How to twist the wires in the distribution box. How to connect electrical wires or cables together? Welding

In a field such as electricity, all work must be carried out strictly, accurately and without a single mistake. Some wish to understand such work 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 junction box

In an apartment or house, wires are routed from an electrical panel along different rooms. Usually there are several connection points: a 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 housing.

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).

Distribution boxes are classified according to the type of attachment. So, there are boxes for outdoor installation and indoor installation. For the second option, it is necessary to prepare a hole in the wall into which the box will be inserted. As a result, the lid of the box is flush with the wall. Often the cover during repair is hidden with wallpaper, plastic. In extreme cases, an outer box is used, which is mounted directly on the wall.

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

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 available, you can easily find the area where the wires are burned out. If the cable was laid in special channels (corrugated tube, for example), then in an hour you can replace the failed cable;
connections can be inspected at any time. As a rule, wiring problems occur at the junctions. If the socket or switch does not work, but there is voltage in the network, check, first of all, the quality of the connection in the junction box;
creates the highest level fire safety. It is believed that dangerous places are connections. With the use of the box, they will be in one place.
minimum time and financial costs when repairing wiring. No need to look for wires in the walls that are out of order.

Connecting 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 electrical wiring.

Method number 1. Twisting method

It is believed that the twisting method is used by amateurs. At the same time, it is one of the most reliable and proven options. PUE do not recommend the use of twisting, since the contact between the wires is unreliable. As a result, the conductors can overheat, the room is threatened by a fire. However, twisting 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 combustible), 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 using caps (no soldering is required).

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

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

Method number 3. Connection of conductors by soldering

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 cores, 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 coating should appear.

After the rosin dries, 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 problem is that it takes a lot of time to prepare. However, if you are doing the work for yourself, you should not spare either effort or time.

Method number 4. Core welding

Using an inverter welding machine, you can connect wires. Welding is used over the twist. On the inverter, you need to set the welding current parameters. 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 the bottom of 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 wires into a special connector, they can be securely connected. Mounting with a clamp terminal connection is very simple.

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

However, terminal connections have a disadvantage. 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 a high current consumption.

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

- terminals with a flat-spring mechanism. Sometimes they are called disposable, since it is impossible to reuse the terminals - the quality of the connection deteriorates. Inside the terminal there is a plate with spring petals. As soon as the conductor is inserted (it must be single-core only), the tab is pressed out and the wire is clamped. The conductor cuts into the metal. If the conductor is pulled out by force, then the petal will not take its previous shape.

Some terminal connections contain wiring paste internally. Such a connection is used if you need to connect a copper and aluminum wire. The paste protects metals from oxidation by protecting conductors;

- universal terminals with a lever mechanism - this is the most best view 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 higher than the specified one will flow, then another type of connection must be used.

Method number 6. Crimping

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

Method number 7. Bolted connection

Connecting multiple wires with bolts is simple and effective method connections. To complete the work, you need to take a bolt and a few 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. At the end, we put on the third washer and press the connection with a nut. The node 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:

- fixation of wires - not of high quality;

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

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

So, the story began with the fact that I was called by a client who was flooded by the neighbors from above. The house is an old two-story barrack, pre-war construction, the wiring is terrible. 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 state.

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

So, I came in that evening, and restored the apartment electrically, connecting the wires in the junction box with what I had in my arsenal - Wago different models, PPE connectors.

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

And now, half a year later - a call! It's time! It burned in the truest sense of the word, the 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 stood at 25A. More precisely, there was actually 1 machine, since one was in phase, the second was in zero. Here is a shield that stood for the whole apartment:

Subscribe! It will be interesting.

Let me remind you that you can’t do this, this bad tradition has gone from the time when such round fuse plugs were placed after the counter. 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 wiring is under the phase voltage potential. Even the zero part, which before that was not dangerous. Therefore, in this case there should be a two-pole machine, but not two single-pole ones.

It is clear that the connection of the wires in the 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) burned out, 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 out the old terminal blocks with wire cutters,
Strip the wires to a good metal that has not darkened from the temperature. If necessary, cut the wire even shorter,
If necessary, grow the wires so that they can be connected,
During all these manipulations, understand the train of thought of an electrician who acted 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 wiring repair in this case.

And what's fresh in the VK group SamElectric.ru ?

Subscribe and read the article further:

After the counter, initially there were two 25Amp machines, from their output terminals I powered the following electrical panel:

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

Installed these boxes:

Why two boxes instead of one? It will be necessary to fit everything - all the wires and terminals. In addition, when cutting the burnt ends of the wires, they become shorter.

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

In this case, I use a TB2504 terminal block to connect the socket circuits.

I will talk about such terminals later in this article.

To connect lighting circuits - Vago terminals. Here, closer:

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, what happens in this article)

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

For a better installation, you need to try to ensure that the contact area of \u200b\u200bthe wire with the terminal pad is maximum, and the wire itself is as clean as possible. Ideally, a flexible stranded wire should be terminated with lugs.

I already wrote about lugs for stranded wires in an article about practical use terminals Vago, 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: a line of screw terminals, a terminal block, a terminal block, a terminal block, and, in the end, a black carbolite terminal block.

In English, this name sounds like Screw Barrier Terminal Block. Abbreviated as Terminal Block, the first letters of these words (TB) are included in the trade name. Next come 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 - terminal blocks for 45 and 60 Amperes.

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

Read more about such important compounds 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. Such terminal blocks do not fit in standard junction boxes, and they have to be placed differently. For example, as shown in this article.

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

Squeeze 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 sections and materials (copper + aluminum). And the best thing that was invented for this is Nuts. Like in this photo:

Nuts for connecting wires

Here is another example of connecting wires with nuts:

Nut connection in the floor board

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

Wire connection video

Summary of the article - connect the wires so as to be 100% sure! I wish you all good contact!

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

Removing the insulating layer from the wires

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

This can be done with a utility 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 some flat surface (like a table).
Press it with the index finger of your left hand.
Take the knife with your right hand and lightly press it into the insulating sheath of the wire. In order not to hook the metal core, position it towards the cut at an angle. If the angle is right, there is a possibility of a circular notch in the core, as a result of which it may subsequently break.
Holding the knife in this position. With the index finger of your left hand, slowly rotate the conductor one full turn, thus notching the insulation around the entire circle.
It remains only to pull off the cut piece of insulation.

Professional electricians now already have in their arsenal such a device as a stripper. This is a multifunctional tool, with it you can strip the insulation from the wire or cut the cable. It can be simple, semi-automatic and automatic. Most importantly, when stripping the insulation with a stripper, the conductive core is not damaged. For each standard core diameter, such a tool has a calibrated hole with a cutting edge.

The length to which it is necessary to strip the wire cores 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 oldest, not for nothing that electricians among themselves call twisting the “grandfather method”.

We will not tell you that such a wire connection is durable and reliable. According to the main document in electrical engineering, PUE (“Rules for Electrical Installations”), 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, core cross-sections and wire connection methods are no longer suitable.

Nevertheless, we will talk about twisting, and even in the first place, because it is the main stage in 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 wire strands and pliers to make the connection.

The second indisputable advantage of twisting is ease of execution. No special knowledge or skills are needed, anyone who has ever held pliers in their hands can do it.

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, it weakens over time. This is due to the fact that there is a residual elastic deformation 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 junction, in the worst case, a fire may occur.

Using 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 pre-tinned with solder.

In electrical engineering, there are concepts of a detachable or one-piece connection. So twisting does not apply to either one or the other. Detachable connection characterized by the fact that its ends can be separated many times. In twisting, this cannot be fully done, each time after the next promotion and twisting of the cores, they will deteriorate. It is also impossible to call twisting an integral connection, because it does not have the concepts of strength, reliability and stability necessary for this. This is another disadvantage of the twisted connection.

Installation

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 with high quality. Very often it is used as a temporary option and is subsequently replaced by more reliable switching methods.

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

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

If the wire section is small, you can twist it by hand. Align the conductors with the insulation shear and hold them firmly in this place with your left hand. Bend all switched tips into one single bend at an angle of 90 degrees (a bend length of 10-15 mm will be enough). 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. As soon as the twist becomes even and beautiful, you can cut the bend.

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

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

There is also a way to twist wires with 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 spare it, wind it in several layers, and isolate not only the connection itself, but also step 2-3 cm over the insulation of the cores. Thus, you will ensure the insulating reliability of the twist and protect the contact connection from moisture.

You can also insulate the connection of wires with the help of 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 on the place of the twist. Under heat, the thermal pipe shrinks, so slightly heat its edges, and it will firmly wrap around the wire, thereby providing reliable insulation.

If the twisting is done with high quality, it is likely 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 junction 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 with aluminum.