Dc Fan Motor (Fan Motor/Indoor Controller Board) - Mitsubishi Electric M Series Service Manual

12-8. DC Fan motor (FAN MOTOR/INDOOR CONTROLLER BOARD)

Check method of DC fan motor (fan motor/indoor controller circuit board)
Notes
1
· High voltage is applied to the connecter (CNMF) for the fan motor. Give attention to the service.
· Do not pull out the connector (CNMF) for the motor with the power supply on.
(It causes trouble of the indoor controller circuit
2 Self check
Symptom : The indoor fan cannot turn around.
Check the fuse (FUSE) on indoor
controller board.
Did the fuse blow?
No
Wiring contact check
Contact of fan motor connector (CNMF)
Is there no contact failure?
Yes
Power supply check (Remove the connector (CNMF))
Measure the voltage in the indoor controller circuit
TEST POINT
1 : V (between 1 (+) and 4 (-) of the fan connector): V
DC
TEST POINT 2 : V (between 5 (+) and 4 (-) of the fan connector): V
CC
Is the voltage normal?
No
Replace indoor
controller board.
OK
Check the operation.
NG
Replace the fan motor.
MVZ-A12,18, 24, 30, 36AA7
Measuring points
pin 1 - pin 4
pin 5 - pin 4
pin 6 - pin 4
pin 7 - pin 4
*To measure the resistance, connect
the negative (-) end of the tester to pin 4.
board and fan motor.)
Check the drain pump (DP)
Yes
Is the resistance between
terminals normal?
No
Replace drain pump (DP).
Wiring recovery
No
board.
Yes Measure the resistance of the fan motor.
Is the resistance of the fan motor
normal?(Refer to below table)
Yes
END Does the fan motor rotate smoothly?
Yes
Turn OFF the power supply and
connect the connector CNMF.
Turn ON the power supply and
measure the voltage of connector
CNMF while rotaing the motor by
the hand.
Does the voltage between pin 7 and pin 4
of connector CNMF repeat 0V and 5V?
Yes
Check the operation of fan.
NG
Replace indoor controller board.
Resistance
O.L.
50k
150k
O.L.
Replace indoor controller board (I.B).
Yes
Replace fan motor (MF).
DC310~340V
DC
DC15V
CC
No
No
Replace the fan motor.
No
OK
Check the operation of fan.
END
Replace indoor controller board.
37
Yes
OK
END
NG
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