Carrier 30HL - Troubleshooting Common Issues; Compressor Start-Up & Operation Problems; Oil Loss & Suction Line Freezing; High Pressure & Continuous Operation

Compressor does not run
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Power line open j
Reset circuit breaker.
Control circuit breaker tripped |
i
Check control circuit for ground or
short.
Reset breaker.
Safety tripped Reset.
Tripped power breaker
Check the controls. Find cause of
trip and reset breaker.
Condenser circulating pump not
running
Power off — restart.
Pump binding — free pump.
Incorrect wiring — rewire.
Pump motor burned out — replace.
Loose terminal connection
Check connections.
Improperly wired controls
Check wiring and rewire.
Low line voltage
Check line voltage — determine
location of voltage drop and
remedy deficiency.
Compressor motor defective
Check motor winding for open or
short. Replace compressor, if
necessary.
Seized compressor Replace compressor.
Compressor cycles on low-
pressure control
Low-pressure control erratic in
action
Raise differential setting.
Check capillary for pinches.
Replace control.
Compressor suction valve leaking Replace valve plate.
Compressor suction shutoff valve
partially closed
Open valve.
Low refrigerant charge
Add refrigerant.
Plugged compressor suction
strainer
Clean strainer or replace.
Compressor loses oil
Leak in system
Repair leak.
Mechanical damage (blown piston
or broken discharge valve)
Repair damage or replace
compressor.
Oil trapped in line
Check piping for oil traps.
Crankcase heaters not energized
during shutdown
Check wiring and crankcase
heater relay. Replace heater if
necessary.
Frosted suction line
Expansion valve admitting excess
refrigerant
Compressor cycles on high-
pressure control
High-pressure control erratic in
action
Check capillary tube for pinches.
Set control as required.
Compressor discharge valve
i partially closed
Open valve, or replace if defective.
i Air in system Purge.
S Condenser scaled
1 Clean condenser.
J Condenser water pump or fans not
1 operating
Start pump — repair or replace if
defective.
Unit operates long or
continuously
1 Low refrigerant charge
Add refrigerant.
1 Control contacts fused
Replace control.
1 Air in system
1 Purge.
1 Partially plugged or plugged
I Clean or replace.
expansion valve or strainer
Defective insulation
Replace or repair.
Service load too high
Keep doors and windows closed.
inefficient compressor
Check valves, replace if necessary.