Carrier GW Series Installation Instructions Manual

Contents

7ELECTRICAL! WARNINGELECTRICAL SHOCK HAZARDFailure to follow this warning could result in personalinjury or death.Before installing, modifying, or servicing system, mainelectrical disconnect switch must be in the OFF position.There may be more than 1 disconnect switch. Lock out andtag switch with a suitable warning label.CAUTION!UNIT OPERATION HAZARDFailure to follow this caution may result in equipmentdamage and/or improper operation.S Field wiring must comply with local and nationalelectrical codes.S Power to the unit must be within the operating voltagerange indicated on the unit nameplate.S On three--phase units, phases must be balanced within2%.S Operation of unit on improper line voltage or withexcessive phase imbalance will be hazardous to the unit,constitutes abuse, and may void the warranty.Properly sized fuses or HACR circuit breakers must be installed forbranch circuit protection. See unit nameplate for maximum fuse orbreaker size.The unit is provided with a concentric knock--out for attachingcommon trade sizes of conduit, route power supply wiring throughthis opening. Flexible wiring and conduit should be used to isolatevibration and noise from the building structure.Always connect the ground lead to the grounding lug provided inthe control box and power leads to the line side of compressorcontactor as indicated on the wiring diagrams.SAFETY DEVICES AND UPMCONTROLLER123456 7 9 10111213171415168A14120(1) Board Power Indicator (10) Compressor Contact Output(2) UPM Status LED Indicator (11) High Pressure Switch Connection(3) Water Coil Freeze ProtectionTemperature Selection [R30](12) Call for Compressor Y1(4) Air Coil Freeze ProtectionTemperature Selection(13) Low Pressure Switch Connection(5) UPM Board Settings (14) 24VAC Power Common(6) Water Coil Freeze Connection (15) Condensate Overflow Sensor(7) Air Coil Freeze Connection (16) Dry Contact(8) LCD Unit Display Connection (17) UPM Ground Standoff(9) 24VAC Power InputFig. 4 -- Unit Protection Module (UPM)Each unit is factory provided with a Unit Protection Module(UPM) that controls the compressor operation and monitors thesafety controls that protect the unit (see Fig. 4).Safety controls include the following:S High pressure switch located in the refrigerant discharge line andwired across the HPC terminals on the UPM.S Low pressure switch located in the unit refrigerant suction lineand wired across terminals LPC1 and LPC2 on the UPM.NOTE: UPM Board Dry Contacts are normally open (NO)S Water side freeze protection sensor, mounted close to condensingwater coil, monitors refrigerant temperature between condensingwater coil and thermal expansion valve. If temperature dropsbelow or remains at freeze limit trip for 30 seconds, the controllerwill shut down the compressor and enter into a soft lockoutcondition.The default freeze limit trip is 26_F, however this can be changedto 15_F by cutting the R30 or Freeze1 resistor located on top ofDIP switch SW1 (Refer to Fig. 4, item (3) for resistor location),Refer to Fig. 5 for sensor location.