How to connect wires in a junction box: methods of connecting conductors according to PUE

Working with electricity requires care. If you thoroughly understand the upcoming process, then everything can be done independently. Many home craftsmen do not know how to connect the wires in the box, because there are several ways to solve the problem. It should be recognized that the performance of all wiring depends on the quality of the connection.

Appointment of the junction box

From the electrical panel, the wires diverge throughout the room. Each apartment must have several connection points - sockets and switches. Junction boxes are used to collect all the wires in one place and thereby simplify the maintenance of the wiring. They lead conductors from all connected devices, and then connect.

It is necessary to connect the wires in the junction box in accordance with the PUE (Electrical Installation Rules). This document requires the conductors to be 15 cm away from the ceiling. Distribution boxes are installed at the branching points of the wires.

It is a simple electrical accessory that can be used for hidden and exposed wiring. The boxes are round or rectangular. Through their use you can get the following benefits:

• The maintainability of the wiring is increased, since access to all conductor connections is open.
• The level of fire safety is increasing.
• Financial costs are reduced and electrical work is simplified.

Connection types

You can use one of several methods to connect the wires in the junction box. All of them allow to ensure reliable contact of the conductors and the home master has the right to choose the most convenient one.

Twisting and crimping

It should be said right away that now the use of twisting wires in a junction box is prohibited, since this method is recognized as the most unreliable.

By deciding to choose such a connection, the electrician accepts responsibility for the possible consequences. In this case, the very method of connecting the conductors is extremely simple. First, you need to remove a layer of insulation from the conductors at a length of about 1 cm, and then carefully wind the wires on top of each other. When connecting wires with a cross section of less than 1 mm, you need to make 5 or more turns. If thicker cables are connected, the minimum number of turns is 3.

Crimping is very popular today. To make the connection in this way, special sleeves are used, the diameter of which is selected in accordance with the size of the conductor bundle.

It is also important to use sleeves made of the same material as the conductors. The sleeve is crimped using a special tool.

Some DIYers use conventional pliers for this, but the quality of such a connection will be lower. To carry out the work, you must first remove the insulation from the wires, then twist them and insert them into the connector. The next step is to crimp the sleeve with a press tongs and then insulate the contact point with electrical tape or heat shrinkage.

Soldering and welding

After connecting the conductors by welding, almost a whole wire is obtained. As a result, such a junction is not afraid of various negative environmental factors. However, due to the need for special equipment, this connection method is the most popular among professional electricians. You can create a welded joint using the following tools:

• Welding machine with a capacity of at least 1 kW.
• Gumboil.
• Carbon electrode.

After removing the insulating layer from the wires, their bare areas must be cleaned to a shine, using sandpaper for this. In the next step, regular twisting is performed. Then flux is poured into the recess of the electrode and after turning on the welding machine, the electrode is pressed against the conductors. When a ball-shaped contact point appears at the junction, the force is removed. At the final stage, you need to clean the welding place from the remains of the flux and cover it with varnish.

The algorithm of actions when connecting conductors by soldering is similar. The differences between the two are in the tools and materials used.

Although the solder joint is quite reliable and durable, it is not recommended to use it in places where conductors can get very hot or significant physical activity is possible.

Screw terminals and bolt connections

The use of contact screw clamps allows you to reliably connect not only homogeneous current-carrying conductors, but also dissimilar wires. Moreover, the cost of such clamps is low, which made the method quite popular. All work is carried out in two stages:

• The insulation is stripped from the conductors over a length of about 5 mm.
• Bare wires are inserted into the clamp and tightened with screws.

In order not to violate the integrity of the current-carrying conductors, it is necessary to control the clamping force. First of all, this applies to work with aluminum wires.

Bolted connections are highly reliable, but at the same time they turn out to be cumbersome. If this method is used, the correct junction box must be selected. Modern models are often small in size.

It is also worth noting the self-clamping joints, which have become very popular in recent years. Such clamps are not only easy to use, but also contain a special compound inside that prevents oxidation of the conductors. After the insulation has been removed from the wires, you need to raise the clip lever. When the bare end of the cable is inserted into it, the lever is lowered and the connection is made.

Installation of boxes

To create high-quality wiring in a room, it is not enough to know how to properly connect the wires in a junction box. Extremely it is important to be able to install the junction box itself. In apartments and private houses, hidden wiring is most often used, since it does not spoil the interior of the room. First, markings must be applied to the walls, indicating the points of installation of electrical equipment and the paths of the conductors.

As a result, the required amount of materials can be easily calculated. It is also advisable to draw up a wiring diagram to simplify the process of connecting electrical appliances. At the next stage, grooves should be made in the surface of the walls using a special tool - a chasing cutter. In addition, you need to cut out niches for the installation of boxes, switches and sockets. Most often, junction boxes for hidden wiring are installed on alabaster.

When all the work on laying conductors and installing electrical equipment is completed, it is necessary to connect the wires in the boxes in one of the ways discussed. At the final stage, sockets and switches are connected, and then the entire system is checked for functionality.

Knowing the features of the installation of junction boxes and the rules for connecting conductors in them, all work can be done independently. They are not very complex and problems should not arise.