Mitsubishi Electric CITY MULTI PUMY-P112VKM6 Service Manual page 49

4210 (UP): Compressor overcurrent interruption
Abnormal points and detection methods
Overcurrent of DC bus or compressor is detected 30 or
more seconds after the compressor starts the operation.
Diagnosis of failure
Check the outdoor stop valve.
Is the stop valve (liquid/gas) fully
open?
Check whether the power supply voltage is
normal or not.
Is the power supply voltage normal?
Check if the model selection switches are set
correctly on the indoor controller board or outdoor
multi controller circuit board.
Are they set properly?
Turn the power OFF to check for looseness,
disconnection, or wrong phases of the compres-
sor wiring.
Continue to the next page.
OCH790 _49
No
Yes
No
Yes
No
Yes
Causes and checkpoints
• Closed outdoor stop valve
• Decrease of power supply voltage
• Looseness, disconnection, or wrong phase of compres-
sor wiring connection
• Model selection error on indoor controller board or out-
door multi controller circuit board
• Defective compressor
• Defective outdoor power circuit board
• Defective outdoor multi controller circuit board
• Malfunction of indoor/outdoor unit fan
• Short-cycle of indoor/outdoor unit
Open the stop valve (liquid/gas) fully.
• Check the looseness, disconnection, or
breakage of compressor wiring.
• Ensure power supply from the facility.
(Check for power supply open phase.)
Set the model selection switches correctly.
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