What is Contactor?

Contactor:

• The contactor is defined as a switching device capable of making, carrying and breaking a load circuit.
• It may be operated by hand, electromagnetic, or using relays.
• Mainly consists of main contacts, auxiliary contacts and no volt coil.
• Auxiliary contacts carry less current than main contacts.
• Contactor is used in applications with higher current carrying capacity.

Operating Principle:

When current passes through the electromagnet a magnetic field is produced, which attracts the moving core of the contactor. The electromagnet coil draws more current initially, until its  inductance increases when the metal core enters the coil. The moving contact is propelled by the moving core; the force developed by the electromagnet holds the moving and fixed contacts together. When the contactor coil is de-energized, gravity or a spring returns the electromagnet core to its initial position and opens the contacts.