Contactors

What are contactors?

A contactor is a control device with two stable positions (on and off), whose drive is automatic (pneumatic, hydraulic, electromagnetic). The most common are electromagnetic contactors. Contactors are devices whose main purpose is to turn on, pass through and turn off the currents of electrical circuits and devices under normal conditions and current loads. The most common are electromagnetic contactors, the structure of which consists of main and auxiliary contacts, a coil, a housing, a magnetic core and an arc extinguishing system. Nowadays, a rich and diverse range of contactor types is offered on the market, each of which has its own peculiarities and distinctive characteristics.

Learn more

Below you will learn which are the main contactor series available in the ENEXT online store, and how they differ from each other. In addition, you will find useful information about the essence of contactors as a product category and the accessories with which you could increase their efficiency. The main components of the contactor are a coil, main and auxiliary contacts, housing, magnetic core and arc extinguishing system. The electromagnetic system of the contactor is formed by the coil and the magnetic core. Contactors have a main, power and auxiliary, control circuit, and it is possible that there may be no auxiliary contacts or arc extinguishing chambers when the current is lower. Contactors for direct and alternating current have differences in their design.

Контактори1 | Енекст България — Contactor e.industrial.ukc.75.380, 75A, 380V, 3P, 1no+1nc

Working principle of contactors

When an electric current flows in the coil, a magnetic flux is excited, which is closed through the magnetic circuit and the armature. As a result, an electromagnetic force is created, which tends to move the armature in such a way as to reduce the total length of the magnetic flux path. The electromagnetic force overcomes the forces of the springs holding the armature in its initial position and moves it until it hits the stop or pole of the stationary part of the magnetic circuit. When the armature moves, the moving contacts of the contact system are also driven.

Контактори2 | Енекст България — Contactor e.pro.ukc.2.25.230.1NC 25A, 230V, 1NC

Contactors – basic terms

There are several basic terms that you need to be aware of in order to better understand the mechanism of contactor operation, as well as to make an adequate choice of products in this category. The contactor system consists of moving and fixed contacts. The difference between the two groups is that the moving contacts are connected to the armature, to which they owe their actuation process. The individual contacts in the contactor can also be normally open and normally closed. The latter classification is made based on their initial state (or the state in which they are in the absence of current in the contactor coil).

Контактори3 | Енекст България — Contactor e.industrial.ukc.85.380, 85A, 380V, 1no+1nc

Characteristics and parameters of contactors

We continue with the most important characteristics and parameters that you would find useful to know regarding contactors. Here is some more information regarding the parameters:

- rated current, measured in amperes (A)
- nominal coil voltage at 50/60Hz (V AC)
- mechanical and electrical durability (or how long the life of the contactor mechanism is, measured in number of switching cycles).
- supply voltage and power consumed by the winding of the driving electromagnet.
- operating mode (mainly referring to the frequency and duration of switching on).
The contactors commonly available on the market are three-pole. However, some manufacturers also include single-pole, two-pole and four-pole contactors in their product ranges. As for the rated current, which is practically one of the main criteria for selecting a contactor, it has certain values, which are observed by almost all manufacturers. In general, the most commonly available contactors on the market can be found with rated current values from 6 A to 800 A and with coil voltage from 12 V to 400 V. Contactors with a lower or higher than the specified rated current are manufactured only and only after orders have been placed for them.

Контактори4 | Енекст България — Contactors-Shunts e.industrial.ac.50 to contactor e.industrial.ukc.85

Contactor series in the Enext online store

Contactors e.pro.ukc – Contactors and thermal relays with used
auxiliary elements – are used in low voltage circuits with
electric drive for: starting, stopping and reversing three-phase
asynchronous electric motors with squirrel-cage rotor, as well as for
control of lighting circuits, active and weakly inductive loads.
The main characteristic elements of the new equipment line are the combination
consistently good quality, wide range and competitive price of products.
The products fully comply with the norms and requirements of the standards of Bulgaria and
of the European Union.
MAIN CHARACTERISTICS OF e.pro.ukc CONTACTORS:

Rated current Ie, A: 9, 12, 18, 25, 32, 40, 50, 65, 80, 95;
Number of poles: 3;
Nominal voltage of the control coil Uc, V: ≈ 24, 36, 110, 230, 400;
Rated operating voltage Ue, V: ≈ 400 (660);
Nominal frequency, Hz: 50;
Application category: AC-3;
Insulation voltage Ui, V: 690;
Degree of protection: IP20;
Mounting: on a 35 mm DIN rail, on a mounting panel.

Contactors e.industrial.ukc. – Contactors are designed for use in low voltage electrical drive control circuits as well as circuit control
lighting, active, weakly inductive and capacitive loads. The main characteristic elements of the new line of equipment are the combination of consistently good quality, a wide range and competitive prices of the products. The products fully comply with the norms and requirements of the standards of Bulgaria and the European Union.
MAIN CHARACTERISTICS OF CONTACTORS e.industrial.ukc. :

Rated current Ie, A:6, 9, 12, 18, 25, 32, 40, 50, 65, 76, 85, 100, 120, 150, 180, 220, 330, 400;
Number of poles: 3;
Nominal voltage of the control coil Uc, V: ≈ 230, 400, 660;
Rated operating voltage Ue, V: ≈ 400 (660);
Nominal frequency, Hz: 50;
Application category: AC-3;
Insulation voltage Ui, V: 690;
Degree of protection: IP20;
Installation: On a mounting panel.

Контактори5 | Енекст България — Contactor e.industrial.ukc.400.220, 400A, 220V, no

Modular contactors from the e.mc series
The modular contactor is designed for switching single-phase and three-phase low-power electrical consumers. They guarantee complete silence during operation and are placed on a DIN rail. The most commonly offered modular contactors have nominal values from 20 A to 100 A. Their functions are related to switching on and off consumers, creating control systems, reliable switching on or off of power contacts. Their switching is carried out with flexible wires with or without cable lugs, and with solid wires. Modular contactors are not deformed under the influence of UV rays or large temperature amplitudes, and are made of materials that are non-combustible.

Additional installation for contactors

Enext has a large range of additional equipment for contactors, such as:
• Reverse blocks;
• Additional contacts for contactors;
• Control coils;
• Contactor reversing device.
e.industrial.au additional contacts are designed to increase the additional contact in contactor groups when used in automatic circuits for entering reserve, reverse, electric motor, etc.

Контактори6 | Енекст България — Contactors-Additional contact e.industrial.au.4.04, 4nc

Shunts e.industrial.as are designed to limit starting currents in switched capacitors in reactive power compensation circuits.
Reversing blocks e.industrial.ar Mechanical interlocking (reversing block) are designed for mutual blocking of contactors from simultaneous switching on in reversing circuits, motor starting, "star-delta", automatic input of reserve, etc.
In the Enext online store you will find contactors from various series, as well as accessories and fittings for them, which will meet all your needs and requirements.

What are contactors?
Working principle of contactors
Contactors basic terms
Characteristics and parameters of contactors
Contactor series in the Enext online store
Additional installation for contactors