Contactor is an electromechanical switching device that performs the opening and closing operations of electrical circuits. During the use of large and powerful devices, a mechanical device is required to perform these operations.

Contactor is used to switch on and off loads such as electric motors, heaters, lighting systems with large powers. Such loads can be difficult to control directly manually or with smaller switches. Contactors make it possible to control these loads safely and effectively.

What is contactor?

They are designed to connect directly to high-current power devices.

Relays and contactors have similar purposes and working principles. However, the difference of contactors from relays is that they can switch more than 15 amps and have an operating power above a certain kW. Contactors come in forms with varying capacities and characteristics. Unlike a circuit breaker, contactors are not intended to interrupt short-circuit current. These devices can have a breaking current of a few amperes or thousands of amperes. They are also very diverse devices in terms of physical size and volume.

The device has two contacts, main and auxiliary.

Main Contacts: These contacts are used to open and close the large current carrying the main power circuit. Main contacts are usually designed to handle large currents safely.

Auxiliary Contacts: These contacts are used to monitor the status of the device, transmit signals or perform control operations. Auxiliary contacts are usually used for lower power signaling circuits. Cores, coils, contacts, pallets and copper rings are also components of the device. Different types of devices for different purposes may have different contents.


Contactor Working Principle

There are contactors for different purposes. For this reason, there may be various changes in the function and other features of the products, but the operation is generally realized through the electromagnet principle and mechanical contacts. If a detailed description is needed, the principle of operation of these devices is as follows;

  • The electromagnet at the center of the device generates or removes a magnetic field to perform the switching process. The magnetic field of the electromagnet attracts/releases the armature, which is a magnetizable material. This movement allows the mechanical contacts to open and close.
  • The part of the contactor that performs the switching is the main contacts. The main contacts have a structure that can carry large currents and control loads. When the magnetic field of the electromagnet is applied to the circuit, the main contacts close.
  • Auxiliary contacts are used to monitor the status of the device, send control signals or perform automation operations. Auxiliary contacts are designed to control lower power levels.

The contactor’s electromagnet has not yet been activated. In this state, the main contacts are open and do not allow a current path.

When a control signal or switch is activated, the contactor’s electromagnet is activated. A magnetic field is created and the armature is pulled. This completes the main power circuit by closing the main contacts.

The main contacts are closed, which allows the electric current to supply the load. The device or machine becomes operational.

When the magnetic field of the electromagnet is cut off, the armature pushes back. This allows the main contacts to open and the electric current is interrupted.

Contactors offer the ability to effectively open and close large power loads. It allows them to have a wide range of uses in industrial plants, energy distribution systems and similar areas.

They can be used in heaters, escalators, pumps, coolers, etc. Dynamic braking systems, shunt motors, filament incandescent lamps are among the areas where these devices can be used.

KRAFTEK provides many devices in this field. You can contact us to get information about contactor price information and other devices suitable for your needs and to create an order.