Mitsubishi Electric PUHZ-W50VHA Service Manual page 63

Check method of DC fan motor (fan motor/outdoor multi 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 may damage 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.
Yes
Is the fuse normal?
No
Wiring contact check
Contact of fan motor connector
(CNF1,2)
Is there contact failure?
No
Power supply check
Measure the voltage on the outdoor controller circuit board.
(W50/85: Remove the connector CNF1
HW112/140: Remove the connectors CNF1 and CNF2)
TEST POINT 1: V 280–380 V DC (between 1 (+) and 4 (−) of CNF1)
DC
TEST POINT 2: V 15 V DC
CC
Is the voltage normal?
No
Replace the outdoor
controller circuit board.
Check fan motor rotation.
Fail
Replace the defective fan motor.
OCH439M
Disconnect the FAN motor connector
and measure the resistance of
connector pins. Refer to "9-4. HOW
TO CHECK THE PARTS".
Yes
Correct the wiring.
(between 5 (+) and 4 (−) of CNF1)
Yes
Replace the defective fan motor.
Check fan motor rotation.
Replace the outdoor
controller circuit board.
OK
Complete.
63
Is the fan motor normal?
No
Replace the outdoor controller
circuit board (C.B) and the
defective fan motor.
<How to check the resistance>
To measure the resistance, connect the negative
(−) end of the tester to pin 4.
UNIT
W50VHA
FAN MOOTR RG61N769
Measuring points
Pin 1–pin 4 400 to 500 k"
Pin 5–pin 4
Pin 6–pin 4
Pin 7–pin 4
Yes
OK
Complete.
Fail
Yes
Replace the outdoor controller
circuit board (C.B).
PUHZ-
W85VHA HA140VHA HW112/140YHA
RG61V143
Resistance
∞
1.2 kΩ 50 kΩ
155 kΩ 150 kΩ
∞ ∞