Mitsubishi Electric MUZ-A09YV-E1 Service Manual page 26

Mitsubishi Electric ilmalämpöpumput korjaa ja huoltaa pääkaupunkiseudulla: Jäähdytinpalvelu RefGroup Oy
When OPERATION INDICATOR lamp flashes 5-time.
Outdoor unit does not operate.
How to check inverter/ compressor
A
Disconnect the connector (CN61)
between compressor and power
transistor module (IPM).
Check the voltage
between terminals.
No
Are the voltages
balanced?
Yes
Check the
compressor.
Check of open phase
B
With the connector between compressor and power transistor
module disconnected, activate the inverter and check if the inverter
is normal by measuring the balance of voltage between terminals.
Output voltage [V]
115V
<< Operation method>>
Start cooling or heating operation by pressing the EMERGENCY OPERATION
switch on the indoor unit. (test-run mode : refer to page 14)
<<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 inverter P.C. board flashes 9 times.
Check of power transistor module
C
Disconnect the connector (CN61) between compressor and
power transistor module, and measure the resistance between
terminals on the power transistor module.
<<Measurement point>>
at 6 points
BLK-WHT, WHT-BLK
BLK-RED, RED-BLK
WHT-RED, RED-WHT
<<Judgement>>
Infinite ["]···········Normal
0~dozens of ······Abnormal (short)
See B "Check of open phase" on page 26.
Check the resistance of power transistor
module.
See D "Check of compressor" on page 27.
w Measure AC voltage between
the lead wires at 3 points.
www.ilmalämpöpumput.com
See C 'Check of power transistor module' on page 26.
Yes
Is the resistance
infinite?
No
(0~several
9-time flash
ohmmeter indication
"
X1
"
X1
26
Replace the inverter P.C.
board.
"
)
Replace the inverter P.C.
board and compressor.
Inverter P.C. board
Flashing
LED
2.5-second OFF
Normal
(infinite)
Abnormal
(0~dozens of ")