26
TROUBLESHOOTING THE COOLING SYSTEM
Refer to Table 4 for additional troubleshooting topics.
Table 4 – Cooling Service Troubleshooting
PROBLEM
CAUSE
REMEDY
Compressor and Con
denser Fan Will Not Start.
Power failure.
Call power company.
Fuse blown or circuit breaker tripped.
Replace fuse or reset circuit breaker.
Defective thermostat, contactor, transformer, or
control relay.
Replace defective component.
Insufficient line voltage.
Determine cause and correct.
Incorrect or faulty wiring.
Check wiring diagram and rewire correctly.
Thermostat setting too high.
Lower thermostat setting below room temperature.
Compressor Will Not
Start But Condenser Fan
Runs.
Faulty wiring or loose connections in compres
sor circuit.
Check wiring and repair or replace. Tighten loose connec
tions.
Compressor motor burned out, seized, or
internal overload open.
Determine cause. Replace compressor.
Defective run/start capacitor, overload, start
relay.
Determine cause and replace defective component.
One leg of three-phase power dead.
Replace fuse or reset circuit breaker. Determine cause.
Compressor Cycles
(other than normally
satisfying thermostat).
Refrigerant overcharge or undercharge.
Recover refrigerant, evacuate system, and recharge to
values on nameplate.
Defective compressor.
Replace defective compressor.
Insufficient line voltage.
Determine cause and correct.
Blocked condenser.
Determine cause and correct.
Defective run/start capacitor, overload, or start
relay.
Determine cause and replace.
Defective thermostat.
Replace thermostat.
Faulty condenser-fan motor or capacitor.
Replace. Defective fan motor or capacitor.
Restriction in refrigerant system.
Locate restriction and remove.
Compressor Operates
Continuously.
Dirty air filter.
Replace filter.
Unit undersized for load.
Decrease load or replace with larger unit.
Thermostat set too low.
Reset thermostat.
Low refrigerant charge.
Locate leak; repair and recharge.
Leaking valves in compressor.
Replace compressor.
Air in system.
Recover refrigerant, evacuate system, and recharge.
Condenser coil dirty or restricted.
Clean coil or remove restriction.
Excessive Head
Pressure.
Dirty air filter.
Replace air filter.
Dirty condenser coil.
Clean condenser coil.
Refrigerant overcharged.
Recover excess refrigerant.
Faulty TXV valve.
1. Check TXV bulb mounting and secure tightly to suction
line and insulate.
2. Replace TXV valve and filter drier if stuck open or closed.
Air in system.
Recover refrigerant, evacuate system, and recharge.
Condenser air restricted or air short-cycling.
Determine cause and correct.
Head Pressure Too Low.
Low refrigerant charge.
Check for leaks; repair and recharge.
Compressor valves leaking.
Replace compressor.
Restriction in liquid tube.
Remove restriction.
Excessive Suction
Pressure.
High head load.
Check for source and eliminate.
Compressor valves leaking.
Replace compressor.
Refrigerant overcharged.
Recover excess refrigerant.
Suction Pressure Too
Low.
Dirty air filter.
Replace filter.
Low refrigerant charge.
Check for leaks; repair and recharge.
Metering device or low side restricted.
Remove source of restriction.
Faulty TXV valve.
1. Check TXV bulb mounting and secure tightly to suction
line and insulate.
2. Replace TXV valve and filter drier if stuck open or closed.
Insufficient evaporator airflow.
Increase air quantity. Check filter and replace if
necessary. Check belt tension on blower.
Temperature too low in conditioned area.
Reset thermostat.
Outdoor ambient below 25°F.
Install low-ambient kit.
Evaporator Fan Will Not
Shut Off.
Time off delay not finished.
Wait for 30-second off delay.
Compressor Makes
Excessive Noise.
Compressor rotating in wrong direction.
Reverse the 3-phase power leads.
Содержание 580J D17
Страница 80: ...80 APPENDIX IV WIRING DIAGRAMS cont C160041 Fig 72 580J D17 D28 Control Diagram 208 230 3 60 460 575 3 60 ...
Страница 81: ...81 APPENDIX IV WIRING DIAGRAMS cont C160042 Fig 73 580J D17 D28 Power Diagram 208 230 3 60 ...
Страница 82: ...82 APPENDIX IV WIRING DIAGRAMS cont C160043 Fig 74 580J D17 D28 Power Diagram 460 3 60 ...
Страница 83: ...83 APPENDIX IV WIRING DIAGRAMS cont C160044 Fig 75 580J D17 D28 Power Diagram 575 3 60 ...
Страница 84: ...84 APPENDIX IV WIRING DIAGRAMS cont C160050 Fig 76 580J D17 D28 Control Diagram with Perfect Humidity ...
Страница 86: ...86 APPENDIX IV WIRING DIAGRAMS cont C160047 Fig 78 580J D17 D28 Power Diagram 460 3 60 with Perfect Humidity ...
Страница 87: ...87 APPENDIX IV WIRING DIAGRAMS cont C160048 Fig 79 580J D17 D28 Power Diagram 575 3 60 with Perfect Humidity ...
Страница 88: ...88 APPENDIX IV WIRING DIAGRAMS cont C160049 Fig 80 RTU OPEN Wiring Diagram ...
Страница 89: ...89 APPENDIX IV WIRING DIAGRAMS cont C160045 Fig 81 RTU OPEN Wiring Diagram with Perfect Humidity ...
