How to properly twist wires in a distribution board. How to connect electrical wires or cables to each other? Welding

In a field such as electricity, all work must be performed strictly, accurately and without a single mistake. Some want to sort out such works on their own, not trusting third parties to carry out a responsible mission. Today we will talk about how to properly connect the wires in the junction box. The work must be done with high quality, because not only the performance of electrical appliances in the house depends on it, but also the fire safety of the room.

About the junction box

In an apartment or house, wires from an electrical panel are bred to different rooms. Usually there are several points of connection: switch, sockets, and so on. In order for all the wires to be collected in one place, junction boxes were created. They start wiring from sockets, switches and are connected in a hollow case.

In order not to have to look for where the wires are hidden in the walls during the repair, the electrical wiring is laid on the basis of special rules prescribed in the PUE (Electrical Installation Rules).

Junction boxes are classified according to the type of attachment. So, there are boxes for outdoor installation and indoor installation. For the second option, a hole must be prepared in the wall into which the box will be inserted. As a result, the box lid is flush with the wall. Often the cover is hidden during repairs with wallpaper, plastic. As a last resort, an external box is used, which is attached directly to the wall.

There are round or rectangular junction boxes. In any case, there will be at least 4 outputs. Each outlet has a nipple or thread to which a corrugated tube is attached. This is done to quickly change the wire. The old wire is pulled out, new wiring is laid. It is not recommended to lay the cable in a gutter on the wall. If the electrical wiring burns out, you will have to gouge the wall, disrupt the finish in order to carry out repair work.

What are junction boxes for?

There are many factors that speak in favor of the existence of junction boxes:

the power system can be repaired in a matter of hours. All connections are accessible, you can easily find the area where the wires are burned out. If the cable was laid in special channels (a corrugated tube, for example), then a failed cable can be replaced in an hour;
connections can be inspected at any time. Typically, wiring problems occur at the connection points. If the outlet or switch does not work, and there is voltage in the network, first of all, check the quality of the connection in the junction box;
the highest level of fire safety is created. Hazardous locations are considered to be compounds. Using a box, they will be in one place.
minimal time and financial costs when repairing wiring. No need to look for wires that are out of order in the walls.

We connect the wires in the box

There are several ways in which conductor connections can be made in junction boxes. Note that there are simple and complex methods, however, if performed correctly, all options will ensure the reliability of the wiring.

Method number 1. Twisting method

It is believed that the method of twisting is used by amateurs. At the same time, it is one of the most reliable and proven options. PUE do not recommend using twisting, since the contact between the wires is unreliable. As a result, the conductors can overheat, the premises are at risk of fire. However, twist can be used as a temporary measure, for example, when testing an assembled circuit.

Method number 2. Mounting caps - PPE

Very often, special caps are used for twisting conductors. As a result, it is possible to obtain a reliable connection with good contact. The outer shell of the cap is plastic (the material is not flammable), and inside there is a metal part with a thread in the form of a cone. The insert increases the contact surface, improving the electrical parameters of the twist. Most often, thick conductors are connected with caps (no soldering required).

It is necessary to remove the insulation from the wire by 2 centimeters, twist the wires slightly. When the cap is put on, it must be turned with force. At this point, the connection can be considered ready.

Before making the connection, you need to count the number of wires. Based on the data obtained (by section), a certain type of caps is selected. The advantages of twisting with plastic caps is that you do not need to waste a lot of time, as with ordinary twisting. In addition, the connection is compact.

Method number 3. Soldering conductor connection

If the household has a soldering iron, and you know how to work with it, then the wires can be connected using soldering. Before connecting the wires, they need to be tinned. Soldering flux or rosin is applied to the conductor. Next, the heated tip of the soldering iron is immersed in rosin, carried out several times along the wire. A reddish bloom should appear.

After the rosin is dry, the wires are twisted. With the help of a soldering iron, tin is taken, the twist is heated until the tin flows between the turns. The end result is a quality connection with excellent contact. However, electricians are not very fond of using this connection method. The thing is, it takes a long time to get ready. However, if you are doing work for yourself, you should not spare either effort or time.

Method number 4. Welding lived

With an inverter welding machine, you can connect wires. Welding is used over the strand. The parameters of the welding current must be set on the inverter. There are certain standards for different connections:

- conductor with a cross section of 1.5 sq. Mm - 30 A;

- conductor with a cross section of 2.5 sq. Mm - 50A.

If the conductor is copper, then a graphite electrode is used for welding. Grounding from the welding machine is connected to the upper part of the resulting twist. An electrode is brought from below the twist, the arc is ignited. The electrode is applied to the twist for a couple of seconds. After a while, the connection will cool down, then it can be isolated.

Read also: Hidden electrical wiring in a wooden house

Method number 5. Terminal blocks

Another option for connecting conductors in a box is using terminal blocks. There are several types of pads: screw, with clamps, but the principle of the device is identical. The most common is a block with a copper plate for attaching wires. By inserting several cores into a special connector, they can be securely connected. Mounting with a screw terminal connection is very simple.

In the screw terminals, the blocks are placed in a plastic case. There are open and closed pads. Closed shoes are a new generation invention. To make the connection, wires are inserted into the socket and clamped with a screw (using a screwdriver).

However, terminal connections have a drawback. It lies in the fact that it is inconvenient to connect several conductors together. Contacts are arranged in pairs. And if you need to connect more than three wires, then several branches are squeezed into one socket, which is very difficult. At the same time, such connections make it possible to operate branches with high current consumption.

Another type of block is Wago terminals. Today, two types of terminals are in demand:

- terminals with flat spring mechanism. Sometimes they are called disposable, since the terminals cannot be reused - the quality of the connection deteriorates. There is a spring tab inside the terminal. As soon as the conductor is inserted (it should only be single-core), the tab is squeezed out and the wire is clamped. The conductor crashes into metal. If you pull out the conductor by force, then the petal will not return to its previous shape.

Some of the terminal connections contain wiring paste inside. This connection is used if you need to connect copper and aluminum wires. The paste protects metals from oxidation, protecting the conductors;

- universal terminals with lever mechanism - this is the best kind of connector. The wire stripped of insulation is inserted into the terminal, a small lever is clamped. At this point, the connection is considered complete. And if you need to re-connect, add contacts, lift the lever, pull out the wire. The pads can be operated at low current (up to 24 A - with a cross-section of 1.5 sq. Mm) and at high current (32 A - with a conductor cross-section of 2.5 sq. Mm). If wires are connected through which a current above the specified one will flow, then you need to use a different type of connection.

Method number 6. Crimping

It is possible to connect the wires in the box by the crimping method only using special pliers, as well as a metal sleeve. A sleeve is put on the twist, after which it is clamped with pliers. This method is suitable when connecting conductors with a large load.

Method number 7. Bolted connection

Bolting multiple wires together is a simple and effective connection method. To complete the work, you need to take a bolt and several washers with a nut.

It is not enough to know how to connect the wires in the junction box. You need to know which conductors are connected to each other. So, a washer is put on the bolt thread. The core is wound, the second washer is put on, and then the next core is put on. At the end, we put on the third washer and press the connection with a nut. The unit is closed with insulation.

There are several advantages of bolting conductors:

- ease of work;

- low cost;

- the ability to connect conductors made of different metals (for example, aluminum and copper).

However, there are also disadvantages:

- wire fixation - not high quality;

- to hide the bolt, you need to use a lot of insulation;

In the article I will tell you about a real case of connecting wires in an apartment. I already have a lot of such articles, along the way I will provide some links. As usual, there will be a lot of photos, tips and instructions)

So, the story began with the fact that a client called me, who was flooded by the neighbors from above. The house is an old two-story barrack, pre-war construction, the wiring is horrible. Namely - aluminum and copper in different combinations. The house and apartment were repeatedly completed and rebuilt, and the wiring was redone accordingly.

Therefore, when water got on the electrical wiring, this led to the fact that the apartment was completely de-energized. The situation was aggravated by the fact that the apartment had just been renovated with good finishes, the walls were covered with expensive wallpaper and decorative stone. And, as always, before making repairs, the owners did not think that the wiring leaves much to be desired. That is, it is in an unsatisfactory condition.

For a Russian person, as usual, until the thunder breaks out ... And while it works - and okay!

So, I came that evening, and restored the apartment from an electrical point of view, connecting the wires in the junction box with what I had in my arsenal - Wago of different models, PPE connectors.

But he immediately said that I did not give any guarantee - perhaps in a day everything would burn out again! And it will be necessary to do all the wire connections in a normal way.

And now, after half a year - a call! It's time! Burned in the literal sense of the word, photo at the beginning of the article, and here:

The consequences of connecting the wires in the box through the Wago terminals. Above - a hole in the stretch ceiling.

The fact is that the machines for the whole apartment were at 25A. More precisely, there was actually 1 machine gun, since one was for a phase, the second for zero. Here is a shield for the whole apartment:

Subscribe! It will be interesting.

Let me remind you that you cannot do this, this bad tradition has gone from the times when round such fuse plugs were placed after the meter. Why is it dangerous - if you knocked out zero (and here the chances are 50/50), and it seems like there is no “light” in the house, but all the electrical wiring is at the potential of phase voltage. Even the zero part, which was not dangerous before. Therefore, in this case there should be a two-pole machine, but not two single-pole ones.

It is clear that the connection of wires in a box with such protection burned out. Moreover, the wires that were connected through the terminals are old, oxidized, of different sections.

Not only the box of input wires (above the meter) was burned, but also the distribution box in the corridor, through which power was supplied to the kitchen and bathroom. Here's what happened to her:

As you can see, a whole collection of different terminal blocks was used to connect the wires.

This photo can be characterized by the words from the song - "I blinded him, from what was ..."

At the same time, Vago's terminal blocks took on bizarre forms of techno art:

Replacing connections

So, we have two junction boxes, the wire connections in which are completely useless. What should be done in such cases? Here are the main points:

Cut old terminal blocks with pliers,
Strip the wires to a good metal, not darkened by temperature. If necessary, cut the wire even shorter,
If necessary, extend the wires so that they can be connected,
During all these manipulations, to understand the train of thought of an electrician, which operated here 20-40-60 years ago. In other words, understand the wiring diagram,
Install a new junction box,
Connect the wires to each other using terminal blocks.

Here's how I did the electrical repair in this case.

And what's new in the VK group SamElektrik.ru ?

Subscribe and read the article further:

After the counter, initially there were two automatic machines for 25 Amperes, from their output terminals I powered such an electrical panel:

I don’t remember the exact connection diagram now, but it’s not important now.

Installed boxes like this:

Why two boxes instead of one? You will need to accommodate everything - all the wires and terminals. In addition, cutting off burnt wire ends will make them shorter.

From this place, wires diverge to the entire apartment (both copper and aluminum), and two VVG 3x2.5 cables come:

In this case, I am using the TB2504 terminal block to connect the socket circuits.

I will talk about such terminals below in this article.

To connect lighting circuits - Vago terminals. Here's a closer look:

For such connections, I am quite calm, and I can give a long-term guarantee for such repair of electrical wiring.

Connecting wires with terminal blocks

Why do I like to make connections with terminal blocks? The fact is that in such connections, I can be quite sure, unlike the Vago terminals (see the photo that happens in this article)

These terminals have very low contact resistance and very high reliability if used correctly. Much the same is the case with crimp connection sleeves. But for sleeves you need a special tool - press tongs, and for a terminal block a screwdriver is often enough.

For better installation, you need to try to maximize the contact area of \u200b\u200bthe wire with the terminal area, and the wire itself is as clean as possible. Ideally, flexible stranded wire should be terminated with ferrules.

I already wrote about lugs for stranded wires in an article about the practical use of Vago terminals, the link was above. In addition, we are talking about stranded wires in the article.

There are many names for such terminals, and sometimes confusion arises.

Possible names are: screw terminal strip, terminal block, terminal block, terminal block, and, finally, black carbolite terminal block.

In the English version, this name sounds like Screw Barrier Terminal Block. Abbreviated - Terminal Block, the first letters of these words (TB) are included in the trade name. Then there are two digits indicating the rated current, two more digits - the number of terminals in the block.

For example:

TB1512 (15Amp 12 terminals),
TB3504 (35A, 4 terminals),
TB45, TB60 - 45 and 60 Amp terminal blocks.

Here's an example of how I used these terminal blocks to power an entire office:

More details on such important connections are in the article.

It is these terminals that I use where there are high currents and a high cost of error. For example, in hard-to-reach places, at the entrance to dwellings, etc.

I see only one minus of such terminals - dimensions. These terminal blocks do not fit into standard junction boxes and must be positioned differently. For example, as shown in this article.

There is one more connection option - through the terminals of the circuit breakers, where the reliability is no less, and this method is used everywhere.

Clamp type "Nut"

And for high currents and cross-sections (more than 63A and more than 10 mm2 for copper) - a completely different story and philosophy.

It often happens here that you need to connect a wire of different cross-section and material (copper + aluminum). And the best thing that was invented for this is Nuts. Here's how in this photo:

Nuts for connecting wires

Here's another example of connecting wires with nuts:

Walnut connection in the dashboard

Most often, they are put on input to private houses and in apartment buildings in shields.

Wire Connection Video

Summary of the article - connect the wires so that you can be 100% sure! I wish you all a good contact!

To ensure that the power supply in your homes is always of high quality, uninterrupted and reliable, it is very important to correctly connect the wires during installation work. There are a lot of methods, we will consider each separately in detail with its advantages and disadvantages, with step-by-step instructions for performing switching. We will also pay attention to the eternal question of electricians - how to connect wires, the cores of which are made of different metals (for example, copper and aluminum).

Removing the insulating layer from the wires

I would like to immediately dwell on a question that will be common to any method. Before connecting the wires to a common electrical unit, they must be stripped from the upper insulating layer.

This can be done with an assembly knife. This method is simple, but there is a high probability of damage to the conductive core. To do everything right, you must clearly follow the step-by-step instructions:

Place the wire on a flat surface (such as a table).
Press it down with your left index finger.
Take a knife with your right hand and lightly press it into the insulating sheath of the wire. To avoid snagging the metal core, position it at an angle towards the cut. If the angle is right, there is a possibility of a circular cut in the core, as a result of which it can subsequently break.
Holding the knife in this position. With the index finger of your left hand, slowly rotate the conductor one full turn, thus cutting the insulation around the entire circle.
It remains only to pull off the cut piece of insulation.

Professional electricians now necessarily have such a device as a stripper in their arsenal. It is a multifunctional tool that can be used to strip a wire or strip a cable. It can be simple, semi-automatic, and automatic. The most important thing is that when the insulation is removed with a stripper, the conductor is not damaged. For each standard core diameter, such a tool has a calibrated hole with a cutting edge.

The length for which it is necessary to strip the conductors of the wires is different for each connection method.

Twisting

Let's start with the simplest and most well-known method - twisting. It can also be called the most ancient, it is not for nothing that electricians call twisting among themselves the “old-fashioned method”.

We will not tell you that such a wire connection is durable and reliable. According to the main document in electrical engineering, PUE ("Electrical Installation Rules"), twisting is generally prohibited, despite the fact that half a century ago it was used everywhere. The fact is that in those days, the load in the apartments consisted only of lighting, radio or TV. Considering the current load in modern apartments with a huge amount of household appliances used daily, then no old insulation, wire cross-sections and wire connection methods are suitable anymore.

Nevertheless, we will talk about twisting, and even in the first place, because it is the main stage of such connection options as welding and soldering.

Positive sides

The most important advantage of twisting is that it requires absolutely no material costs. All you need is a knife to remove the insulating layer from the wires and pliers to make the connection.

The second indisputable advantage of twisting is the simplicity of execution. You do not need any special knowledge or skills, it can be done by anyone who has ever held pliers in his hands.

In a twist, several wires can be connected at the same time, but their total number should not exceed six.

Negative sides

The main disadvantage of twisting is its unreliability; over time, it weakens. This is due to the fact that residual elastic deformation is present in the cores of the cable or wire. In the place of twisting, the transition resistance increases, which is fraught with a breakdown in contact and heating. In the best case, you will find it in time and re-seal the connection, in the worst case, a fire can occur.

By means of twisting, it is impossible to connect electrical wires made of different metals. As an exception, you can twist copper and aluminum wire, but only if the copper core is previously tinned with solder.

In electrical engineering, there are concepts of a detachable or non-detachable connection. So twisting does not apply to either one or the other. A detachable connection is characterized by the fact that its ends can be disconnected many times. In twisting, this cannot be fully done, every time after the next promotion and twisting of the veins, they will deteriorate. It is also impossible to call twisting an integral connection, because it lacks the necessary concepts of strength, reliability and stability for this. This is another drawback of the twist connection.

Mounting

If for some reason you do not have the opportunity to use other methods of connecting electrical wires, you can use twisting, just do it well. Very often it is used as a temporary option and is subsequently replaced by more reliable switching methods.

How to connect wires using twists? To begin with, the veins are stripped by 70-80 mm. The main thing is to twist all the switched conductors into one single twist at the same time, and not wind one around the other.

Many people mistakenly begin to twist the wires together from the place where the insulating layer ends. But it is better in this place to clamp both veins with some pliers, and with the second to grab the ends of the wires and make rotational movements in a clockwise direction.

If the wire is small, you can twist it by hand. Align the conductors with the insulation cutoff and hold them firmly in place with your left hand. Bend all the switched ends into one single bend at an angle of 90 degrees (a bend length of 10-15 mm will be sufficient). Hold this fold with your right hand and rotate it clockwise. This must be done firmly and firmly. If it is already difficult to twist with your hands at the end, use the pliers as described above. Once the curl is smooth and beautiful, you can trim the fold.

You can also connect several wires in this way, but then, to make it easier to twist them, make the bend longer, somewhere on the order of 20-30 mm.

How to properly twist the wires is shown in this video:

There is also a way to twist wires using a screwdriver, see about it here:

For twisting wires with a special tool, see here:

Now the resulting twist must be carefully insulated. For this, electrical tape is used. Do not feel sorry for it, wind it in several layers, and not only isolate the connection itself, but also step 2-3 cm over the insulation of the veins. Thus, you will provide insulating reliability to the twist and protect the contact connection from moisture.

It is also possible to insulate the connection of wires using thermotubes. The main thing is not to forget to put the tube on one of the wires to be connected in advance, and then put it in place of the twist. Heat shrinks the heat pipe, so slightly heat its edges, and it will firmly grip the wire, thereby providing reliable insulation.

If the twisting is done with high quality, there is a possibility that it will serve you for many years, provided that the load current in the network is normal. But still, it is better not to stop at this stage and strengthen the joint by welding or soldering.

Soldering

Soldering is when electrical wires are connected using molten solder. This type of connection is most suitable for copper wires. Although there are now various fluxes for aluminum, experienced electricians prefer to refrain from such soldering. But if necessary, you can use special fluxes and even solder copper to aluminum.