55
b) Three-phase systems 400V - 3N - 50 Hz
Rewire power supply wires.
Check negative phase relay (47C)
to see if it has operated.
Check magnetic contactor. (MG)
Check thermal relay (51C) to see if
it has operated.
Check power supply voltage.
Voltage is abnormally low.
Contact power utility company to
have power voltage restored to
normal
Check compressor.
There is a possibility of locked
rotor.
NO
90% or more of
rated voltage.
YES
YES
YES
O.K.
NO
Check compressor motor internal
protector. (49C)
Temperature of compressor is
abnormally high.
Refrigerant gas shortage.
Compressor is defective.
YES
NO
Charge refrigerant gas.
