Distribution box diagrams. How to connect wires in a junction box according to PUE

The correct connection of the wires in the junction box is largely the key to the reliability of your electrical network. Indeed, unlike connections in a distribution board, distribution boxes or, as they are also called, junction boxes are more closed for maintenance and contact connections here are much more difficult to check. That is why, even at the installation stage, maximum attention should be paid to their quality and correctness.

Before connecting wires in the junction box, we advise you to study the rules for their installation. After all, it is important not only to properly connect the wires to each other, but also to correctly insert them into the junction box, and also conveniently position them for possible inspection or repair.

Rules for installing wires in a junction box

First of all, let's look at the rules for the arrangement and installation of wiring in the distribution network. After all, it is with this factor that any installation begins.

So:

• First of all, you should remember that no more than eight groups of wires can be laid in one groove, box or pipe.
• All connections must be made in accordance with paragraphs 2.1.17 - 2.1.30 PUE. These clauses provide for a whole range of restrictions. First of all, remember that the wire in front of any contact must have a reserve sufficient for at least one reconnection.
• Before connecting the wires in the junction box, make sure that they are free from tension.. Or that this tension will not occur due to temperature changes.
• Any wire connection points must be accessible for repair and inspection.. At the same time, these places should be organized so that inspection is not hampered by structural elements.
• Any connection must be insulated. In this case, this insulation must correspond to the level of the main insulation. To achieve these parameters, it is better to use electrical tape or heat shrink.
• The distribution boxes themselves must be made of fireproof or fire-resistant materials, as in the video. This is especially true for the installation of wiring on combustible structures, which are subject to additional requirements.

Options for connecting wires in a junction box

First, let's look at how to connect the wires in a junction box. After all, it is the contact connections that are often the most vulnerable point of any electrical network and any shortcomings appear very quickly.

According to clause 2.1.21 of the PUE, all connections of wires and cables must be made by welding, soldering, crimping, screw or bolt compression. Other connection methods, especially twisting, are not allowed. Based on this, let's look at each of the possible connection methods separately.

So:

• The most reliable connection of wires is considered to be the welding method.. It has the lowest transition resistance, resulting in virtually no increased heating. In addition, over time, such a compound does not lose its properties.

Welding of wires in the junction box is carried out using a special welding transformer and a carbon electrode. The cost of such products is high enough for a simple replacement of wiring in an apartment, so you can often find homemade devices. Typically these are transformers up to 600 W and voltage 9 - 36V.

• The second place in reliability is the connection using the soldering method. This method is more accessible for home use because it does not require special equipment other than a regular soldering iron.

Soldering of wires in the junction box is carried out using conventional technology and does not impose any special requirements. The only point worth paying attention to is the quality of such connections. After all, if heated, the tin will heat up quickly enough and the contact will disappear. To prevent this, soldering is often combined with a twisted connection.

• Wire crimping has recently become increasingly popular. After all, a large number of fairly cheap tools for crimping wires have appeared on the market, and the price of consumables for this method is quite low.

• But the most common method is still the screw or spring clamp method. A huge number of buses and terminals currently on the market allow for a fairly reliable connection of wires.

Cables and wires in residential and non-residential buildings are laid from a switchboard with an electricity consumption meter, safety plugs or circuit breakers under the floor, along the walls to distribution boxes, where they are connected by twisting or using terminal blocks (electrical clamps).

From the distribution boxes, electrical wiring is laid to other junction boxes or switch boxes, which are connected to one machine or the same group and to switches, sockets, and lamps. It is possible to make a connection without special education or experience as an electrician; just follow these instructions.

Usually 3 - 4 groups come to the apartment (including a separate group that comes to the electric stove, which is laid with independent cables or wires). Thus, if there is a fault on the line, only part of the building or apartment is disconnected from the power supply. Pay special attention to the proportional and uniform distribution of the load between the circuit breakers or safety plugs in the electrical panel.

Before starting work, it is necessary to de-energize the line on which work will be performed by unscrewing the plugs or turning off the machine.

As a rule, one distribution box is installed for each room; if the sockets are significantly distant, an additional one can be installed, specifically for the sockets.

Step-by-step guide to installing a junction box

Learn more about choosing a connection method and features of video editing

Distribution box wiring diagram

All protective or grounding (marked as PE in the diagram, highlighted in yellow) and neutral conductors (marked N in the figure, marked in blue) are connected to each other by color, as shown in the diagram. There will be no ground conductor if the wiring is two-wire.

Phase conductors (highlighted in black and red) are a little more difficult to disconnect; if the wiring from the distribution box goes only to the sockets, then the phases are also connected to each other.

In the case when the wiring goes to a lamp with a single-key switch (as shown in the figure), the wire that comes from the switch is connected to the phase going to the lamp (in the picture L to lighting), and the phase coming to the switch is connected to all phase wires (on the diagram L for the switch). There should be 4 connections.

When distributing conductors to a luminaire with a two-key switch, a four-core cable is laid before it (2 on-phase conductors, 1 off-phase, 1 neutral, 1 “ground”). In the case of two-wire wiring, it is three-wire, since there is no ground conductor. The phase conductors going to the sockets are connected to each other. The phases of the power cable coming to the common terminal of the two-key switch are also connected, 2 wires from which go to the lamp lamps separately. Below are wiring diagrams for a two-key switch without ground.

All neutral and grounding conductors (if the latter are present) are connected together. There should be 5 connections inside the box (including the connection of the grounding conductors). Below is a wiring diagram for a two-key switch with ground.

When repairing electrical wiring yourself, you should pay special attention to the connection of wires in junction boxes, because electrical engineering, as electricians say, is the science of contacts, both desirable ones, ensuring an uninterrupted supply of electricity, and unacceptable ones, due to which many accidents occur.

This article, with the help of links to other materials of this resource, will present all the minimum knowledge and skills required by a home handyman for successful electrical installation, and will also describe step by step the entire process of connecting wires in a distribution box, starting from the preparatory stages, ending with the introduction of a mounted home network into operation.

The scheme is the most important stage

For an experienced electrician, it will not be difficult to connect a switch and a light bulb without a drawing, making a connection of wires in a junction box, guided by the color marking of the cable cores or by the results of testing already installed wiring.

But experienced craftsmen succeed in such work only because connection diagram clearly imprinted in the mind thanks to many years of practice.

A simple diagram of wire connections in a junction box when connecting a switch and a light bulb

If a master needs to carry out electrical wiring at any facility, then he will begin first by designing a circuit, if other specialists have not done this before him. Of course, there are standards, GOST and SNiP, according to which all electrical wiring drawings are made, but for an apartment or private house, a hand-drawn diagram is suitable, the main thing is that it subsequently works properly and safely.

This approach not only protects against errors, but also allows you to save time by dividing labor - when carrying out electrical installation in a junction box, the electrician will not be distracted by drawing up a wiring plan, while simultaneously trying to keep the planned lines and connections in his head.

A more complex connection diagram for a two-key switch

Examples of schemes for and apartments can be viewed by following the links. You will also need to familiarize yourself with the graphic symbols of the network elements so that you can consult with a familiar mechanic by showing him the diagram, or in the future carry out electrical wiring repairs by checking the saved drawing.

The importance of planning electrical wiring is also determined by rationality and efficiency. When drawing up a wiring diagram, you need to draw up a plan in such a way that there are as few junction boxes in the apartment as possible, because each connection of wires increases the risk of losing contact.

Example of a hand-drawn wiring diagram (blue circles indicate junction boxes)

When connecting one socket or switch, many electricians advise doing without a distribution box altogether and connecting the wires in the socket box. This decision is determined by the reluctance of apartment owners to provide access to the distribution box, as required by the PUE (in their opinion, the interior of the home is deteriorating). The socket or switch can be easily disassembled, which provides access to the connection of wires in the socket box.

Quote from PUE

A detailed story about the various wiring diagrams in junction boxes is shown in the video:

Correct pin markings

In order to connect the wires in the junction box according to the diagram without undue doubt, it is necessary that the terminals of the laid electrical wiring be marked. Very often, disconnection (dividing the main electrical wiring line into several branches) is made when all the wires have already been laid and hidden under the plaster, and there will be no way to visually trace the purpose of the cables.

It's easy to get confused without being sure of the purpose of the same cables

In order not to waste time on cables, which is also described on this site, you need to mark their ends at the stage of laying the cables. In some cases, if there are few wires in the distribution box, you can be guided by the color of the insulation of the current-carrying conductors. But with a large accumulation of cables, the colors of the wire insulation will be repeated, so the likelihood of error increases.

To eliminate the possibility of incorrect connection, you must label ending laid cables in any available way. The industry produces many different tags designed to mark terminals. Very often, electricians use transparent heat-shrinkable tubing by inserting a strip of paper with a terminal symbol inside.

Samples of industrially produced cable marking tags

You can also use transparent tape to wrap it around tags with inscriptions. As a last resort, use a marker or felt-tip pen to write the designations directly on the wire insulation or on the wall - but there is a risk that the inscriptions will be erased during the installation process.

Electrical wiring terminals are marked on the wall

You should also strictly adhere to the color marking of the cables (brown, red, black - phase, blue - working zero, green with yellow stripes - protective conductor PE).

Generally accepted color coding for cable core insulation

Installation of distribution box

Before starting electrical installation, you need to make sure that the junction box is securely fixed. , which depend on the type of wiring, are also described on this site. The importance of fixation is determined by the possibility of damage to already connected wires when manipulating the junction box and cables.

When working with single-core wires, frequent bending of the current-carrying wires should be avoided. Although stranded wires allow frequent bending, mechanical loads and the weight of a loose cable of hanging electrical wiring can damage the finished connection, so it is important not to violate electrical installation technology.

PUE requirement for fixing cables and boxes

If hidden wiring is installed in a brick or concrete wall, then the wires are laid in a groove made manually or using tools (grooving), and socket boxes and distribution boxes are mounted in holes that are drilled into the wall using a special crown. Fixation is carried out using plaster or alabaster.

Box bit for drilling holes for distribution boxes

Each type of wire connection requires a certain length of leads. For example, when using very bulky connecting blocks that have bolted connection terminals, craftsmen try to leave as little free length of wires as possible so that all connections fit into the box.

But, if welding of wires is used, then the length of the bare conductors should be about seven centimeters to prevent the insulation from melting during strong heating, plus the length of the insulated conductors for convenient and safe installation. Long exposed connected wires are insulated and laid in a junction box.

Wire connections are made by welding

The above examples mean that, regardless of the chosen method of connecting the wires, the length of the leads protruding from the junction box must be at least ten centimeters, because excess conductors can always be cut off, but it will be extremely difficult to extend them, and the reliability of the entire electrical wiring line will deteriorate. .

Conductor training

At this stage, the master must finally decide how to connect the wires in the junction box, and accordingly prepare guides– remove the insulation and bend the cable cores. A list of existing types of wire connections is given below, and now, regardless of the chosen method, special attention should be paid to the quality of stripping and preparation of conductors for electrical installation.

Stripped wires are ready for connection in the junction box

To carry out any electrical installation, the master must have, which you can familiarize yourself with by clicking on the link. At this stage, the wires are prepared for connection - stripping of insulation. Particular care should be taken in this process, since when using improvised means (knife, pliers, wire cutters), invisible damage to the current-carrying wires is possible.

Professional electrician's tool kit

As wires are bent and subsequently installed, subtle cracks in the metal can become larger, impairing electrical conductivity and possibly leading to breakage and loss of contact. At high currents, a large amount of heat will be released in the thinnest section of the circuit (at the crack site), which can heat the insulation and even the metal of the conductor itself to the melting point.

With a large current in a broken conductor, an avalanche-like process occurs - when heated, the resistance of the material increases, which further increases the heat release. This process ends with the melting of the conductor metal and the appearance of an electric arc, which, burning other wire connections in the junction box, renders them completely unusable.

Photo of an electric arc burning in a junction box

Without a doubt, a real master, even with the help of a kitchen knife, will be able to carefully and quickly remove the insulation without damaging the current-carrying conductor. But for people without experience it will be very difficult to avoid subtle damage to the material of the conductors, therefore, in order for the connection of wires in the junction box to be of high quality, it is necessary to use special ones (strippers).

Variety of stripping tools

Many people have seen the picture that some craftsmen remove insulation with the help of teeth. There is absolutely no need to follow this example, in which case purchasing a professional insulation stripping tool will cost less than the services of a dentist.

An overview of various stripping tools is shown in the video:

Wire connection methods

As already mentioned, for various methods of connecting wires to a junction box, there is its own electrical installation technology, which consists of the length of stripped conductors, their bending and the use of appropriate tools.

Since each of the possible methods has many specific nuances and requires the use of special tools and skills, the types of wire connections are presented below in the form of a list with links:

• Terminal blocks;
• PPE caps;
• Connecting sleeves;
• Welding of conductors.

Wiring in a junction box using terminal blocks

Each of the above methods has its own advantages and disadvantages, which you must familiarize yourself with by studying the materials and following the links provided. You should choose the type of connections for doing electrical installation yourself based on the availability of tools, skills, the ability to purchase materials and the expected quality of contacts.

Most reliable welding of wires is considered, but it requires a special welding machine and specific skills. Soldering conductors, which also has good performance, requires soldering iron skills. Wago terminal blocks are quite easy to install, reliable if the products are correctly selected according to the load, and allow the connection of multi-core wires without the use of special lugs, but you should be wary of counterfeits.

Connections in the junction box are made using Wago terminal blocks

The use of sleeves is reliable; when using special products, it is possible to connect copper and aluminum, but the connection itself requires special pliers and is non-separable, which does not give a chance for easy correction of electrical installation errors. PPE caps are reliable if the technology is followed and the diameter is selected correctly. Terminal blocks require bolted connections to be securely tightened.

PPE caps in distribution box

It should be remembered that according to the PUE, twisting of wires is not allowed in its pure form

Twisting in its pure form is not included in the list of compounds allowed by the PUE

Testing wire connections in junction boxes

After all connections have been made, the exposed areas of the conductors are insulated using heat-shrinkable tubing, and the wires are laid in junction boxes. The boxes themselves are left open until the installed electrical wiring is tested. First, voltage is supplied to the connected lines by turning on the corresponding circuit breakers.

Insulating connections in the junction box using heat shrink tubing

If, after switching on, nothing sparked anywhere and the machine was not knocked out due to a short circuit due to an erroneous connection of wires or poor-quality insulation of connections, carry out tests electrical wiring with load current (loading), which is carried out by connecting various electrical appliances to mounted lines. It is recommended to load each line with the maximum permissible current.

The download should continue for some time (preferably several hours). During this period, possible electrical installation defects will have time to manifest themselves. A visual inspection of the connections in the junction boxes should be carried out - signs of high temperature will be visible by melting of the insulation or terminal blocks. It is also important that there is no characteristic odor of overheated or burnt insulation.

Melted insulation of one of the connections in the junction box

After relieving the voltage, you should check all connections by touch - they should not be hot. If, when loading the electrical wiring with the maximum rated current for several hours, no comments are identified regarding the operation of the connections, then the electrical installation is considered normal, the junction boxes can be closed and the wiring can be put into operation.

Installation of a distribution box in an apartment is an important stage of electrical wiring; thanks to it, the electric current is evenly distributed to points that consume electricity (lamps, sockets, switches). A properly installed box ensures 100% uninterrupted use of electrical wiring. In appearance, the junction box is a metal or plastic structure with holes on the sides. Wires extend from the box, which provide current to all important electrical devices.

To distribute electricity evenly, the wiring is divided into separate groups of consumers. In rooms, distribution boxes are installed at the wiring connections.

Distribution boxes perform several important functions in residential premises:

• ensuring fire safety;
• creating an aesthetic appearance in the apartment.

The wires are located inside the box; thanks to the housing, they are not subject to mechanical stress, which ensures their safety.

According to the installation principle, the boxes are built-in and external. Built-in ones are installed in specially prepared recesses in the wall, and overhead ones are fixed on the wall surface.

Main function of distribution box

Distribution The box allows you to reduce wire costs. If it weren't for it, each electricity consuming device would be connected with a separate cable. No box provides an increase in the channels for laying wires, and visually this looks unaesthetic.

The advantage of using junction boxes is undeniable, and proper connection of wires will ensure the safety of the premises. This device isolates contact points from the effects of flammable wall materials.

The ease of use of the junction box ensures ease of repair. The main function of the box is that it ensures uniform distribution of electricity to the locations of the main consumers. In addition, such designs of switching boxes involve adding new branches of electrical networks to the existing wire if necessary.

Types of distribution boxes

Distribution boxes according to the type of fastening are divided into:

• overheads, which are installed outside on the wall;
• internal, installed in the prepared wall recess.

The main purpose of the junction box is to provide easy access to the electrician in the event of a system malfunction. For convenience and to preserve the integrity of the wires, the box is closed with a lid. To carry out any manipulations with the electrical wiring, specialists just need to remove the cover and get acquainted with the causes of the problems.

Distribution boxes are made from the following materials:

1. Plastic.
2. Metal.

Metal cases are made of tinned steel sheets or aluminum alloys. The main requirement for materials is that they are not subject to corrosive changes.

If a distribution box is needed for strategically important facilities, then it must be selected with the following characteristics:

• screw cap;
• waterproofing gaskets.

The metal case has universal properties and perfectly protects the wiring during a fire, that is, during a fire, the metal structure is able to preserve the contents of the box for some time, during which it is possible to de-energize the network.

The plastic case also has positive properties: resistance to oxidative processes and the ability to isolate electric current.

Distribution boxes vary in geometric shape and are:

• round;
• square;
• rectangular.

If a small number of wires are supplied to the box, then a round box configuration can be used. In cases of a large number of wires, it is better to use a rectangular distribution structure.

Important! If the walls are concrete, then it is easier and more convenient to install round box structures.

The dimensions of distribution boxes depend on the number of wires and their cross-section.

Internal structure of distribution box

The design of the junction box consists of a housing and a cover, as well as side inlet holes.

The internal cavity of the box is equipped with terminals and clamps for fastening wires. Typically, the input cable is secured using terminals, and separate wires are secured using clamps. If the box is not equipped with terminals, the wires are secured together by twisting.

The disadvantage of a terminal connection is that after use the bolts can become loose and disrupt the wiring contact. Loose contact causes heating and subsequently burning of the wires. Twisting is considered a more reliable method.

It should be taken into account that the connection of aluminum and copper wires in the junction box leads to destruction of the connection and the occurrence of an electrochemical process.

Important! Brass terminals provide high-quality connection of aluminum and copper wires.

Installation Rules

Electricity distribution boxes are mounted approximately 25 centimeters from the ceiling. In cases where the distribution box is installed in a hidden way, the cover must be on the surface so that it can be easily opened and work carried out.

When choosing a place to install the box in a hidden way, you need to ensure access to it while respecting the design intent of the interior of the apartment.

Installation

In concrete or brick construction, electrical appliances are placed in the wall cavity in specially prepared holes in the wall. Such recesses are made with a hammer drill; in cases of a round design of the distribution panel, the holes are made with a special crown. In the seat, the box is attached to the wall using alabaster mortar, which guarantees a strong connection between the housing and the wall.

After determining the installation location of the box, you need to prepare the wire network and make the connection. In order to bring them to the switching box, you need to prepare grooves into which the wires will be laid. If the walls allow the possibility of wiring in a horizontal position, then the gaps between the walls and the ceiling are quite useful for this.

After preparing the channels and socket boxes, the wiring of the switching box wiring system is carried out.

Important ! To ensure the correct connection of the wires in the junction box for the purpose of quickly carrying out subsequent repair work, the wires are marked.

The input cable from the electrical panel is designated as “input”; the wire from the sockets should also be marked, because labeled wires will not allow mistakes during maintenance and repair. In order for the wires to be used correctly, the cross-section must be strictly observed; for example, to supply electricity from the panel, a two or three-core cable with a cross-section of 4 square millimeters is used.

Such a cable guarantees full use of any high-power consumer. For the lighting system, a cross-section of 2.5 square millimeters is used, and for sockets - 1.5 square mm.

After familiarizing yourself with all the nuances, they begin to install the junction box. The basic principle of installing the switching structure is indicated by precise adherence to the sequence of wiring connections. The wiring diagram in the distribution box includes the following parameters: phase is connected to phase, zero is connected to zero, and grounding is connected to grounding.

Laying of wires occurs subject to compliance with all parameters and requirements of the drawn up connection diagram. The wires are laid inside the box, preferably with an allowance of about 10 centimeters. When connecting wires, it is necessary to strip the ends of insulation and secure them in the terminals.

If there are no fasteners, you can simply fix the connections by twisting. This method involves twisting the wires at the points of contact; this method is often used and is considered reliable. After this, the joints are fixed with insulating material (insulating tape or plastic caps).

Important! The wires are mounted in pipes made of metal or plastic, which provide insulation from external negative factors.

Various modifications of switching devices are widely presented in specialized electrical stores. The included instructions indicate the main characteristics and current voltage ratings.

Connection principles

For quick connection and to avoid confusion, the wires are marked with colors of different shades. The following color combination is considered popular: white indicates phase, blue indicates zero, and light green symbolizes grounding. When connecting, strict compliance and consistency must be observed.

Like any other work, electrical wiring in a junction box also begins with a design. To draw up a competent electrical wiring diagram, you need to determine the exact location of electrical installation points - lamps, sockets, switches. In accordance with the diagram, distribution boxes are placed in convenient places. Providing access is necessary in case of interruptions in the electricity supply.

The rules for electrical installations stipulate that wires must be connected by soldering, welding or using clamps. However, the “old-fashioned” method of twisting wires has proven itself among the people; this method ensures the manufacturability and reliability of the system.

Sometimes twisting the wires is not enough; to ensure reliability, the contact area is treated with soldering. After connecting, the wires are insulated and placed in the box body so that they do not come into contact with each other.

After carrying out the entire complex of work, diagnostics are carried out; for this, the most powerful electrical appliance in the apartment is connected to the network and the wires are checked for the presence of heating. If you find any wire heating up, this means that it does not have enough contact area, and in such cases you should probably replace the wire with a larger cross-section wire.

Conclusion

All types of work with electricity are strictly related to the installation of a junction box. Such a device is an important link in the electrical network, and proper installation ensures that the facility is fully supplied with electricity.

Experts recommend installing boxes in every room, because they connect all the wires from sockets, lamps and switches. In cases of electrical problems, it is quite easy to determine the location of the breakdown and thereby carry out repairs quickly and without damage to other premises.

The above information will serve as instructions for the correct installation of the junction box.

Working with electricity does not tolerate negligence, so you need to thoroughly understand the upcoming process. One of the important aspects is the connection of wires in the junction box, since the performance of the system itself and its safety, both electrical and fire, depend on the quality of the work performed.

All wires that supply electricity to a house or apartment come out of the electrical panel. Each room has several. To collect everything in one place and assemble a wiring diagram, distribution boxes were invented. This is where they are connected for the further operation of all devices. To use the established rules described by the PUE, which stipulate the rules for laying wires and cables. It also contains recommendations regarding the conduct of connections and branches of wires, specifically in the junction box.
According to these recommendations, the wires are laid along the top of the wall, at a distance of 15 cm from the ceiling surface. As soon as the wire reaches the turning point, it is lowered perpendicularly downwards, and at the branch point a specialist. According to this principle, all wiring cores are connected according to a given diagram.
Depending on the type of installation, the boxes are:

• internal, used for hidden wiring;
• external, used for external connection.

When installing an internal box, you need to make a hole in the wall, into which the box is then installed. When the cable is supplied and connected, the box is closed and the lid is flush with the wall surface. In some cases, such a box is masked with wallpaper or a thin layer of plaster.
If the thickness of the walls does not allow installing an internal box, then the only solution is to install an external type box. It is mounted on the wall surface, so complex preparatory work is not required.
Depending on the shape, the box can be:

• round;
• rectangular.

The number of pins varies, in most cases there are 4, but sometimes there are more. Each terminal is equipped with a thread or fitting to which it will be convenient to attach a corrugated hose. The corrugated hose is designed for convenient location of electrical wires, so replacing a damaged cable will not cause difficulties even for a beginner:

• disconnect the corrugated hose from the junction box;
• disconnect from the socket or switch;
• pull a little;
• pull out;
• put another in its place.

If the cable was laid in a groove, then replacing it will be more difficult. You will need to dig into the wall and remove the damaged cable, and lay a new one in its place. After such work, the wall will have to be repaired.
The task of distribution boxes:

• Increase the maintainability of the power supply system. The accessibility of all connections allows you to identify the damaged section of the circuit. If all the wires were laid in corrugated hoses or pipes, then replacing damaged ones will not cause much difficulty.
• Providing free access to connection points. Since the majority of electrical problems arise due to poor quality or, you can easily check their condition by opening the junction box.
• Ensuring fire safety.
• Financial savings. By using a distribution box, you don't have to run a cable to each outlet.

Types of connections

The distribution box is designed to connect electrical wires. It doesn’t matter how this will be done, the main thing is that the end result ensures the reliability, safety and performance of all devices. Several methods are used to connect:

• by using ;
• with help ;
• with help ;
• by using ;
• twist;
• with help .

To determine for yourself the optimal method of connecting wires, you need to disassemble each of them and find out the advantages and disadvantages of each method.

Terminal blocks

These are plastic parts, inside of which there is a brass bushing with screws on both sides. To do this, you need to insert the stripped ends on both sides of the block and tighten the screws with a little force. This method is not complicated, but you need to keep in mind that the pads come with different outlet holes, suitable for a certain wire cross-section size.
Advantages:

• low cost;
• reliable connection;
• possibility of connecting aluminum conductors with copper ones.

Flaws:

• Such products are often found with poor quality, so it is difficult to talk about a high-quality connection.
• They allow you to connect only two wires to each other.
• Such blocks are not recommended for connecting aluminum and stranded wires. This is because aluminum is very brittle and the wires are very thin, so if the screws are over-tightened, the contacts may be damaged.
• Soldering can provide a more reliable connection.

connects wires by a clip

Spring terminals

This is a more modern invention, which has become an indispensable and effective assistant when performing such work.
Unlike the previous option, a special mechanism is used instead of a screw, which allows you to carefully fix the wire without damaging it. The connection principle is very simple, the stripped ends are inserted into the holes of the box.
You can find several models of these products on the market. They come in disposable and reusable types. Disposable pads are intended for one-time use; if they are damaged and need to be replaced, the pads must be replaced with new ones, since the previous ones cannot be saved. They are not reused.
Reusable terminals cost a little more, but you can change wires and reconnect them using the same spring terminals.
Advantages:

• possibility of connecting wires made of aluminum and copper;
• the ability to connect several cores at a time;
• connecting a thin stranded wire without damage;
• compact dimensions;
• it will not take much time to work;
• high-quality connection;
• built-in indicator to monitor the operation of the electrical network.

The only drawback of such terminals is their high price.

PPE caps

Connecting, this is how PPE stands for. People call them more simply, caps. Externally, they resemble caps made of plastic. There is a spring inside that holds the wires.
Such products are more often used than others for fastening cores in junction boxes.
Advantages:

• affordable price;
• lack of possibility of fire, which is explained by the material of manufacture;
• quick installation;
• large selection of products in sizes and colors.

Flaws:

• insulation and fixation are not of high quality;
• connecting aluminum to copper is impossible.

Crimping with sleeves

This . Its essence is simple: for joining, insert the stripped ends into a special sleeve and crimp. Finally, the sleeve is insulated.
The arrangement of the wires can be any, either from two stolons of the sleeve or from one. In the first case, the junction of the wires should be in the middle of the sleeve; in the second case, the total cross-section of the wires should not be larger than the cross-section of the sleeve.
Advantages:

• high quality connection and insulation;
• low cost.

Flaws:

• Once a cartridge has been used, it cannot be restored; it is disposable.
• Availability of special tools: press jaws and pipe cutter.
• the presence of a special sleeve for fastening aluminum and copper cores.
• Installation work this way will require more time.

Soldering or welding

• expose the ends of the wires;
• twist the prepared ends;
• solder the wires with a soldering iron or gas torch;
• let the solder cool;
• insulate the ends with electrical tape, heat-shrink tubing or cambric.

Please note that cooling ends with solder in water is strictly prohibited, as this may lead to deterioration in the quality of the bond.
Advantages:

• reliable and strong fastening of wires.

Flaws:

• availability of special tools and skills to work with them;
• complexity of the soldering process;
• permanent connection point;
• restrictions on some conditions of use, stated in the PUE;

Stranding and insulation

An old but effective way of fastening two or more wires. The principle of work is simple: strip the ends and carefully twist them together using pliers. The twisting area must be insulated.
Advantages:

• ease of operation;
• minimal material costs or their complete absence if you already have purchased electrical tape.

Flaws:

• not the best quality bonding;
• Aluminum and copper conductors cannot be connected.
• increase in twist resistance over time.

In most cases, this method is used when carrying out temporary electrical wiring, and cambrics are used for insulation.
At the moment, the PUE prohibits this method of connection because over time the twisting resistance increases and the contacts begin to heat up.

Walnut clamp

Fastening with a “Nut” clamp is used quite often. This is a clamp with two plates and 4 screws at the corners. To fasten, you need to strip the ends of the wires, insert them into the plate and secure them with bolts. Place a carbolite shell on top.
Advantages:

• low cost;
• no difficulties during fastening;
• connection of copper and aluminum conductors;
• high class insulation.

Flaws:

• such fastening requires periodic checking, and if loosened, the screws must be tightened;
• The dimensions of such a clamp will not allow it to fit into the junction box.

Using a bolt

Fastening with bolts is not only the simplest method, but also quite effective. All you need for the job is a bolt, 3 washers and a nut.
The essence of the fastening is very simple, you need to put a washer on the bolt thread, screw on the protected core, again a washer on top, again a core, and the washer finishes again. At the end of everything, the bolt is firmly tightened with a nut and insulated.
Advantages:

• minimal costs and easy execution of work;
• connection of aluminum and copper conductors.

Flaws:

• poor quality of fastening;
• high consumption of electrical tape;
• the bolt with electrical tape may not fit into the junction box.

What to do if there are several wires?

In a normal situation, you only had to connect two wires. But what if there are several such wires?
There are several solutions for this:

• perform fastening using ;
• use the method;
• wires;
• twist the ends of the wires using ;
• twist the ends of the wires and...

We have already told you how to connect the wires in the junction box, and which one you use is up to you. But experts advise giving preference to the first method, as it is the most effective.

What to do if the wires are of different sections?

For high-quality joining of wires with different cross-sections, experts recommend using spring or regular terminal blocks. Your goal is to firmly secure the wires with a screw.
If the cores used are made of different materials, then to prevent oxidation you need to use pads with paste.
An alternative method of fastening would be to solder them.

How to connect stranded and solid wires

There are no special conditions for fastening such wires separately, so you can use any of the above methods. For convenience, we have given the advantages and disadvantages of each of them, so after studying them carefully, you can easily decide on the fastening method.