Self Check - Mitsubishi Electric PUMY-P112VKM4 Technical & Service Manual

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 causes trouble of the outdoor multi controller circuit board and fan motor.)

2 Self check

Symptom: The outdoor fan cannot rotate.
Fuse check
Check the fuse (F500) on outdoor
multi controller circuit board.
Did the fuse blow?
No
Wiring contact check
Contact of fan motor connector
(CNF1,2)
Is there contact failure?
No
Power supply check (Remove the connector (CNF1,2))
1 While the breaker is OFF, disconnect the compressor wirings (U/V/W) from the outdoor power circuit board.
2 While the breaker is OFF, disconnect the fan motor connector CNF1,2.
3 When 5 minutes have passed since turning ON the breaker, turn SW7-1 ON.
4 Check the voltage of the outdoor multi controller circuit board.
Measure the voltage in the outdoor controller circuit board.
TEST POINT 1: V (between 1 (+) and 4 (−) of the fan connector): 310–350 V DC (Y)
DC
: V (between 1 (+) and 4 (−) of the fan connector): 310–340 V DC (when PAM stops),
DC
TEST POINT 2: V (between 5 (+) and 4 (−) of the fan connector): V
CC
TEST POINT 3: V (between 6 (+) and 4 (−) of the fan connector): V
CC
Is the voltage normal?
No
Replace the outdoor multi
controller circuit board.
Check the operation.
Fail
Replace the defective fan motor.
Note:
• Turn SW7-1 OFF after the troubleshooting completes.
• The fan sometimes starts on-off cycle operation during low load operation or cooling at low ourside temperature.
It is not abnormal; the operation ensures reliability of the product.
OCH673D
Disconnect the FAN motor
Yes
connector and measure the
resistance of connector pins.
Refer to "8-7. HOW TO
CHECK THE PARTS".
Yes
Correct the wiring.
Yes
Replace the defective fan motor.
Check the operation of fan.
Replace the outdoor multi
controller circuit board.
OK
Complete.
Is the fan motor normal?
No
Replace the outdoor multi controller circuit
board (MULTI.B.) and the defective fan motor.
350 V DC (when PAM is operating) (V)
15 V DC
CC
0–6.5 V DC
CC
Yes
OK
Fail
115
Yes
Replace the outdoor multi
controller circuit board (MULTI.B.).
Complete.