Problem
Power source
Wiring
Compressor
Control devices
failure to start
Compressor
Power source
Refrigerant circuit
Electrical
components
Temperature
controller
Compressor shut
down shortly after
starting
Compressor
Wiring
Inverter Driver
Components
failure to start
Driver Cooling
Compressor
5. 0 Troubleshooting
Check Point
Power source switch off
Fuse blown
Too low voltage at compressor terminals
Disconnection of wiring
Improper setting of temperature controller
Protection devices trip (Discharge temp. High-Low pressure
Switch etc.)
Loss of Phase
Wrong phase sequence
Internal motor protector trips
Excessive liquid in compressor
Inside components broken
Motor burns out (windings broken or short to ground)
Failure of breaker
High pressure side blockage
Low pressure side blockage
Failure of contactor (rapid fluctuation or contacts welded)
Temperature controller trips
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
Miss-wiring or disconnection of wiring
Loosen or burned parts
Insufficient cooling lead to overheating
Operation out of envelope
Probable Causes
25