Power Contactor Working Principle

Low voltage contactor is an electrically controlled switch used for switching an electrical power circuit similar to a relay except with higher current ratings.

Power contactor working principle.

On supplying definite voltage to the coil the moving core gets attracted towards the fixed core closing the contactor. A contactor really has only two basic parts. 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. These contacts are connected to the contact springs.

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. Contactor is in fact an electromechanical switch. 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. 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.

The contacts transmit the current from the source to the load. This causes the core of the contactor to move the armature. Working principle of contactors an electromagnetic field is generated whenever current flows where the moving coils attract each other. The contact part of the contactor includes the power contacts as well as the auxiliary contacts.

Heat can destroy either of them so take a good look at both. The contacts and the coil. Unlike general purpose relays contactors are designed to be directly connected to high current load devices. 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.

A large amount of current is drawn initially by an electromagnetic coil. Perhaps the most common industrial use for contactors is the control of electric motors. 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. The coil energizes the contactor moving the contacts into position.

The current flowing through the contactor energizes the electromagnet. The operating principle of the contactor is quite simple. 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 energized electromagnet then creates a magnetic field.