Carrier 38AK024-044 - Manual (Page 23)

TROUBLESHOOTING
SYMPTOM AND PROBABLE CAUSE PROBABLE REMEDY
COMPRESSOR DOES NOT RUN
1. Power line open
2. Oil pressure switch tripped
3. Safety device tripped
4. Contactor stuck open
5. Loose terminal connection
6. Improperly wired controls
7. Seized compressor
8. Low line voltage
9. Compressor motor defective
1. Reset circuit breaker
2. Reset oil pressure switch at unit
3. Reset control circuit with thermostat
4. Replace contactor
5. Check connections
6. Check and rewire
7. Check motor winding for open or short. Replace
compressor, if necessary
8. Check line voltage — determine location of
voltage drop and remedy deficiency
9. Check motor winding for open or short. Replace
compressor, if necessary
COMPRESSOR STOPS ON LOW-PRESSURE
CONTROL
1. Compressor suction shutoff valve partially closed
2. Low refrigerant charge
3. Liquid line solenoid valve(s) fails to open
1. Open valve
2. Add refrigerant
3. Check liquid line solenoid valve for proper operation.
Replace if necessary
COMPRESSOR STOPS ON HIGH-PRESSURE
CONTROL
1. Compressor discharge valve partially closed
2. Air in system
3. Condenser fan(s) not operating 1. Open valve or replace if defective
2. Purge and evacuate system
3. Check motor wiring and repair or replace if defective
UNIT OPERATES TOO LONG OR CONTINUOUSLY
1. Low refrigerant charge
2. Control contacts fused
3. Air in system
4. Partially 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. Crankcrase heaters not energized during shutdown
3. Inadequate piping
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
1. Expansion valve admitting excess refrigerant 1. 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 1. Remove restriction or replace
COMPRESSOR WILL NOT UNLOAD
1. Defective unloader
2. Defective capacity control solenoid valve
3. Miswired liquid line solenoid
4. Weak, broken or wrong valve body spring 1. Replace
2. Replace valve
3. Rewire correctly
4. Replace spring
COMPRESSOR WILL NOT LOAD
1. Miswired capacity control liquid solenoid
2. Defective capacity control solenoid valve
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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