Check Of Compressor Winding; Check Of Compressor Operation Time; Check Of Compressor Start Failure - Mitsubishi Electric MUZ-AP25VG - E1 Service Manual

D Check of compressor winding
● Disconnect the connector between the compressor and the power module (IC700), and measure the resistance between the
compressor terminals.
<<Measurement point>>
At 3 points
BLK-WHT
Measure the resistance between the lead wires at 3 points.
BLK-RED
WHT-RED
<<Judgement>>
Refer to 12-4.
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 overcurrent.
<<Operation method>>
Start heating or cooling operation by pressing EMERGENCY
OPERATION switch on the indoor unit. (TEST RUN OPERATION:
Refer to 9-3.)
<<Measurement>>
Measure the time from the start of compressor to the stop of
compressor due to overcurrent.
F Check of compressor start failure
Confi rm that ~ is normal.
•Electrical circuit check
. Contact of the compressor connector
. Output voltage of inverter P.C. board and balance of them (See 12-5. )
. Direct current voltage between DB61(+) and (-) on the inverter P.C. board
. 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?
Yes
Compressor start failure. Activate pre-heat control.
(Refer to 11-2. "PRE-HEAT CONTROL SETTING")
OBH789
Check the refrigerant circuit.
Yes Check the stop valve.
Replace the compressor.
No
1
<<Judgement>>
0 second
1 second
2 seconds
10 seconds
10 minutes
40
Compressor starts
Abnormal
(IC700 failure)
(Compressor winding short)
Abnormal
(Compressor lock out)
(Starting defect)
Abnormal
(Poor contact)
(Inverter P.C. board defect)
(Disconnected connector)
Abnormal
(Refrigerant circuit defect)
(Closed valve)
Normal
1
Heat the compressor with
a drier for about 20 minutes.
Do not recover refrigerant
gas while heating.
Heating part