Mitsubishi Electric CITY MULTI PFFY-W20VCM-A, Technical & Service Manual

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[
VII
Troubleshooting ]
- 15 -
HWE18170 GB
2. DC fan motor (fan motor/indoor control board)
1. CAUTION
 A high voltage is applied to the connector for connection to the fan motor (CNMF1).
 Do not unplug the connector CNMF1 with the unit energized to avoid damage to the indoor control board and fan motor.
2. Troubleshooting
 Symptom: Indoor unit fan does not run.
Check fan motor connector contact
(CNMF1).
Replace the indoor control board.
Replace the indoor control board.
Fix the connection.
Yes
No
Yes
No
Yes
No
Check the fan motor position thermistor signal.
Get the motor to make a full rotation or more, and measure the voltage at the test point
V
FG
.
(same with the voltage between fan connector 7 (+) and 4(-))
Is the fan motor connector
(CNMF1) fully inserted?
Is the voltage within the
normal range?
Replace the motor.
Are 0VDC and 15VDC
displayed alternately?
Check the power supply.
Measure the voltage at the indoor control board.
310 - 340VDC (same with the voltage between fan connector 1 (+) and 4(-))
15VDC (same with the voltage between fan connector 5 (+) and 4(-))
1 - 6.5VDC (same with the voltage between fan connector 6 (+) and 4(-))
[Values for Vsp are the values that are measured with the fan motor in operation.
Vsp is 0V when the fan motor is stopped.]
V
DC
Power supply voltage
HWE18170.book 15 ページ ２０１９年５月８日 水曜日 午前１０時３２分