M thermal Mono
56 200204
Midea M thermal Mono Service Manual
Procedure
The phase sequence of the 3-phase
power supply
is incrorrect
1
Exchange any two of the 3 phase wires
Some power supply terminals are loose
2
Ensure all supply terminals are securely
fastened
The power supply is abnormal
Check the power supply equipment
Replace refrigerant system main PCB
Notes:
1. The A, B, C terminals of 3-phase power supply should match compressor phase sequence requirements. If the phase sequence is inverted, the compressor
will operate inversely. If the wiring connection of each outdoor unit is in A, B, C phase sequence, and multiple units are connected, the current difference
between C phase and A, B phases will be very large as the power supply load of each outdoor unit will be on C phase. This can easily lead to tripped
circuits and terminal wiring burnout. Therefore if multiple units are to be used, the phase sequence should be staggered, so that the current is distributed
among the three phases equally.
2. Loose power supply terminals can cause the compressors to operate abnormally and compressor current to be very large.