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Problem
Probable Cause
Solution
Compressor Cuts Out
On Thermal Overload
Low voltage
Check incoming voltage leg-to-leg
All three legs must be within 10% of the
required voltage and the leg-to-three-leg
average voltage variation must be less than
2% on each leg
Sustained high discharge pressure
Check running amperage and conditions
described under high discharge pressure
High suction and discharge pressures
Check TXV setting, check for air in system
Defective compressor overload
Allow compressor to cool for two hours if
compressor is hot, recheck for open circuit
Defective run capacitor
Check run capacitor for compressor and
fan motor
Improper refrigerant charge
Check subcooling
Bearings or pistons too tight
Check for low oil level
Allow time for compressor to cool
Check dome temperature of compressor
Noisy Compressor
Scroll compressors are rotation sensitive
Reverse wiring at disconnect switch may
require blower be rechecked for rotation
Refrigerant overcharged
Check pressures and subcooling
Excess or insufficient oil in compressor
crankcase
Check oil level on hermetic compressors,
check total equivalent feet of piping, add oil
as recommended
Liquid floodback
Check TXV setting, refrigerant overcharge
refrigerant circuit problem
Tubing rattle
Dampen by taping or clamping, bend tubing
away from contact where possible
Compressor defective
Replace compressor
Table 14.2: Compressor, Cont.
RC/FC Series Installation, Operation, and Maintenance Manual
