Check code
Abnormal points and detection methods
Causes and checkpoints
If no rotational frequency is detected, or detected a value outside the
specified range during fan motor operation.
Malfunction of fan motor
Disconnection of CNF connector
Defective outdoor multi controller circuit board
●Diagnosis of defects
Make sure to turn the power OFF before connecting/disconnecting any connectors, or replacing boards.
Diagnosis
Remedy
z
4400
(U8)
Fan trouble (Outdoor unit)
*For the detail, refer to "Check method of
DC fan motor (fan motor/outdoor multi
controller circuit board" in chapter 8-7.
No
No
Yes
Yes
Yes
No
63
OCH634C
Has the fuse melted?
Is there any abnormality such
as 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 breakage.
Replace the outdoor multi
controller circuit board.
Replace the defective fan motor.
Check the fuse on the outdoor multi
controller circuit board.
Check the fan motor connector (CNF1 and
CNF2) for 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)"
(Melted)
(Not melted)
