Mitsubishi MXZ-8C60NA-U1 - Page 78

Check code
Abnormal points and detection methods Causes and check points
Abnormal if both of the following conditions are satised:
1. Overcurrent of DC bus or compressor is detected during compressor
operation.
2. Inverter power module is determined to be defected.
Short-circuit caused by looseness or disconnection
of compressor wiring
Defective compressor
Defective outdoor power circuit board
●Diagnosis of defectives
Make sure to turn the power OFF before connecting/disconnecting any connectors, or replacing boards.
Diagnosis Remedy
4250
(U6)
Power module trouble or overcurrent trouble
Yes
Yes
No
No
Are they connected properly?
Is the check code <4250> still
displayed?
Connect the compressor wiring (U, V and
W phase) properly, then turn the power
back ON.
Replace the outdoor power circuit board or
the outdoor multi controller circuit board
(Defective outdoor power circuit board).
Replace the compressor
(Defective compressor).
Turn the power OFF to check for looseness
or disconnection of the compressor wiring.
1
Disconnect the compressor wiring
(U-V-W phase).
2
Turn ON the SW7-1(*) on the outdoor
multi controller circuit board.
3
Operate the unit.
* SW7-1 ON: Ignore 5300(UH) error.
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