Methods for connecting electric wires. Reliable ways to connect electrical wires. Connections of different materials with a bolt

In the article we will talk about ways to connect wires in junction boxes, talk about preparing conductors for connecting household appliances and installation products.

The wiring of residential premises consists of many elements, these are various current-carrying conductors (cables), protective devices, electrical installation products, individual current consumers. In order to assemble all the components of the system into a single circuit and at the same time make the power supply functional and safe, it is necessary to connect them to each other qualitatively, or, as they say, to commute (switching is the process that occurs when electrical circuits are closed or opened).

At first glance, it may seem to an unprepared person that there should not be anything complicated here. But, working with an electrician “on a whim”, it doesn’t matter if we transfer some single outlet, connect a lamp or assemble a complex control system, we are at serious risk. Experienced electricians know that wiring is primarily a "contact fight", since it is an open circuit, not a short circuit, that is the most common problem that one has to face. Obviously, the connections in the circuit (terminals, twists) are the most vulnerable, since at these points the mechanical density of the contact can weaken (the contact area decreases), an oxide film with a very high resistance forms on the conductors over time. Poor contact causes heating of current-carrying conductors, sparking at switching points - these are the consequences of the occurrence of transient contact resistance. Complete burnout of the wire and de-energization of the site, when household appliances do not work, or the light is gone, this is unpleasant, but the problem is solved. Worse, if the insulation of the wires heats up and breaks down, which threatens to cause electric shock or a fire.

Recently, the load on the wiring has seriously increased, so switching is now subject to even more stringent fire and electrical safety requirements. However, if earlier there were not many connection options, now reliable modern devices have appeared that facilitate wiring switching. In addition to welding and soldering, followed by tape insulation of the twist, PPE caps, various terminal screw and spring blocks, all kinds of insulated and open lugs, branch clamps can be used in the household network. These products will help to qualitatively connect wires in junction boxes, assemble a switchboard, connect household appliances and lighting fixtures, sockets and switches.

There are several key objective factors influencing the choice of switching method, or the use of specific devices. Let's just list the main ones:

• power and number of consumers (read: total cross section of conductors);
• conductor material (copper or aluminum);
• type of cables (flat or round, hard or soft stranded, in single or double insulation);
• node assignment (group or single branch, end connection);
• the presence of mobility of wires or vibrations near them;
• elevated temperature, humidity;
• indoor or outdoor use.

Connecting wires in junction boxes

According to the provisions of the PUE, branching of the wires of a household network can only be done in a junction (junction) box. Junction boxes allow, during the operation of the wiring, to quickly reach the ends of any individual branch, if necessary, to find which of them is broken or has a short circuit. You can also always inspect the condition of the contacts inside the box, and perform their maintenance. Modern PVC boxes are used for open and hidden wiring, they have sufficient reliability and extended functionality: they are easy to install on various surfaces, convenient for electrical installation manipulations.

In order to always have access to the connected wires, all junction boxes are located on free sections of the walls, it is most rational to install them from the side of the corridors, for example, above the door of a powered room. Naturally, the boxes cannot be tightly plastered, or sewn up inside building frames, the permissible decorative maximum is a thin-layer finish on top of the lid (paint, wallpaper, decorative plaster).

For the arrangement of lighting and power circuits (pins and sockets), it is recommended to use separate junction boxes for each room. Such a divided power supply makes it possible to make the electrical wiring of the home more balanced and safe, since “lights” and “sockets” differ in workloads and operating conditions, they are subject to different requirements. Moreover, it is much easier to upgrade or repair the wiring later, and not always all the wires in the room can be properly marked in one housing.

Switching wires in any junction box can be carried out according to the same principle. In most cases, “twisting” is initially used, but simply wrapping the conductors with electrical tape is not enough - it must be reinforced with additional operations that are designed to increase the contact area of ​​the connected current-carrying wires and reduce the oxidation of materials. Paragraph 2.1.21 of the PUE offers the following options:

• soldering
• welding
• crimping
• crimping (bolts, screws, etc.)

Wire crimping

The essence of this method lies in the fact that twisted wires are inserted into a special metal sleeve-tip, which is compressed by hand tongs, mechanical or hydraulic press. Crimping can be done either by local indentation or by continuous compression. Such a connection of wires is considered one of the most reliable. Crimping allows you to compress the cores very tightly, increasing the contact area, the mechanical strength of such switching is the highest. This method is used for both copper wires and aluminum.

The crimping process consists of several operations, each of which has its own nuances:

1. The wires are released from the insulation by 20-40 mm from the edge, depending on the working length of the sleeve.
2. The veins are cleaned with a brush or emery to a shine.
3. With the help of pliers, a tight twist is made.
4. According to the total cross section of the twist, a GAO sleeve with the required internal diameter is selected, as well as a suitable punch and matrix.
5. The sleeve is treated from the inside with quartz-vaseline paste (if it comes “dry” from the factory).
6. The twist is inserted into the sleeve.
7. The twist is compressed with press tongs. It is necessary that the tool rig is completely closed.
8. The quality of the connection is checked - the wires should not move in the tip.
9. The sleeve of the connected conductors is wrapped with electrical tape in three layers, with a tip thickness of up to 9 mm, a polyethylene insulating cap can be used.

Crimping conductors

The conductors can be crimped using terminal blocks, PPE caps or WAGO clamps.

The body of the terminal block is made of plastic, inside it there are nests with threads and clamping screws. The wires can be wound under the individual screws of the terminal towards each other, or one conductor passes through the entire block and is fixed with two screws. Some junction boxes are assembled with standard blocks.

A clear advantage of switching on the terminal block is the ability to connect copper and aluminum wires, which in this case do not have direct contact. The disadvantage is the need to tighten the bolt clamp if aluminum conductors are used.

PPE caps (connecting insulating clips) are also made of durable non-flammable polymer, which, as an insulator, provides mechanical and fire protection. They are twisted with force on the twisting of the conductors, then the conical metal spring located inside the cap expands and compresses the current-carrying wires. As a rule, the internal cavity of PPE is treated with a paste that prevents oxidation.

WAGO terminals for junction boxes are screwless, here the compression is performed by a spring, it is only necessary to insert the stripped wire into the terminal. These terminal blocks are designed to connect up to eight wires with a cross section of 1-2.5 mm 2 or three cores with a cross section of 2.5 to 6 mm 2, while the spring acts on the conductor with a force suitable for each wire. The clamps function normally with operating currents up to 41A for 6 squares, 32A for 4 squares and 25A for 2.5 squares. Interestingly, WAGO universal clamps allow you to connect wires of various cross sections (from 0.75 to 4 mm 2) in one housing.

These devices can be designed for a rigid conductor, or for a soft stranded one. Due to the fact that there is no direct contact of the connected cores, it is possible to switch copper wires and aluminum wires, while there is no need to make a regular audit of aluminum compression. Inside, WAGO terminal blocks also have a paste that destroys the oxide film and improves contact, however, clamps for copper conductors are not filled with contact paste. It is very easy to work with such connecting products, they are quickly installed without the use of additional tools, they are compact and reliable. It must be said that WAGO is not the only company producing screwless spring-loaded terminal blocks.

Whatever type of crimping device is used, it is necessary to accurately select it according to the cross section of an individual conductor or strand, since a terminal that is too large may not provide normal contact. It is not always possible to trust the marking in this case - it is better to check the compliance of fasteners and conductors on site. We recommend that you have an assortment of crimp terminal blocks according to standard sizes during installation. Please note that contact gel must be used to work with aluminum, copper and aluminum conductors cannot be connected in one twist. After crimping, it is always necessary to check the strength of the wires in the terminal.

Soldering wires

Due to the technological complexity, this connection method is used quite rarely, mainly when for some reason it is impossible to use crimping, crimping or welding. You can solder wires made of aluminum and copper, you just need to choose the right solder. For branching wires with a cross section of up to 6-10 mm 2, an ordinary soldering iron is suitable, but more massive wires will have to be heated with a portable gas burner (propane + oxygen). For soldering, it is necessary to use flux in the form of rosin or its alcohol solution.

The advantages of soldering are considered to be high reliability of the connection, compared with crimping (in particular, we have an increased contact area). Also, this method is quite inexpensive. The disadvantages of switching construction wires by soldering include the duration of work, the technical complexity of the process.

Soldering wires looks like this:

• wires are stripped of insulation;
• the veins are polished with emery to a metallic sheen;
• a twist is made 50-70 mm long;
• the core is heated by a burner flame or a soldering iron;
• the metal is covered with flux;
• solder is introduced into the working area or hot twist is immersed in a bath with molten solder for 1-2 seconds;
• after cooling, the soldered twist is insulated with electrical tape or polymer caps-tips.

Welding

Most often, for reliable switching of wires in a junction box, electricians use contact heating welding. You can weld a twist with a total cross section of up to 25 mm 2. Under the action of an electric arc at the end of the twist, the metal of several strands is fused into a single drop, and then the current during the operation of the electrical circuit does not even flow through the body of the twist, but through the formed monolith. If everything is done correctly, then the connection is no less reliable than a solid wire. This method has no technological and operational disadvantages, the only thing is that you need to purchase a suitable welding machine.

Welding of copper conductors is carried out with direct or alternating current with a voltage of 12 to 36 V. If we talk about factory welding units, it is better to use inverter devices with sensitive adjustment of the welding current, which are light in weight and dimensions (during operation they are sometimes worn on the shoulder) , can be powered from the household network. In addition, inverters provide good arc stability at low welding currents. Due to the high cost of inverters, very often electricians use home-made welding machines made from a transformer with a power of more than 500 W, with a secondary winding voltage of 12-36 volts. The mass and the electrode holder are connected to the secondary winding. The electrode itself for welding copper conductors must be infusible - coal, this is a factory copper-plated "pencil" or a home-made element from a similar material.

If a factory inverter is used for welding wires, then it is recommended to set the following operating current indicators for wires of various sections: 70-90 amperes is suitable for connecting two or three wires with a cross section of 1.5 squares, wires with a cross section of 2.5 mm 2 are welded at amperes. These indicators are indicative, since the exact composition of the core may vary from manufacturer to manufacturer - it is recommended to test the device and a certain current strength on the conductor cuts. Correctly selected indicators are when the arc is stable, and the electrode does not stick on the twist.

The wire welding process includes the following operations:

• the cores are cleaned of insulation (about 40-50 mm);
• a tight twist is made with pliers, its end is cut so that the ends of the wires have the same length;
• a mass clamp is connected to the twist;
• the carbon electrode is brought to the end of the twist for 1-2 seconds (so that the insulation does not melt, but a solid copper ball is formed;
• after cooling, the welded twist is insulated with electrical tape, heat shrink tubing or a plastic tip.

When connecting wires, you should follow safety precautions and take fire prevention measures, as for any welding work. It is recommended to use a welding mask or special glasses with a light filter; welding leggings or mittens will not be superfluous.

Connecting wires to electrical equipment terminals

Connecting household appliances and various electrical installation products is also an important step in wiring wiring. The reliability of electrical connections in these nodes depends on the performance of consumers, as well as the protection of users and fire safety.

The technology for connecting current-carrying conductors to equipment is regulated by the PUE, the current SNiPs, as well as the "Instructions for terminating, connecting and branching aluminum and copper conductors of insulated wires and cables and connecting them to the contact terminals of electrical devices." As well as branching conductors in junction boxes, soldering, welding, crimping, screw or spring crimping are used for termination and connection. This or that method is chosen primarily depending on the design of the equipment, as well as on the properties of the current-carrying conductor.

Screw crimping is used in most types of modern equipment. There are screw terminals in sockets and switches, chandeliers and lamps, in various household appliances (built-in fan, air conditioner, hob). Crimp sockets are supplied with switchboard elements: circuit breakers, RCD, electric meter, here switching busbars with screw terminals are also used.

It should be noted that convenient spring-loaded terminal blocks can also be used to connect equipment. For example, switches are often equipped with screwless terminals, WAGO produces a special series of clamps for connecting chandeliers and lamps, as well as for switching in ASU (terminals mounted on a DIN rail).

Please note that for crimping, soft stranded conductors must be terminated with insulated lugs (connectors). For rigid monolithic cores, connectors are not needed. If you do not use tips, then the soft core should be tightly twisted and tinned with solder before connecting. The size of the lug is selected depending on the cross section of the conductor, and the geometry of the contact part - depending on the type of terminal on the connected device and the features of operation. For example, a connector in the form of a pin is used for a clamping tunnel socket, and a ring or fork connector is used to fix it with a nut on a bolt. In turn, the fork tip is not recommended for use if the device is mobile or vibration is possible in the switching zone.

If it is necessary to clamp a rigid single-wire conductor (copper or aluminum) with a cross section of up to 10 mm 2 under the bolt, then it can be bent using round-nose pliers in the form of a ring of a suitable radius. The ring is cleaned with glass sandpaper or sandpaper from the oxide film, lubricated with quartz-vaseline gel and put on the bolt (the ring should wrap around the bolt clockwise), after which it is covered with an asterisk washer (prevents the extrusion of the conductor), a grover (springs the connection, does not allow to unwind when vibrations), and the clamp assembly is tightly tightened with a nut. If a large cross-section core (from 10 mm 2) should be clamped under the bolt, then a metal sleeve with a ring is mounted on the conductor by crimping.

Switching wires is a very responsible job, while the process of assembling a circuit has a lot of nuances that, for convenience, should be combined into one list:

1. Strip the wires with special pliers, since when removing the insulation with a knife, the cross section of the core is often reduced.
2. Always remove the oxide film from the conductor. Use glass skin or emery, use special liquids and contact paste.
3. Make the twist a couple of centimeters longer, and then cut off the excess.
4. Select the diameter of the sleeve or tip as accurately as possible.
5. Lead the conductor under the terminal or sleeve / lug to the very insulation.
6. Make sure that the wire insulation does not get under the clamp.
7. If possible, insert into the tunnel screw terminal and clamp there not a single soft core, but a double-folded one.
8. When using electrical tape, wind it with an overlap of turns in three layers, be sure to go to the insulating sheath of the conductor. Electrical tape can be replaced with heat shrink or plastic caps.
9. Be sure to wrap the screw terminal blocks with electrical tape.
10. Always mechanically check the strength of the connection - pull the conductors.
11. Never connect copper and aluminum directly.
12. Fasten the cable firmly near the switching area so that the wire does not pull down and there is no mechanical impact on the connection.
13. Use the color marking of the conductors, for example, in the entire house network, the brown conductor will be the phase, blue - zero, yellow - grounding.
14. Accept a single connection scheme for mounting all devices (for example, the phase on the sockets is clamped on the right terminal, and the neutral is not on the left).
15. Mark both ends of all wires yourself - with a ballpoint pen on the outer sheath, at a distance of 100-150 mm from the edge of the conductor, write its purpose (for example, "pink kitchen desktop" or "bedroom light"). You can also use tags or pieces of masking tape.
16. Leave a supply of wires convenient for installation. For junction boxes, sockets and switches, the normal length of the ends will be 100-200 mm. To switch the shield, you may need wires up to one meter long, so that you can lead some of them from the bottom of the box, and some from the top.
17. Bring external cable channels close to the junction boxes, it is better to lead round corrugation or pipes into the housing a few millimeters.
18. We connect sockets in parallel, and switches - in series. The switch should break the phase, not zero.
19. Compress all the wires of one switched twist into a bundle and fix it with electrical tape. Inside the box, separate the insulated connections to the maximum distance between them.
20. Use only certified materials and specialized tools.

In conclusion, I would like to once again note the importance of high-quality performance of switching work. In fact, the technologies used are quite simple, you just need to make them a habit, and then the “installation culture” will appear by itself, and the wiring will be reliable and durable.

The electrical network of a single house is a complex system of wires, electrical installations and a protective automatic group. The most vulnerable points are the switching points of two or more conductors.

The task of the electrician is to select and correctly install wire connectors that will be as suitable as possible in terms of characteristics, perform their function perfectly and, most importantly, ensure reliability and safety.

Let's figure out what types of connectors are most often used in everyday life, for what work certain switching devices are suitable, what are the features of their installation. In addition, we provide practical advice on choosing the right type of connector.

Wire connectors are any devices that serve to close / open an electrical circuit. These can be electrical installation products - sockets, switches, as well as metal tires and plates, lugs, terminals and terminal blocks - blocks with several sockets.

We will focus on connectors in a narrower sense - on elements that create collapsible and non-separable connections and ensure their reliability and functionality - that is, on all kinds of terminals, terminal blocks and sleeves.

The simplest example of a ferrule for stranded wire. The terminal is a metal sleeve-tube fixed at the end of the conductor using crimping pliers

Terminals are called both metal elements for decorating the ends of single- and stranded wires, as well as small plates inside connecting devices - sockets, terminal blocks, patch panels.

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 a good finish, 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 of various 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 it 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, which 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, flexible stranded wire should be terminated with lugs.

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

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

Possible names are: 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!

Requirements are requirements, and the most popular type of connection is twisting. Where quick installation is required, terminal blocks of various shapes are used. One of the types of terminal connections is spring terminals. Particularly widespread are Wago products.

To perform a branch without breaking the line, clamps are used, which among electricians are called nuts. It is some kind of terminal connection.

Use of terminal blocks

The terminal block consists of contacts fixed on a plate of insulating material. The contact plate has a screw on both sides, which tightens the wire. This allows one side of the plate to press a copper wire, and on the other side an aluminum wire without fear of chemical interaction between these metals.

You can connect different types of wires. On the one hand, a single-core wire can be fixed to the plate, and on the other, a stranded one. Another problem that is easy to solve with a terminal block is the connection of wires with different core diameters.

The terminal block can consist of one or more contact plates, which is very convenient in terms of installation. To do this, just dial the required number of plates and fix in the right place.

Spring terminals

Terminals of this type are very similar in design to terminal blocks. The difference is that a spring-loaded plate is used as a clamp. Using spring terminals is very simple - you need to strip the wire to the depth of the terminal.

The pressure plate is removed and the stripped wire is inserted into the terminal. The wire is inserted so that there are no exposed sections of the wire. Then the pressure plate snaps into place and the process is complete.

Spring terminals can be used to mount solid, stranded wires and wires of different diameters. Installation of wires from different metals is allowed. The most widely used contacts are Wago, which contain bimetal plates with a special contact paste against metal oxidation.

Installing PPE caps

PPE caps are often used when wiring. In appearance, they are very reminiscent of the back plastic cap of a ballpoint pen. Inside it is laid a spring in the form of a cone. The spring is covered with oxidation-resistant anodized metal.

To connect wires must be stripped to a length of 10 - 15 mm and fold the cleaned areas into one bundle. The ends of the beam are inserted into the cap, which is then screwed onto them until it stops. The PPE cap can connect several wires, in which the total cross section will not exceed 20 mm².

They come in a variety of sizes so it's easy to find the right one for you. The caps are color-coded, which is convenient for highlighting the phase or neutral wire.

PPE caps can significantly increase the installation time, because this connection does not require additional insulation. The material of the cap is made of non-combustible material and will not provoke spontaneous combustion when overheated at the junction.

The quality of the PPE connection with caps is worse than the terminal ones and do not allow connecting wires from different metals.

Crimping with special sleeves

Where it is necessary to create a high-quality and reliable connection, special sleeves can be used. The sleeve is a piece of copper tube of the required diameter. The diameter of the sleeve is selected depending on the total diameter of the connected wires.

The stripped ends of the wires are inserted into the sleeve and clamped. Then a heat shrink tube is put on the sleeve, with which this sleeve is insulated. If there is no heat shrink tubing, then you can use cambric or electrical tape. Wires can be inserted into the sleeve from one or both sides. For crimping, they try to use special manual press tongs.

With this connection, the sleeve cannot be used twice. During the repair, it is simply thrown away. By using manual stripping pliers and pressing pliers, installation can be carried out with good productivity.

Soldering or welding

Soldering is not very common. Soldering always guarantees a reliable connection. The contact has low resistance and good mechanical strength. Soldered wires are less susceptible to damage due to ingress of moisture.

To connect by soldering, it is necessary to strip the wires by 40 - 50 mm, irradiate with rosin and twist. Then solder is applied to the twisted ends, heated until it spreads evenly over the entire twist and flows inside. The appearance of the soldered wires should be shiny.

After soldering, the sharp ends are treated to prevent damage to the insulating material. As insulation, you can use any available type.

Such a connection can be attributed to the most laborious. The soldering process requires certain skills. Installation in this way at a height with improvised means is not very convenient. When connecting by soldering, it is necessary to leave some margin in case of repair.

In some cases, a contact welding method is used. The process itself is similar to the soldering method, but the stripped twisted wires are not covered with solder. A welding transformer is used for connection. The ends of the wires are heated until they fuse into one metal ball.

Heat shrink tubing is put on the welded ends for insulation or wrapped with electrical tape.

Twisting and insulation

Twisting is completely rejected by the rules of the PUE, but in practice, twisting wires is used almost everywhere. But twisting must be able to do and then it will last for decades. To do this, they clean the wires with such a calculation. That the twist should be at least 4 - 5 cm long.

The cleaned areas are cleaned of the oxide film with a knife blade or fine sandpaper. The ends of the wires are crossed at a certain angle at the end of the insulation and tightly twisted with pliers. The twist should be even and tight. From above, it is insulated with the existing insulation.

Twisting connection cannot be made for wires of different sizes. Do not twist wires of different metals. It is not allowed to twist a single-core wire with a stranded one. Such a connection is used only where there is no fire-technical acceptance of repairs.

Clamp "nut"

The nut-type branch clamp is designed to carry out branches from the main wires without breaking. At the connection point of the outlet, a section of insulation is removed and a “nut” is attached to this place. The clamp consists of a carbolite body and a steel clamp. The clamp consists of two plates and screws. Each plate has a recess for a certain section of the wire.

One plate is placed under the wire, and covered with another plate on top. Both plates are clamped with screws, and between them is a wire and a tap. To choose the right "nut" depending on the diameter of the wire, you must use the table.

To make the connection, it is necessary to disassemble the carbolite body. It consists of two halves compressed by two retaining rings. If the rings are pryed off and removed, the case will disintegrate. If the wires are made of different metals, then an additional plate must be used. It will prevent the contact of different metals and the further oxidation process, which will worsen the contact. The screws are tightened with reasonable force, and inserted into the case.

Bolt use

Bolt connection is used most often when it is necessary to connect copper and aluminum wires. Stripped wires are put on a regular steel bolt, and steel washers and Grover's washer are put between them. The whole "sandwich" is pulled together and wrapped with insulating tape.

What if there are several wires?

To connect multiple wires, you can use a terminal block. To do this, one half of the contact plates must be connected with one wire. The number of such plates should be equal to the number of wires. The rest of the wires are attached to the opposite contacts of the plates.

You can take a terminal block with the number of plates equal to the number of wires divided in half. Then one half of the wires is clamped to one half, and the other half to the other half of the contacts.

Several wires can be connected with a bolt. Lay a steel washer between the wires, and put Grover's washer under the nut.

Identical wires can be connected using a PPE cap using known technology or by welding.

What to do if the conductors are of different sections?

If it is necessary to connect wires with conductors of different sections, then you can apply:

• soldering or welding;
• Bolted connection;
• Connection by self-clamping terminals;
• Screw terminals;
• branch clamp;
• Copper tips and bolted connection.

Combining stranded and solid products

The connection of stranded and solid wires can be performed using:

• Solder connection;
• Connection with special sleeves;
• Terminal connections;
• Tip connection.

How to carry out work in water and on land?

All outdoor wiring must be carefully protected from moisture. For laying, it is necessary to choose cable products that are designed for such work. The cable must have at least two insulating layers. In addition to the existing insulation, the wire must be placed in the corrugation. For laying in the ground - in a pipe with tight couplings.

All sockets, switches, lamps and other elements must be made in the appropriate design. On water, only low voltage is used for power supply. All connecting elements are placed above the water level.

In the article we will tell you how to connect the power cable to the shield / battery / amplifier / outlet, etc., consider diagrams and instructions. Industrial enterprises produce a large number of varieties of power cables and circuit elements through which they are connected:

• Switchboards;
• Sockets, single-phase, three-phase;
• Connectors of various designs for household and industrial equipment;
• Batteries in DC networks and others.

In all cases, there are features of installation work that are recommended to be observed in order to provide high-quality contacts. Reliable cable connection with other elements of the network ensures long-term and trouble-free operation of the power line itself, all its elements and equipment connected to it.

Connecting the power cable to the switchboard

Before laying the cable to the switchboard, many factors are taken into account:

• Location of the RSC;
• Outdoors, in a dry room or with high humidity;
• The design of the shield, the location of the tires and cable fastening elements;
• Locations of inlet openings on the switchboard housing for cables and other points.

First of all, it is planned from which side the cable will approach the switchboard. In the plastic and metal enclosures of the switchboard, the contours of technological holes are stamped at the factory for cable entry from several sides. Such stamping allows you to quickly open the hole from the right side. Please note that, according to the requirements of the PUE, clauses 1.1.7 and 1.1.8, on the street in the open air or in rooms with high humidity, cables are brought in only from the bottom side of the switchboard. This reduces the chance of moisture getting under the outer insulating shell and inside the cabinet.

Cable termination and connection

Almost all input cables for high current loads have at least double insulation, on each core and an outer sheath. Therefore, regardless of what brand of cable for installation, the following operations are performed:

• 
  

  With a mounting knife, the outer insulating layer is removed by 150 - 250 mm from the end of the cable;

• Separate the cores, it is recommended to immediately mark the cable and each wire. There are many ways of marking, one of the simplest is to put cambric wires on the wires with the appropriate inscriptions. A sticker is glued onto the common sheath, wrapped with transparent tape, it indicates where the cable comes from and where, the cable brand, the number and cross section of the cores, and the length. Wires of the same color can be marked with colored cambric or electrical tape; for professional electricians, this marking is understandable. Blue, black color indicates neutral wire, red, brown or white phase, yellow-green ground.
• The cable is brought into the switchboard with a margin of up to 0.5 m for cutting and in case of possible changes in the connection scheme. To do this, near the cabinet, it is folded into a loop, if space permits, the loop can be placed inside the cabinet.
• In modern switchboards, holders or crossbars are made for laying cables in vertical or horizontal positions. The cable is fixed to the fastening elements with plastic clamps with a lock.
• Inside the cabinet, the cable is mounted towards the busbars or towards the contacts of the input circuit breaker.
• The ends of the wires are stripped of insulation by 1-1.5 cm, tubular lugs of the appropriate diameter are put on them and pressed with a special press.

• The contact tips are flattened on one side and have holes for bolts, with which the contact plane is pressed against the busbar or terminal of the circuit breaker.

• In some models of automatic protective switches, tips are not required, the bare ends of the wires are inserted into the contact group and clamped with bolts.

For reliable contact, it is very important that the planes of the tips adjoin the tires as much as possible. Under such conditions, good current flow will be ensured. Wires with a cross section of up to 10 mm 2 in the switchboard and VRU can be connected to special blocks with clamping bolts, where lugs are not required.

When connecting the cable to the three-phase line shields, the requirements for laying the cable to the cabinet and inside remain the same, except for marking the neutral wire and grounding are marked with the letter "N" in blue, blue and "PEN" - yellow-green. Phases are designated by the letters "A", "B" and "C". All cables are marked on both sides and the wire designations on both ends must match. Read also the article: → "".

Connecting power cables to sockets

For wiring in the outlet group of rooms, it is recommended to use a cable of the VVG brand. In wooden structures, VVGng is laid with insulation from non-combustible material, there is an imported analogue of this NYM wire, but it is much more expensive.

Council number 1. It is not recommended to install wires of the PUNP brand, they are convenient for laying, but very rarely correspond to the declared characteristics. This is due to unscrupulous manufacturers, 80% of products on the market are defective, the percentage of copper in the alloy is underestimated, the insulation layer and wire cross section are thinner, and many other inconsistencies. These shortcomings lead to emergency situations, the cable does not withstand the calculated current loads, the wires burn out.

When planning, the maximum power of electrical appliances connected to the socket group is taken into account, the choice of wire section depends on this. Statistics and practical experience show that for an apartment or a private house, wires with a cross section of 4 mm 2 are laid between junction boxes in socket groups. From the junction box to a 2.5 mm 2 socket, subject to the inclusion of ordinary household appliances of low power, a TV, an iron, a refrigerator, hand-held power tools and other equipment.

The cable is inserted into junction boxes and socket boxes by 15 - 20 cm, the outer sheath is removed up to 10 cm, the insulation from the wires is 5 cm in the junction box, in the socket boxes up to 1 cm. The bare ends in the junction box for connection to the socket are twisted together with two pliers . Both wires are clamped together near the end of the insulation, and near the bare ends. The former remain stationary, while the latter make rotational movements to twist a pair or more wires.

In this case, you must have a sense of proportion, twist tightly, but do not overtighten until the twist breaks. In the classic version, the ends of the twists in junction boxes are welded with a welding machine, a DC step-down transformer, with a graphite electrode. But most often, installers do not adhere to these technologies; twists are simply insulated with electrical tape or plastic caps. Read also the article: → "".

From the switchboard to the socket, the cable wires are connected in accordance with the requirements of the PUE, by color. A red or brown wire comes from the phase contact, they are also connected in the junction box and lowered to the outlet. Neutral wires with blue insulation and yellow-green are connected throughout the network, starting from the ground bus in the switchboard.

The socket is connected to the wires coming out of the socket, the phase and neutral conductors are attached to the contacts into which the plug from electrical appliances is inserted. Grounding wire to the contact with the grounding designation, the ways of fixing the wires on the contacts may be different, it depends on the type of sockets.

There are contact groups with screw clamps or spring clamps. After connecting the wires and the socket body, they are packed into the socket box, the spacer screws are screwed in, everything is closed with a front decorative cover.

Features of connecting power cables to a battery or other DC sources

Industrial facilities and domestic activities often use equipment powered by direct current sources. The most common batteries are:

• They are installed for the starter, starting the engine and powering other automotive equipment;
• Connect to chargers
• To inverters (converters) of DC voltage to AC 12/220V; 24/220V and others;
• Batteries are actively used as backup power sources in the absence of voltage in the industrial network and in other cases.

In all these cases, in order to ensure long-term and trouble-free operation of the equipment, it is very important to correctly connect the cable:

• The most important requirement for connecting a cable or individual wires to a battery is polarity. Otherwise, the electronic components of the equipment may burn out and the battery may be discharged. The wire connected to the positive terminal is usually installed with red insulation, blue or black wires are connected to the minus.

On the battery case near the contacts, the signs "+" and "-" are indicated. The same designations are placed on the connected equipment and at the ends of the wires on both sides;

• It is imperative to take into account the cross section of the wires, it must correspond to the currents of the connected load, this can be correctly determined from pre-calculated tables.
• The reliability of the connected contacts is of great importance; for this, special terminals are made for acid batteries, lead or brass. The design of the terminals provides for the installation of wires and battery contacts; the clamp is carried out with bolts. For lithium-ion batteries, contact connections may be of a different design.

Before attaching all elements to the battery contacts, it is very important to ensure their cleanliness, especially on acid batteries that have been in operation. On lead and brass elements, oxide builds up, which prevents the passage of current. To remove it, metal brushes are used, you can take a hard toothbrush to treat contacts with an alkaline solution that neutralizes acidic components. After cleaning, you can put the terminals with wires on the battery contacts and clamp them with bolts.

Connecting an amplifier (subwoofer) to a car battery

Some lovers of loud music install power amplifiers to car radios and players. The problem of this scheme is the consumption of high power, not always a car battery is enough to provide power for automotive equipment and musical equipment. In this case, use a separate additional battery. In any case, it is important to correctly calculate all the necessary parameters and correctly perform the installation:

• First of all, they determine the installation location of the amplifier, usually this is done in the rear of the car in the trunk;
• The distance for laying power cables to the battery is calculated;
• The brand of cable is selected and the cross-section of wires is calculated based on the power of the amplifier.

For car radios, amplifiers with a power of 50 - 80 W are used, calculations are carried out according to the formula:

I \u003d P / U The flowing current "I" flowing through the wires is equal to the ratio of the power "P" of the amplifier to the voltage of the car battery "U". If your quad amplifier is 60W x 4 = 240W, total power consumption. The current in the subwoofer power circuit will be 240W/12V = 20A. For a power reserve, add about 20% and, according to the table, select the required wire cross-section based on a current of 24A. At direct current, the power significantly depends on the length of the wire from the power source to the consumer.

Practice shows that a cross section of 1.5 - 2.5 mm is quite enough to power the amplifier from an on-board 12V battery.

The wires are selected flexible, stranded with a reliable insulating layer. Red is connected to the positive terminal of the battery and the corresponding terminal on the amplifier, through the fuse of the calculated current value.

From the trunk to the engine compartment, where the battery is 4-5m, the cable is laid in a corrugated hose. The corrugation is laid into the partition of the front panel through technological holes with rubber seals to prevent chafing of the insulation and short circuits under vibration conditions. The negative polarity wire is attached between the negative terminal of the amplifier and the nearest bolt on the car body in the luggage compartment.

Council number 2. It is not recommended to run control and speaker wires in parallel next to power wires. Doing so will result in noise and distortion in the sound reproduction.

To connect on-board equipment to the battery, cables with flexible stranded wires are usually used. For the installation of outdoor lighting lines, hidden wiring of socket groups, grades with monolithic rigid wires, not of large cross section, are laid. To connect the switchboard from substations and overhead lines, large-section cables of 10, 16 mm 2 or more with monolithic conductors and stranded wires made of aluminum or copper alloy are used.

Some brands of power cables

Manufacturers make a large number of wire brands with stranded wires, but only a few types are in great demand for connecting household, industrial equipment and individual structures. Read also the article: → "".

VVG. A power cable with stranded copper wires, sealed and durable PVC insulation, is laid to connect the switchboard over the air on cables, along walls, underground and cable channels in various structures. It is very flexible and is suitable for trails where there are a lot of turns and bends.

AVVG. In practice, this is the same cable as VVG, but the letter “A” means that the conductive cores are made of aluminum wire, without a letter, by default, it means that the wires are copper.

Two letters "B" mean that each core and outer sheath are covered with a vinyl insulation layer, "G" - the bare cable does not have additional armor protection.

Specifications:

AVK. The cable has a coaxial design, in the center there is a monolithic aluminum core, then an insulating vinyl layer, which is shielded with thin aluminum wires arranged in a row around the diameter along the entire length. The outer shell is made of durable sealed plastic.

The cable is very practical, it can be laid from overhead lines with voltage up to 380V, underground from substations to switchboards of buildings. One of its main advantages is considered to be the exclusion of the possibility of unauthorized connection on uncontrolled sections of the route.

SIP-4. A feature of this cable is its self-supporting design, which allows the cable to be placed on overhead lines without a cable suspension.

This quality makes it universal, it can be laid along the walls of structures, underground and cable channels, in rooms with high humidity. It has a reliable sealed PVC insulation on each wire with a stranded structure.

The main parameters of SIP-4:

To supply from the overhead line to the switchboard of a residential building, 3x16 or 4x16 cables are usually used, such a number of wires in the cable and the cross section is quite sufficient for the power consumed in domestic conditions.

AVBbShv / VBbShv. The design feature of this cable is the presence of an armored layer, two steel tapes are wound onto the surface of the cable so that the upper one covers the gaps between the turns of the lower tape. The cable is fully armored, in addition, PVC insulation on each core and a common sheath.

Marking decoding:

• A - aluminum conductors can be monolithic or twisted from individual wires, the absence of this letter by default means copper alloy wires.
• B - vinyl insulation of wires;
• BB - armored steel tapes;
• Shv - PVC hose as an outer insulating sheath.
• Shv ng - may indicate that the insulation is made of non-combustible materials.

In the cable structure, there can be from 1 to 5 cores of the same or different cross-sections, usually the yellow-green or neutral blue ground wire is made of a smaller diameter. To connect private houses, do not use a cable with a wire cross section of more than 16mm 2. At industrial facilities, the cross section can reach 300 mm 2 and more.

Specifications:

Cable with armored protection is allowed to be laid in an environment with high humidity and underground, but this does not exclude the possibility of using it in other more favorable conditions.

Errors when choosing a cable and connecting

• Most often, gross errors during installation work are made when choosing a cable. Be sure to consider the conditions in which it will be operated, and calculate the required cross section. If you install a large-section armored cable where VVG 3x6 is enough, there will be extra financial costs and problems in installation work. You will not receive advantages during operation and savings.
• When connecting to PSB busbars, do not install copper lugs on aluminum wires and vice versa. Inhomogeneous metals have different resistances, this leads to large current losses and heating of the wires at the connection points.
• Try to ensure that the busbars in the switchboard and the wires are of the same metal, copper or aluminum. If they are different, then use combination lugs to connect aluminum to copper.
• After connecting the cable to the busbars or circuit breakers, connect the maximum possible load for a couple of hours. After that, de-energize the switchboard and stretch all the bolted connections on the contacts. This is especially important at industrial facilities, where there are large current loads in the network for a long time, the contacts are inspected and stretched once a week. With insufficient clamping, the contacts will burn out.
• It is not recommended to loop the end of the bare wire around the clamp bolt with washer to contact the busbar. Such a connection has a smaller touch area than the tip, the current loss will be greater.

Frequently Asked Questions in polls

Question number 1. Can aluminum wires from AVVG be connected to the battery?

No, especially to acid, there will be large current losses due to the difference in resistance at the junctions. The contacts are lead, the terminals can be copper, and the wires are aluminum.

Question number 2. In a car, can a 220V powered amplifier be connected via a 12/220V inverter?

It is practically possible, but it is better to use 12V equipment in order to save energy and safety.

Question number 3. What wire is better to connect welding machines?

You can use multi-core VVG, but it is better with rubber insulation KG, the cross section is calculated based on the power of the device.

Question number 4. From power lines to switchboards at home, which cable is better to use?

Best of all, the SIP brand with a cross section of 10 - 16 mm2, this is quite enough, there are less costs for laying, at a distance of up to 20 m, additional cable is not required.

Question number 5. The cable runs along a concrete fence, they are constantly connected, they steal electricity, spoil the insulation, how to avoid this?

Of course, you can drip the cable, or run it through an overhead line, if it is expensive or impossible, the best option is to install an AVK brand cable. Its design eliminates the possibility of unauthorized connection in uncontrolled areas.