A Soft Starter is a device that starts motors with reduced power supplied at start-up. Reducing the power reduces potentially damaging electrical and mechanical shocks on the system.
Soft Starters are a combination of a controller and overload protection.
CONTROLLERS - turns electric current to the motor on and off. A contactor is a controller that is controlled by an electromagnet.
OVERLOAD PROTECTION - protects a motor from drawing too much current and "burning out" from overheating. The overload relay is the motor overload protection used in soft starters. It limits the time the overload current is drawn and protects the motor from overheating.
Soft Starters place a device called a reduced voltage starter, or soft starter, between the motor and the incoming utility line to regulate the amount of current fed to the motor. Soft Starters enable the AC induction motor to speed up in smaller, resulting in less current drawn than with a traditional motor starter. Due to decreased voltage, torque is also reduced resulting in a soft, or easy start. Soft Starters are used on all types of AC and DC motors. They are most commonly used with the AC squirrel cage induction motor because of its simplicity, ruggedness and reliability.