Check code
Abnormal points and detection methods
Causes and checkpoints
If overcurrent of DC bus or compressor is detected after 30 seconds since
the compressor starts operating.
1. Closed outdoor stop valve
2. Decrease of power supply voltage
3. Looseness, disconnection, or wrong phase of
compressor
wiring connection
4. Model selection error on indoor controller board or
outdoor multi controller circuit board
5. Defective compressor
6.
Defective outdoor power circuit board
7.
Defective
outdoor multi controller circuit board
8. Malfunction of indoor/outdoor unit fan
9. Short-cycle of indoor/outdoor unit
●Diagnosis of defects
Make sure to turn the power OFF before connecting/disconnecting any connectors, or replacing boards.
Diagnosis
Remedy
4210
(UP)
Compressor overcurrent interruption
Chart 1 of 2
Yes
Yes
Yes
No
No
No
Is the stop valve (liquid/gas)
fully
opened?
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 correctly.
Check the outdoor stop valve.
Check whether the power supply voltage is
normal or not.
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 phases
of the compressor wiring.
Continue to the next page.
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OCH668G
