OCH791 _41
4210 (UP): Compressor overcurrent interruption
Chart 2 of 2
Diagnosis of failure
Connect the compressor wiring (U, V and W
phase) properly, then turn the power back ON.
Check the DC fan motor.
Remove factor(s) causing the short-cycle.
Replace the compressor.
Replace the outdoor power circuit board.
Replace the outdoor multi controller circuit
board.
Check the operation of indoor/outdoor fan
motors.
Check for indoor/outdoor short-cycle.
Disconnect the compressor wiring from the outdoor
power circuit board, then check the voltage among each
phases U, V and W during test run (SW7-1 ON).
Make sure to perform a voltage check with
the same performing frequencies.
Replace the outdoor multi controller circuit
board.
Continued from the previous page.
Are they connected properly?
Does it operate normally?
Are those units short-cycled?
Are the voltage among the phases
U-V, V-W and W-U different?
Does it operate normally?
Yes
(Short-cycled)
No
No
No
No
No
(Not short-cycled)
Yes
Yes
Yes
Yes
