Motor Starter: Function, Types, Diagram, and Working

Motor starter is an electrical device which used to safely start, stop and protect electric motors from damage caused by overcurrent, short circuits, or other faults. By regulating the flow of electrical power to the motor, motor starters control motor systems and ensures its smooth operation. 

An electric motor draws a significantly high current which is often 5 to 7 times higher than its rated current. This sudden change in current can damage the motor or other connected components like microcontrollers, relays, or sensors. To overcome this issue, we use a motor starter that limits the initial current flow and gradually increases it to bring the motor up to its full speed. 

Motor starter is widely used for industrial and commercial applications. Motor starters are also used in college projects, which include microcontrollers, sensors, and relays as sensitive components. Motor starter provide operational control as well as crucial protection for electric motors which ensures long life and optimal performance.

What is a Motor Starter?

A motor starter is a device which plays an important role in controlling and protecting electric motors. The main function of this electrical device is to safely start and stop an electric motor. It provides protection against electrical faults, particularly overcurrent and overload conditions. 

Motor starter includes features to prevent damage caused by overcurrent, short circuits or motor overload. Electric motor draws a very high inrush current which can be 5 to 7 times higher than its rated current which can cause overheating or damage to the motor windings. Motor starter is able to manage this current and provides a controlled start-up sequence.

Motor Starter Diagram

Motor starter diagram includes the electrical connections and components which are involved in the starting, stopping and protection of an electric motor. Below are key elements in a motor diagram: