Soft Starters

Soft Starters
Soft Starters
A soft starter is a device used to temporarily reduce load and torque during motor startup.

A motor typically draws inrush current up to 10 times higher than their running current during startup, and up to 3 times higher torque. This kind of mechanical stress dramatically reduces the motorís service life, and the large power draw can propagate to other equipment in the system. Soft starters are designed to eliminate these undesired side effects of motor startup.

Soft starters reduce starting torque by temporarily reducing voltage or current input, allowing the motor to accelerate smoothly. Soft starters are also able to control motor deceleration, reverse motor direction, and provide overload protection. They are an ideal alternative to drives where a more cost-effective, simple solution is required.

Soft Starters: Learn About Soft Starters Here > 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.

As the name implies, starters "start" motors. They can also stop, reverse, accelerate and protect them. Whether it's a small fan, or piece of mining equipment, electric motor are often the driving force behind them. Electric motors consume 60% to 70% of all energy used in the United States.

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.