As we mentioned above, the primary situation in which you'll want to use a contactor is in any high-powered circuit in which an overload condition is likely to occur. This is particularly true if subsequently leaving the circuit in an energized state will create a hazardous environment for people and/or equipment.

Why is a contactor necessary?

A contactor is an electrical device which is used for switching an electrical circuit on or off. ... These contacts are in most cases normally open and provide operating power to the load when the contactor coil is energized. Contactors are most commonly used for controlling electric motors.

Does a motor need a contactor?

Contactors are a specialized form of relay capable of switching higher power loads such as motors, lighting and electric heaters. Turning large electrical power loads such as motors, lighting and heaters on and off is a common automation requirement.