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FORM NO. 5500CSupersedes Form No. 5500B

MODEL HWSC-DSMALL SCREW

WATER COOLEDPACKAGED CHILLERS

INSTALLATION, OPERATION&

MAINTENANCE INSTRUCTIONS

TABLE OF CONTENTS

DESCRIPTION PAGE NO.

Inspection & Handling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2Location & Mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2Chilled Water Piping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2Water Cooled Condenser Piping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2Cooling Tower Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3Condenser Water Balancing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3Preliminary Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 & 4Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4Slide Valve Unloading System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5Control Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6Unit Operating Limitations - Safety Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6Typical Sequence of Operation (2 Compressor) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 & 8

Models HWSC 110-150Star-Delta Starting Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8Typical Power Wiring Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9Typical Control Wiring Diagram Model HWSC 100 to 150 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 & 11Electrical Data HWSC 50-150 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12Electrical Data HWSC 180-300D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13Cooler & Condenser Pressure Drops . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14Unit Loading/Suspension Points (HWSC 50 - 150) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15Unit Loading/Suspension Points (HWSC 180 - 300) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16Troubleshooting Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17Causes & Prevention of Freeze-Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17Start-Up Check List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18Operation Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19Physical Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

GENERALThe packaged liquid chillers are designed and built for the purpose ofcooling water or other non-corrosive liquids. The chilled water iscirculated through a direct expansion cooler where the temperature isdropped to the desired level and the water is then circulated to coils forair conditioning or to heat exchangers for process cooling.

Care should be taken to see that the equipment is properly installed andadjusted. The installer and the operator should first become familiarwith the information contained in this manual.

INSPECTIONWhen the unit is delivered, make an immediate and thorough inspectionin the presence of the carrier's representative, for damage in shipment.If any damage is found, a notation should be made on the deliveryreceipt before signing. A claim should be filed immediately against thedelivering carrier.

RIGGINGEach packaged chiller is carefully tested and crated at the factory,where every precaution is taken to assure that the unit reaches itsdestination in perfect condition. It is very important the installer usesthe same care in handling. The riggers and movers should use everyprecaution in moving the equipment into place. Make sure chains,cables, or other moving equipment are placed to avoid damage to theunit or piping. The refrigerant piping should not be used as a ladder oras a hand hold. The skids, on which the unit is mounted, should not beremoved until the unit is at its final resting place. Do not attach a chainhoist sling to the piping or equipment (see rigging drawing Pages 15 &16). Move the unit in an upright position and set it down gently fromtrucks or rollers.

FOUNDATIONA flat concrete foundation or floor, which can support the weight of theequipment, must be provided. The unit must be level for properoperation and functioning of controls.

VIBRATION ISOLATIONUnder certain critical conditions, it is recommended that vibrationisolators, of a suitable type, be installed under the base. The isolatorsmust be designed for the operating weight of the unit. Rubber-in-shearor spring type isolators are available as optional equipment. To furtherreduce the transmission of vibrations, it is recommended that flexibleconnections, suitable for the system water pressure, be installed on thewater inlet connections of the cooler and condenser. Flexible electricalconduit should also be used at the unit connection.

LOCATION & CLEARANCELocation of the equipment and the size of the equipment room requirecareful consideration of the following factors:1. Route by which the chiller will be moved within the building to the

equipment room. Make sure there is adequate clearances and floorstrength through doors and passage ways.

2. Space required for final connections and for normal equipmentmaintenance. Sufficient clearance should be allowed, between unitand walls, to permit cleaning or repair of cooler and/or condensertubes.

3. Effect of location on piping sizes and piping layout.4. Location of service facilities; power supply, water and approved

drainage.5. Motor starting restrictions of local power company.6. Adequacy of water supply for condenser(s) when city water is to be

used.7. Effect of equipment sound level on adjacent areas.

APPLICATIONIt is not the intent of these instructions to give complete designprocedure, but only to guard against some common misapplications.Standard forced water system practice should be followed in designingand installing the system. A good reference on these subject is the"Heating, Ventilating and Air Conditioning Guide", published byASHRAE.

The reverse return system is recommended for all piping systemsserving a number of fan-coil units for chilled water coils. The directreturn system is inherently unbalanced and is not generally recommended.

Chilled Water PipingFor proper operation, the chiller inlet and outlet water piping should beconnected as detailed on the chiller submittals.

A flow switch must be installed in a straight horizontal section of thechilled water piping.

Gauges should be installed in the chiller water piping to and from thecooler to measure the pressure drop and to insure proper (GPM) flowrate.

A strainer should be installed in the piping on the inlet side of the coolerand vibration eliminators should be employed on both the inlet andoutlet pipes. Air vents should be located at all high points in the pipingsystem. Vents should be located to be accessible for servicing. Drainconnections should be provided at all low points to allow completedrainage of the cooler and piping system. The chilled water pipingshould be insulated to reduce heat pick-up and to preventcondensation.

Water Flow Through CoolerUnder no conditions should the water flow thru the cooler be reducedduring the cooling cycle. If water coils are used in connection withtwo-way control valves, a by-pass line with a control valve must beinstalled to divert water back to the circulating pump. This bypass isinstalled between the discharge water line of the chiller and the suctionside of the chilled water circulating pump. It is recommended that amotorized valve, operated in response to a pressure actuated controllerbe used. If three-way control valves are used at the cooling coils, abypass arrangement is not required, as water is bypassed around eachcoil individually.

If the system is arranged for the dual purpose of cooling in the summerand heating in the winter, the cooler must be valved off during theheating season so that the water will not pass through the cooler. Thismay be either a manual or an automatic change-over operation.

Water Cooled Condenser PipingIn designing the condenser piping circuit, the pipe must be sized so thatthe total resistance of the circuit, when supplying the maximum rate ofwater flow required by the condenser, does not exceed the minimumwater pressure available in the main supply line. The total resistanceof the piping circuit is the sum of the following items:

1. Piping, fittings and service valves2. Strainer3. Water regulating valve (if used)4. Condenser5. Vertical lift or net static head

A check should be made to determine that the maximum water pressureat the condenser does not exceed the design working pressure listed forthe condenser. The manufacturer of the water regulating valve, in orderto insure a quiet and satisfactory operation of the valve, may limit theworking pressure to which the valve can be subjected. Whereexcessive water pressures are encountered, a water pressure reducingvalve should be installed ahead of the water regulating valve to permitreduction of the water pressure in accordance with the requirements ofthe condenser and/or water regulating valve.

Figure 1 shows typical piping of water cooled condenser using city, wellor river water. The return is run higher than the condenser so that thecondenser is always full of water. Water flow thru the condenser ismodulated by the control valve in the supply or return line.

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Cooling Tower WaterA cooling tower can be used with all water cooled liquid chiller units.Figure 2 indicates a typical piping set-up for one or more condensers,discharging into a single cooling tower. Normally, the system will ventitself thru the tower nozzles, air vents being needed only at the highpoints if piping is trapped between condenser(s) and tower(s). Goodstrainers are a requisite and should be located in the tower sump orpump suction line. Pump placement and valve arrangement are de-pendent upon the requirements of each installation.

The following recommendations should be observed when piping cool-ing towers:1. Piping should be adequately sized according to standard com-

mercial practices.2. The piping should contain a certain amount of flexibility between

the component parts of system, allowing for expansion and con-traction. Never install piping so it is completely rigid.

3. When two or more condensers are used with a cooling tower,always cross-connect the warm water lines from the condensersaccording to standard practice. Then use a single discharge lineto carry the hot water to the tower.

Condenser Water Balancing (Models 110, 135, 210, 225, and 270)These units consist of two unequal tonnage circuits. Throttling-typevalves must be used as shut-off valves, to adjust water flow betweenthe two condensers, if the system is not designed for automatic waterregulating valves.

To adjust flow, start with both valves at wide open position and com-pressors operating at full load under design conditions. Minimum con-densing temperature should be no less that 18° F. above the con-denser entering water temperature: e.g. 103° to 105° F. (203 to 211psig) with 85° F. condenser water. If either circuit has its condensingtemperature lower than specified above, that condenser is using ex-cessive water.

A typical system frequently has a cooling tower totally dedicated toone package chiller. Assume condenser A, on such a system hashead pressure lower than specified above. As condenser A waterflow is throttled to increase the head pressure, the head pressure oncondenser B will decrease. This happens because the water flow tocondenser B will automatically increase as you restrict the flow tocondenser A.

Discharge Pressure ControlIt is recommended that condenser water regulating valves be used tomaintain compressor discharge pressure. Pressure taps are providedon the condenser shell to allow control directly from head pressure. Itis recommended that a cooling tower control method be employed tomaintain a minimum of 60°F. The most common methods of towercapacity control are:1. Two speed fan motors2. Modulating dampers in fan discharge (centrifugal fan)3. Combination two speed motors and modulating dampers4. By-pass or throttling valves in the water piping

However, with the variety of towers available, it would be best to se-cure recommendations from the manufacturer whose tower is beingused on the installation.

Cooling Tower Year-Around OperationAdditional precautions should be taken when a cooling tower is to beused throughout the year.

As with capacity control operation, it would be best to secure recom-mendations, for freeze-up protection, from the manufacturer whosetower is being used on the installation.

PRELIMINARY TESTINGRefrigerant PipingAll water cooled packaged chillers have been leak tested, dehydratedand fully charged at the factory. All units are functionally tested, in-cluding the check of all control settings. Rough handling in shipmentand rigging may result in a refrigerant leak. Check refrigerant pipingfor damage.

On all units, the refrigerant has been pumped down into thecondenser(s). Open the king valve(s) and let a small amount ofrefrigerant into the rest of the system and check for leaks. Afterleak checking, king valve(s) and discharge valve(s) (if supplied)must be fully open before starting unit.

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Electrical and controls Compressor1. All control wiring should be checked against the wiring diagram 1. OIL LEVEL - The oil level in the compressor(s) should be checked

furnished with the unit. Connections may loosen in transport, allterminals must be checked and tightened.

2. Push reset buttons on the high pressure switch, low pressure freeze(if supplied), and low temperature freeze thermostat, to make surethey are in operating position.

3. A unit wiring diagram showing the required power supplycharacteristics and all factory supplied wiring details is provided withthe unit. Check the power supply to make sure it agrees with theelectrical characteristics shown on the unit nameplate.

4. The packaged chillers are supplied with terminals which must bewired in series with normally open contacts of the flow switch. Theflow switch must be mounted in a position so as to indicatewater-flow thorough the cooler only.

5. Separate, field supplied, disconnects must be installed in the powersupply and must be "in-sight" of the unit. Where applicable, aseparate 115 volt power source, field supplied, must be provided tosupply power for control and crankcase heater(s) circuit.

6. Activate compressor crankcase heater(s) at least 24 hour prior tostart-up.

Control settingsAll factory controls are factory set for intended customer operation,however, they must be carefully checked prior to start-up to insure thatrough handling in shipment and rigging have not changed the settings.See Table 1.

Water system1. Units are shipped with condenser and chiller drain plugs removed

and placed in the unit control panel. Install cooler and condenserdrain plugs prior to start-up.

2. Before starting the unit, open all water valves that are installedleading to the chiller and the condenser water lines.

3. Check the condenser and cooler water pumps.4. Start the condenser and cooler water pumps.5. Bleed air off the condenser and the cooler at the highest point in the

water system to be sure the cooler and condenser are not air bound.Precautions should be taken in the piping system to make sure thechiller does not become air bound.

Motor AmperageCheck the motor amperage draw against the nameplate rating. If actualamperage draw is 20% more than the nameplate rating, check themotor connections and voltage. Refer to Service Chart for overloadsymptoms.

Water regulating valveIf a water regulating valve is used on condenser piping, it should beadjusted to maintain design condensing pressure. Refer to ServiceChart if excessive head pressure exists.

MAINTENANCEThe package chiller should be checked periodically. Use only theservices of a qualified refrigeration mechanic for inspection andmaintenance checks or service operations.

Water TreatmentFor proper operation of the condenser water system, the water shouldbe tested by a local testing agency and their recommendation adheredto.

It is recommended that water cooled condensers be cleaned as oftenas necessary, depending on the local water conditions.

On cooling tower systems, the condition of the water and the air in thelocality of the installation determines the amount of service necessaryto maintain the equipment in good operating condition. Besides theconcentration of impurities caused by evaporation of the water, harmfulatmospheric conditions like industrial smoke, chemical fumes, salt airand heavy dust can form corrosive solutions with the spray water. If thewater and air conditions are so adverse that bleed-off water cannot takecare of the harmful effect of accumulated impurities, then the use ofwater treatment is necessary.

periodically, with the compressor stopped. Stage the unit down untilall compressors are off and check the compressor crankcase sightglass for oil level. If the oil level is below one half (1/2) the sightglass, oil must be added.

2. A. RECOMMENDED OIL FOR R-22 MACHINESCompressor Model Series SSCA - The compressor is factorycharged with DB Karlube #10 Oil. Compressor Model Series SSCB - The compressor is factorycharged with DB Karlube #21 Oil.

Do not mix above oils or attempt to operate the screwcompressor with any other oil. It is suggested that a gallon ormore of the appropriate oil be obtained and kept at the job site.DB Karlube #10DB Karlube #21

B. RECOMMENDED OIL FOR R134a MACHINESDO NOT USE DB Karlube #10.Compressor Models SSCA use DB Karlube #15 Oil.Compressor Models SSCB use DB Karlube #21 Oil. Contact factory for price.

The above-listed oils are synthetic lubricants of the Polyol Ester(POE) type. Due to the complex nature of the POE, great precautionmust be taken to prevent any moisture from entering the systemwhen servicing or adding oil. POE oil has a greater solvency forwater. Water reacts chemically with the ester to form acids andalcohols in a process called "hydrolysis". POE molecules attractmoisture. Moisture removal by evacuation is more difficult becausethe POE "holds water more tightly" than mineral oil. Moisture causescorrosion and copper plating at an unacceptable, high level. Thisreaction occurs where temperatures are the highest within thecompressor.

To prevent moisture entering the system and contaminating the oilextra care is necessary. Follow the enclosed procedure to add orremove oil from the system.

The holding tank must be clean and free of any moisture. (Evacuatetank to 200 microns). The holding tank can be a receiver orreclaiming tank of a size large enough for the total oil change andmust be able to withstand the operating pressure of the system.When adding oil, it should be transferred from the container suppliedto a holding tank and then evacuated through the vapor port down to200 microns. Do not allow the container to vent to the atmosphereas the transfer must be done through a closed loop. An oil pump willbe required.

PROCEDURE FOR ADDING OILManually close liquid line service valve. Lower return water T-stat(4TAS) setting to start the compressor. Run compressor until unitshuts down on low pressure. Place the control circuit on/off switchin the off position. Locate the high pressure port adjacent to solenoidvalve UL-3 (see drawing page 8) and remove the cap. Attach oilpump to holding tank high pressure port. Pump oil into this port untilthe oil level is 1/2 of the sight glass.

Replace the port cap, open the liquid line shut off valve and place thecontrol circuit on/off switch in the on position. Set the operatingT-stat to the normal operating temperature and reset the lowpressure switch.

Oil can also be added, through the suction port of the compressor,while running the compressor.

3. COMPRESSOR REPAIRS (Internal) - Contact factory or anauthorized DB Service Agency if a compressor malfunction issuspected.

4. COMPRESSOR REPAIRS (External) - Proper operation ofunloaded start, loading, and unloading is controlled by solenoidvalves UL-1, UL-2 and UL-3. Any of these three (3) solenoid valvesmay be repaired or replaced in the field, as required. Also thecompressor crankcase heater may be replaced.

5. Standard oil acid test kit is not compatible with synthetic oil. See DBcolor chart for oil condition.

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HWSC CONTROL SETTINGS

TABLE 1

PRESSURE ACTUATED LEGEND FACTORY SETTING

HIGH PRESSURE CONTROL HP 1-4 Cut-In 203 PSIG(MANUAL RESET) Cut-Out 270 PSIGPUMPDOWN CONTROL LP 1-4 Cut-In 55 PSIG(AUTO RESET) Cut-Out 35 PSIG

LOW PRESSURE FREEZE CONTROL LPF 1-4 Cut-Out 54 PSIG(MANUAL RESET) OPTIONAL

TEMPERATURE ACTUATED LEGEND FACTORY SETTING

LOW CHILLED WATER TEMPERATURETHERMOSTAT T2 Cut-Out 37°F

OIL TEMPERATURE SAFETY CONTROL(ADJUSTABLE) OTS 1-4 Cut-Out 240°FMANUAL RESET

W7100 CONTROLLER SETTINGS T1 Control Point Set At 44°F

NOTE: For special units supplied with the NC25-4 microcomputer controller, refer to the "Operations Guide" Form 6874.

UNIT OPERATING LIMITATIONS

1. Maximum allowable condenser water pressure is 150 PSIG.2. Maximum allowable cooler water pressure is 200 PSIG.3. Maximum allowable operating water temperature to cooler is 85°F.4. Minimum allowable water temperature from cooler is 42°F. If lower temperatures are required, a glycol solution must be used.5. Maximum recommended design condensing temperature is 120°F.6. Unit should not be installed where it may be subjected to freezing temperatures. Provisions should be made to maintain the ambient air

temperature at least 37°F. to avoid possible damage from freezing.7. Line voltage should not vary more than the voltage tolerances listed for the unit. Refer to the Electrical Data table, Page 18 and 19.

SAFETY CONTROLS

The unit is protected by the following safety controls.

1. High Pressure (HP)2. Low Pressure (LP)3. High Discharge Temperature (OTS)4. Compressor Solid State Module (CSTM)5. Low Water Temperature (T2)6. Compressor Starter Overloads (OLH)7. Phase Loss Monitor (PLM)8. Control Circuit Breaker (CB1)

If any of these devices should open due to abnormal conditions, the compressor(s) automatically stop. All controls must be manually reset, exceptthe phase loss monitor (PLM).

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Stage 1 LoadingUpon demand for cooling, the first step of the staging thermostat (T1)will close energizing relays (R1) and time delay (TD1). If all the safety Subsequent to the start of Compressor No.1 an approximate five minutecontrols and switches are closed, (see "Safety Controls" section for time delay is incorporated into the microcomputer. After this time delay,more detail) the control circuit for Compressor No. 1 will energize, and a further call for cooling, the second step of the staging thermostatallowing the compressor to start. Relay (R5) will energize, closing the (T1) will close. This will energize relay (R2) and time delay (TD2). If allnormally open set of contacts, which energize the liquid line solenoid the safety controls and switches are closed, (see "Safety Control"valve (SOL1). Another set of normally open contacts on (R5) provide section for more details) the control circuit for compressor No.2 willa series interlock with all the safety and operating controls, which will energize, allowing the compressor to start. Relay (R6) will energize,lockout the compressor if any safety trips during normal operation. (See allowing the liquid line solenoid valve (SOL2) to energize. Relay (R6)Note 6 on Wire Diagram). The last set of normally closed contacts on will energize the safety controls the same as compressor No.1 circuit.(R5) open and de-energizes (CCH1).

Time Delay (TD1) has two (2) sets of contacts: The first set of (TD1) pressure control (LP2) and will energize the full unload solenoid (UL3-2)normally closed contacts provides a 30 second jumper around the low for 30 seconds then energize relay (R4). Upon energizing relay (R6),pressure control (LP1) to prevent short cycling during start-up. The the crankcase heater (CCH2) is de-energized and the normally opensecond set of (TD1) normally closed contacts powers the unloader contacts of relay (R4) are closed, allowing the thermostat (T1) tosolenoid (UL3-1) which holds the compressor in the full unload position energize the load solenoid (UL2-1) and the unload solenoid (UL2-2)for 30 seconds. After (TD1) times out (30 seconds), the contacts for the upon demand. Relays (R1) and (R2) will interlock the water pumpunloader solenoid (UL3-1) open and the normally open contacts close, starters.which energizes the relay (R3). Upon energizing relay (R3) thenormally open contacts of relay (R3) are closed, allowing the thermostat(T1) to energize the load (UL1-1) and the unload solenoid (UL2-1) upondemand.

Stage 2 Loading

Time delay (TD2) will provide a 30 second jumper around the low

SHUTDOWN SEQUENCEStage 2 ShutdownAfter both compressors have unloaded fully and the leaving watertemperature is still lower than the set-point, the second step of the If the leaving water temperature is still lower than the set-point, the firstthermostat (T1) will open and de-energize relay (R2), providing an step of the thermostat (T1) will open and de-energize relay (R1). Thisapproximate five minute time delay, again integral with the will close the liquid line solenoid (SOL1) and turn off Compressor No.1microcomputer, has expired subsequent to the start of Compressor as long as it has run for approximately three minutes. Compressor No.1No.2. This will close the liquid line solenoid (SOL2) and turn off will not be able to restart for five minutes.Compressor No.2. Compressor No.1 will load and unload as required.Compressor No.2 will not be able to restart for five minutes due tointegral time delays.

Stage 1 Shutdown

STAR-DELTA STARTINGOPEN TRANSITION

Time delay relay (TD1) closes, energizing start contactor (S1) and the After five seconds (TD9) N.O. contacts close, de-energizing "Star"five second transition timer (TD9). Contactor (S1) closes, tying the contactor (S1) and energizing run contactor C2 through (S1) N.O.center legs of the motor windings together into the "Star" (wye) auxiliary contacts. The compressor motor now runs in the "Delta"configuration. (S1) N.O. auxiliary contacts close and energize motor configuration.starter (C1), starting the compressor motor. This motor starter is then"held in" by (C1) N.O. auxiliary contacts. There is an instant of time (the "open transition") between the opening

of (S1) power contacts and the closing of (C2) power contacts, in whichpower across the motor windings is interrupted.

NOTE: For units supplied with the special NC25-4 microcomputer controller, refer to the "Users Guide", Form No. 6374 for the microcomputer operation.

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HWSC ELECTRICAL DATA (50 - 150)

Model 60 Hz of CircuitHWSC 3 Ph. Start Ampacity

Volts Type Minimum

COMPRESSORS RECOMMENDED

RATED LOAD AMPS LOCKED ROTORMOTOR NO. AMPS Wire Max. Fuse

MOTOR NO. Size Size

1 2 1 2

50

208/230 XL 148 - 1040 - 185 000 300

208/230 Y-D 148 - 347 - 185 000 300

460 XL 64 - 422 - 80 4 125

460 Y-D 64 - 141 - 80 4 125

60

208/230 XL 178 - 1228 - 223 0000 350

208/230 Y-D 178 - 409 - 223 0000 350

460 XL 78 - 485 - 98 3 150

460 Y-D 78 - 162 - 98 3 150

75

208/230 XL 208 - 1415 - 260 300 450

208/230 Y-D 208 - 472 - 260 300 450

460 XL 95 - 539 - 119 1 175

460 Y-D 95 - 180 - 119 1 175

100

208/230 XL 148 148 1040 1040 333 400 450

208/230 Y-D 148 148 347 347 333 400 450

460 XL 64 64 422 422 144 0 175

460 Y-D 64 64 141 141 144 0 175

110

208/230 XL 178 148 1228 1040 371 500 500

208/230 Y-D 178 148 409 347 371 500 500

460 XL 78 64 485 422 162 00 200

460 Y-D 78 64 162 141 162 00 200

120

208/230 XL 178 178 1228 1228 400 (2)250 500

208/230 Y-D 178 178 409 409 400 (2)250 500

460 XL 78 78 485 485 176 00 225

460 Y-D 78 78 162 162 176 00 225

135

208/230 XL 208 178 1415 1228 438 (2)300 600

208/230 Y-D 208 178 472 409 438 (2)300 600

460 XL 95 78 539 485 197 000 250

460 Y-D 95 78 180 162 197 000 250

150

208/230 XL 208 208 1415 1415 468 (2)350 600

208/230 Y-D 208 208 472 472 468 (2)350 600

460 XL 95 95 539 539 214 0000 300

46O Y-D 95 95 180 180 214 0000 300

NOTES:1. XL: Across the Line; Y-D: Star-Delta2. RLA (Rated Load Amps) rated in accordance with ARI Standard 590.3. Starting current for normal Y-D start is shown. In certain compressor failure modes, Y-D inrush can be as high as XL inrush.4. Wire Size Amps equal 125% of the rated load amps for the largest motor in the circuit plus 100% of the rated load amps for all other motors in the

circuit, per N.E.C.5. Based on copper conductors with 75°C. insulation, per N.E.C. Table 310-16.6. Maximum fuse size is based on 225% of the rated load amps for the largest motor in the circuit plus 100% of the rated load amps for all other motors

in the circuit. This is the largest fuse allowed per N.E.C. A smaller fuse is often recommended based on unit application and ambient temperature.

VOLTAGE TOLERANCES:1) 208 volt: min. 187, max. 2292) 230 volt: min. 207, max. 2533) 460 volt: min. 414, max. 506

12

HWSC ELECTRICAL DATA (180-300)

ModelHWSC

Volts Type Ampacity Size Size60 HZ of3 PH. Unit

COMPRESSORS Minimum Minimum MaximumCircuit Wire Fuse

RATED LOAD AMPS LOCKED ROTOR AMPSMOTOR NO. MOTOR NO.

1 2 3 4 1 2 3 4 Cir.1 Cir.2 Cir.1 Cir.2 Cir.1 Cir.2

180

208/230 XL 178 178 178 - 1228 1228 1228 - 579 - (2)500 - 700 -

208/230 Y-D 178 178 178 - 409 409 409 - 579 - (2)500 - 700 -

460 XL 78 78 78 - 485 485 485 - 254 - 300 - 300 -

460 Y-D 78 78 78 - 162 162 162 - 254 - 300 - 300 -

210

208/230 XL 208 208 178 - 1415 1415 1228 - 438 260 (2)300 300 600 450

208/230 Y-D 208 208 178 - 472 472 409 - 438 260 (2)300 300 600 450

460 XL 95 95 78 - 539 539 485 - 292 - 350 - 350 -

460 Y-D 95 95 78 - 180 180 162 - 292 - 350 - 350 -

225

208/230 XL 208 208 208 - 1415 1415 1415 - 468 260 (2)350 350 600 450

208/230 Y-D 208 208 208 - 472 472 472 - 468 260 (2)350 350 600 450

460 XL 95 95 95 - 539 539 539 - 309 - 350 - 400 -

460 Y-D 95 95 95 - 180 180 180 - 309 - 350 - 400 -

240

208/230 XL 178 178 178 178 1228 1228 1228 1228 401 401 (2)250 (2)250 500 500

208/230 Y-D 178 178 178 178 409 409 409 409 401 401 (2)250 (2)250 500 500

460 XL 78 78 78 78 485 485 485 485 332 - 400 - 400 -

460 Y-D 78 78 78 78 162 162 162 162 332 - 400 - 400 -

255

208/230 XL 208 178 178 178 1415 1228 1228 1228 438 401 (2)300 (2)300 600 500

208/230 Y-D 208 178 178 178 472 409 409 409 438 401 (2)300 (2)300 600 500

460 XL 95 78 78 78 539 485 485 485 353 - 500 - 400 -

460 Y-D 95 78 78 78 180 162 162 162 353 - 500 - 400 -

270

208/230 XL 208 208 178 178 1415 1415 1228 1228 438 438 (2)300 (2)300 600 600

208/230 Y-D 208 208 178 178 472 472 409 409 438 438 (2)300 (2)300 600 600

460 XL 95 95 78 78 539 539 485 485 370 - 500 - 450 -

460 Y-D 95 95 78 78 180 180 162 162 370 - 500 - 450 -

300

208/230 XL 208 208 208 208 1415 1415 1415 1415 468 468 (2)350 (2)350 600 600

208/230 Y-D 208 208 208 208 472 472 472 47 468 468 (2)350 (2)350 600 600

460 XL 95 95 95 95 539 539 539 539 404 - (2)300 - 450 -

460 Y-D 95 95 95 95 180 180 180 180 404 - (2)300 - 450 -

NOTES:1. XL: Across the Line; Y-D: Star-Delta2. RLA (Rated Load Amps) rated in accordance with ARI Standard 590.3. Starting current for normal Y-D start is shown. In certain compressor failure modes, Y-D inrush can be as high as XL inrush.4. Wire Size Amps equal 125% of the rated load amps for the largest motor in the circuit plus 100% of the rated load amps for all other motors in the

circuit, per N.E.C.5. Based on copper conductors with 75°C. insulation, per N.E.C. Table 310-16.6. Maximum fuse size is based on 225% of the rated load amps for the largest motor in the circuit plus 100% of the rated load amps for all other motors

in the circuit. This is the largest fuse allowed per N.E.C. A smaller fuse is often recommended based on unit application and ambient temperature.

VOLTAGE TOLERANCES:1) 208 volt: min. 187, max. 2292) 230 volt: min. 207, max. 2533) 460 volt: min. 414, max. 506

13

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HWSC 50-150 RIGGING INSTRUCTIONS

HWSC 50-150 ISOLATOR INSTRUCTIONS

Model Weight (Lbs)HWSC 1 2 3

50 208 375 25060 240 435 29075 300 540 360

100 390 705 470110 430 772 515120 515 930 620135 585 1050 700150 625 1125 750

15

HWSC 180-300 RIGGING INSTRUCTIONS


Model Weight (Lbs)HWSC 1 2 3180 1890 1600 1800210 2000 1700 2000225 2100 1800 2050240 2100 2000 2300255 2350 2000 2350270 2400 2150 2400300 2700 2350 2700

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16


TROUBLESHOOTING GUIDE

CHILLER UNIT WILL NOT START

Possible Cause Remedy1. Power off 1. Check main disconnect switch2. Main line open 2. Check main fuses3. Incorrect wiring 3. Check the wiring diagram4. Loose terminals 4. Tighten5. Control circuit open 5. Check interlocks with auxiliary equipment, pressure and

6. Improper phasing of main power 6. Change any 2 of 3 phases of main power.temperature controls.

COMPRESSOR HUMS BUT DOES NOT START

Possible Cause Remedy1. Low voltage 1. Check at main entrance and at unit. Consult power company.2. Only one contactor energized 2. Check contactors - replace if necessary.

COMPRESSOR CUTS OUT ON LOW PRESSURE SAFETY CONTROL

Possible Cause Remedy1. Refrigerant shortage 1. Check for leaks - add refrigerant2. No load on water chiller 2. Check water pump operation3. Restriction in liquid line 3. Plugged strainer - clean or replace liquid line filters or suction valve

4. Low discharge pressure 4. Raise and control discharge pressure within design limits5. Low water flow thru cooler 5. Check water flow thru cooler

partially closed - open valves fully. Expansion valve clogged orinoperative

COMPRESSOR CYCLES ON HIGH PRESSURE CONTROL

Possible Cause Remedy1. Main water valve closed 1. Open water valve2. Water regulating valve incorrectly set or defective 2. Reset or replace3. Compressor discharge valve partially closed 3. Open valve fully4. Non-condensable gases in system 4. Flush water with unit off -- if pressure in system exceeds pressure

5. Overcharge of R-22 5. Reclaim R-22 from system while in operation until bubbles shown

6. Water temperature high or insufficient water 6. Check water supply against requirements; if cooling tower is used,

7. Dirty condenser 7. Clean condenser.

corresponding to water temperature, purge system from valve oncondenser

in sight glass clear. Add charge until bubbles disappear.

check spray nozzles.

CAUSES AND PREVENTION OF FREEZE-UP

Cause Prevention1. Improper charging 1. Charge per manufacturer's recommendation2. Improperly set safety time delay low pressure freeze control 2. Check the safety time delay low pressure control for proper setting

3. Operating with safety time delay low pressure control bypassed 3. The safety time delay low pressure control is wired in series with the

4. Improper chilled water circulation 4. Use an ample sized cleanable strainer in the chilled water circuit.

5. Not draining for winter shutdown 5. When the system is shut down for the winter, remove the drain

6. Improper setting of low water temperature control 6. Check setting of temperature control.

at the beginning of each season

compressor motor contractors. (Do not bypass it).

Make certain the strainer is clean to insure full flow and velocity ofchilled water. It may sometimes be necessary to treat the water toprevent formation of deposits.

plugs and drain the cooler. Blow out any remaining water with air.

NOTE:If the ambient temperature is below 32°F., freezing can be prevented by one of two methods:1. Drain all water from the equipment.2. Add industrial antifreeze to the water. Do not use automotive antifreeze solutions.

17

START-UP CHECK LIST

Job Name ________________________________________________________________ Location ____________________________________________________________________Unit Model No. __________________________________________________________Unit Serial No. _____________________________________________________________Compressor Serial Nos. 1 _______________ 2 _______________ 2 _______________ 4 _______________

Start Up Procedure Check Points YES NO

Equipment Inspection a. Unit damaged on arrival. (If yes, was carrier notified?) ______ ______b. Material received agrees with shipping papers ______ ______

Setting Unit a. Vibration isolators used ______ ______b. Spring isolators adjusted for equal height ______ ______c. If rubber-in-shear isolators are used, is unit leveled by shimming? ______ ______

Wiring a. Power wiring complete ______ ______b. Main power wiring ± 10% proper phase (phase monitor) (phase rotation

meter) check with guages at start-up. No oil pressure therefore no oilseal on rotors failure at max. 3 min. run. Circuit breakers and/or fuses agree with unit spec. plate. ______ ______

c. Control wiring complete ______ ______d. Electrical service adequate for load ______ ______e. Power source voltage correct for motor(s) used ______ ______f. External disconnect has fusetrons in place and they are of proper size ______ ______g. System wired per diagram ______ ______h. All lead connections tight ______ ______i. Wiring complies with local codes ______ ______

Piping a. Piping complies with applicable codes ______ ______b. Condensing temperature regulation means used ______ ______c. External piping independently supported ______ ______d. Chilled water line insulated ______ ______e. Chilled water loop filled and vented at high points in system ______ ______f. Sediment traps and strainers checked for cleanliness. (Creates false head,

low flow rates). ______ ______

Before Start-Up a. Check compressor(s) for proper oil level ______ ______b. Open compressor(s) discharge service valves ______ ______c. All isolation valves on condenser or chiller barrel opened. Automatic

valves such as 3-way valves and bypasses in cooling position. Verify damper position and start fans in AHU's. ______ ______

d. Open suction, discharge and oil pressure valves to pressure guages(if supplied). ______ ______

e. Check interlock of chiller water flow switch, chiller water and condenserpumps. Also check rotation of pumps. ______ ______

f. Start auxiliary equipment (pumps, fans, etc.) ______ ______g. CCH energized 24 hrs. before start-up ______ ______h. Check for proper pressure drop across chiller barrel and condensers.

Pressure gauges and thermometers should be installed on entering and leaving water lines.

i. Check for leaks, oily areas, flare nuts, control lines damaged in shipment ______ ______

After Start-Up a. Recheck oil in crankcase(s) ______ ______b. Check high pressure control ______ ______c. Check low pressure freeze control ______ ______d. Check and adjust (if necessary) operating thermostat ______ ______e. Check low pressure control ______ ______f. Check superheat and adjust if necessary ______ ______

Clean Up a. Final leak tests made ______ ______b. Shut-off valves backseated, packing nuts tightened and caps replaced ______ ______c. Control panel doors and/or covers secured ______ ______d. Clean up around unit ______ ______

Operating Personnel a. Proper instructions given to customer's personnel in operation of unit. ______ ______

18

OPERATING DATA

Voltage: L1__________ L2__________ L3__________Amperage: Compressor 1__________ 2__________ 3__________ 4__________Pressure Gauge Readings: #1 Suction__________psig, #1 Discharge__________psig, #2 Suction__________psig, #2 Discharge__________psig

#3 Suction__________psig, #3 Discharge__________psig, #4 Suction__________psig, #4 Discharge__________psig 1. High Pressure Setting: #1 Cut-in__________psig, #1 Cut-out__________psig, #2 Cut-in__________psig, #2 Cut-out__________psig

#3 Cut-in__________psig, #3 Cut-out__________psig, #4 Cut-in__________psig, #4 Cut-out__________psig 2. Checked Setting: Yes _____ No _____ 3. Low Pressure Setting: #1 Cut-in__________psig, #1 Cut-out__________psig, #2 Cut-in__________psig, #2 Cut-out__________psig

#3 Cut-in__________psig, #3 Cut-out__________psig, #4 Cut-in__________psig, #4 Cut-out__________psig 4. Checked Setting: Yes _____ No _____ 5. Low Pressure Freeze Control: #1 Cut-in__________psig, #1 Cut-out__________psig, #2 Cut-in__________psig, #2 Cut-out__________psig

#3 Cut-in__________psig, #3 Cut-out__________psig, #4 Cut-in__________psig, #4 Cut-out__________psig 6. Checked Setting: Yes _____ No _____ 7. If Part Winding Start, Time Delay is: _______ seconds 8. Condenser Water Temperature: #1 Water in________°F.; #1 Water out________°F.; #2 Water in________°F.; #2 Water out________°F.

#3 Water in________°F.; #3 Water out________°F.; #4 Water in________°F.; #4 Water out________°F. 9. Chilled Water Temperature: Water in ________°F.; Water out________°F.10. Low Water Temperature Cutout Setting ________________________°F.

PHYSICAL DATAMODELS HWSC-50 THRU 150

Model HWSC 50 60 75 100 110 120 135 150

Nominal Capacity - Tons 45 55 64 89 99 109 121 130

SEMI-HERMETIC SCREW TYPE COMPRESSORSNo. of Compressors 1 1 1 2 2 2 2 2

Nominal Size (HP) 50 60 75 (2)50 50-60 (2)60 60-75 (2)75

Oil Charge (Oz.) 202 236 236 (2)202 (1)202(1)236 (2)236 (2)236 (2)236

Crankcase Heater (Watts) 200 200 200 (2)200 (2)200 (2)200 (2)200 (2)200

COOLERStorage Capacity (Gal.) 6.25 9.4 11.1 17.6 25.4 25.4 29.4 29.4

Diameter x Length 860 1060 1160 1360 12102 12102 14102 14102

CONDENSERSNo. of Condensers 1 1 1 2 2 2 2 2

Diameter x Length 1279 1279 1279 1279 1279 1279 1279 1279

UNITRefrigerant Charge - R22 (Lbs.) 70 73 100 150 170 175 190 200

Net Weight (Lbs.) 2500 2900 3600 4700 5150 6200 7000 7500

MODELS HWSC-180 THRU 300Model HWSC 180 210 225 240 255 270 300

Nominal Capacity - Tons 165 184 193 218 226 236 256

SEMI-HERMETIC SCREW TYPE COMPRESSORSNo. of Compressors 3 3 3 4 4 4 4

Nominal Size (HP) (3)60 (1)60(2)75 (3)75 (4)60 (3)60(1)75 (2)60(2)75 (4)75

Oil Charge (Oz.) (3)236 (3)236 (3)236 (4)236 (4)236 (4)236 (4)236

Crankcase Heater (Watts) (3)200 (3)200 (3)200 (4)200 (4)200 (4)200 (4)200

COOLERStorage Capacity (Gal.) 60.5 60.5 60.5 67.7 67.7 67.7 67.7

Diameter x Length 18122 18122 18122 20122 20122 20122 20122

CONDENSERSNo. of Condensers 3 3 3 4 4 4 4

Diameter x Length 1279 1279 1279 1279 1279 1279 1279

UNITRefrigerant Charge - R22 (Lbs.) 216 248 264 288 304 320 352

Net Weight (Lbs.) 10500 11500 12000 13000 13500 14000 14500

19

model hwsc-d small screw water cooled …dunhambushla.com/pdf/installation_manuals/hwsc-d.pdf ·...

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