Airwell VVFA Series Service Manual page 60

[75-0, 75-4] Pressure difference between high pressure and low pressure is abnormal
Check if compressor wire is
If wire of inverter compressor
Measure if there is voltage
multimeter, and if it is normal
Replace inverter compressor
Check if high/ low pressure
sensor is connected well
Yes
connected normally
Yes
are connected oppositely
No
If 4-way valve is
interconnected
No
U, V, W of compressor by
Yes
No
Re-connect
No
Correct compressor wire
No
Correct compressor wire
Yes
Replace 4-way valve
No
Replace inverter module
58