How To Check Inverter/Compressor; Check Of Open Phase; Check Of Open Ipm - Mitsubishi Electric Mr.Slim MSZ09UN Service Manual

When OPERATION INDICATOR lamp flashes 5-time.
Outdoor unit does not operate.
How to check inverter/ compressor
A
Disconnect the connector
between compressor and
IPM.
Check the voltage
between terminals.
No
Are voltages
balanced?
Yes
Check the
compressor.

Check of open phase

B
Be sure to use the analog voltmeter for measurement.
With the connector between compressor and IPM disconnected, activate the inverter and measure the balance of voltage between terminals.
Operation
Model
mode
MSZ09UN
COOL
MSZ12UN
MSZ09UN
HEAT
MSZ12UN
<< Operation method>>
Start heating operation by pressing the EMERGENCY OPERATION switch
on the indoor unit. (test-run mode)
<<Measurement point>>
at 3 points
BLK-WHT
BLK-RED
WHT-RED
<<Judgment>>
Balanced································normal
Unbalanced···························abnomal (open phase)
Shutdown by overcurrent·······abnormal (short)
NOTE 1. Measure AC voltage, at 3 points more than one minute after the outdoor fan motor starts running.
2. The output voltage values in above table have tolerance withinJ i20%.

Check of open IPM

C
Disconnect the connector between compressor and IPM, and
measure resistance between terminals on the IPM.
<<Measurement point>>
at 6 points
BLK-WHT, WHT-BLK
BLK-RED, RED-BLK
WHT-RED, RED-WHT
<<Judgment>>
Infinite ["]···········normal
0~dozens of ······abnormal (short)
Refer to B "Check of open phase" on page 47.
Replace the outdoor
electronic control P.C.
board.
Refer to D "Check of compressor" on page 48.
Operational Output
frequency voltage
[Hz]
64
120
70
130
110
58
w Measure AC voltage between
the lead wires at 3 points.
w Measure resistance between
the lead wires at 3 points
[V]
Voltmeter indication
BLK-WHT
ACV
300
BLK-WHT
ACV
300
ohmmeter indication
47
BLK-RED WHT-RED
ACV ACV
300 300
BLK-RED WHT-RED
ACV ACV
300 300
"
normal
(infinite)
X1
"
abnormal
(0~dozens of ")
X1
Normal
(Balanced)
Abnormal
(unbalanced)