Mitsubishi Electric PFFY Series, Technical & Service Manual

Page: 18 / 34

18
10-2. FAN MOTOR
Notes
· High voltage is applied to the connecter (CNMF1) for the fan motor. Pay attention to the service.
· Do not pull out the connector (CNMF1,2) for the motor with the power supply on.
(It causes trouble of the control
P.C.board)
Self check
Conditions : The indoor fan cannot turn around.
N0
Wiring contact check
Contact of fan motor connector (CNMF1,2)
Power supply check
Check the voltage in the indoor control P.C.board
TEST POINT
FAN MOTOR (upper)
CNMF1
CNMF2 : DC310 ~ 340V
CNMF2 : DC15V
CNMF2 : DC0 ~ 6.5V
FAN MOTOR (lower)
CNMF1
CNMF2 : DC310 ~ 340V
CNMF2 : DC15V
CNMF2 : DC0 ~ 6.5V
The voltage between CNMF2 and are values during the
fan motor operation. In the case that the fan motor off, the voltage is 0V.
Check method of indoor fan motor (fan motor/control P.C.board)
Wiring recovery
Was contact caused good?
Yes
NG
Replace the indoor
controller board.
Replace the fan motor.
Is the voltage normal?
Yes
No
Check the operation END
OK
Does the voltage repeat
DC 0V and DC 15V?
No
Yes
Fan motor position sensor signal check
Turn around the fan motor more than one revolution slowly,
and check the voltage between the connecter
FAN MOTOR (upper)
CNMF2
/FAN MOTOR (lower) CNMF2
NG
Replace the indoor controller board.
Replace the fan motor.
Check the operation of fan. END
Yes OK
Indoor controller board fuse check
Is the fuse normal?
Replace
the fuse.
Check the operation END
OK
Replace the indoor
controller board.
Check the operation
END
OK
NG
Replace the fan motor.
Yes
No
NG