Commutation devices. Types of switching electrical devices

In an electrician, all the processes of closing and opening a network are commonly called commutation. These functions are performed by special equipment. It is installed in a variety of circuits and ensures the normal operation of the system. представляют собой устройства, которые призваны подавать или прекращать поступление электрического тока в сеть. Switchgear devices are devices that are designed to supply or stop the flow of electrical current to the network.

Today, many varieties of presented aggregates are used. They differ in the design and specificity of the action. In order to choose the right machine, it is necessary to consider the existing types and their features.

general characteristics

The purpose of switching devices is reduced to the process of transmission of electricity due to the closure and opening of the circuit. Today, all existing units of this type can be divided into two categories. The first group includes contact (mechanical) devices, and to the second group - contactless (semiconductor or gas-discharge) varieties.

The most common devices of switching type are switches, circuit breakers, contactors, relays, fuses. They have certain characteristics that must be taken into account when choosing. It is necessary to purchase the switching device in accordance with the operating conditions.

The presented units may have several poles in their design. Their number can be from one to four. In accordance with this indicator, the instruments are also divided into groups. Most often on sale are bipolar products. They have two positions - "off" or "on".

Knife switch

может производиться вручную или посредством бесконтактного реагирования на изменения в окружающей среде. Control of switching devices can be done manually or through a non-contact response to changes in the environment. The simplest version of the mechanical type is the switch. Its management is done manually.

The device is used for switching in electrical circuits with a voltage that does not exceed 660V. One-, two- and three-pole versions of the units are available for sale. By means of the switch, the circuit is disconnected under voltage or without it. The well-known manufacturer in our country of the presented equipment is the Kursk Electroequipment Plant.

Knife switches can be household or industrial. The first category is designed for use in a low-voltage network, and the second - in a high-voltage network. This is a demanded equipment, which is used almost everywhere.

Types of knife switches

которые относятся к типу рубильников, в свою очередь, делятся на подгруппы. Switchboards, which are of the type of switches, in turn, are divided into subgroups. Allocate a disconnector, a switch and a short-circuit. In the first case, the device interrupts the supply of electricity to the circuit, which has an insignificant current strength. This type of instrument is used to inspect or repair the system. The disconnector has a distance between the contacts for insulation.

Switches transfer electric current from one circuit to another. A short-circuit is not produced and is not used in modern equipment. It creates a short circuit.

On sale are the machines that combine the presented functions. For example, it could be a switch-disconnector. This is a switch with a camera to extinguish an arc. It can work in one or two directions. If in such a switch there is no chamber for damping the arc, this device belongs to the group of disconnectors.

Switch

(переменный ток) и до 440 В (постоянный ток). The general-purpose circuit-breaker is a switching device up to 1000 V (alternating current) and up to 440 V (direct current). This unit refers to devices of a mechanical type. It can include, pass or turn off the supply of electrical current. It helps protect electrical networks from overloads, critical voltage drops or short circuits. In this case , the RCD circuit is classical (presented below).

I - RCD.

II - Electrical consumer (measuring instrument).

The circuit breaker can control the network. To do this, their design provides for the availability of various drives.

There are many different modifications of the presented devices. This makes it possible to apply them practically in all fields of energy. Most often in household and industrial networks they use packet types of switches.

The main types of switches

The switching devices presented have many options. Automatic variants include circuit breakers and differential switches. способно защитить человека от поражения электрическим током при возникновении аварийной ситуации. In the first case , the RCD circuit can protect a person from electric shock when an emergency occurs. Differential switches are a special type of circuit breaker. In its design, the RCD is connected to a switch. This provides a comprehensive protection against electric shock.

Batch switches are used for circuits with a voltage of 110-380 V. They are installed to control asynchronous motors, complete devices. Such switching devices are assembled on the surface of a square shaft. In the system, in this case, there is a certain number of such aggregates. There is a handle and a mechanism for fixing it. When it is turned, the shaft is set in motion. The commuting cams of the device open the circuit.

Они могут работать как при переменном, так и постоянном токе. Circuit-breakers of general purpose are switching devices up to 1000 V. They can work with both alternating current and direct current. They include a drive, trip units.

Drive and release

приводится в движение ручным или бесконтактным способом. The drive of the switching device is driven by a manual or non-contact method. There are systems with a combined control system. Switching off is done by means of springs. They are set in motion after the release is released. This part excludes the possibility of holding the contacts in the on position when an emergency situation occurs.

The release is a system of ligament hinge levers. They connect the drive to the movable contacts, which in turn are adjacent to the trip spring.

It is the trip units that are responsible for maintaining the required circuit parameters that they protect. If there are deviations in the system from the normal value, these elements turn off the power.

Automatic tripping methods

имеют в своей конструкции реле. Protective-switching devices have in their design a relay. They are part of the release. The relays can be electromechanical or statistical. The semiconductor materials are controlled and compared with the specified parameters. This principle is laid down in the introductory automata.

Electromechanical varieties can be made on the basis of electrothermal, electromagnetic or combined elements. представленного типа устанавливается в квартирах, домах, на промышленных объектах и т. д. An introductory switching device of the type shown is installed in apartments, houses, industrial facilities, etc.

Trip units may not have a set time interval when the trip is performed. Also on sale there are devices with an independent holding or operation with an inverse dependence on the current.

Other varieties

также включают в себя предохранители, контакторы и реле. Switchgear also includes fuses, contactors and relays. In the first case, interruption is performed by destroying special elements. They conduct current.

The contactors are used for the operations of switching on, switching off the power. This category of devices includes starters, rheostats of starting and starting control type. The electrical relay can be a separate device. It serves to open the network with the specified parameters.

применяемые в современной электрике, можно принять правильное решение при выборе представленного оборудования. Having considered switching devices used in modern electricians, one can make the right decision when choosing the presented equipment.