Why contactor is used in motor?

Why are Contactors Used? Contactors are used for high power applications. They allow a lower voltage and current to switch a much higher power circuit, so they are generally larger and more heavy-duty than control relays, enabling them to switch higher power loads on and off for many thousands of cycles (Figure 1).

What is the purpose of a contactor?

A contactor is an electrical device which is used for switching an electrical circuit on or off. It is considered to be a special type of relay.

Why contactor is used instead of MCB?

The contactor also has an advantage i.e. it is designed to rapidly open and close contacts. A contactor is mainly required when we need to control or switch high voltage, current by low voltage, current. … So, in the normal condition a circuit breaker act as a switch also.

What is NO and NC In contactor?

In every control circuits and automation systems, logic is developed based on the open or closed state of switches, sensors or relays. … Normally open(NO) and Normally closed (NC) are terms used to define the states of switches, sensors or relay contacts under when its coil is not excited.

What causes a contactor to fail?

Electrical failure – Three different electrical issues can cause contactor failure. The insulation between the coil wires can break down and cause a short. The coil can become grounded through another metal component when the wiring insulation deteriorates. The coil can also become stuck in an open position.

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What are the parts of a contactor?

A contactor consists of three basic parts: the operating coil, the associated magnetic circuit and the contacts that are actuated by the coil.

Why do contactors chatter?

Low voltage to the contactor coil will allow the contactor to chatter. Contactor chatter can also occur due to chattering switches or loose connections in the control circuit. A low voltage situation can also occur due an unbalanced loading of the motor.

What is the difference between contactor and fuse?

Switches, circuit breakers, and contactors are used to control what parts of an electrical system are energized or de-energized. Fuses are used to protect the electrical system when something goes wrong, and can isolate the faulted parts from the normal parts.