Carrier 38AH024-034 - Manual (Page 23)

TROUBLESHOOTING (cont)
PROBLEM SOLUTION
UNIT OPERATES TOO LONG OR CONTINUOUSLY
1. Low refrigerant charge.
2. Control contacts fused.
3. Air in system.
4. Partiaily plugged expansion valve or filter drier.
1. Add refrigerant.
2. Replace control.
3. Purge and evacuate system.
4. Clean or replace.
SYSTEM IS NOISY
1. Piping vibration.
2. Compressor noisy.
1. Support piping as required.
2. Check valve plates for valve noise. Replace compressor if
bearings are worn.
COMPRESSOR LOSES OIL
1. Leak in system.
2. Crankcase heaters not energized during shutdown.
3. Improper interconnecting piping design.
1. Repair leak.
2. Check wiring and relays. Check heater and replace if
defective.
3. Check piping for oil return. Replace if necessary.
FROSTED SUCTION LINE
Expansion valve admitting excess refrigerant.
Adjust expansion valve.
HOT LIQUID LINE
1. Shortage of refrigerant due to leak.
2. Expansion valve opens too wide.
1. Repair leak and recharge.
2. Adjust expansion valve.
FROSTED LIQUID LINE
1. Restricted filter drier.
2. Liquid line solenoid valve partially closed.
1. Remove restriction or replace.
2. Replace valve.
COMPRESSOR WILL NOT UNLOAD
1. Defective unloader.
2. Defective capacity control solenoid valve (if used).
3. Miswired capacity control liquid line solenoid (if used).
4. Weak, broken, or wrong valve body spring.
1. Replace unloader.
2. Replace valve.
3. Rewire correctly.
4. Replace spring.
COMPRESSOR WILL NOT LOAD
1. Miswired capacity control liquid line solenoid (if used).
2. Defective capacity control solenoid valve (if used).
3. Plugged strainer (high side).
4. Stuck or damaged unloader piston or piston ring(s).
1. Rewire correctly.
2. Replace valve.
3. Clean or replace strainer.
4. Clean or replace the necessary parts.
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