MXZ-SM48NAMHZ Service Manual

81
OCH789
Check code
Abnormal points and detection methods Causes and checkpoints
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 controller 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
*For the detail, refer to "Check method of
DC fan motor (fan motor/outdoor multi
controller circuit board" in chapter 8-7.
Notes
· Set SW7-1 OFF after the troubleshooting completes.
· The fan sometimes starts on-o󰀨 cycle operation during low-load operation or cooling
at low outside temperature on SM36/42/48.
It is not abnormal; the operation ensures reliability of the product.
No
No
Yes
Yes
Yes
No
Has the fuse melted?
Is there any abnormality such
as disconnection, looseness or
breakage?
Is the voltage normal?
Replace the outdoor controller board.
Replace the defective fan motor.*
Connect the wiring/connector properly.
Replace it in case of a breakage.
Replace the outdoor controller board.
Replace the defective fan motor.
Check the fuse on the outdoor controller
board.
Check the fan motor connector (CNF1 and
CNF2) for a disconnection or looseness.
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 and
CNF2.
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.
Test points are;
· VDC approx. 310 to 350 V DC (fan connector 1–4)
· VCC approx. 15 V DC (fan connector 5–4)
· VCC approx. 0–6.5 V DC (fan connector 6–4)
(Melted)
(Not melted)