1.  Compressor  inverter module  address is  set through  dial switch S7  on the inverter  module.  The compressor inverter module  A/B  location  refers  to  the 
L4 protection
ODU ventilation is not good
Remove barriers from heat 
exchanger and air outlet of ODU
ODU stop valves are closed Open the ODU stop valves
Reconnect the cables based on 
wiring diagram
The resistance between 3 phases of 
compressor is over 5Ω 
Replace the compressor
The insulation resistance of 
compressor is less than 100Ω 
Replace the compressor inverter 
board, restart the unit and the error is 
solved
Refer to P1 or P3 troubleshooting
No
No
Yes
Yes
Disconnect
the power
supply
Compressor wiring is not properly
Inverter module address setting
1
 and 
discharge temperature sensor wiring is 
not properly
Reset the inverter module address 
and reconnect the discharge 
temperature sensor cables
Yes
Normal
Yes
Yes
Yes
Yes
No
No
No
No
No