Mitsubishi MXZ-4C36NAHZ - Page 79

Check code
Abnormal points and detection methods Causes and check points
Abnormal if no rotational frequency is detected, or detected a value
outside the specied range during fan motor operation.
Malfunction of fan motor
Disconnection of CNF connector
Defective outdoor multi controller circuit board
●Diagnosis of defectives
Make sure to turn the power OFF before connecting/disconnecting any connectors, or replacing boards.
Diagnosis Remedy
z
4400
(U8)
Fan trouble
*For the detail, refer to "Check method of
DC fan motor (fan motor/outdoor multi
controller circuit board" in chapter 8-6.
No
No
Yes
Yes
Yes
No
Is the fuse melting?
Is there any abnormality such
as a disconnection, looseness or
breakage?
Is the voltage normal?
Replace the outdoor multi controller circuit
board.
Replace the defective fan motor.*
Connect the wiring/connector properly.
Replace it in case of a breakage.
Replace the outdoor multi
controller circuit board.
Replace the fan motor.
Check the fuse on the outdoor multi
controller circuit board.
Check the fan motor connector (CNF1 and
CNF2) for a disconnection or looseness.
Remove the fan motor by disconnecting the fan
motor connector CNF1 and CNF2, then check
the voltage of outdoor multi controller circuit
board
"Test points are;
V
DC
approx. 280 to 380 V DC (fan connector 1–4)
V
CC
approx. 15 V DC (fan connector 5–4)"
(Melting)
(Not melting)
79
OCH573C