Comment on the previous posting: Link no. 3 in my previous posting addresses impact of the soft starters on the motor inrush currents. Perhaps, an elaboration on the link content will clarify my posting better, namely:
"""Soft starters are ideal for meeting utility restrictions for limiting the inrush current while starting high horse
power motors. It provides a multitude of benefits for process & machine applications due to their smooth
output voltage ramp, torque limiting & overriding adjustable current limit feature. Typical motor loads that
are good candidates for soft starters include centrifugal pumps, fans, batch centrifuges, unloaded rock
crusher, unloaded compressors & lightly loaded compressors.
Most soft starters use voltage control to limit the motor starting current & torque by continuously ramping
the applied voltage when starting & stopping."""
Another situation exists when the motor is excessively loaded and remains in the locked-rotor condition. Then the inrush current and motor starting current become equal to the motor locked-rotor current.
Also, the current into L-R circuit exponentially rises until it levels off on V/R asymptote.
Visit
etc. for more info. There is not anything very difficult in the motor circuitry. It is essentially a combination of resistors and inductors (for lower frequencies); especially, when it comes to the locked-rotor conditions.