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SYMPTOM
Compressor and con-
denser fan will not
start.
Compressor will not
start but condenser
fan runs.
Compressor cycles
(other than normally
satisfying thermostat).
Compressor operates
continuously.
Excessive head
pressure.
Head pressure too low.
Excessive suction
pressure.
Suction pressure too
low.
COOLING TROUBLESHOOTING CHART
CAUSE
Power failure
Fuse blown or circuit breaker tripped
Defective thermostat, contactor, transformer,
or control relay
Insufficient line voltage
Incorrect or faulty wiring
Thermostat setting too high
Faulty wiring or loose connections in
compressor circuit
Compressor motor burned out, seized, or
internal overload open
Defective run/start capacitor, overload, or
start relay
One leg of 3-phase power dead
Refrigerant overcharge or undercharge
Defective compressor
Insufficient line voltage
Blocked condenser
Defective run/start capacitor, overload,
or start relay
Defective thermostat
Faulty condenser-fan motor or capacitor
Restriction in refrigerant system
Dirty air filter
Unit undersized for load
Thermostat set too low
Low refrigerant charge
Leaking valves in compressor
Air in system
Condenser coil dirty or restricted
Dirty air filter
Dirty condenser coil
Refrigerant overcharged
Air in system
Condenser air restricted or air short-cycling
Low refrigerant charge
Compressor valves leaking
Restriction in liquid tube
High heat load
Compressor valves leaking
Refrigerant overcharged
Dirty air filter
Low refrigerant charge
Metering device or low side restricted
Insufficient evaporator airflow
Temperature too low in conditioned area
Outdoor ambient below 40 F
Field-installed filter-drier restricted
Call power company.
Replace fuse or reset circuit breaker.
Replace component.
Determine cause and correct.
Check wiring diagram and rewire correctly.
Lower thermostat setting below room temperature.
Check wiring and repair or replace.
Determine cause. Replace compressor.
Determine cause and replace.
Replace fuse or reset circuit breaker.
Determine cause.
Recover refrigerant, evacuate system, and recharge
to capacities shown on nameplate.
Replace and determine cause.
Determine cause and correct.
Determine cause and correct.
Determine cause and replace.
Replace thermostat.
Replace.
Locate restriction and remove.
Replace filter.
Decrease load or increase unit size.
Reset thermostat.
Locate leak, repair, and recharge.
Replace compressor.
Recover refrigerant, evacuate system, and recharge.
Clean coil or remove restriction.
Replace filter.
Clean coil.
Recover excess refrigerant.
Recover refrigerant, evacuate system, and recharge.
Determine cause and correct.
Check for leaks, repair and recharge.
Replace compressor.
Remove restriction.
Check for source and eliminate.
Replace compressor.
Recover excess refrigerant.
Replace filter.
Check for leaks, repair, and recharge.
Remove source of restriction.
Increase air quantity. Check filter, and replace if
necessary.
Reset thermostat.
Install low-ambient kit.
Replace.
—19—
REMEDY
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