Since the input current has a distorted waveform and the waveform ratio is low, the total inverter input power factor is very poor depending on the power supply voltage and load factor, and is 75 to 80% for a regular inverter.
The input current (effective value) grows accordingly.

If the power supply voltage is imbalanced, the current value may greatly differ depending on the phase measured.
It is recommended to check if the current values of phases are balanced.
If the power supply voltage is imbalanced, you can improve it by installing the power factor improving AC reactor.

The input current can be calculated as "Inverter input current I = Power supply capacity [KVA]/√3?V [A]".

By connecting a power factor improving reactor to the inverter, the current waveform is cleaned and the power factor is improved. Also, the effective value of the input current is reduced.