Mitsubishi Electric Mr. Slim MUZ-GE15NA-1, Service Manual

Page: 52 / 74

52
10-5. TROUBLESHOOTING FLOW
Are the voltages balanced?
Disconnect the connector between compressor
and the intelligent power module (IPM)/power
module (IPM) 1.
Replace the inverter P.C. board.
Check the voltage between terminals.
Check the compressor. See 10-5. “Check of compressor”.
No
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”.
OK.
No
Yes
Refer to 10-5. “Check of compressor
winding”.
Is the compressor normal?
Replace the compressor.
No
Yes
B Check of open phase
A How to check inverter/compressor
C Check of compressor
1
Intelligent power module:
MUZ-GE09/12/15/18/24NA
,
MUY-GE09/12/15/18/24NA
Power module:
Other models
OBH549F