25
Technical Information
YES
YES
YES
YES
YES
NO
YES
NO
YES
NO
NO
NO
YES
NO
NO
9. Malfunction of Overcurrent Protection
Main detection points:
• Is the supply voltage unstable with big fluctuation?
• Is the supply voltage too low with overload?
• Hardware trouble?
Fault diagnosis process:
Start
Is the supply voltage unstable
with big fluctuation?
Is the supply voltage too low
with overload?
Fan speed is too low or fan
doesn’t rotate
Is the indoor / outdoor
heat exchanger dirty,or are the
air inlet and outlets blocked?
Measure the current of live wire
on the main board with a clamp
ampere meter. Is the current
higher than the value of the
overcurrent protection?
End
Is there blockage inside the
system? (Filth blockage, ice
plug, greasy blockage, cut
off valve hasn't been opened
completely)
Is the compressor running
abnormally? Is there an
abnormal sound or oil leakage;
Is the temperature of the shell
too high, etc.?
NO
Replace the mainboard with the
same model
NO
NO
NO
NO
NO
NO
Normal fluctuation should be within 10 %
of the rated voltage on the nameplate
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
to have fan run normally
Replace the mainboard with the
same model
Flush the heat exchangers with
high pressure nitrogen
Replace the compressor
Is malfunction
eliminated
NO
Is malfunction
eliminated
Is malfunction
eliminated
Is malfunction
eliminated
Is malfunction
eliminated
Is malfunction
eliminated
Is malfunction
eliminated
YES
YES
YES
YES
YES
