MXZ-SM48NAMHZ Service Manual

73
OCH789
Check code
Abnormal points and detection methods Causes and checkpoints
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
Incorrect DIP-SW setting of model selection on the
outdoor controller board
Defective compressor
Defective outdoor power circuit board
●Diagnosis of defects
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 .
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 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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