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4. 0 Troubleshooting
Problem
Check Point
Probable Causes
Compressor
failure to start
Power source
Power source switch off
Fuse blown
Too low voltage at compressor terminals
Wiring
Disconnection of wiring
Control devices
Improper setting of temperature controller
Protection devices trip (Discharge temp. High-Low pressure
Switch etc.)
Loss of Phase
Wrong phase sequence
Compressor
Internal motor protector trips
Excessive liquid in compressor
Inside components broken
Motor burns out (windings broken or short to ground)
Compressor shut
down shortly after
starting
Power source
Failure of breaker
Refrigerant circuit
High pressure side blockage
Low pressure side blockage
Electrical
components
Failure of contactor (rapid fluctuation or contacts welded)
Temperature
controller
Temperature controller trips
Compressor
Abnormal line voltage
Motor winding overheating due to lack of phase
Motor winding overheating caused by unbalanced voltage
Motor winding overheating caused by loss of refrigerant
Too high discharge pressure
Too high suction superheating degree
Non-condensable gas mixed in system
Insufficient cooling for compressor
Inside failure of compressor