 1 deg. F.water temperature.

    Page 42

  • APPENDIX E

    PHYSICAL DATA

    WHCUNITSIZE

    145A158~183A200A228A254111284A300A325A362~

    OILCHARGE(GALLONS)

    4444477777

    -r

    I

    COOLERAREA TO

    3E INSULATE1(FT2)

    6666838383929292

    109109

    COND.*PUMPDOWN CAP.(LBS.-R-12)

    396396548522492926886866827769

    RELIEF VALVESETTING(PSI)

    VAP.150150150150150150150150150150

    COND .180180180180180180180180180180

    *Based on 80% of condenser volume and liquid R-12 at 100 F.

    WARRANTY RETURN

    Material may not be returned except by permission of authorizedfactory service personnel of McQUAY Division McQUAY-PERFEX INC.at Minneapolis, Minnesota. A "Return Goods" tag will be sentto be included with the returned material. Enter theinformation as called for on the tag in order to expeditehandling at our factories and prompt issuance of credits.All parts shall be returned to the McQUAY factory, designatedon the "Return Goods" tag, transportation charges prepaid.

    The return of the part does not constitute an order forreplacement. Therefore, a purchase order must be enteredthrough your nearest McQUAY Representative. The order shouldinclude part number, model number and serial number of theunit involved.

    Following our personal inspection of the returned part and if itis determined that the failure is due to faulty material orworkmanship, credit will be issued on customer's purchase order.

    REPLACEMENT PARTS

    When writing to McQUAY for service Or replacement parts, refer to

    the model number and serial number Of the unit as stamped on the

    serial plate, attached to the unit. If replacement parts are

    required, mention the date of installation of the unit and dateof failure, along with an explanation of the malfunctions and adescription of the replacement parts required.

    Page 47

  • APPENDIX FTROUBLE SHOOTING

    As an aid to servicing your WHC Seasonpak centrifugal chillerseveral trouble shooting charts have been prepared. The troubleshooting should only be performed by a qualified refrigerationservice man. If additional information is required, call yourMcQuay Service Representative.

    The following steps should be taken prior to attempting any serviceon the control center:

    1. Check wiring diagram so that you understand the operation ofthe Seasonpak, centrifugal chiller.

    2. Before investigating trouble in the control center, check forburned out light bulbs by testing across the appropriate ter-minals. Caution - the panel is always partially energizedeven though the system switch is off. If it is necessary tode-energize the complete panel, including crankcase heaters,pull main disconnect.

    3. Check lights and compare with the trouble chart. The possibletrouble area o f the panel can then be easily isolated.

    This chart is merely a quick indication of possible major troublespots in the panel or unit. By comparing the indicator lightswith the unit wiring diagram, additional comparisons can be made.

    It is important to have a qualified control panel electricianservice this panel. Unqualified tampering with the controls cancause serious damage to equipment and void the warranty.

    W A R N I N G

    Warranty is voided if wiring is not in accordance with specifica-tions. A blown fuse or tripped protector indicates a short groundor overload - before replacing a fuse or re-starting compressor,the trouble must be found and corrected.

    Page 48

  • Home PageTable of ContentsControlsSequence of OperationSet PointsWiring Diagram

    ChargingDimensional DataElectricalAuxiliary InterlocksMotor DataPower Wiring

    Electronic ControlOperationCalibration

    EvacuationLeak TestsLiquid Flow ControlLocationMotor CoolingMoving and MountingOil SystemPhysical DataPre-InstallationPre-Start UpPressure Drop EvaporatorPressure Drop CondenserShutdownStart UpTrouble ShootingVane ControlWarranty InformationWater PipingChilled WaterCondenser WaterOil CoolerSystem Schematic