R410A All DC Inverter V5 X Series 50Hz      MCAC-VTSM-2015-10 
138 Troubleshooting 
4.2  E1: Phase sequence error 
The error will only display on the faulty unit, all the ODUs will be on standby. 
 
 
 
Note: 
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 phase will be very large as the power supply load of each outdoor unit is on C phase, this 
can easily lead to tripped breakers and terminal wiring burnout. Therefore if multiple units are to be used, the phase sequence 
should be staggered, so that the current can be distributed among the three phases equally. 
   
The 3-phase sequence of power supply
 
is 
wrong. (The A, B, C terminal of three-phase 
power supply should meet compressor phase 
sequence requirements. If the phase 
sequence is inverted, the compressor will 
Exchange any two of the 3 
phase sequence 
Some power supply terminals are loose, if 
this occurs, the compressor will operate 
abnormally, and the current is very large 
Ensure all supply terminals are 
securely fastened 
Outdoor main PCB is damaged 
Replace the outdoor main PCB 
The power voltage supply is abnormal, or the 
neutral line and live line are connected in 
equipment and adjust the