Service manual

51
b) Three - phase systems 400V - 3N - 50 Hz
•Measure resistance of compres-
sor motor winding.
YES
Clean heat exchanger or remove
obstacles.
Is outdoor heat exchanger coil dirty
or are there obstacles near air suc-
tion inlet?
•Check compressor motor over-
current relay (51C).
•Check power supply voltage. Is
voltage abnormally low?
•Check compressor.
There is a possibility of locked
rotor.
Is temperature of compressor
abnormally high?
Refrigerant gas shortage.
Charge refrigerant gas.
YES
YES
NO
It’s operated
NO
90% or more of
rated voltage
R22 or R407C.