Service Manual
48
Installation and Maintenance
5. 
Malfunction of Overcurrent Protection 
(
E5)
 
 
 
   
 
no 
no 
no 
no 
yes 
no 
no 
 
 
End 
yes 
Malfunction is 
eliminated
Is the supply voltage unstable
 with big fluctuation?
Is the supply voltage too low 
with overload?
       The fan is abnormal? Fan 
speed is too low or fan doesn’t rotate
                           Measure the 
              current of live wireon the main 
     board with a clamp ampere meter. Is the 
       current higher than the value of the 
                 overcurrent protection?
                           Is there blockage inside 
               the system? (Filth blockage, ice plug, 
   greasy blockage, the Y-valve hasn’t been opened 
                                  completely)
                           Is the compressor running
          abnormally? Is there abnormal sound or oil 
              leakage; is the temperature of the shell 
                                  too high, etc.?
                Is the indoor / outdoor 
heat exchanger too dirty,or are the air inlet 
                and outlet blocked?
Normal fluctuation is within 10 % of the rated 
voltage on the nameplate
Malfunction is 
eliminated
. 
no 
yes 
. 
no 
yes 
. 
no 
 
yes 
no 
no 
no 
yes 
no 
yes 
. 
no 
yes 
yes 
yes 
yes 
yes 
yes 
yes 
Malfunction is 
eliminated
Malfunction is 
eliminated
Malfunction is 
eliminated
Malfunction is 
eliminated
Malfunction is 
eliminated
Malfunction is 
eliminated
Troubleshooting 
for E5 malfunction
Adjust the supply voltage to maintain it within 
normal range
Clean the indoor and outdoor heat exchangers 
and remove the blockage of air inlet and outlet
Check the motor and reinstall the motor to have
the fan run normally
Replace the mainboard with the same model
Replace the mainboard with the same model
Flush the heat exchangers with high pressure 
nitrogen
Replace the mainboard with 
the same model