Mitsubishi Electronics MUZ-GE15NA How to check inverter/compressor, Check of open phase

Measure AC voltage between the lead wires at 3 points.

10-5. TROUBLESHOOTING FLOW

A How to check inverter/compressor

Disconnect the connector (CN61) between compressor and the intelligent power module (IPM).

Check the voltage between terminals.

Are the voltages balanced?

Yes

Check the compressor.

See 10-5. “Check of open phase”.

No Replace the inverter P.C. board.

See 10-5. “Check of compressor”.

BCheck of open phase

●With the connector between the compressor and the intelligent power module disconnected, activate the inverter and check if the inverter is normal by measuring the voltage balance between the terminals.

Output voltage is 50 - 130 V. (The voltage may differ according to the tester.)

<< Operation method>>

Start cooling or heating operation by pressing EMERGENCY OPERATION switch on the indoor unit. (TEST RUN OPERA- TION: Refer to 7-6.)

<<Measurement point>> at 3 points

BLK (U) - WHT (V)

BLK (U) - RED (W)

WHT(V) - RED (W)

NOTE: 1. Output voltage varies according to power supply voltage.

2.Measure the voltage by analog type tester.

3.During this check, LED of the inverter P.C. board flashes 9 times. (Refer to 10-6.1.)

C Check of compressor

Refer to 10-5. “Check of compressor winding”.

Is the compressor normal? Yes

Refer to 10-5. “Check of compressor operation time”.

Does the compressor operate continuously? Yes

OK.

	Replace the compressor.
No

	Refer to 10-5. “Check of compressor start failure”.
No

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