M-Series MUZ-GE Technical & Service Manual

10-5. TROUBLESHOOTING FLOW

Are the voltages balanced?

Disconnect the connector between compressor

and the intelligent power module (IPM)/power

module (IPM)

Replace the inverter P.C. board.

Check the voltage between terminals.

Check the compressor.

See 10-5. “Check of compressor”.

Yes

See 10-5. “Check of open phase”.

● With the connector between the compressor and intelligent power module/power module 1 disconnected, activate the in-

verter 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 ﬂ ashes 9 times. (Refer to 10-6.1.)

Measure AC voltage between the lead wires at 3 points.

Refer to 10-5. “Check of compressor

operation time”.

Does the compressor operate continuously?

Refer to 10-5. “Check of compressor start failure”.

Yes

Refer to 10-5. “Check of compressor

winding”.

Is the compressor normal?

Replace the compressor.

Yes

B Check of open phase

A How to check inverter/compressor

C Check of compressor

Intelligent power module: MUZ-GE09/12/15/18/24NA, MUY-GE09/12/15/18/24NA

Power module: Other models

OBH549G