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Table 36—Cooling Service Analysis
PROBLEM CAUSE REMEDY
Compressor and Condenser Fan
Will Not Start.
Power failure. Call power c ompany.
Fuse bl own or circuit breaker tripped. Replace fuse or reset circuit breaker.
Defective thermostat,contactor, transformer,or
control r elay .
Replace c omponent.
Insufficient line v oltage. Determine cau se and correct.
Incorrect or faulty wiring. Check wiring diagram and rewire correctly.
Thermostat setting too high. Lower thermostat setting below room temperature.
Compressor Will Not Start
But Condenser Fan Runs.
Faulty wiring or loose connectionsin compres-
sor circuit.
Check wiring an d repair or replace.
Compressor motor burned out, seized, or in-
ternal overload open.
Determine cause. Replace co mpressor.
Defective run/start capacitor, overload,start
relay.
Determine cause and replace.
One leg of 3-phase pow er dead. Replace fuse or reset circuit breaker. Determine
cause.
CompressorCycles(OtherThan
Normally Satisfying Thermostat).
Refrigerant overcharge orundercharge. Recover refrigerant, evacuate system, and recharge
to nameplate.
Defective compressor. Replace and determine cause.
Insufficient line v oltage. Determine cau se and correct.
Blocked condenser. Determ ine cause and correct.
Defective run/start capacitor, overload,or start
relay.
Determine cause and replace.
Defective thermostat. Replace thermostat.
Fault y condenser-fan motor or capacitor. Replace.
Restriction in refrigerant system. Locate restriction and remove.
Compressor Operates Continuously.
Dirty air filter. Replace filter.
Unit undersizedfor load. Decrease load or in crease un it size.
Thermostat set too low. Reset thermostat.
Low refrigerant charge. Locate leak, repair, and recharge.
Leaking valves in com pressor. Replace compressor.
Air in system. Recover refrigerant, evacuate system, and recharge.
Condenser coil dirty or restricted. Clean coil or remove restriction.
Excessive Head Pressure.
Dirty air filter. Replace filter.
Dirty condenser coil. Clean coil.
Refrigerant overcharged. Recover excessrefrigerant.
Air in system. Recover refrigerant, evacuate system, and recharge.
Condenser air restricted or airshort-cycling. Determine cause and correct.
Head Pressure Too Low.
Low refrigerant charge. Check for leaks,repair,and recharge.
Compressor valves leaking. Replace compressor.
Restrictioninliquidtube. Remove restriction.
Excessive Suction Pressure.
High h eat load. Check forsource and eliminate.
Compressor valves leaking. Replace compressor.
Refrigerant overcharged. Recover excessrefrigerant.
Suction Pressure Too Low.
Dirty air filter. Replace filter.
Low refrigerant charge. Check for leaks,repair,and recharge.
Metering device or low side restricted. Remove source of restriction.
Insufficient evaporator airflow. Increase air quantity. Check filter an d replace if neces-
sary.
Temperature too low in conditioned area. Reset thermostat.
Outdoor ambient below 25 F. Install low-ambient kit.
Evaporator Fan Will Not Shut Off.
Time off delay not finished. Wait for 30-second off delay.
50HE,HJ