York DHP30NWB21SDCP30NWB21SDHP36NWB21SDCP36NWB21S Service Manual page 59

(4) Start-up failure (following AP1 for outdoor unit control board)
Mainly detect:
Whether the compressor wiring is connected correctly?
Is compressor broken?
Is time for compressor stopping enough time?
Fault diagnosis process:
N
Power on the unit
Is stop time of the compressor
longer than 3 minutes?
Y
Does startup fail?
Y
Are the wires for the compressor connected
correctly? Is connection sequence right?
Y
Replace the control panel AP1
If the fault is eliminated?
N
Replace the
compressor
End
Restart it after
N
3 minutes
Connect the wires as
N
per the connection
diagram
Y
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