Lennox LI012CI-160P432-1 Service Manual page 72

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
N
compressor longer than
Are the wires for the compressor connected
correctly? Is connection sequence right?
Is the connection made in clockwise
N
Connect the
wires correctly
If the fault is eliminated?
Y
Installation and Maintenance
unit is powered on.
Is stop time of the
3 minutes?
Y
direction?
Y
Replace the control
panel AP1
N
Replace the
compressor
End
Out of step occurs in
operation
Is the outdoor fan working
normally?
Y
Is the outdoor unit blocked
Y
by foreign objects?
N
Replace the
control panel AP1
If the fault is eliminated?
N
Replace the
compressor
End
Check if the fan terminal
OFAN is connected correctly
N
Remove foreign objects
Y
Replace the fan
capacitor C1
Replace the
outdoor fan
69