How to connect wires of different sections to each other?

Connecting wires

To ensure full electrical conductivity, the integrity of the wiring is an important point. Damage or poor-quality adhesion is unacceptable.

It is important to ensure tight contact contacts and reliable connections in the “electrical node” areas. There are certain methods for eliminating cable breaks.

Among them, welding should be noted. It applies to copper and aluminum wires. This ensures a particularly reliable grip.

Connections can be divided into types:

• twist;
• welding;
• soldering;
• pressure testing;
• terminal blocks;
• self-clamping terminal blocks (WAGO terminals);
• PPE caps;
• bolt clamp.

The most complete connection for wires made of copper is soldering. It can be easily accomplished using flux (rosin, borax) and tin solder. Terminal blocks are also used - a special device that is made using screw terminals. They are selected separately in accordance with the cross-section of the cores.

Self-clamping terminal blocks are often used to save time on electrical installation work. In order to isolate a twisted or soldered electrical connection, PPE insulating caps are used. Today in the energy sector, WAGO terminals are widely used, which are produced for wires and cables of various diameters. In addition, WAGO terminals allow you to connect conductors made of different materials (copper and aluminum).

The choice of which connection to use depends on various factors:

• material (steel, copper, aluminum);
• number of twisted elements;
• section;
• place of work (house, street, in the ground, etc.).

Is it possible to twist wires of different sections? — Metals, equipment, instructions

Today, there are many ways to connect wires in a junction box.

Here are the factors that determine the choice of connector:

1. Core material (copper, steel, aluminum).
2. Working conditions (outdoors, in an apartment, in water, in the ground, in the floor, normal conditions).
3. Number of conductors (two, three, four, etc.).
4. Core cross-section (same, different).

Based on these factors, the most suitable and correct method is selected. First, let's look at the materials that can be used to connect electrical wires in a junction box.

Existing methods

The following connection options are considered the most popular and effective:

• use of terminal blocks;
• installation of spring terminals (wago);
• fixation with PPE (plastic caps);
• crimping with sleeves;
• soldering;
• twist;
• installation of “nuts”;
• use of bolts.

Let's consider the essence, advantages and disadvantages of each method!

Using Terminal Blocks

Terminal blocks are plastic products containing a brass bushing with screws on both sides.

In order to connect two wires to each other using a terminal block, you need to insert one end of the product on each side and tighten them thoroughly with screws (with force). This connection method is most often used in junction boxes, as well as when installing chandeliers, switches and sockets.

Please note that terminal blocks come with different inlet holes, suitable for a specific cross-section of the wire.

Advantages:

• low price of terminal blocks;
• fast and convenient installation of products;
• good quality of fastening;
• You can combine aluminum with copper.

Flaws:

• Very often the terminal blocks are of poor quality, which can lead to breakage of the connector during installation.
• Possibility of combining only two conductors with each other.
• It is not recommended to tighten aluminum and stranded products with terminal blocks. This is due to the high fragility of aluminum and the thinness of the stranded wire: when tightening the screws, the contacts may be damaged.
• When using soldering, reliability will be significantly higher.

Spring terminals

Wago spring terminals appeared on the market relatively recently and have undoubtedly become the most effective and safe connectors.

The difference between Vago terminal blocks and conventional terminal blocks is that a special mechanism is used to connect electrical wires, rather than a screw. This lever-type mechanism allows you to carefully fix the product without damaging it. In order to carry out the vagami fastening yourself, you need to strip the insulation and insert the cores into the hole.

Please note that there are disposable and reusable Vago terminal blocks. The first option involves a one-time connection, and it will no longer be possible to restore it when repairing the electrical wiring: it will be necessary to cut off the cable, repair the problem and install a new terminal block. Wago reusable terminals are more expensive, but with their help you can easily disconnect the contact if necessary.

Wago advantage:

• possibility of combining aluminum and copper conductors;
• the ability to connect several cores at the same time (more than two);
• wago clamps allow you to fix a thin stranded wire without damage;
• terminal blocks are very compact;
• the work does not take much time;
• good quality of fastening;
• The Vago terminal block has a special hole that allows you to control the operation of the electrical network using an indicator screwdriver.

The only drawback is the higher cost of the terminals.

Installation of PPE caps

PPE stands for connecting insulating clips. The products are ordinary plastic caps that have a special spring inside that holds the wires.

How to connect electrical wires with lugs

Another way is to use tips. The tip looks like a piece of tube, cut and turned flat on one side. A hole for a bolt is drilled in the flat part. The lugs allow you to connect cables of any diameter in any combination. If it is necessary to connect a copper cable to an aluminum cable, special lugs are used, in which one part is copper and the other is aluminum. It is also possible to place a washer, brass or tinned copper, between the tips.

The ferrule is pressed onto the cable using a crimper, similar to how wires are connected using crimping.

Is it possible to twist copper and aluminum?

To the question of whether it is possible to twist a copper wire with an aluminum one, the answer is clearly negative, for two reasons:

1. corrosion. Different metals in the contact zone are always destroyed due to corrosion, electrolytic or atmospheric. The rate of destruction for each combination is different and in some cases it is relatively low. But there are pairs of metals, upon contact of which corrosion occurs especially intensely. The combination “aluminum - copper” belongs to this group. As a result of chemical changes, the conductivity of metals drops sharply and the connection heats up;
2. difference in coefficient of thermal expansion. Because of it, heating-cooling cycles will lead to weakening of the twist and, as a result, deterioration of the contact.

There must be an intermediary between aluminum and copper - brass or galvanized steel; to connect such conductors the following is used:

1. terminal blocks: wires are inserted into different terminals;
2. sleeves for crimping of the GAM brand (half is made of aluminum, the other is copper);
3. soldering using special solder and flux;
4. bolt clamp with a galvanized washer between the aluminum and copper conductors.

Sequence of actions when using bolt clamps:

• put a washer on a small diameter bolt or screw;
• twist the end of one strand into a ring and put it on next;
• put on a galvanized washer;
• twist the second core into a ring and also put it on;
• use another washer and tighten the connection with a nut.

Contact of aluminum with tinned copper is also allowed.

In air, aluminum quickly becomes covered with an oxide film with high resistivity, to avoid which the ends of the cores of this metal are lubricated with quartz-vaseline paste before making the connection. This paste is added to terminals and connecting insulating clips (PIC) for aluminum wires at the production stage.

Options for twisting stranded wires

In practice, 3 methods of twisting flexible stranded wires are used. The choice of method is made according to the situation and based on the preferences of the master. The methods are:

• serial connection;
• parallel connection;
• thin wire bandage;

Serial twisting

The stripped wires are applied to each other so that they form a crosshair. Then the conductors are twisted together. The connection made is symmetrical relative to the crosshairs. The ends of the wires stick out in opposite directions. After twisting, it is advisable to slightly tighten it so that it tightens.

The method is good due to the compactness of the resulting connection. Its thickness does not exceed 3 diameters of the insulated wire. Care must be taken. If the twist is protected from moisture by a heat-shrinkable tube, then the insulation is put on the core before making the connection.

Parallel

The insulation is removed from the ends of the wires. The cores should be connected so that the stripped sections are parallel. The ends of the wires point in the same direction. The current conductors are then wound onto each other in a spiral shape

It is important to make the connection as tight as possible, but not to break the conductors with excessive force

This twist can be found in the junction box. To protect the contact, electrical tape or heat shrink is used. For temporary and non-essential connections, it is allowed to use a PVC pipe (cambric) for insulation.

Bandage twist

The banded connection of cores is suitable for connecting thick wires that are difficult to bend with your hands or pliers. Current-carrying conductors are laid next to each other. They must first be properly cleaned on all sides using a needle file or file. Then the bare wires are tightly wrapped in a circle with the maximum number of thinner wires. A similar connection is used on power transmission towers.

Important! Do not connect the cable cores in a knot. The contact will be maximally tensile strength, but extremely unreliable in terms of electrical conductivity

We twist it ourselves

During professional installation, special clamps are used to make the connection - PPE (connecting insulating clamp); when using them, the final twisting is allowed from the point of view of the PUE, but it is worth remembering that such a device is not designed for high currents.

So, how to properly twist wires at home? To carry out this manipulation you need:

• take into account all the nuances in advance (location, load of connected equipment, etc.);
• acquire the necessary tools (pliers, knife, sandpaper, heat shrink, it is advisable to have a hot air gun and a device for removing insulation, a screwdriver if available).

Let's consider the situation with weaving from a cord with a monolithic core:

It is necessary to strip the ends of each wire by 3–4 cm using a special tool (stripper) or a construction knife

It is extremely important to remove the insulation and not leave deep cuts on the core. Then we put heat shrink on one of the ends. Then degrease the cleaned surfaces with alcohol/acetone/white spirit. Then, taking sandpaper, we clean the wire strands. We lay the wires parallel to each other and hold them with pliers. We weave (in accordance with the diagram) clockwise, at least 5 turns for one core. The wires must fit tightly to each other. We move the heat shrink to the contact point and warm it up with a hairdryer or lighter

It is important that the heat shrink fits tightly at the twisting site.

With a stranded cord the situation is a little different:

We strip the ends of each wire by 3–4 cm using a special tool (stripper) or a construction knife

It is extremely important to carefully remove the insulation and not damage/cut off the cord cores. We put heat shrink on one end of the cord. We unravel the strands of each cord into small “braids”. We degrease the resulting “braids” with alcohol/acetone and so on. We lay the cores on top of each other from each cord. We weave together, making the connection tight (at least 5-6 turns per braid). We move the heat shrink to the place of twisting, warm it up with a hairdryer/lighter. The heat shrink should fit tightly at the joint.

If it is necessary to create a “braid” from monocore and multicore cords, the algorithm also changes, and it is highly advisable to weave using the “Branching” method:

1. We strip the ends of each wire by 3–4 cm using a special tool (stripper) or a construction knife. We take care not to damage the cores of each cord.
2. We put heat shrink on one of the cords.
3. We degrease the cleaned areas with alcohol/acetone and so on.
4. We bend the single-core end 180 degrees, so that it then presses the twist.
5. We twist the multi-core cord around the single-core end in accordance with the diagram (clockwise), at least 5-6 turns, the more the better.
6. We clamp the pre-bent end of the single-core wire and press it against the twist made with pliers.
7. We move the heat shrink to the contact area and heat it with a hairdryer/lighter. We make sure that the heat shrink is well fixed at the twisting site.

At this point, we can consider the work done competently and efficiently. If you follow the instructions and take all necessary measures, you are guaranteed to get a high-quality connection for a long time.

Sleeves

The third simple way to connect conductors is crimping with sleeves.
GML sleeves are most often used for joining copper wires. Deciphered as:

Sleeve

Copper

Tinned

For connecting pure aluminum - GA (aluminum sleeve):

To switch from copper to aluminum, special adapters GAM:

What is the crimping method? Everything is quite simple. Take two conductors and strip them to the required distance.

After this, on each side of the sleeve, the conductors are inserted inside, and the whole thing is crimped with press pliers.

Despite its obvious simplicity, there are several rules and nuances in this procedure, if not followed, you can easily ruin a seemingly reliable contact. Read about these mistakes and rules on how to avoid them in the articles “5 Rules of Crimping” and “Crimping Insulated Tips, Sleeves and Terminals”.

To work with conductors of large sections 35mm2-240mm2, a hydraulic press is used.

Up to cross-sections of 35mm2, you can also use a mechanical one with a large span of handles.

The sleeve must be crimped two to four times, depending on the cross-section of the wire and the length of the tube.

The most important thing in this work is to choose the correct sleeve size. For example, when connecting a monocore, the sleeve is usually taken to a smaller cross-sectional size.

For example, when connecting a monocore, the sleeve is usually taken to a smaller cross-sectional size.

And in this way you can connect several conductors at one point at the same time. In this case, only one sleeve will be used.

The main thing is to completely fill its internal space. If you are crimping three conductors at the same time, and you still have voids inside, then you need to “fill” this free space with additional pieces of the same wire, or with conductors of a smaller cross-section.

Only after this can you press.

After crimping, such a connection must be insulated. The most convenient way to do this is with a heat-shrinkable tube HERE.

There are tubes with an adhesive base. When heated, this glue flows out and ensures the tightness of the connection.

Insulation using a thermal tube is also a fairly simple process. In the absence of a gas burner or hair dryer, even a lighter is sufficient for small sections.

Sleeve crimping is one of the most versatile and reliable connections, especially when it is necessary to extend the cable, including the input cable.

In this case, the insulation turns out to be almost equivalent to the main one, when also using the outer tube HERE as a casing.

Conclusions and useful video on the topic

To properly compress the sleeve when connecting electrical wires, you will need training and a special tool - press pliers. Detailed crimping process in the video: Even the most expensive terminal block can turn out to be a cheap fake. The video clip demonstrates the main differences between the original Wago: The video shows the method of bolting copper and aluminum wires: Connecting wires using welding can be seen in the video clip:

When choosing a method for connecting electrical wires, you should focus on the feasibility of its use in a particular situation. If you need to completely replace the wiring in your house/apartment, but have no personal experience in electrical work, as well as special tools, the best option is to invite a professional electrician. This solution will allow you not to worry about the safety of your home.

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How many wires should be in a twist?

Most often, it is recommended to collect no more than 6 cores with a cross section of 2.5 mm2. in one twist, or better, especially if you have little experience, no more than 4 times. Cables with this cross-section are used in apartments for socket groups.

You can take more conductors with a cross section of 1.5 mm2 used for lighting. And the cables going to the electric stove have a conductor cross-section of 6 mm sq. As you understand, even six pieces are very difficult to neatly twist together without experience.

In order not to memorize the maximum number of wires recommended for twisting:

There is a simple rule:

The total cross-section of all wires in a twist should not exceed 16 mm2, and the total number of wires is 6 pieces

Standard distribution boxes most often have up to 6 cable entry points, so twisting with a large number of conductors usually does not work.

Another simple explanation for the limitation of the maximum number of cores is the following: a larger number simply will not allow the tool to properly grasp them when working.

Therefore, I recommend not twisting more than 6 wires at the same time. But, with some skill and strong hands, or using various devices, in rare cases you can twist up to 8 pieces.

Below is a table that shows the recommended maximum number of wires in one twist for different cable sections:

When making electrical installations, try to avoid cases where it is necessary to twist more wires than are recommended here.

It is always better to make an additional junction box than to get a poor-quality connection, which will then cause you a lot of problems.

And once again I would like to remind you that officially, simple twisting in electrical applications is prohibited and is used only in combination with other connection methods - compression, welding, etc.

I am sure that there are a lot of people who will say that they can easily twist a larger number of wires with high quality, and the resulting connection is as reliable as possible. I won’t argue with this; moreover, in my practice I’ve had to do something like this (I always weld conductors after twisting).

A striking example of this could be an article about extending the input cable to an apartment, where 3 wires of 6 mm square were twisted. When using certain technologies, this is possible, but I do not recommend doing this all the time; use this opportunity only as an exception.

What do you think? Tell us about your experience in installing twists and the maximum number of wires that can be done efficiently. I am especially interested in the opinion of novice electricians who have decided to do wiring in an apartment or country house.

Is it possible to connect cables by twisting?

According to the rules of the PUE, twisting is prohibited, as it does not provide reliable contact. It can only be used in conjunction with another connection method. It is also unacceptable to use twisting to join two different metals.

Stranded and single-core

When connecting multi-core wires, the following rules should be followed:

• strip the insulation by 4 cm;
• unwind the conductors by 2 cm;
• connect to the junction of untwisted conductors;
• twist the wires only with your fingers;
• You can tighten the twist using pliers;
• bare wires are insulated with special tape or heat shrink tubing.

Twisting solid wires is much easier. They need to be stripped of insulation, twisted by hand along the entire length, then clamped with pliers and insulated.

Twisting methods

You can do twisting in different ways. It can be made by branch, parallel or series connection. Also, to improve the reliability of contact, caps and clamps are additionally used.

Correct twisting of electrical wiring in a junction box

When twisting, you need to follow the following procedure:

• cut off power to a house or apartment;
• clear the wiring of 4 cm or more of insulation;
• unwind the wires by 2 cm;
• connect untwisted wires to the junction;
• twist the veins with your fingers;
• tighten the twist with pliers;
• insulate exposed wires.

Both single-core and multi-core cables can be connected.

Twisting of different sections

Do not twist wires with very different diameters. Such contact is not reliable and stable. You can twist wires of adjacent sections - for example, 4 sq. mm and 2.5 sq. mm. When twisting, you need to make sure that both wires wrap around each other. A thin wire should not be wound onto a thick one, otherwise the contact will be unreliable. Then you need to solder or weld the joint.

Twist caps

The caps help to reliably insulate the contact point.
The cap is made of fire-resistant material, inside it there is a metal part with threads. Making twists using caps is quite simple - you need to remove 2 cm of insulation and lightly twist the wires. A cap is put on them and turned several times until the metal wires are inside.

With terminal clamps

The contact clamp consists of a screw, a spring washer, a base, a current-carrying core and a stop that limits the spreading of the aluminum conductor. Making a connection using a contact clamp is simple - just strip the ends of the wires by 12 mm and insert them into the hole in the clamp. Contact clamps are used for both solid and stranded conductors.

How to brew twist

After twisting, the wires need to be soldered. To do this, the wires are tinned and rosin is applied to them before twisting. The heated soldering iron is lowered into the rosin; it needs to be passed along the stripped part of the wiring. After twisting, take tin on a soldering iron and heat the joint until tin begins to flow between the turns. This method takes a lot of time, but it is reliable and of high quality.

Methods for connecting wires or cables to each other

The junction of two conductors must meet the following requirements:

• reliability;
• mechanical strength.

These conditions can also be met when connecting conductors without soldering.

Crimping

This method requires special equipment. Crimping of wires with sleeves is carried out for both copper and aluminum wires of different diameters. Depending on the cross-section and material, the sleeve is selected.

Crimping algorithm:

• stripping of insulation;
• stripping wires to bare metal;
• the wires need to be twisted and inserted into the sleeve;
• the conductors are crimped using special pliers.

Selection of a sleeve causes major difficulties. An incorrectly selected diameter will not ensure reliable contact.

Bolted connection

Bolts, nuts and several washers are used for contact. The connection point turns out to be reliable, but the structure itself takes up a lot of space and is inconvenient to install.

The connection order is as follows:

• stripping of insulation;
• the stripped part is laid in the form of a loop with a diameter equal to the cross-section of the bolt;
• a washer is put on the bolt, then one of the conductors, another washer, a second conductor and a third washer;
• the structure is tightened with a nut.

Using a bolt, you can connect several wires. The nut is tightened not only by hand, but also by a wrench.

Terminal blocks

The terminal block is a contact plate in a polymer or carbolite housing. With their help, any user can connect wires. The connection occurs in several stages:

• stripping the insulation by 5-7 mm;
• removal of oxide film;
• installing conductors in sockets opposite each other;
• fixation with bolts.

Pros - you can connect cables of different diameters. Disadvantages - you can only connect 2 wires.

Types of terminal blocks for multi-core and single-core cables

There are 5 main types of terminal blocks:

• knife and pin;
• screw;
• clamping and self-clamping;
• cap-shaped;
• "walnut" type clamps.

The first type is rarely used; they are not designed for high currents and have an open design. Screw terminals provide reliable contact but are not suitable for connecting multi-core cables. Clamp terminal blocks are the most convenient devices to use; their installation does not require special equipment. Cap-type devices are also often used, but unlike clamping devices, caps can be used repeatedly. "Nut" is practically not used.

Terminals in junction box (copper or metal)

Terminals are the most common connection method in a junction box. They are cheap, easy to install, provide reliable contact fixation and can be used to connect copper and aluminum. Flaws:

• cheap devices are of low quality;
• Only 2 wires can be connected;
• Not suitable for stranded wires.

Self-clamping terminal blocks WAGO

There are 2 types of Vago terminal blocks used:

• With a flat spring mechanism - they are also called disposable, since reuse is impossible. Inside there is a plate with spring petals. When installing the conductor, the petal is pressed out and the wire is clamped.
• With lever mechanism. This is the best connector option. The stripped conductor is inserted into the terminal and the lever is clamped. Re-installation is possible.

With proper use, Vago terminal blocks last 25-30 years.

Using Tips

For connection, 2 types of tips and sleeves are used:

• in the first, the connection is made inside the product;
• in the second, two electrical wires are terminated with different tips.

The connection inside the sleeve or tip is strong and reliable. There are also special sleeves for connecting copper and aluminum wires.

Soldering of electrical wiring lugs

The tips are connected to the wiring using a press. If it is not there, contact can be ensured by soldering.

The electrical wire and the tip inside are tinned, the stripped cable is inserted inside.

The entire structure on the contact must be wrapped with fiberglass tape and heated with a burner until the tin melts.

1 Why twisting - the main advantages

If you need to connect two copper wires together, you can solder them. But not everyone has this useful skill, and a soldering iron may not be at hand, for example, if the cable of a power tool or a wire in a junction box in the countryside breaks. Therefore, such a property of copper and aluminum cores as flexibility is very convenient - they can simply be folded together and twisted into neat turns. In this case, you won’t even need pliers if the metal cores of the wires have a small diameter. This applies not only to electrical wiring, but also to television cable, antenna, telephone and many others, including computer cables.

Another advantage is the fairly high quality of the connection without soldering. If the wire is used to transmit a signal, interference due to twisting usually does not appear, and if it does occur, then in very rare cases

It is very important that this connection saves time and sometimes money. In particular, there is no need to wait for the soldering iron to warm up or equip a special welding inverter for wires; there is no need to tin every wire

When scorched, very thin veins easily burn or become brittle, which can already be considered a disadvantage.

Important Notes on Wiring Connections

Let us note important points regarding electrical wires.

1. All wires twisted together should not dangle somewhere in the air! They must be placed in a junction box.
2. For all wire connections, ensure that the bare ends of the wires are completely hidden in the connection block. That is, try to make the connection so that after this connection it would be impossible to reach the bare end of the wire with your hand.
3. Do not try to remove the wire from terminals that are not intended for this purpose. For example, there are craftsmen who manage to remove wires from wago terminals. But I do not recommend doing this, since such removal is always associated with deformation of the wire. And this is unacceptable, because the load on the network should be experienced by whole wires, and not half-broken ones, which can lead to short circuits.

This is where the article ends. We have studied in detail the issue of how to connect wires in an apartment. Now, when moving the socket from one place to another, you can easily extend the wires by laying them in the wall and making the correct connection.

They installed these pads for me at home... It would be better if they did everything with twists. The socket doesn't work and that's it. I called an electrician, he immediately said that the problem was in the pads and that they (the problems) would appear periodically. I reached into the box and sure enough: I turned the wire in the block, the socket started working. But problems cannot help but appear: in the block the wires are pressed with thin petals, very similar to steel ones. So I'll look for something else instead of pads...

I’ll honestly tell you that I made all the connections at home through the blocks. The kitchen has a lot of electricity supply: 3 sockets, heated floor. dishwasher, hood, microwave and everything is on blocks that are hidden in junction boxes or sockets.

I don’t argue that there are cases, but these are the exception rather than the rule. There might have been a defective batch. And the examples are very different. Some people's walls fall apart after plastering, while others have had no problems for 25 years. But this does not mean that now there is no need to plaster the walls. Somewhere the technology was broken. Therefore, here we need to study the problem, look deeper into why this is happening. And if twists were the most reliable, then firefighters would not prohibit them.

Hello. I am installing electrical wiring for a mini-bakery. Everything is great except for one thing. The fact is that I am opening a company in a remote corner from civilization in a small village. The city is 2000 km away and only by plane. Therefore, I stocked up on everything in advance. Except of course the wires. And then I somehow found the usual white two-wire and three-core aluminum noodles with a cross-section of 1.5 sq. mm. and copper three-core 2.5 sq. mm. Three-phase electrics. I installed 2-wire noodles for lighting, and three-wire for sockets with chargers. I have only three equipment supplying 380 W. Dough mixer 2.4 kW, Flour sifter 1.2 kW, Oven 19.2 kW. Since there is no choice, all three of them carried out wiring with a cross-section of 2.5 sq. mm. In addition to the stove, the dough mixer and flour sifter work perfectly. But when I turn on the stove after 5 minutes, the RCD 63A 30Ma turns off the electrical supply. I think this is due to the cross-section of the wire because... I found on the instructions that you need to use a wire with a cross-section of 6 sq. mm. How can you get out of the situation? Of course it would be great to find a 6 sq. mm wire. But I only have 2.5 sq mm. Please tell me whether it is possible to use a three-core wire as one wire, i.e. connect all three to one?

Yes. It would be optimal to make all three wires of one wire 1 phase (7.5 sq. mm), another 3-core wire for the second phase, and also for the third phase, also for zero (also 7.5 sq. mm, respectively), and grounding. With such loads (about 60 A), no terminals will withstand (except screw ones. But for myself I wouldn’t risk it), it is necessary to twist, which should be tinned and soldered (use acid-free flux, solder and a simple gas torch + futor (copper tube with a diameter of 25mm, one end is rolled onto a holder so that the solder does not leak out, approximately 3cm deep), or a welding machine and a copper electrode (boil the ends of the twists until all the cores are welded together into a ball at the end).

Before you start connecting wires

Any electrical installation work should be carried out competently. It is important to remember that the safety and life of all people and animals living in a house, apartment or country house depends on the correctness of their implementation. A mistake is unacceptable - at best there will be no good contact. And these are non-working electrical points.

In the worst case scenario, a visiting family member, friend or acquaintance could be electrocuted by an improperly insulated connection. Or the wiring will catch fire, which could lead to a fire.

For high-quality and correct execution of electrical wire connections, you need:

• knowledge of the basic types and principles of connections;
• availability of special tools for electrical installation work;
• availability of all consumables that will be useful when performing a specific type of connection;
• preliminary training on individual sections of wires.

When everything you need is available, you should carefully prepare your future place of work. To do this, you need to de-energize all the wires that you have to deal with. This is a very important step that cannot be ignored!

To avoid getting an electric shock, it is better to make sure once again that the apartment or house is actually de-energized. In this case, it is convenient to use an indicator screwdriver - this is an inexpensive tool that can even be purchased in an online store.

In a situation where there are serious concerns about the advisability of carrying out electrical installation work yourself, it is better to contact an electrician. Moreover, you should invite only an experienced craftsman who has not only experience in carrying out such work, but also special education.

Electrician services will be especially relevant if the wiring in the entire house/apartment needs to be replaced. You can’t save on this - you can end up paying double or triple the price, or even pay with your property. Overview of popular connection types

The main types of connections used to connect wires for household needs have about 10 options. Among them, there are both simple ones that can be performed without many years of experience, and more complex methods that require not only experience, but also special tools and skills to work with them.

Complex connection options

The connection of two or more wires is carried out in order to obtain high-quality contact. It is he who will ensure the operability of all electrical points in a particular house or apartment. You can establish reliable contact between conductors on your own or invite a specialist. It all depends on the type of connection chosen, the availability of tools and skills in carrying out such work.

Complex types of connections include:

• soldering;
• welding;
• crimping.

These options will be quite difficult for a beginner to cope with. The fact is that to solder an assembly of two or more conductors you will need a special tool, the skills to work with it are one awkward movement and instead of reliable contact you can get the opposite result.

The essence of this method is to remove the insulation from the conductors of the connected conductors and sand them to a shine. Then you need to apply rosin to each vein with a brush and heat it thoroughly with a soldering iron - the stripped metal should be covered with an even layer of rosin on all sides.

When all the conductor strands are prepared, all that remains is to twist them well and heat the solder with a soldering iron, and also heat the resulting twist until the rosin boils. Now you need to apply solder with a soldering iron to the heated assembly of conductors and ensure that it flows evenly between the individual wires.

Once it has been possible to obtain a complete distribution of liquid solder over the entire surface to be soldered, soldering can be completed. Now all that remains is to wait until the resulting assembly cools down naturally.

Welding is an even more complex type of connection. To complete it you will need:

• welding machine;
• carbon electrode;
• flux, which will protect the melt from exposure to oxygen;
• protective mask for the face and special heat-resistant gloves for the hands.

And the most important thing when working with welding is the ability to use the device. In the hands of an amateur, instead of a reliable contact that can last 30-50 years, a melted conductor and damaged insulation will come out from under the welding machine.

Before starting welding, you need to twist, as before soldering, having first stripped the ends of the wires to a shine. The essence of welding is to obtain a monolithic metal joint. To do this, you need to pour flux into the recess of the carbon electrode, turn on the welding machine and lower the end of the twist into the same recess.

As a result of welding, the ends will melt and a metal ball will form on them. You need to wait for it to cool, clean it of flux and varnish it.

For crimping, you will also need special equipment - press pliers, also called a crimper, and a metal sleeve made of copper, aluminum, a combined alloy or insulation.

To obtain high-quality contact using this method, you need to prepare the conductor cores in the same way as before soldering. Then take the sleeve and place the prepared conductors of one conductor into it on one side, and the second conductor on the other.

Now you have to use press pliers to compress the connection on both sides. It is important that the diameter of the sleeve matches the cross-section of the wires being connected - the cores must fit freely inside. After compression with a crimper, you should check the quality of the crimping - you need to tug one and the other wire. If they are tightly clamped and do not fall out of the sleeve, then the contact is successful.

All connections obtained as a result of soldering, welding or crimping must be insulated. To do this, use electrical tape or heat shrink tubing. The second option is more convenient and is now used by both professional electricians and home craftsmen. Moreover, when creating a contact using crimping, the heat-shrinkable tube must be put on before inserting the cores into the sleeve.

Easy ways to create contacts

In addition to labor-intensive and complex options for creating a contact, which require skill and special tools, there are simpler ones that can be easily mastered with your own hands. Such methods are acceptable for connecting two or more wires with different cross-sections or the same. And the material of the cores can be different - copper, aluminum or steel.

Simple methods most often used at home include the following compounds:

• twist;
• bolted;
• screw;
• self-clamping.

There are two options for twisting, which can be done at home. The first is to simply twist the wires, stripped to a shine, and wrap electrical tape or heat-shrink tubing over it. The second option is to screw a PPE cap over the twist.

The first option is a relic of the past. Such connections are unreliable, they can fall apart and contact is lost. In the second case, reliability is opposed by the high price for one cap. It is not worth buying cheaper products - they cannot withstand the inclusion of a powerful heater in the network or other electrical appliances.

For a bolted connection, you need to prepare a bolt, washers one more than the number of conductors to be connected, and a nut. When creating a contact, the conductors are prepared in the same way as before welding or soldering. One condition is that the length of the stripped core should be enough to wrap around the bolt 3-4 times.

First, a washer is put on, then the conductor core is wound, then the washer again, again the core of the second conductor, the washer again, etc. When the cores of all conductors are wound, the last washer is put on and the whole thing is secured with a nut. The key must be used to tighten the connection well to ensure good contact. The resulting node must be isolated.

Another simple and inexpensive method is screw connections. They are made using terminal blocks. Moreover, the length of the section that needs to be cleaned from insulation to a shine depends on the model of the device and the cross-section of the conductor.

The simplest option is self-clamping devices or WAGO terminal blocks. They create a reliable contact and are easy to use. Another advantage is the possibility of reusable use. Even a person very far from electrical installation can remove and reinstall WAGO.

Which option should you prefer?

To choose the right method for making conductor connections, you should take into account the specifics of your situation, assess the volume of future work and your skills. If we are talking about replacing a chandelier, then there is no point in learning the intricacies of welding and buying a welding machine. Here you can spend money on buying original German WAGO terminal blocks.

When there is a full-scale renovation of an apartment or house with replacement of wiring, it is more advisable to use the welding method. If you don’t have the skills to work with this equipment, then you can practice doing high-quality crimping and create all the contacts yourself.

Screw terminal blocks are often used in distribution boxes. But there is one caveat - they should be tightened periodically. Therefore, it is necessary to arrange the boxes in such a way as to ensure easy access to them for inspection.

Using regular twisting and, as before, wrapping electrical tape on top is extremely dangerous. Moreover, this option is prohibited by electrical regulations.

Methods of connecting wires: procedure for performing the operation

Twisting is considered the most common option for fastening several conductors together. For this method, it is enough to remove the insulation from the current-carrying wires and twist them tightly together.

Important! For maximum reliability of such a connection, it is recommended to remove the insulation material by at least 5 cm. For good contact, the wires are pressed with pliers

The method of soldering two conductors takes a little longer than the previous one, but it is more reliable. The ends of the conductors are coated with tin or rosin, and then carefully soldered. Such fastening does not create much resistance in the conductors.

The welding method is similar to soldering, but requires more care and the involvement of specialists for such work.

Connection terminals are the most popular and advanced option. Similar fasteners are used in switchboard devices and distribution boxes. The convenience of the connection lies in the ability to use current-carrying conductors of various cross-sections and materials of manufacture.

Spring fasteners are not inferior to pads. The method of such a connection is no less reliable, but efficient. With this, everyone can cope with the task of connecting electrical wiring. In home improvement, the use of bolted clamps and connections is practiced. The only drawback of such fasteners is the mandatory and durable insulation. These devices are used to fasten stranded wires and conductors with different cross-sections.

Spring terminal blocks for wires of different sections

Types of twists

There are dozens of twist options. They differ in the structure of current-carrying conductors, material and complexity of manufacture. If we consider from the point of view of purpose, twists are divided into 2 categories:

1. Branch. The 1st wire remains intact. Only a piece of insulation is removed from it. Another wire is wound onto the bare current-carrying wire.
2. Extension. Used to connect the free ends of 2 wires of the same cross-section. Cables are lengthened in this way.

Stranded wire branch

Connection between 6 wires

YOU'RE LYING!!!

In fact, INSULTING the members of the forum who have repeatedly and extensively discussed the types of contact connections, for example, RESEARCH Kamikaze, who described the different types of contact connections in the MOST DETAILS of anyone on the Russian-speaking Internet!

This is not to mention VIOLATION of the forum rules which state that before creating a topic you need to read the forum to see if there is a discussion of something that interests you.

Welding, soldering, IDEALLY a combination of them, in extreme cases crimping, if in combination with soldering then also IDEAL, for example, in high-current circuits I solder the NShV(I) tips after crimping from the end, since the classic termination of NShV(I) in high-current circuits is not refers to the best solutions, in the worst case scenario, clamping with two screws at the same time!

To be on the safe side, you can use 4 screws at the same time.

In the link below, in my next message in that topic, a photo where 7 cores of 2.5 mm2 are connected by soldering, I immediately took “on my knees” after reading the message that it is not clear how to connect 7 cores of 2.5 mm2 by soldering, to show that if hands artisans, there is nothing complicated.

Yes:

Flat spring terminals, so-called screwless, self-clamping, produced by WAGO, Weidmuller, Legrand, ABB, Schneider, Hager and other manufacturers, either according to the standards for contact connections, or by common sense, or by the instinct of self-preservation, CANNOT be used in distribution, installation boxes, shields, sockets, about which I have been warning everyone in more detail for a long time on the vastness of the Russian-speaking Internet, for example on this forum in the topic!

In the topic he added that self-clamping, without screw, flat spring terminals CANNOT be installed even on lighting groups with a 1A automatic machine, since they will not withstand the pulse current that the core will withstand! That is, the conductors connected through such a terminal are essentially connected through a FUSED link! Which was subsequently confirmed by the case described on a similar forum in the topic!

Flat spring terminals, the so-called screwless, self-clamping ones, are recommended to be used in stationary wiring only by those who do not understand electrical/fire safety or by INTENTIONAL hacks, since it is many times, and sometimes even orders of magnitude, more convenient and faster to install contact connections!

SELF-CLAMPING, SCREW-LESS, FLAT SPRING TERMINALS ARE WORSE THAN Twisted!!!

Plastic junction box, plastic corrugated wiring behind a suspended, suspended ceiling, in cavities, money down the drain and DECORATION in the fire resistance of the room!

It is optimal to make RELIABLE contact connections behind a suspended, stretch ceiling, in cavities without boxes and to insulate them WELL!

If you make distribution boxes behind a suspended, suspended ceiling, or in cavities, then use steel!

Also, behind a suspended ceiling, especially a suspended ceiling, in cavities, plastic wiring fasteners are not among the best solutions!

MORE RELIABLE and cheaper than plastic wiring fasteners, the remaining cores, flexibility class 1, from the wiring!

Where aesthetics are visible and required, steel reinforcement!

You need to try, from the same cable manufacturer, the sleeves often have different dimensions.

If you spend money on a tool, then on soldering irons, it’s cheaper and there’s a higher chance that it will be useful later in everyday life.

Technical nuances of the main types of connections

Each of the popular types of contact creation has its own characteristics. Thus, only single-core conductors of the same material can be connected by twisting.

If you need to create a contact with multi-core wires, then you need to use special tips - they compress the bundle of small wires. After installing the lug, the conductor can be connected to the terminal clamp without a clamping strip.

When you have to make up to ten connections, it is convenient to choose German Vago terminal blocks. They allow you to connect conductor cores of different cross-sections and materials. For different materials, it is better to choose Wago with anti-corrosion paste.

But here you should be extremely careful not to buy a Chinese counterfeit. The main differences between the original WAGO and the Chinese ones:

• The Chinese fake has a contact strip that is 2 times thinner than the original. It is dangerous to hang more than 5 Amps on a Chinese terminal block;
• the original mechanism is not magnetic, but the Chinese one is;
• There are no instructions for use on the back of the Chinese fake.

And the plastic of a real self-clamping terminal block is many times better quality. Therefore, it can easily withstand the load indicated on the reverse side.

You can also use soldering or welding to create contact between wires with different cross-sections. Such a connection will be strong and durable. Of course, if it was done professionally.

Another important nuance is to always isolate contacts. This is true for simple twisting, soldering, crimping and welding. And also to create contact using a bolt.

The bolted connection is a cheap, easy-to-use and durable option. And conductors of different cross-sections and materials are capable of creating reliable contact here. True, it takes up a lot of space when compared with the PPE cap or Vago terminal blocks.

Useful tips from professionals

Twisting of wires as such is prohibited by the PUE, but if it is used in conjunction with other means, it does not contradict anything:

1. Welding. If you simply attach two wires to each other and weld them, you will get a good permanent contact. And if the cores are also twisted before this, the contact area will increase significantly, see the photo below.
2. Soldering. The situation is the same as with twisting, only in soldering there is a main problem - solders, for example the widely used POS-60, do not provide mechanical strength. So if you solder two complex wires side by side and insulate them and hide them in a junction box, then such a connection will of course work. But if the wire moves even a little during operation, the soldering will break. Therefore, always twist the wires if you choose soldering as a method of connecting wires.
3. Use PPE caps. To do this, you need to fold the connected wires together, insert them into the cap and begin to twist the cap clockwise. The spring in it will clamp the veins and they will twist.
4. Clamp the twisted wires with a screw terminal block (they are also called polyethylene terminal blocks).

It is important to note that none of the above options makes the twist waterproof, so if you decide to fasten the conductors under the plaster in the wall, without a box, be sure to insulate the connector with cambrics. That's all you need to know about how to properly twist wires with your own hands.

We strongly recommend that you use more modern methods, and use twisting only when installing temporary electrical wiring! Do not twist under tension under any circumstances, because Today there is no such safe method. Any electrical installation work must be done with the lights turned off!

That's all you need to know about how to properly twist wires with your own hands. We strongly recommend that you use more modern methods, and use twisting only when installing temporary electrical wiring! Do not twist under tension under any circumstances, because Today there is no such safe method. Any electrical installation work must be done with the lights turned off!

Errors when making twists

Most errors are related to the shape, size and tension of the twist. To properly connect two wires, they should be wound evenly around each other. Between the current conductors there should be a maximum contact patch area. It is considered incorrect to wind one core onto another if they have a different cross-section.

Another mistake is twisting it too short. The longer it is, the larger the contact area. This means lower resistance and possible heating. The length of a good twist is at least 5 cm.

When making a connection, it is necessary to select the correct tension. Too much force can break the twist, and too little will lead to poor electrical contact.

When installing wiring, electricians often use various tightening devices. They are a bit with a special attachment for wires, which is inserted into any drill. This device turns the power tool into a semi-automatic wiring installation machine. It is possible to do it yourself. But it’s much easier to buy ready-made ones. For example, the screwdriver attachment from Tundra, in addition to connecting wires, is capable of removing insulation.

How to connect 3 wires

Quite often a situation arises when it is necessary to connect not two, but three wires, for example, when supplying energy from one phase to two consumers at once, and in such cases, the most convenient method of connection is a mechanical clamp.

Depending on how large the load will be, it is necessary to select the appropriate model of the clamp used. The simplest option is a metal sleeve into which wires are inserted on both sides, on the one hand supplying, and on the other, pre-twisted together, feeding.

If one of the wires has a larger cross-section, then it is this wire that is inserted into the sleeve without twisting. After the wires are inserted, the connection is secured with clamping screws.

If the wires are of small cross-section, then the usual twisting of all three is used; pliers are used to ensure a tight connection. The twisting area can be covered with a plastic threaded cap.

Why is twisting dangerous?

The main danger is high resistance. In addition, if the connection is poorly tightened or gets hot, then this indicator becomes even worse.

The twisting point acts as a low-resistance resistor. Under the influence of current, thermal energy is released on it. It promotes oxidation of the twist and further deterioration of the contact. As a result, the wires connected in this way simply burn out. Often this is what causes device breakdowns and wiring short circuits.

Burnt twist

Let's take a closer look at the types of clamps

There are different types of terminal blocks designed to perform specific jobs. We will now try to consider the most common products.

Screw terminal block

The screw connection remains familiar and popular. The mechanism of the product is quite simple and reliable. Screw terminal blocks can be found on household wiring connections, inside many electrical appliances, and even car battery terminal clamps also belong to this group. But, if the electrical terminal blocks for electrical wiring have a copper or brass jumper inside, then the battery terminals are most often made of lead. This is due to the fact that there is acid inside the battery.

The advantage of screw terminal block models for connection is the high-quality contact of the entire area of ​​the cable core with the metal jumper of the clamp. The screw allows you to easily connect and disconnect the wire. On many screw models you can find a screw marked green. It is used to connect the grounding conductor. The special feature of the clamp is its teeth. When pressed hard with a screw, they cut into the metal, improving grip.

The disadvantage of a screw clamp is that it can only be used with copper wire. You can, of course, clamp an aluminum core, but if you don’t calculate the force, the brittle metal will deform. Another disadvantage is the inconvenience of use. In order to connect many wires with screws, it will take more time than to perform a similar operation with spring mechanisms. When in a hurry, inexperienced craftsmen often completely unscrew the clamping screw and lose it. However, these minor problems do not deteriorate the quality of the screw connection, but the fact that the screw connection can become loose during vibration determines its main disadvantage.

Crimp terminal block

This type of electrical product is intended for connecting cable cores with a maximum permissible current of 24 A. The terminal block attached to the cable can withstand up to 5 thousand volts. With one product you can immediately crimp up to 8 prepared terminals for connection. This design greatly simplifies the installation of electrical wiring. According to the type of fixation, the terminal block can automatically fix the contact inside the socket or mechanically, which is done manually. If you correctly calculate the force when crimping the terminal block, you will get reliable contact.

Product labeled PPE

Such terminal blocks are called insulating and look like a plastic cap. The clip is made of heat-resistant polymer that is flame resistant. There is an opinion that PPE is intended to protect the connection from fire. In fact, the terminal block creates a strong mechanical contact and will withstand voltages up to 600 volts.

The principle of operation is simple. There is a usual twist of exposed wire strands. Moreover, all wires must be made of homogeneous metal. To avoid oxidation, it is advisable to treat the twist with paste. There is a cone-shaped spring inside the plastic cap. This will create a strong connection. The cap is put on the twist, twisting clockwise. At this time, the spring presses the veins in turns, creating a strong contact. If two wires of equal thickness are connected, they do not need to be twisted. The bare ends are forcefully inserted into the cap and rotated. The spring inside will do its job itself.

Power terminal blocks on DIN rail

Power terminal blocks are installed on a circuit board or DIN rail. Their complex design allows you to connect wires of different thicknesses up to 300 mm 2. connect aluminum wire with copper, and also simultaneously connect cable cores designed for different power. The power terminal blocks have a tinned copper plate, to which the wire is pressed with a special conical washer, which does not allow the connection to loosen.

Universal and Barrier Clamps

These products have a special design feature - a metal plate. It is divided by cells of insulating material. The cell jumpers prevent the wires being connected from touching. Reliable fastening of the cores is ensured by screws. On metal terminals, aluminum wire practically does not oxidize, which allows the use of such terminal blocks without restrictions. Most often, the connections of wires in the distribution box are made using barrier clamps.

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Preparing for twisting

Before twisting, it is necessary to remove the layer of protective insulation from the current-carrying conductors. Usually this operation is performed using a knife. During operation, you should try not to damage the metal current conductor with the tool blade. Otherwise, it is capable of breaking in a weak spot. This is especially true for soft stranded cable cores.

If you are going to remove the insulation from an aluminum cable, you must avoid kinking it. This metal does not cope well with frequent deformations. Therefore, an aluminum cable can break during stripping.

Removing the insulation from the cable

Note! Aluminum wire can break even under insulation. This usually happens within 20 cm of the connection. This problem cannot be identified visually. The break is looked for by touch.

Self-clamping terminal blocks WAGO

In addition to terminal blocks with bolts, there are also terminal blocks with clamps. They are more expensive than usual, but they allow the connection to be made much faster, especially in connection with the new requirements of the PUE and the ban on twisting.

The most famous manufacturer of such terminal blocks is WAGO. Each terminal is a separate device with several holes for connecting wires, each of which is inserted into a separate wire. Depending on the version, it connects from 2 to 8 conductors. Some types are filled inside with conductive paste for better contact.

They are available for both detachable and permanent connections.

The stripped wire is simply inserted into the terminals for a permanent connection and spring tendrils fix the wire inside. Only hard (single-core) wire can be used.

In plug-in terminals, the wire is clamped using a folding lever and a spring clamp, making it easy to connect and disconnect wires.

Since the wires do not touch each other, the terminals allow you to connect wires of different sections, single-core to stranded, copper to aluminum.

This method of connecting conductors has proven to work best at low currents and is most widespread in lighting networks. These terminals are small in size and easily fit into adapter boxes.

Twists for distribution boxes with welding

If we need to connect two or more solid copper wires and hide them in the junction box, then for a reliable connection it is better to weld the contacts. To do this, we will additionally need a special welding machine with carbon electrodes. For example, the TSS Compact-160 welder is suitable for such a task. You will also need graphite electrodes (you can take rods from AA batteries or a graphite block from the engine) and flux.

First we twist the two wires, as in the picture, starting from the ends and ending with the base.

Then, using a welding machine, weld the ends (only them, no need to weld along the entire length).

After this, you need to insulate the twists with electrical tape/heat shrink and carefully place them in the junction box.

Of course, welding takes more time than, for example, WAGO clamps or other terminal blocks, but such twists last for decades, and your grandchildren will change them.

Junction box and what it is

All wires that supply electricity to a house or apartment come out of the electrical panel. Each room has several sockets and switches. To collect all the wires in one place and assemble a wiring diagram, junction boxes were invented. This is where they are connected for the further operation of all devices. For laying the wiring, established rules are used, 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 down, and the specialist installs a box at the branch point. 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 from poor-quality or incorrect connections, 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.

What is PUE

Pue is a collection of regulatory documentation for the design and installation of electrical circuits; in fact, it is a desktop Bible for all people who begin to engage in electrical work. The collection shows the basic principles of creating circuits, the rules for their calculation, protection and communication devices. Further, all descriptions of electrical devices will be in accordance with the rules according to the PUE.

Selecting the cross-section and brand of wire

To lay electrical wiring in rooms and connect wires in a junction box according to the PUE, the conductors must have a different color insulating coating, from the same manufacturer with the same color scheme. For wiring, it is best to use VVGNG wire - a single-core copper wire, flat, double insulated, best with the additional designation NG, which means non-flammable. It is best to purchase wires from a well-known brand of the manufacturer; they must have a certificate. There is no need to take a wire without markings; wiring in the house is, first of all, safety and is done for more than one year, so saving is inappropriate here. It must be taken into account that a copper wire with the same cross-section can withstand one and a half times more load than aluminum.

Attention! For a capital circuit, you cannot use stranded wire PVS or SHVVP. Although these wires are soft and more convenient to lay, they have a higher current resistance, and accordingly they will heat up more when a load is connected.

Power calculation

One of the basic rules for calculating the cable cross-section: it is used in the calculation of 1 sq. mm of 9 A. electric current, that is, a cable with a cross-section of 1 mm can withstand the load of a kettle or iron with a power of 2 kW. Based on these recommendations, at least the following should be used for wiring in the house:

• lighting core is 1.5 mm square, which corresponds to 10 - 12 A.;
• sockets in rooms are 16A, which corresponds to a cross-section of 2.5 mm. sq.
• kitchen electric ovens, the wire for which must withstand 25A. – this is a 4mm section. kv;
• The core of a four-burner electric stove must withstand 32A. – cross section 6 mm 2. The correct choice of connecting electrical wires in the junction box depends on the cross-section of the wire.

Attention! You cannot use wires from different manufacturers, as they have different specific (ohmic) resistance per 1 linear meter.

Electrical junction box and wire connection

After laying the wires, according to the drawn up diagram, they must be connected to each other. In order for the connection to be in one place, there are communication boxes (distribution boxes). Depending on the installation, device connections can be round or square, deep or shallow, and are divided into internal or external according to the method of fastening. According to the requirements of the PUE, the wires must pass at least 15 cm from the ceiling, taking into account all canopies. At the same distance, a device for switching cable cores is also attached. To install the internal box, a niche corresponding to the outer diameter of the sleeve is drilled in the wall; for external mounting, it is made directly to the wall.

Methods for connecting cable cores in a junction box

Methods for connecting power cable cores to each other in the distribution cavity depend on the specific situation, which takes into account:

• The metal from which the cores are made;
• External operating environment;
• Number of connected cores;
• Section of the connected cores;

For example, connecting by twisting, soldering, welding only a core made of the same metal (all PUE methods are prohibited); terminal clamps are used to connect wires made of different materials (copper, aluminum, steel, composite).

The connection can also be made in the following way: terminal blocks with bolt or spring clamps, Wago clamps; PPE clips (self-insulating); crimping with sleeves, bolted connections or a “Walnut” type clamp.

Terminal block

consists of screw terminals installed on one plate for each individual cable, which are mounted in plastic housings. There may be two or more clamps. The stripped cable core is inserted into the hole at the end of the housing and clamped with screws. Terminal blocks for connecting wires in the distribution box allow you to connect different diameters and cable materials. However, it has a drawback: approximately once a year a preventive inspection and tightening of the clamp screws is necessary. So - as the current passing through the contact heats up and the threaded clamp gradually weakens. Such blocks can be used when connecting a low-current network, for example, installing lighting or backlighting.

Walnut connection

This type of switching is a steel plate with screw fastening at the edges. The principle of operation is an ordinary threaded clamp of the bare core of the power cable with the possibility of branching with a smaller cross-section. The steel clamp is housed in a round carbolic (thermoset rubber) housing. The design is quite reliable and has been tested for many years of operation. Requires constant prevention at least once a year.

One of the most common disadvantages of threaded connections is loose contact in the terminals for connecting wires in the junction box, eliminating spring-loaded clamps or lever devices. One of the most famous and popular devices is the Wago eccentric clamp. The Wago device is designed in such a way that the clamping is performed by a lever with an offset axis. When the lever is turned inward, the eccentric securely clamps the end of the wire. Eccentric clamps are very easy to use and reliable in operation. In addition, the ends of power cables made of different materials and slight differences in diameter are reliably connected.

You can learn more about the types of terminal clamps from the video:

Spring clamps are also very popular

the principle of operation of such a device is clear from the figure: when you press the key, the lever presses the contact with the terminal, forming a cavity into which the end of the protected core is inserted. Unlike contacts that are clamped with screws, spring contacts clamp the ends quickly and reliably and there is no need to tighten them with a screwdriver from an awkward position. In such devices, it is very important to comply with the requirements of the electrical wiring in the junction box and the maximum current load for which the contact is designed (the value is written on the case). Exceeding the maximum permissible current in the contact will cause it to heat up, which will change the properties of the spring steel, which can weaken with all the ensuing negative consequences.

Self-isolating caps (PPE)

Another simple and quick joining method is self-insulating caps, or (PPE). This device is available in five standard sizes with a cross section of 1.4 mm. up to 5, 6mm. They are easy to use: just first twist the wires to be connected, then select a cap of the appropriate diameter and screw it onto the prepared twist. The cone spring inside the cap additionally twists the wires and compresses them together. The advantages of such a connection point are speed, but you should not trust the main network to such a device. When connecting the wires in the junction box correctly, it is best to use a more reliable method.

Joint with a sleeve

Another method of switching wires in an electrical distribution box is to connect the wires by pressing them into a connecting sleeve. This method is more reliable than twists and connecting caps. Clamping done correctly in this way is more reliable and simpler. The principle is carried out by inserting the stripped ends on one side of the sleeve or the opposite sides into a pre-prepared metal tube (brass or copper sleeve). Why is a metal tube clamped with a special device, reliably connecting the wires together? The metal sleeve is insulated either with a heat-shrinkable tube or with insulating tape with an overlap of half the width of the tape (half-overlap). This method is most suitable for splicing stranded wires in a junction box.

Twist

Despite the apparent simplicity of the method, such an operation is quite complex; in order for the twisting to work correctly, several conditions must be met: uniform and tight twist pitch; the attachment must be at least 5 turns; a bandage of thin copper wire should be applied to the twist, either directly on the twist itself or on electrical tape on top to increase the rigidity of the knot.

It is best to use twists for installing a temporary electrical network.

Attention! Use in twists in wooden or damp rooms is prohibited. It is prohibited to switch wires of different cross-sections and materials in a distribution box by twisting.

The joint insulation can be cambric, heat-shrinkable tubing or electrical tape.

Soldering

In order to eliminate some of the disadvantages of twisting copper switching cables, soldering is used. For it, tin-lead solder of the POS 40 - POS 60 brand is used. To perform the procedure efficiently, it is necessary to degrease the ends intended for soldering with hydrochloric acid treated with zinc. Then solder by dipping the ends into molten solder, or with a soldering iron of at least 100 W. Solder coverage must be at least 70% twist. This makes it easier to work with conductors whose ends are pre-tinned with tin or solder. There is no need for adhesive bandage. The insulation can be heat-shrinkable tube, cambric or electrical tape. Before the soldering procedure, it is necessary to check the rules for connecting the wires in the junction box because After soldering the cable cores it becomes permanent.

Welding

Welding is considered the most reliable connection of copper wires in a distribution box. With the development of electronic technology, the industry began to produce small-sized welding transformers with adjustable current on the electrode - inverters. With the small dimensions of the inverter, welding the ends of the copper ends is not difficult, and it does not matter whether multi-core or single-core power cables are welded. Modes: 20-30 Volt voltage and 70A are enough. current load. When welding, a metal melt is formed, after which reliable contact between the cables is ensured. In addition to reliability, the method has another advantage: when preparing for welding, it is enough to remove only the surface layer of insulation without further processing. For a more reliable assimilation of the material presented in the article, we suggest watching the material on connecting wires in a junction box video

Twist welding machine of the TS-700 family

The device is a step-down transformer with adjustment on a thyristor control circuit, it allows you to weld any twists with a total cross-section of up to 25 mm 2.
The device can weld with pulsed, alternating or direct current, which allows you to connect not only copper conductors in the junction box, but other conductor materials, for example, aluminum, composite, steel. The device is very compact: dimensions 105x181x67 mm. Weight 5.5 kg. comes in a leather bag that slings over your shoulder. It’s easy to operate the equipment; you don’t need any welding skills; you can see how this happens in the video. Power supply is 220V household voltage, in welding mode consumption is 1.4 kW. The shielded metal housing protects household appliances from magnetic fields. The device is protected from possible overloads by a built-in thermal fuse.

Contents: 1. bag, the strap of which can be thrown over the shoulder; 2. safety glasses with “Chameleon” type lenses, which instantly react to the amount of light depending on the brightness of the lighting; when working, there is no need to constantly remove the glasses; 3. two power cables 1.4 m long for the holder and the electrode and the twist holder; 4. network cable 3 m; 5. Also included are 10 electrodes, which is enough for 10,000 welding times;

The estimated cost of the fully equipped device is only 7,300 rubles.