Power Contactor Working Principle

The contacts and the coil.

Power contactor working principle.

The contacts transmit the current from the source to the load. Contactors typically have multiple contacts and those contacts are usually but not always normally open so that power to the load is shut off when the coil is de energized. Unlike general purpose relays contactors are designed to be directly connected to high current load devices. The contact part of the contactor includes the power contacts as well as the auxiliary contacts.

On supplying definite voltage to the coil the moving core gets attracted towards the fixed core closing the contactor. The energized electromagnet then creates a magnetic field. The coil energizes the contactor moving the contacts into position. These contacts is directly proposal to the setting coil and when magnetic contactor coil energize and set the normally close contacts become a normally open contacts and normally open contacts change to the normally close contacts.

A contactor is controlled by a circuit which has a much lower power level than the switched circuit. A large amount of current is drawn initially by an electromagnetic coil. The top three contacts switch the respective phases of the incoming 3 phase ac power typically at least 480 volts for motors 1 horsepower or greater. Working principle of contactors an electromagnetic field is generated whenever current flows where the moving coils attract each other.

This causes the core of the contactor to move the armature. Its working principle can understand so when the coil is energized a static iron core generates electromagnetic force will be moving iron core is attracted because the contact system and the movable iron core linkage the movable iron core drives the three movable contact piece run at the same time contact is closed thereby connecting the power supply. Operating principle of a contactor. A contactor is typically controlled by a circuit which has a much lower power level than the switched circuit such as a 24 volt coil electromagnet controlling a 230 volt motor switch.

Contactor is in fact an electromechanical switch. Power contactors can make carry and break the current. It consists of a coil and two separate laminated cores one fixed and another moving making an electromagnetic system as shown in below image. The current flowing through the contactor energizes the electromagnet.

A contactor really has only two basic parts. These contacts are connected to the contact springs. Heat can destroy either of them so take a good look at both. The power contacts gains the power for the contactor and the auxiliary contacts is used to bring a loop with the rest of the rest of the devices it is attached to.