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(1) IPM protection malfunction
Main checking point
●
If the input voltage of the unit is within normal range?
●
If the connection wire of compressor is connected well? Is it loose?
●
If the connection sequence is correct?
●
If the resistance of compressor coil is normal?
●
If the isolation of compressor coil with copper pipe is good?
●
If the unit is overloaded?
●
If the heat radiation of the unit is good?
●
If the refrigerant charge is suitable?
Energize the unit
Please check:
1. if the indoor and outdoor heat exchanges are dirty, if there
is obstacle to affect the radiation;
2. if the indoor and outdoor fans are running normally;
3. if the pressure of the system is too high;
4. if the refrigerant is too much which causes the high level of
pressure;
If the wire of compressor is connected
well and correctly?
If the above cases are existed?
Test the resistance between
the three phases
If the resistance is normal?
Test the isolation impedance between the three
phases of the compressor and the copper pipe
If the resistance is above 500M ?
Replace the compressor
Malfunction is eliminated
Replace the outdoor mainboard
End
Correct according to the service
manual and then energize the
unit to operate
Reconnect the wire of the
compressor according to the
correct wiring method
Yes
No
Yes
Yes
Yes
Yes
No
No
No
No
