Midea MHC-96HWD1N1(A) Service Manual page 47

MCAC-UTSM-201503
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P3: Over-current protection of compressor
P3: When the current of inverter compressor is over12A, the system will display P3 protection, the ODU in
standby. When the current goes back to normal range, P3 disappears and normal operation resumes.
P3: Compressor current protection
The indoor load is too large①
No
The heat exchange of condenser
is not good. It may be caused by
dirty heat changer, abnormal ODU
fan running, ODU are too near to
each other, etc.
No
The high pressure side of the system is
blocked② for squashed pipe, blocked
valve or closed stop valve
No
Refrigerant is excess③
No
System contains air or nitrogen④
No
High voltage short circuit or
compressor error⑤
No
Outdoor main control
board is damaged
R410A Full DC Inverter Split Duct Type Technical Manual
Yes Make sure the ratio of connectable
IDU is less than 130% or add ODU
Yes
Check the system and
fixed up the error
Make sure all valves are open,
Yes
check the system, and remove
the obstacle
Yes
Discharge part of the refrigerant. Add
some oil if it leaks during the discharge
Discharge the entire refrigerant. Then
Yes
vacuum the system and refill the refrigerant.
Add oil to the system if it leaks.
Yes
Make sure the high voltage circuit is normal,
or replace the compressor
Replace the outdoor
main control board
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