Mitsubishi Electric PVA-A30AA4, Service Manual

Page: 34 / 44

32
12-8. DC FAN MOTOR (FAN MOTOR/INDOOR CONTROLLER BOARD)
Notes
· 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
board and fan motor.)
Self check
Symptom : The indoor fan cannot turn around.
No
NG
NG
Wiring contact check
Contact of fan motor connector (CNMF)
Check the fuse (FUSE) on indoor
controller board.
Power supply check (Remove the connector (CNMF))
Measure the voltage in the indoor controller circuit board.
TEST POINT 1 : V
DC
(between 1 (+) and 3 (-) of the fan connector): V
DC
DC310~340V
TEST POINT 2 : V
CC
(between 4 (+) and 3 (-) of the fan connector): V
CC
DC15V
Wiring recovery
Replace drain pump (DP).
Replace indoor controller board.
Measuring points Resistance
pin 1 - pin 3
pin 4 - pin 3 50k
Ω
O.L.
pin 5 - pin 3 150k
Ω
O.L.
47k
Ω
1M
Ω
PVA-A30AA4 PVA-A36,42AA4
143k
Ω
O.L.
pin 6 - pin 3
Replace indoor controller board (I.B).
Replace fan motor (MF).
Replace indoor
controller board.
Is the resistance of the fan motor
normal?(Refer to below table)
Does the voltage between pin 6 and pin 3
of connector CNMF repeat 0V and 5V?
Replace the fan motor.
Is the voltage normal?
Is there no contact failure?
Yes
Yes
1
2
Yes
No
No
No
No
Yes
Did the fuse blow?
Check the drain pump (DP)
Is the resistance between
terminals normal?
No
Yes Yes
No
Check the operation of fan.
*To measure the resistance, connect
the negative (-) end of the tester to pin 3.
Yes
Check the operation. Does the fan motor rotate smoothly?
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.
END
OK
END
OK
NG
Replace indoor controller board.
Replace the fan motor.
Check the operation of fan.
Measure the resistance of the fan motor.
Yes
END
OK
Check method of DC fan motor (fan motor/indoor controller circuit board)
HWE1406A.qx 3/19/15 9:02 AM Page 32