67
Installation and Maintenance
Service Manual
(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?
Malfunction diagnosis process:
Start
Is the supply voltage unstable
with big fluctuation?
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 the
motor to have the fan run normally
Replace the mainboard with the same
model
Flush the heat exchangers with high
pressure nitrogen
Replace the compressor
Replace the mainboard
with the same model
End
Is the supply voltage too low
with overload?
Is the indoor / outdoor
heat exchanger dirty,or are the air inlet
and outlet blocked?
The fan is abnormal? Fan
speed is too low or fan doesnt rotate
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?
Is there blockage inside the system?
(Filth blockage, ice plug, greasy
blockage, the cut off valve hasnt 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 malfunction
eliminated
Is malfunction
eliminated
Is malfunction
eliminated
Is malfunction
eliminated
Is malfunction
eliminated
Is malfunction
eliminated
Is malfunction
eliminated
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
No
No
No
No
No
No
No
