Midea MV5-X252W/V2GN1 Service Manual page 54

4.3.4 Procedure
The phase sequence of the 3-phase
power supply is incrorrect
Some power supply terminals are loose
The power supply is abnormal
Replace outdoor main PCB
Notes:
1. The A, B, C terminals of the 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. Refer to Figures 5-1.2 and 5-1.4 in Part 5, 1 "Outdoor Unit Electric Control Box Layout".
2. Loose power supply terminals can cause the compressors to operate abnormally and compressor current to be very large. Refer to Figures 5-1.2 and 5-1.4
in Part 5, 1 "Outdoor Unit Electric Control Box Layout".
201608
E1
1
No
2
No
No
Yes
Exchange any two of the 3 phase wires
Ensure all supply terminals are securely
Yes
fastened
Yes
Check the power supply equipment
V5 X VRF 50/60Hz
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