Check code
Abnormal points and detection methods
Causes and checkpoints
Abnormal if overcurrent of DC bus or compressor is detected before 30
seconds after the compressor starts operating.
Closed stop valve
Decrease of power supply voltage
Looseness, disconnection, or wrong phase of
compressor wiring connection
Model selection error on indoor controller board or
outdoor multi controller circuit board
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
4100
(UF)
Compressor current interruption (Locked compressor)
Chart 1 of 2
Yes
Yes
Yes
No
No
No
Is the stop valve (liquid/gas) fully
open?
Is the power supply voltage normal?
Are they set properly?
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 switch correctly,
then restart.
Check the stop valve.
Check the power supply voltage.
Check if the model selection switch is set
correctly on the indoor controller board or
outdoor multi controller circuit board.
Turn the power OFF to check for
looseness, disconnection, or wrong phase
of compressor wiring connection.
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OCH668B
