Modular contactors - brief description, application in home wiring

A contactor is an electric electromagnetic device that is designed for frequent switching of power circuits in normal conditions. The contactor is switched off and on remotely in manual mode or by applying a control pulse from other devices. Depending on the type, contactors can have from one to four poles of power contacts and can be used in circuits, both alternating and direct current. To extinguish the arc arising in the process of switching the load currents, arc chambers are provided in the design of the contactors.

Structurally, contactors are electromagnetic switching devices in which the closure and opening of power electrical contacts is carried out using an electromagnetic drive, the main element of which is an electromagnet (coil). To build the control circuit of the contactor, as well as to connect additional elements, additional contact pairs of normally open and normally closed types are provided in its design (see - wiring diagrams of starters and contactors).

Modular contactors Are compact electric devices that are designed to be installed on a special DIN rail. The rated current of the modular contactors is up to 100 A, the rated voltage is up to 660 V.

As mentioned above,The contactor is designed for switching currents in normal mode. That is, this electrical apparatus does not protect the electrical circuit from emergency conditions - overload and short circuit. Therefore, in the case of building circuits using contactors, it is necessary to provide circuit breakers or fuses in their circuit that protect the circuit from emergency conditions. If contactors are used to start electric motors, then a thermal relay should be included in their circuit, which protects the motor from overload.

The use of modular contactors in home wiring

Modular contactors are used in automatic control devices for various electrical appliances.

Here are some examples of using contactors in home wiring.

If the heating of a house or apartment is done on electric heaters, for example, electric convectors, you can provide for their automatic inclusion in accordance with the temperature in the room. In this case, contactors carry out the function of supplying voltage to the power circuit by electric convectors in case of receiving a signal from a temperature switch.

Also, with the help of modular contactors, it is possible to perform a scheme for automatic control of a well pump, lighting devices, ventilation, and, in the case of a backup source of power supply at home, to build a scheme for automatically switching on a reserve (ATS) in case of loss of power from one of the sources.

As for the electric motor control circuits, using contactors it is possible to assemble both the traditional starting and stopping circuit of the motor, and the reversing circuit, which allows changing the direction of rotation of the motor.

The presence of additional contact pairs in the contactors allows them to be used in tandem with other equipment. For example, you can arrange for a signal to be sent to another contactor or execute a signaling circuit of the contactor operating mode.

Thanks to the modular design of these electrical devices, the mounted control circuits are more compact, which can significantly save space in the distribution panel.