MITSUBISHI ELECTRIC MUZ-FD09NA- U1 - Manual (Page 23)

23
10-5. TROUBLESHOOTING FLOW
Are the voltages balanced?
Disconnect the connector (CN61) between
compressor and the intelligent power module
(IPM).
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 the intelligent power module disconnected,
activate the inverter and check if the inverter is normal by measuring the balance of voltage
between the terminals.
Output voltage 115 V
<< Operation method>>
Start cooling or heating operation by pressing EMERGENCY OPERATION switch on the
indoor unit. (TEST RUN OPERATION : Refer to 7-6.)
<>
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
9-time flash
2.5-second OFF