1. Check line voltage (Phase to phase the voltage should be balanced)
2. PRO Menu check the following values Ubt and Ubd
a. Ubd – Unbalance threshold (trips the soft start in case of motor current imbalance between 2 or 3 phases. The value is Con % of IN in the COnF menu. This setting can be disabled.
b. Ubt – Unbalance time delay ( Time delay before the PHbd fault is taken into account if there is a current imbalance equal to or greater than Ubd.)
3. With Ubd turned off, run the motor and check the current draw on each phase ( check input and output currents. Between the three phases the current should be balanced. If the current is not balanced and the voltage is balanced problem is related to the motor. If both are balanced, then the problem could be related to the soft start.