Midea MOU-12HN1 User Manual page 124

Troubleshooting
(2) For the outdoor unit
a. Phase sequence error:
Change the order of two of the wires to power supply.
If the problem can not be solved, the outdoor PCB is defective
b. Overload of current
Is the current in rated range?
The outdoor PCB is defective
c. Lack of phase
Check the power supply, is it 3 phase, 380-415V?
Yes
Check the connection between power supply and terminal, is
the voltage in outdoor terminal is 3 phase, 380-415V?
122
Phase sequence error
Switch on the unit again
Overload of current
Check the current, normally
Yes
Lack of phase
Yes
Outdoor PCB is defective
.
No
Possible reason
1.
2.
3.
4.
5.
MCAC-UTSM-2008-11
Outdoor fan is defective
The compressor is defective
Refrigerant is over charged
Air enter the refrigerant system
Heat exchanger is too dirty
Outdoor Units