44
10-5. TROUBLESHOOTING FLOW
Are the voltages balanced?
Disconnect the connector between the compressor and the
power module (IPM) (
MUZ-HM09/12NA(2)
-
U8
)/(IC700)
(
MUZ-HM09/12NA(2)
-
U1
, MUZ-HM15/18/24NA(2)
)
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”.
A How to check inverter/compressor
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
C Check of compressor
●
With the connector between the compressor and the power module (IPM) (
MUZ-HM09/12NA(2)
-
U8
)/(IC700) (
MUZ-
HM09/12NA(2)
-
U1
, MUZ-HM15/18/24NA(2)
) disconnected, activate the inverter and check if the inverter is normal by meas-
uring
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.
OBH747C
