DOL Resistance Starting Current

you can have it by using an open transition RVS (wye-delta) motor control...employing the use of a control transformer tapped either fro 50-60% in wye and 80% in delta..

In todays solid state world, Simon's answer is much better.. and cheaper

Except for VFD, all other motor starters will reduce the starting current at the cost of starting torque since they all reduce the voltage supplied to the motor with the consequent reduction in torque by square of the voltage. So the starter you choose would mainly depend on your connected load and its speed-torque curve.

In a VFD, since the frequency is also reduced along with the voltage, the motor starting torque and the starting current would remain the same through out the starting period.

What is your connected load ?

What is your connected load ?

A very good question and probably the first thing anyone should ask before deciding which type of system to select.

You can have it set for constant torque but the current is definitely going to vary from start to full speed! You can maintain a V/f ratio...

It is true that the current will be low from zero to rated for the connected load and avoid the DOL surge at start.

soft starter