How to choose the contactor

How to choose the contactor

The contactor is the switching device operated remotely. Its main objective is to switch powerful loadings of variable or constant currents. Devices are used where frequent launches shutdowns of devices with heavy load are carried out, and therefore their choice considerably influences work of all system.


1. Contactors choose proceeding from conditions of their operation, considering their technical characteristics: assignment and range of application, category, size of wear resistance and pin count (main and auxiliary). Both the size and tension of current of main circuit, rated voltage and power of coils, the mode of its work, climatic modification matters.

2. Electromagnetic contactors are both constant and variable currents, and constant alternating current. On rated voltage devices of two types are issued: on tension 220 and 440V, and on tension of 380 and 660 V. Common industrial contactors can work at rated current of main circuit from 1.5 to 4800 And.

3. Before buying the switching device, attentively get acquainted with the necessary mode of its work. It can be: faltering, long, faltering and long, short-term, repeated and short-term.

4. Pay attention to poles. Contactors can have from 1 to 5 poles. When choosing consider also way of accession of wires, way of fastening. Usually devices fasten vertically, the deviation angle should not exceed 5-100, but there are contactors and to horizontal fastening.

5. Contactors can have or not have auxiliary contacts. Main categories of application of contactors: AS-1, 2, 3, 4; and DC-4, 5. For control circuits AS-11 and DC-11 switchboards are used.

6. All data of switchboards undersign for special tables which are provided to consumers by manufacturer, surely get acquainted with them and compare to those specifications which you have.

Author: «MirrorInfo» Dream Team