50
Installation and Maintenance
Service Manual
(5) Out of step diagnosis for the compressor (AP1 hereinafter refers to the control board of the outdoor unit)
Mainly detect:
●Is the system pressure too high?
●Is the input voltage too low?
Fault diagnosis process:
Out of step occurs once the
unit is powered on.
Is stop time of the
compressor longer than
3 minutes?
Are the wires for the compressor connected
correctly? Is connection sequence right?
Is the connection made in clockwise
direction?
Connect the
wires correctly
Replace the control
panel AP1
If the fault is eliminated?
Replace the
compressor
End
Out of step occurs in
operation
Is the outdoor fan working
normally?
Is the outdoor unit blocked
by foreign objects?
Replace the
control panel AP1
If the fault is eliminated?
Replace the
compressor
End
Check if the fan terminal
OFAN is connected correctly
Remove foreign objects
Replace the fan
capacitor C1
Replace the
outdoor fan
No
No
No
No
No
No
Yes
Yes
Yes
Yes
Yes
Yes
