Different from standard soft starter cabinet, the design and manufacture of general mining HV/MV solid soft starter cabinet consider various aspects including insulation, creepage distance, electric clearance, moisture proof and dust proof to meet requirements of related national standards.

Stone Crushing Machine Motors required high starting torque at the time of starting the motor. It is not required all the time this motors are the short time duty cycle, so Soft starter only limit the starting current to motor. The torque Compensation or the Torque Boosting function is absent in the Soft Starter.

The drilling machine started and stopped by 2-3 minutes. It drilled and removed the drilling tool. Using motor speed drive the energy saving appeared, because there was soft start and no inrush current. In 24 hour this was enormous saving. At the oil pump, which used these machines, the regulation of pressure worked by bypass valves. I closed the bypass valve and regulated the oil pressure by motor speed driver too.

Normally High capacity pump motors like 450 KW are designed to start with rheostat starting (Slip ring Motors) switch gear. In recent times soft starters have come and started with low voltage starting smoothly using solid state devices. Here the question asked is can he switch over the 450 KW pump motor running with grid supply to generator supply of capacity 500 KVA with a bypass contractor.

A soft starter can be used to start a high inertia load provided that the motor is capable of starting that load, but a soft starter does not directly control the acceleration of the motor as the inverter.
A solid state soft starter is a reduced voltage starter and does not alter the frequency of the voltage applied to the motor. During start, the acceleration field is at line frequency and the torque is a function of the full voltage starting torque curve of the motor and the current reduction caused by the soft starter. The torque is reduced by the current reduction squared.