Mitsubishi Electric CITY MULTI PUMY-P112VKM5 Technical & Service Manual page 62

Check code
Compressor current interruption (Locked compressor)
4100
(UF)
Abnormal points and detection methods
If overcurrent of DC bus or compressor is detected before 30 seconds
since the compressor starts operating.
●Diagnosis of defects
Make sure to turn the power OFF before connecting/disconnecting any connectors, or replacing boards.
Check the stop valve.
Is the stop valve (liquid/gas) fully
open?
Check the power supply voltage.
Is the power supply voltage normal?
Check if the model selection switch is 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 phase
of compressor wiring connection.
Continue to the next page.
OCH740
Diagnosis
Yes
Yes
Yes
Causes and checkpoints
Closed stop valve
Decrease of power supply voltage
Looseness, disconnection, or wrong phase of
compressor wiring connection
Incorrect DIP-SW setting of model selection on the
outdoor controller board
Defective compressor
Defective outdoor power circuit board
Open the stop valve (liquid/gas) fully.
No
• Check the looseness, disconnection, or
breakage of compressor wiring.
No
• Ensure power supply from the facility.
(Check for power supply open phase.)
Set the model selection switch correctly,
No
then restart.
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Chart 1 of 2
Remedy