Midea MHC-96HWD1N1(A) Service Manual page 39

MCAC-UTSM-201503
8.2 Troubleshooting

E1: Phase sequence error
E1: Phase sequence error
The 3-phase sequence of power supply is
wrong. (The A, B, C terminal of three-phase
power supply should meet compressor phase
sequence
sequence is adverse, the compressor will
operate inversely.
No
Some power supply terminals are
loose, if there has phase loose, the
compressor will operate abnormally,
and the current is very large
No
Outdoor main control
board is damaged
If the wiring connection of each outdoor unit is according to A, B, C phase sequence, when the quantity of
outdoor units is large, the current difference between C phase and A, B phase will be very large for the
power supply load of each outdoor unit is on C phase, it is very easy to lead to air switch break and wiring
terminal burnout. So when the quantity of outdoor units is large, the phase sequence should be staggered,
then the current can be distributed to the three phases equally.
R410A Full DC Inverter Split Duct Type Technical Manual
requirement. If the
Yes
Exchange any two of the
phase 3-sequence
Yes
Fasten each phase joint of
power supply.
Replace the outdoor
main control board
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