Soft starts are used to reduce both torque and load for the powertrain on AC electric motors. They can also help to reign in the surge of currency while the motor is starting up. By doing this, it reduces excess stress on both the motor and corresponding shaft and other components such as power cables. When soft starts are used, they help to extend the life of the motor they are used on. Soft starts can be made of either electrical or mechanical devices or some type of combination of the two.more Mechanical soft starts limit the torque while electrical soft starts reduce the current input. less