Terminal box: purpose, description. Terminal box - how to choose, purpose

Before selecting and buy terminal box  it is necessary to get acquainted with its characteristics and qualities, purpose. It is quite simple and not expensive.

What you need to know about the terminal box

Buying terminal boxes wholesale  you need to pay attention to whether it is completed with a pad or not, its size and the number of possible connections. On purpose, it can be designed for installation inside or outside, in an aggressive environment. By the method of installation there is a box:

For open installation;

Hidden in concrete, plasterboard or plaster.

Manufacturers for their manufacture use modern materials, for example, polypropylene or plastic, non-inflammable PVC, metal. They are divided into IP20, IP44, IP54, IP65 and explosion proof according to the requirements of moisture and dust protection. According to the shape of the box terminal blocks are rectangular, square, round. They are sold with or without shoe.

For the supply of cables in the box can be used packing or plastic pipes, metal. They quite reliably protect the wires from moisture and snow. Rubber glands are produced with cut concentric circles, and plastic allows to adjust the mounting hole. The box is closed with a secure lid and fastened to the body by snaps or screws.

The quick selection of the desired product will help marking. It contains information on the degree of protection and the scope of application of the terminal box. This universal product is necessary for connecting power and control cables, enabling the connection of various elements on the DIN-rail, for example, distribution blocks, clamps, tires will last for a long time without requiring maintenance.

Practically in every object there are terminal and junction boxes. Therefore, this article deals with the classification of terminal and junction boxes, the selection and application of terminal boxes, an overview of the main manufacturers of terminal boxes, so that if necessary, you can quickly select the desired terminal or junction box.

Honestly, I do not know the difference in principle between the terminal box and the junction box. For me, it's the same thing, because all branches are performed via terminals.

Classification of terminal boxes:

1 By way of installation, the terminal boxes are distinguished:

- boxes for concealed installation in concrete;

- boxes for concealed installation under plaster, in plasterboard;

- boxes for open installation.

2 According to the material of manufacture:

- boxes made of ABC-plastic, polypropylene, PVC self-extinguishing and other similar materials;

- metal boxes.

3 According to the degree of protection against penetration of moisture and dust:

- IP20 boxes;

- boxes IP44, IP54, IP65;

- explosion proof boxes.

4 For climatic performance:

- boxes for premises У3;

- boxes for installation under the canopy of U2;

- boxes for installation on open air  V1.

5 According to the form of execution:

- round;

- square;

- Rectangular.

6 By the presence of the terminal block:

- boxes with terminal block;

- boxes without terminal block.

It should also be mentioned about the instrument boxes. In size they are slightly larger and allow you to install small appliances, sockets, switches.

In a separate group it is necessary to allocate test terminal boxes. They should be installed when organizing electricity metering with a transformer inclusion meter.

Now I will go specifically to the terminal boxes, their manufacturers and requirements normative documents  on their application.

According to PUE all connections of wires and cables must be carried out in connecting and junction boxes. The terminal boxes must comply with the environmental conditions and be made of a non-combustible material.

Metal attic boxes should be used in the attic space.

In junction boxes, junction boxes must comply with the requirements of 7.3.103 PUE. The degree of protection of the connection boxes in an explosive atmosphere depends on the class of the hazardous area.

In bathrooms and shower rooms in zones 0, 1 and 2, the installation of junction boxes is not permitted.

Among all manufacturers of connecting and branching boxes I want to highlight DKS. They can find in the catalog almost any junction box with the required degree of protection and category of placement, select the required cable entry, see the installation methods. More detailed information on the various terminal blocks, which are used for connecting and branching the veins of the cable, can be read in the Quadro section of the DKC website.

COPOS also produces a variety of boxes. They can find junction boxes of open and concealed installation, with terminal blocks and without, with a degree of protection IP20 and IP44. The climatic performance of these boxes, apparently, is V3. Separately, you can order the required terminal block. The catalog of products presents a good assortment of metal boxes.

From the Belarusian manufacturers produces terminal boxes SVETOPRIBOR. Terminal box KM-212 for concealed installation, KM-222 - for open installation IP44,

There are also KZN boxes with terminal block for 8, 16, 32, 48 clamps and degree of protection IP65. Terminal box У614АУ2 for 10 clips, У615АУ2 - for 20 clips.

In each power system, there are two main tools - a junction box and a protective device. In this article we will talk about what a junction box with terminals is and how it is applied. Also we will discuss the rules correct installation  installation.

Attention!  The main reason for unpleasant and sometimes tragic cases is the mistaken connection of wires  in the junction box.

AT switchgear  connects several input conductors, which are a source of power for certain rooms.

By appointment, the boxes are divided into several types:

The design of the valves differs in its strength and has a resistance to mechanical influences. A similar box is installed on a horizontal surface using special fasteners. Also has cable outlets, their number depends on the type of installation used.

Fastening of conductors to each other is carried out by special terminal blocks. They are reliable, safe and not inflammable.

Important!  When choosing a junction box for installation in a domestic environment, make sure that there is enough room to expand the electrical network.

Technique of installation of a distributive case

If you take into account all the rules and nuances, it turns out that the distributors are considered to be the lightest installation device, despite its importance in the integrity of the power system. For a decent and high-quality installation, you will have to use several methods, on the basis of which the algorithm of work is kept.

Attention!  The initial connection is made at the end of all installation work and connected in the meter.

Try not to use the twisting method in connecting conductors, as in the current conditions for a person this is unsafe. If your box is not equipped with terminals, it is better to buy them yourself.

Distribution Box Assignments

First of all, the distribution boxes are intended for switching the conductors of several consumers. The structures have different shapes and composition of the fabrication material.

The metal junction box is a reliable protector not for all conditions, such predominantly installed in industry and manufacturing. In other words, where there is a high risk of fire. But the junction box with terminal block made of plastic is perfect for everyday life.

In addition, the plant serves as an excellent insulator against combustible surface compositions, to which it is fixed. If you approach the issue from a theoretical point of view, you can do without distributors, however, in such a situation it will be necessary to throw a separate cable from the main shield to each consumer. Such a thing is impractical and expensive.

Important!  Thanks to the distributors, electricity throughout the living area is diluted in an even ratio.

How to find a junction box in an apartment?

Sometimes there are difficulties in the search for an old junction box. Each separate building requires certain standards for the installation of welding boxes. Here are a few areas, where most often placed devices for switching wires:

• in the buildings of Stalin's time, the boxes are located in the area of ​​the joint ceiling and walls. Find such a device manually will be difficult, so it's better to immediately get a metal detector;
• houses, built during the reign of Brezhnev, have a construction in a prominent place. Such boxes are located at a distance of 20-25 cm below the ceiling;
• at panel houses  or so-called "Khrushchev", you can find the distributor by tapping the wall under the ceiling. If you hear a deaf sound, then the distributor is found;
• in some houses of the current construction there are optical junction boxes  , they are easy to find with a test screwdriver at a height of two meters parallel to the sockets.

Important!  Do not try to pick the walls to search for the old wiring and the distributor, you risk getting an electric shock or damaging a working electrician.

Distribution box distribution

To disconnect the box with the consumer wires that came into it, in our case it does not take much time. It is enough just to place the conductors with the same insulation in special terminals and cover them.

If you purchased a box and terminals for the connection separately, make sure that the conductors are held tight. Before conducting joints of conductors, be sure to remove the insulation layer. In this case, the assistant will serve as special mites  . It is important to clean the insulation according to the dimensions. It is ideal to remove no more than 15-20 mm layer. After the work done, close the box and start the voltage. Now we need to make sure that there is no sparking and hissing in the conductors. If you have achieved this, then the connection of the wires is made unmistakably.

  It should be borne in mind that all the boxes have individual characteristics. For example, an electrical junction box with a terminal block can be used for both a hidden and an open electrical network.

First and foremost, and an experienced electrician is recommended to follow safety rules and be guided by regulatory requirements for the design. It is forbidden to use conductive materials and non-working clothes in the process of work. It is important to use special rubber kits that are sold in electric shops. Ideally, if you have a set on the farm for working with electricity.

Many years ago, with the introduction of electricity into everyday life, people decidedly adopted the technogenic purpose of our civilization. In this regard, now we are everywhere surrounded by all kinds of electrical appliances and a variety of equipment. Almost all houses have electric wiring. But in the case when the house is located in a remote area, then people found a way out of this difficult situation. They create wind generators, solar panels  etc. But it must be noted that not everyone is notified that almost everyone electrical device  an element such as a terminal box is required. What she really is, and what her main role in this article is trying to figure out.

The terminal box is a rectangular or round box with a terminal block inside. As a rule, the shoe is designed for largest section  switched wire (35mm) and the number of exact combinations of 7-12 pcs. The terminal box, depending on its purpose, is divided for a dry room, for an object with a harmful environment, for external use.

There is a separation of the terminal boxes:

1. The installation method is used for open installation, for concealed installation in concrete, for a hidden installation in plaster.

2. Depending on the use of different materials.

3. The value of protection from dust, moisture, etc.

4. Divide by natural use. For external use, U1 - for distribution under a canopy. V2 - for placing different directions.

5. Depending on the type of execution are distributed on a rectangular, square, round shape.

6. Depending on the area of ​​application common industrial or explosion-proof.

In addition, you need to know what is the instrument box. They are slightly larger in size than the terminal boxes. They provide an excellent opportunity to place in itself, in addition to the pads, small-sized instruments. They make it possible to distribute small-size devices, switches and sockets in addition to the pads. The terminal box sometimes contains sealed glands or cable glands intended for wires and cables. Often, the stuffing box is changed to metal and plastic pipes. Omentums are rubber with cut circles. In some cases, use plastic, they allow you to adjust the mounting hole. The use of glands makes it possible to significantly increase the tightness of the product. The box is closed with a lid, it is fixed to the body, using screws or latches with tight gaskets. Each terminal box, depending on its use, has different markings. This helps a person in a short time to find the right product. Since the terminal box can be used under water and at high altitude it can be mounted in a wall.

All information on the use of the terminal box is indicated on the code of the product itself. For example, the terminal box is explosion-proof, it has the marking 1ExeIIT5. There is a large number of types of markings among explosion-proof boxes. The marking contains all data on the degree of protection against explosions and the place of their application. Explosion-proof terminal box must have appropriate explosion protection certificates. The cable entries used in this terminal box must also be certified.

One of the necessary elements electrical circuit - terminal box  . How is it arranged and what is its purpose?

Terminal box device

The box consists of a plastic rectangular or round body and a cover that connects to the body with screws. In the case there are inputs for cables and wires. Inside the box is a terminal block with terminals for wire summary and wiring. In the terminals, the copper cables are connected to the aluminum cables, and branch wires are made. The case of the box is durable and resistant to mechanical influences. Plastic distribution boxes are installed in domestic and other non-industrial premises. For the latter, there are junction boxes in a metal casing.

Terminal box assignment

When performing wiring in the house, it is divided into separate sections. Each room has its own wiring, to which power consumers are connected. At the nodal points, the wiring is reduced to one trunk. A terminal box is installed in each of the units.

The purpose of the boxes is to ensure the fire safety of the electrical wiring. Since the places of wire twisting in this respect are the most risky, the box is designed to minimize the risk of fire. This is possible only in the case of correct connection  wires and create the necessary contact density between them. Junction box  separates the place of twisting of wires from the material of walls. In addition, it performs an aesthetic function. After all, open twisted wires on the wall look unattractive and not safe.

On the scope of the box are:

• Outdoor, which are installed outdoors.
• Internal open type. Such structures are installed in suspended ceilings.
• Internal closed type. They are designed for wall sealing of concealed wiring.

In the junction boxes it is possible to install various equipment, control and measuring equipment. Since they are unified in accordance with the accepted standards of electrical installation equipment, they can be assembled with elements of electrical circuits of any manufacturer.