37
Turn OFF power supply of indoor and outdoor unit,
and measure the compressor winding resistance
between the compressor terminals.
Is the resistance between each terminal normal?
(Refer to 11-4.)
Measure the voltage between each lead wire lead-
ing to the compressor.
U (BLK) - V (WHT)
V (WHT) - W (RED)
W (RED) - U (BLK)
MUZ-FD50
Disconnect the terminal of the compressor. 3 minutes after turn-
ing on the power supply, start EMERGENCY OPERATION.
After the outdoor fan starts running, wait for 1 minute or more before meas-
uring the voltage.
Output voltage is 50 - 130 V. (The voltage may differ according to the tester.)
•
•
Is output balanced?
Yes
No
Is the input voltage to the outdoor electronic control
P.C. board 370 V or more?
Yes
No
Replace the power board.
Yes
No
Replace the compressor.
Reconnect the lead wire of compressor, and turn ON pow-
er supply to indoor and outdoor unit.
3 minutes later, starts EMERGENCY OPERATION.
After the compressor is heated with a drier, does
the compressor start? 1
Refer to <<Judgement>>.
Replace the compressor.
Compressor start failure. Activate pre-heat control.
(Refer to 10-2. "PRE-HEAT CONTROL SETTING")
No
Yes
Does the compressor run for 10 seconds or more
after it starts?
Refer to <<Judgement>>.
Check the refrigerant circuit.
Check the stop valve.
Yes
No
Compressor starts
Abnormal
(IPM failure)
(Compressor winding short)
Abnormal
(Compressor lock out)
(Starting defect)
Abnormal
(Poor contact,)
(Outdoor P.C. board defect)
(Disconnected connector)
Abnormal
(Refrigerant circuit defect)
(Closed valve)
Normal
0 second
1 second
2 seconds
10 seconds
10 minutes
<<Judgement>>
1
Heat the compressor with
a drier for about 20 minutes.
Do not recover refrigerant
gas while heating.
Heating part
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