Mitsubishi Electric PUZ-HA24NHA1 Service Manual page 53

Check method of DC fan motor (fan motor/outdoor controller circuit board)
1 Notes
· High voltage is applied to the connector (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 board and fan motor.)
2 Self check
Symptom: The outdoor fan cannot rotate.
Fuse check
Check the fuse (F5) on outdoor controller
circuit board.
Did the fuse blow?
No
Wiring contact check
Contact of fan motor connector (CNF1
Is there contact failure?
No
Power supply check (Remove the connector (CNF1, 2))
Measure the voltage in the outdoor controller circuit board.
TEST POINT 1: V (between 1 (+) and 4 (−) of the fan connector): 250–380 VDC
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.
Fail
Replace the defective fan motor.
FAN MOTOR (MF1)
Motor
HA30/HA36/HA42 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.
OCH750A
Disconnect the FAN motor
Yes
connector and measure the
resistance of connector pins.
Refer to "10-5. HOW TO
CHECK THE PARTS".
, 2
)
Yes
Correct the wiring.
Yes
OK
Complete.
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
Is the fan motor normal?
No
Replace the outdoor controller circuit board (C.B.)
and the defective fan motor (MF1
15 VDC
CC
Replace the defective fan motor.
Yes
Check the operation of fan.
Fail
Replace the outdoor controller
circuit board.
Outdoor controller circuit board
7
PC5D
0-15 VDC pulse
6
C5B 0-6.5 VDC
5
C5D 15 VDC
4
-
-
1
C5E F5
CNF1
CHECK POINT
CHECK POINT
7
PC5C
0-15 VDC pulse
6
C5A 0-6.5 VDC
5
4
-
-
1
CNF2
DC
CHECK POINT
53
Yes
Replace the outdoor controller
circuit board (C.B.).
, 2
).
OK
Complete.
TESTS POINT ④ V
FG
TESTS POINT ③ Vsp
TESTS POINT ② Vcc
3 3
- - 280-380 VDC
+
1 1
CNDC CNDC
Power circuit board
TESTS POINT ④ V
FG
TESTS POINT ③ Vsp