When laying electrical wiring with your own hands, you need to be careful and accurate. But without certain knowledge in the field of electrical engineering, difficulties can arise when performing these works. In the process of creating electrical wiring, the metal junction box performs the function of a switching unit not only for a single room, but for the entire apartment.
Content
- Classification of devices according to different criteria
- Design features
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Main characteristics
- Plastic products
- Metal fittings
- Installation recommendations
Classification of devices according to different criteria
The main purpose of the electrical junction box is to provide high-quality insulation of the wire connection points. This product has an extremely simple design and is easy to assemble. It is by the type of installation first of all, they are classified:
- For hidden wiring, the device is mounted at the wire connection point located in a specially prepared wall niche.
- For surface mounting, the external electrical distribution box is installed on the surface of the walls, like the conductors laid in special boxes.
In residential premises, hidden wiring is most often used. Outdoor is mainly used in technical and auxiliary buildings. This division of products does not provide complete information on the characteristics of the junction boxes. They are also usually classified according to their purpose and degree of safety.
Thus, the following classes of electrical junction boxes exist:
- Regular security products. They are designed for a voltage of 220 V and can be installed not only in residential but also in industrial premises.
- Dustproof devices. They are used for installation in rooms with a high content of various dust particles, entering the housing of which negatively affects the performance of the entire wiring system.
- Splash-proof products. They are mounted in places with high humidity and equipped with special rubber seals.
- Fire resistant increased strength. Designed for use in rooms where flammable substances are located or explosive work is carried out.
Design features
Distribution boxes should not only provide high-quality insulation of conductor switching points, but also have a relatively small size. Most often, these products are round or rectangular boxes. They differ in size and have special holes for entering conductors into the structure.
Outdoor devices also differ in the way they are attached to the wall surface. Mounting holes in them can be located outside the case or inside. There are also models that are used for installation on tension power lines. They are attached to the cables using special structural elements.
Boxes for interior installation are installed in a wall niche using alabaster. To increase the reliability of fastening, there are special grooves on the outside of the body.
If the fittings are intended for installation in plasterboard partitions, then their fastening can be carried out using special structural elements or screws through the mounting holes located in the bottom products. In outer boxes, the cover is most often fixed using screw connections or latches. The flush-mounted hardware can be closed by simply snapping on the cover.
There are also boxes in which protective grounding is provided. They are equipped with a strip with holes and clamping screws for fixing the protective conductors.
Main characteristics
The choice of a product for installation depends on how it meets the technical requirements and is suitable for installation in a particular place. Most often, switchboxes are selected in accordance with the dimensions and material of the housing.
Plastic products
Most popular with electricians are plastic wiring junction boxes. They can be rectangular or round. At home, products with an IP 55 protection class are most often used. They are equipped with four rubber grommets. These structural elements also serve as a seal.
The popularity of plastic boxes is associated with several factors:
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Good dielectric properties of the material. - Low cost of production.
- Possibility to complete the product with various additional elements.
- Long service life.
It is difficult to give specific recommendations on the choice of plastic boxes. In this matter, one should focus on ease of installation and operation.
These products are used in rooms where it is necessary to achieve rigid fastening of conductors, and external unfavorable factors are also present. Such premises include, for example, hangars, workshops, etc., where one cannot do without high-performance switchboxes, which metal products possess.
Most often they are made by stamping from sheet iron with subsequent painting. Screw connections are used to secure the cover. High tightness of the product is achieved thanks to the rubber seal. At home, their use seems impractical. During the installation of electrical wiring in residential premises, it is cheaper and more convenient to use plastic products.
Installation recommendations
The installation of the distribution boxes must be carried out in accordance with the wiring plan. Most often they are mounted at a distance of 20-30 cm from the ceiling. The algorithm of actions when installing fittings is as follows:
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The box must be installed at the point of entry of the main conductor. - Wires from all wiring elements are drawn into the accessory for a length of 5 to 7 cm.
- For the convenience of switching, the conductors should be marked.
- After the installation connection of the cables, it is necessary to insulate the twist points and sink them into the housing.
- At the final stage of installation, it remains only to tightly close the lid.
It is also necessary to note the peculiarities of connecting wires inside the box. First, you need to remove the protective coating from the conductors at a length of 1.5 to 2 cm. The easiest way to connect is to match the color of the wires. Then each twist must be crimped with pliers and insulated with plastic caps or electrical tape.
If terminals are provided in the box, the installation process is simplified. To connect the wires, their stripped ends must be pressed with screws. When all the wires are connected, they should be carefully placed in the box and the lid should be closed.
Even for a novice home electrician, the process of installing junction boxes is straightforward. If you pre-mark all the wires in the product, then it will also be easy to connect them.
