Out Of Step Diagnosis For The Compressor - Lennox LI036CI-180P432 Service Manual

Service Manual
(5) Out of step diagnosis for the compressor (AP1 hereinafter refers to the control board of the outdoor unit)
Mainly detect:
Whether the system pressure is too high?
Whether the input voltage is too low?
Fault diagnosis process:
Are the wires for the compressor connected
correctly? Is connection sequence right?
Is the connection made in clockwise
Connect the
wires correctly
Installation and Maintenance
Out of step occurs once the
unit is powered on.
Is stop time of the
compressor longer than
3 minutes?
direction?
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 Remove foreign
by foreign objects? objects
Replace the
control panel AP1
If the fault is eliminated?
Replace the
compressor
End
Disconnect
the needle stand of
fan and measure the resistance
between two terminals of fan with
ohmmeter. The resistance shall
be less than 1K Ohm.
Replace the
outdoor fan
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