Mitsubishi Electric PUZ-A12NKA7 Service Manual page 57

10-6-5. Check method of DC fan motor (fan motor/outdoor controller circuit board)
Notes
1
· High voltage is applied to the connecter (CNF1, 2) for the fan motor. Pay attention to the service.
· Do not pull out the connector (CNF1, 2) for the motor with the power supply on.
(It causes trouble of the outdoor controller circuit
Self check
2
Symptom : The outdoor fan cannot rotate.
Fuse check
Check F5 on outdoor
controller board.
Did the F5 open?
No
Wiring contact check
Contact of fan motor connector (CNF1, 2)
Is there contact failure?
No
Power supply check(Remove the connector (CNF1, 2))
Measure the voltage in the outdoor 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 the outdoor
controller circuit board.
Check the operation.
No
Replace the fan motor.
FAN MOTOR (MF1)
Motor
A36/A42 only
FAN MOTOR (MF2)
Motor
· The inverter control P.C. board is built in the fan motor of this outdoor unit.
· When F5 that is on controller board is opened, change the fan motor and outdoor controller board at the same time (F5 is
impossible to change).
· It is abnormal when the abnormality is detected from either both fan motors or only one side.
OCH636A
board and fan motor.)
Replace the outdoor controller circuit board (C.B)
Yes
and fan motor (MF1, 2).
Recover wiring.
Yes
board.
280–340 V DC (When PFC stops), 380 V DC (When PFC is operating)
DC
15 V DC
CC
Replace the fan motor.
Yes
Check the operation of fan.
Replace the outdoor controller circuit board.
OK
END
TESTS POINT ④ V
FG
TESTS POINT ③ Vsp
-> rotation signal
<- control voltage
Inverter
driver <- power supply (gate drive)
Ground
TESTS POINT ② Vcc
<- power supply (inverter drive)
TESTS POINT ① V
DC
TESTS POINT ④ V
FG
TESTS POINT ③ Vsp
-> rotation signal
Inverter <- control voltage
driver <- power supply (gate drive)
Ground
TESTS POINT ② Vcc
<- power supply (inverter drive)
TESTS POINT ① V
Yes OK
END
No
Outdoor controller circuit board
7
PC5D
0-15 V DC pulse
6
C5B
0-6.5 V DC
5
C5D 15 V DC
4
-
-
1
C5E
CNF1
CHECK POINT
7
PC5C
0-15 V DC pulse
6
C5A
0-6.5 V DC
5
4
-
-
1
CNF2
DC
CHECK POINT
57
TESTS POINT ④ V
TESTS POINT ③ Vsp
TESTS POINT ② Vcc
3 3
- -
280-380 V DC
+
1 1
F5 CNDC CNDC
Power circuit board
CHECK POINT
TESTS POINT ④ V
TESTS POINT ③ Vsp
FG
FG