M-Series MUZ-GE Technical & Service Manual

Is there 230 VAC between CN721 (MUZ-

GE09/12/15/18)/CN602 (MUZ-GE24)

and

on the inverter P.C. board 3 minutes after

the power supply is turned ON?

Yes

Replace the inverter

P.C. board.

Replace the 4-way valve.

Unit operates HEAT mode even if it is set to COOL mode.

Disconnect connector between the

compressor and intelligent power

module/ power module

Turn ON the power supply and press

EMERGENCY OPERATION switch

once (COOL mode).

I Check of outdoor fan motor

Is the resistance between each ter-

minal of outdoor fan motor normal?

(Refer to 10-4.)

Disconnect the connectors CN931 and CN932

from the inverter P.C. board.Check the connec-

tion between the connector CN931 and CN932.

Disconnect CN932 from the inverter P.C. board, and turn on the

power supply.

Rotate the outdoor fan motor manually and measure the voltage

of CN931.

Between 1(+) and 5(-)

Between 2(+) and 5(-)

Between 3(+) and 5(-)

Does the voltage between each terminal become 5 and 0

VDC repeatedly?

Does the outdoor fan motor rotate smoothly?

Replace the outdoor fan motor.

Replace the inverter P.C. board.

Yes

(Fixed to either 5 or 0 VDC)

Yes

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

Power module: Other models

OBH549G