Willis WST12MC16S Service Manual page 45

Troubleshooting
(4) Diagnosis of losing synchronism for compressor
Main detection points:
Is pressure of the system too high?
Is voltage too low?
Malfunction diagnosis process:
Losing synchronism
upon startup of
the unit
Is the stop time
of compressor
N
more than 3min
Y
Is wire of compressor(U,V,W)
well connected?
N
Y
Replace parts of
Adjust
connec ting wire
outdoor electric box
Y
Remove error?
N
Replace
compressor
Finish
Energize the
unit and start it
Is the stop time
of compressor more
than 3min
Y
N
Startup failure?
Y
Is compressor wire
COMP(UVW)
connected correctly?
Y
Replace parts if outdoor
electric box
Remove the error?
N
Replace
compressor
finish
Losing synchronism
during running
Is outdoor fan normal?
Y
Is outdoor
fan blocked by stuff?
N
Replace parts of
outdoor electric box
Remove error?
N
Replace
compressor
Finish
N
Start it 3 min later
Connect it according
N
to line chart
Y
N
Is fan well connected?
Reliable connected?
Y
Remove staff
Replace parts of
outdoor electric box
Y
Remove error?
Replace
Y
outdoor fan
Y
N
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