Mitsubishi Electronics MUZ-GE18NA Check of compressor winding, Check of compressor operation time

Measure the resistance between the lead wires at 3 points.

DCheck of compressor winding

●Disconnect the connector (CN61) between the compressor and intelligent power module, and measure the resistance be- tween the compressor terminals.

<<Measurement point>> at 3 points

BLK - WHT

BLK - RED WHT - RED

<<Judgement>> Refer to 10-4.

0[Ω] ················· Abnormal [short] Infinite [Ω]········ Abnormal [open]

NOTE: Be sure to zero the ohmmeter before measurement.

E Check of compressor operation time

●Connect the compressor and activate the inverter. Then measure the time until the inverter stops due to over current.

<<Operation method>>

Start heating or cooling operation by pressing EMERGENCY OPERATION switch on the indoor unit.

(TEST RUN OPERATION: Refer to 7-6.) <<Measurement>>

Measure the time from the start of compressor to the stop of compressor due to overcurrent.

F Check of compressor start failure

<<Judgement>>

0 second

1 second

2 seconds

10 seconds

10 minutes

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

Confirm that 1~4 is normal.

• Electrical circuit check

1.Contact of the compressor connector (including CN61)

2.Output voltage of inverter P.C. board and balance of them (See 10-5.)

3.Direct current voltage between DB61(+) and (-) on the inverter P.C. board

4.Voltage between outdoor terminal block S1-S2

Does the compressor run for 10 seconds or more after it starts?

No

After the compressor is heated with a drier, does the compressor start? 1

Yes

	Check the refrigerant circuit.
Yes	Check the stop valve.
	Replace the compressor.
No

1

Compressor start failure. Activate pre-heat control. (Refer to 9-2. "PRE-HEAT CONTROL SETTING")

Heat the compressor with

a drier for about 20 minutes. Do not recover refrigerant gas while heating.

Heating part

30