TROUBLESHOOTING
SYMPTOM AND PROBABLE CAUSE
COMPRESSOR DOES NOT RUN
Power tine open
2. Control circuit stop-start switch is open
3. Safety device tripped
4. Contactor stuck open
5. Loose terminat connection
6.
wired controls
7. Seized compressor
8. Chilled water
switch open
9. Low line voltage
Compressor motor defective
COMPRESSOR STOPS ON LOW-PRESSURE
CONTROL
1. Compressor suction shutoff valve partially
2. Low refrigerant charge
3. Liquid line solenoid valve(s) fails to open
COMPRESSOR STOPS ON
CONTROL
Compressor discharge valve partialiy closed
2. Air in system
3. Condenser fan(s) not operating
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
SYSTEM IS NOISY
Piping vibration
2. Compressor noisy
COMPRESSOR LOSES OIL
1. Leak in system
2. Crankcase heaters not energized during shutdown
FROSTED SUCTION LINE
Expansion valve admitting excess refrigerant
HOT LIQUID LINE
Shortage of refrigerant due to leak.
2. Expansion valve opens too wide
FROSTED LIQUID LINE
1. Restricted filter drier
COMPRESSOR WILL NOT UNLOAD
Burned-out coil
2, Defective capacity control valve
3. Miswired. solenoid
4. Weak, broken or wrong valve body spring
COMPRESSOR WILL NOT LOAD
Miswired solenoid
2. Defective capacity control valve
3. Plugged strainer (high side)
4. Stuck or damaged unloader piston or piston ring(s)
PROBABLE REMEDY
1. Reset circuit breaker.
2. Reset switch.
3. Reset control circuit with stop-start switch.
4. Replace contactor.
5. Check connections.
6. Check and rewire.
7. Check motor winding for open or short. Replace
compressor, if necessary.
8. Check chilled water pump, check switch.
9. Check tine voltage
determine location of
voltage drop and remedy deficiency.
IO. Check motor winding for open or short. Replace
compressor, if necessary.
valve.
Add refrigerant.
3. Check
valve for
Replace if necessary.
Open valve or replace if defective.
2. Purge system.
3. Check motor wiring and repair or replace if defective.
Add refrigerant.
2. Replace control.
3. Purge system.
4. Clean or replace.
1. Support piping as required.
2. Check valve plates for valve noise. Replace
compressor if bearings are worn.
1. Repair leak.
2. Check wiring and relays. Check heater and replace
if defective.
Adjust expansion valve.
Repair leak and recharge.
2. Adjust expansion valve.
Remove restriction or
1. Replace coil.
2. Replace valve.
3. Rewire correctly.
4. Replace spring.
Rewire correctly.
2. Replace valve.
3. Clean or replace strainer.
4. Clean or replace the necessary parts.
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