10-6. Troubleshooting flow

MUZ-GB50VA

A How to check inverter/ compressor

Disconnect the terminal of the compressor. 3 minutes after turning on the power supply, start

EMERGENCY OPERATION.

 

 

 

W • After the outdoor fan starts running, wait for 1 minutes or more before

 

 

 

Measure the voltage between each

 

measuring the voltage.

 

lead wire leading to the compressor.

 

• The output voltage values have the tolerance of i20%.

 

U (BLK) - V (WHT)

 

No

 

V (WHT) - W (RED)

 

 

 

 

 

 

 

 

COOL

HEAT

W (RED) - U (BLK)

 

 

 

 

 

 

 

 

Is voltage output on right table?

 

 

 

 

 

 

 

122V~154V

74V~126V

 

Yes

No

 

 

 

 

 

 

 

(56Hz~71Hz)

(30Hz~58Hz)

 

Is output balanced?

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Yes

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Is the input voltage to the outdoor electronic No

 

 

 

 

 

 

 

 

 

control P.C. board 370V or more?

 

 

 

Replace the power board.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Yes

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Turn off power supply of indoor and outdoor unit,

 

and measure the compressor winding resistance No

 

between the compressor terminals.

 

 

 

 

 

 

 

 

 

Is the resistance between each terminal normal?

 

 

 

Yes

 

 

 

 

 

 

 

Replace the

 

 

 

 

 

 

 

 

 

compressor.

 

 

 

 

 

 

 

 

 

 

 

Reconnect the lead wire of compressor, and turn on power supply to indoor and outdoor unit.

3 minutes later, starts EMERGENCY OPERATION.

Clarify the causes by counting time until the inverter stops. 0 to 10 seconds: compressor rare short

10 to 60 seconds: compressor lock

60 seconds to 5minutes: refrigerant circuit defective

5 minutes or more: normal

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Mitsubishi Electronics MUZ-GB50VA service manual How to check inverter/ compressor, Troubleshooting flow