Get to Know About the Contactors in Detail

A magnetic contactor is a tool or switch that, when needed, uses magnetism to close or open an electric circuit.

Contactor construction

Three components make up a contactor;

• An electromagnet or a coil
• Contacts
• Encloser or Frame

Electric coil or magnet

The coil functions as an electromagnet because it is looped around an electromagnetic core. It typically consists of two parts: a fixed component and a moveable part. The two pieces are joined together by a spring. Consequently, a spring return system exists. The movable component is attached to a rod. An armature is another name for this road. Both contacts are linked when the force of the coil is greater than the force of the spring, and both contacts are withdrawn when the force of the spring is more than the coil force.

To activate the electromagnet's core, a very small amount of current will pass through the spring from the supply or external control circuit. To lessen the eddy current in AC applications, the electromagnetic core is constructed of laminated soft iron. Eddy current is not a problem for DC applications since the core is built of solid steel. The electric contactor is also a useful part.

Embedding or Framing

The contactor's interior components are safeguarded by the enclosure. Plastic, nylon 6, ceramic, or Bakelite are used in its construction. The contacts and magnets are housed by it. The enclosure is used to protect the contacts from weather, dust, oil, and other explosive risks as well as to insulate them from them. When energized, it prevents direct touching or contact.

Contacts 

The whole load current will only flow from this one component. As a result, it is a crucial part of the contactor. Power contact, auxiliary contact, and contact spring are the different types of contacts. Power contacts come in two varieties: stationary contact and moveable contact.

The contacts' substance offers a strong welding resistance and consistent arc resistance. These materials must be resistant to arc, erosion, and mechanical stress. Due to the full load current passing through the contacts, this material has the lowest resistance conceivable. These magnetic contactors are constructed of silver cadmium oxide and silver nickel for low-current applications and silver tin oxide for high-current applications including DC.

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