Theoretically speaking, three-phase voltage balance, three-phase current should be balanced. But the voltage can not be absolutely balanced, the current also has a difference, a normal motor three-phase current difference depends on the size of the voltage difference.

A little deviation is allowed during normal operation. 5% is a safe range. That is, the phase current error of 5% is normal three-phase asynchronous motor according to GB1032, and the factory test standard, the three-phase current imbalance can be controlled at 10%, more than this value will have a negative impact on the operation of the motor. Of course, the smaller the error, the better, if 1-3A are normal, greater than 3A should pay attention.