58
Installation and Maintenance
Service Manual
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
(6) 
Malfunction of IPM Protection (H5)
Main check point:
Whether input voltage is within the normal range?
Whether wires of compressor are connected reliably, tightly or correctly? 
Whether the resistance of compressor coil is normal? Whether the insulation between compressor coil and copper 
pipe is in good condition? 
Whether the unit is overloading? Whether the radiation for the unit is in good condition? 
Whether the volume of charged refrigerant is proper?
Malfunction diagnosis process:
Energize and 
turn on the unit
Whether compressor wires 
are connected correctly?
Whether there’re above 
circumstances?
Connect compressor wires 
according to correct wiring 
method
Modify it according to Service 
Manual and then energize 
and turn on the unit
Measure the resistance 
beween two phases of three 
phases of compressor
Is resistance value normal?
Measure the resistance 
between three-phase of 
compressor and copper pipe 
Is resistance value more than 
500MΩ?
Replace compressor
Is malfunction eliminated?
Replace main board of 
outdoor unit
End
Please check:
1.Whether the heat exchangers for indoor unit and 
outdoor unit are dirty? Whether the heater exchangers 
are covered by other objects? 
2.Whether indoor fan and outdoor fan operate normally?
3.Whether system pressure is too high?
4.Whether voltage is too high due to superuous 
refrigerant?