MCAC-UTSM-201503 R410A Full DC Inverter Split Duct Type Technical Manual
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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 large
①
Make sure the ratio of connectable
IDU is less than 130% or add ODU
No
Yes
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.
Check the system and
fixed up the error
No
Yes
The high pressure side of the system is
blocked
②
for squashed pipe, blocked
valve or closed stop valve
Make sure all valves are open,
check the system, and remove
the obstacle
Refrigerant is excess
③
Discharge part of the refrigerant. Add
some oil if it leaks during the discharge
System contains air or nitrogen
④
Discharge the entire refrigerant. Then
vacuum the system and refill the refrigerant.
Add oil to the system if it leaks.
Yes
No
No
Yes
Yes
High voltage short circuit or
compressor error
⑤
Make sure the high voltage circuit is normal,
or replace the compressor
Yes
No
No
Outdoor main control
board is damaged
Replace the outdoor
main control board
