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

The electrical wiring of residential premises consists of many elements, these are various current-carrying conductors (cables), protective devices, wiring accessories, and individual current consumers. In order to collect 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 with high quality, or, as they say, to connect (switching refers to the processes that occur when electrical circuits are closed or opened).

At first glance, it may seem to an untrained person that nothing complicated should be here. But, working with an electrician "on a whim", it does not matter whether we transfer a single outlet, connect a lamp or assemble a complex control system, we are at serious risk. Experienced electricians know that wiring is primarily a "struggle for contact", since it is an open circuit, and not a short circuit, that is the most common problem that one has to face. Obviously, the places of connections in the circuit (terminals, twists) are the most vulnerable, since at these points the mechanical contact density can weaken (the contact area decreases), an oxide film with a very high resistance forms on the conductors over time. Poor contact becomes the cause of heating of current-carrying conductors, sparking at the points of commutation is a consequence of the appearance of a transient contact resistance. Complete burnout of the wire and de-energizing the site when household appliances do not work, or the light goes out, this is unpleasant, but the problem is solved. Worse if the insulation of the wires heats up and collapses, which threatens to damage a person electric shock or a fire.

Recently, the load on the wiring has seriously increased, therefore, even more stringent fire and electrical safety requirements are now imposed on switching. However, if earlier there were not many connection options, now there are reliable modern fixtures facilitating wiring commutation. 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 the 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);
• material of current-carrying conductors (copper or aluminum);
• type of cables (flat or round, rigid or soft stranded, single or double insulation);
• the purpose of the node (group or single branch, end connection);
• the presence of mobility of wires or vibrations near them;
• high temperature, humidity;
• indoor or outdoor use.

Connection of wires in junction boxes

According to the provisions of the PUE, the branching of the wires of the household network can only be made in the distribution (soldering) box. Junction boxes allow, during the operation of the wiring, to quickly reach the ends of any individual branch, if necessary, find out which one is broken or has a short circuit. You can also always inspect the condition of the contacts inside the box, make them Maintenance... Modern PVC boxes are used for open and hidden wiring, they have sufficient reliability and extended functionality: they can be easily installed on different surfaces, are convenient for wiring 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 (outputs and sockets), it is recommended to use separate junction boxes for each room. Such a split power supply makes it possible to make the electrical wiring of the home more balanced and safe, since "light" and "sockets" differ in workloads and operating conditions, and different requirements are imposed on them. Moreover, it is much easier to upgrade or repair the wiring later, and not always all the wires in a room can be normally marked in one case.

The commutation of wires in any junction box can be carried out according to the same principle. In most cases, "twisting" is initially used, but simply wrapping 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 conductors and reduce the oxidation of materials. Clause 2.1.21 of the PUE offers the following options:

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

Crimping of wires

The essence of this method lies in the fact that the twisted wires are inserted into a special sleeve made of metal, which is compressed with manual pliers, a mechanical or hydraulic press. Pressing can be done either by local pressing or by solid pressing. This wire connection is considered one of the most reliable. Crimping allows the conductors to be compressed very tightly, increasing the contact area, the mechanical strength of such a commutation is the highest. This method is used for both copper and aluminum wires.

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

1. The wires are freed from 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 inner diameter is selected, as well as a suitable punch and matrix.
5. The liner is processed from the inside with quartz-vaseline paste (if it comes from the factory "dry").
6. The twist is inserted into the sleeve.
7. The stranding is compressed with press tongs. It is necessary that the tooling of the tool 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

Crimping conductors can be done using terminal blocks, PPE caps or WAGO clamps.

The terminal block housing is made of plastic; inside it there are sockets with threads and clamping screws. The wires can be wound under single terminal screws towards each other, or one conductor goes through the entire block and is fixed with two screws. Some junction boxes are assembled with standard strips.

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

PPE caps (connecting insulating clamps) are also made of durable non-combustible polymer, which, being an insulator, provides mechanical and fire protection... They are wound with effort on the twisting of the conductors, then the conical metal spring inside the cap expands and compresses the current-carrying conductors. As a rule, the inside of the PPE is treated with a paste to prevent oxidation.

WAGO clamps for junction boxes are screwless, here the compression is performed by a spring, you just need 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 wires 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 at operating currents up to 41 A for 6 squares, 32 A for 4 squares and 25 A for 2.5 squares. Interestingly, WAGO universal clamps allow you to connect wires of different 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 conductor. Due to the fact that there is no direct contact of the wires to be connected, it is possible to commute copper wires and aluminum, while there is no need to regularly audit the compression of aluminum. Inside, WAGO terminal blocks also have a paste that destroys the oxide film and improves contact, however, the 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 using additional tools, they are compact and reliable. It must be said that WAGO is not the only company that produces screwless spring-loaded terminal blocks.

Whatever type of crimping device is used, it is necessary to accurately select it according to the section of a separate conductor or twisted, since a terminal that is too large may not provide normal contact. In this case, you can not always trust the marking - it is better to check the conformity of the fasteners and conductors on site. We recommend having an assortment of crimp terminals by standard size 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 tightness of the fixation of the cores 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 pressure testing, crimping or welding. You can solder wires made of aluminum and copper, you just need to choose the right solder. An ordinary soldering iron is suitable for branching wires with a cross section of up to 6-10 mm 2, but more massive wires will have to be heated with a portable gas burner(propane + oxygen). For soldering, it is necessary to use a flux in the form of rosin or its alcohol solution.

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

Soldering the conductors is as follows:

• wires are stripped of insulation;
• veins are sanded with emery to a metallic sheen;
• twisting is done with a length of 50-70 mm;
• the core heats up with a burner flame or a soldering iron;
• the metal is covered with flux;
• v working area solder is injected or the hot twist is immersed in a bath with molten solder for 1-2 seconds;
• after cooling, the brazed twist is insulated with electrical tape or polymer caps-tips.

Welding

Most often, electricians use contact heating to reliably switch wires in a junction box. It is possible to weld twisting 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 conductors is fused into single drop, and then the current during the operation of the electric circuit does not even flow through the twisting body, but through the formed monolith. If everything is done correctly, then the connection turns out to be no less reliable than a solid wire. This method has no technological and operational drawbacks, the only thing is that it is necessary to purchase a suitable welding machine.

Welding of copper conductors is carried out permanently 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 regulation welding current, which are light and lightweight (during operation they are sometimes worn on the shoulder), can be powered from a household network. In addition, inverters provide good arc stability at low welding currents. Due to the high cost of inverters, electricians often use homemade devices for welding, made from a transformer with a power of more than 500 W, with a secondary winding voltage of 12-36 volts. The earth and the electrode holder are connected to the secondary winding. The electrode itself for welding copper conductors must be infusible - carbon, it is a factory copper-plated "pencil" or a homemade element made of a similar material.

If a factory inverter is used for welding wires, then it is recommended to set the following operating current indicators for conductors of different cross-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 80-120 amperes. These indicators are approximate, 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 wire cuttings. Correctly selected indicators are when the arc is stable, and the electrode on the twist does not stick.

The wire welding process includes the following operations:

• the conductors 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 forms;
• after cooling, the welded twist is insulated with electrical tape, heat shrink tubing or a plastic tip.

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

Connecting wires to terminals of electrical equipment

Connecting household appliances and various wiring accessories are also an important milestone wiring commutation. The operability of consumers, as well as the protection of users and fire safety, depend on the reliability of electrical connections in these nodes.

The technology for connecting current-carrying conductors to equipment is regulated by the PUE, current SNiPs, as well as the "Instructions for the termination, connection and branching of aluminum and copper conductors of insulated wires and cables and their connection to contact terminals electrical devices". As well as the branching of conductors in junction boxes, soldering, welding, crimping, screw or spring crimping are used for termination and connection. One way or another 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). The elements of the switchboard are supplied with crimp sockets: circuit breakers, RCDs, an electric meter; here, switching buses with screw terminals are used.

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

Please note that for crimp connection, soft stranded conductors must be terminated with insulated ferrules (connectors). Connectors are not needed for rigid monolithic conductors. If you do not use ferrules, then the soft core should be twisted tightly and irradiated with solder before connecting. The size of the tip 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, for a clamping tunnel socket, a connector in the form of a pin is used, for fixing with a nut on a bolt - a ring or fork. In turn, the forked tip is not recommended for use if the device is movable 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 into a ring of a suitable radius using round-nose pliers. Glass skin ring or sandpaper It is cleaned 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 conductor from being squeezed out), a grover (springs the connection, prevents it from unwinding during vibrations), and an assembly clamp tightly tightened with a nut. If a large cross-sectional core (from 10 mm 2) should be clamped under the bolt, then a metal sleeve with a ring is pushed onto the conductor by crimping.

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

1. Strip the wires with special pliers, as when removing the insulation with a knife, the cross-section of the core is very often reduced.
2. Always remove the oxide film from the conductor. Use glass skin or emery, use special fluids and contact paste.
3. Twist 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. Run the conductor under the terminal or sleeve / lug up to the insulation itself.
6. Make sure that the wire insulation does not get under the clamp.
7. If possible, wind and clamp not a single soft core into the tunnel screw terminal, but a twisted one.
8. Using electrical tape, wind it with an overlap of turns in three layers, be sure to go to the insulating sheath of the conductor. The 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 check the tightness of the connection mechanically - tug on the conductors.
11. Never connect copper and aluminum directly.
12. Fasten the cable firmly near the patching area so that the wire does not pull downwards and the connection is not subjected to any mechanical stress.
13. Use color coded conductors, for example, in the entire intra-house network, the brown conductor will be the phase, the blue conductor will be zero, and the yellow conductor will be the ground.
14. Accept a single connection diagram for the installation of all devices (for example, the phase on the sockets is clamped on the right terminal, and the neutral is not on the left).
15. Label both ends of all wires yourself - 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 "light bedroom"). 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 end length will be 100-200 mm. To switch the panel, you may need wires up to one meter long, so that you can wind some of them from the bottom of the box, and some from the top.
17. Bring the external cable ducts to the junction boxes close to each other; it is better to insert a round corrugation or pipes into the housing a few millimeters.
18. We connect the sockets in parallel, and the switches in series. The switch should break a phase, not zero.
19. Squeeze all wires of one switched twist into a bundle and fix it with electrical tape. Inside the box, separate the insulated connections as far apart as possible.
20. Use only certified materials and specialized tools.

In conclusion, I would like to reiterate the importance of quality execution switching works. 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.

It often happens that wires of different cross-sections come to the junction box and they need to be connected. It seems that everything should be simple, as with the connection of wires of the same cross-section, but there are some peculiarities here. There are several ways to connect cables of different thicknesses.

Remember that you cannot connect two wires of different cross-sections in an outlet for one contact, since the thin one will not be strongly pressed by the bolt. This will lead to poor contact, high contact resistance, overheating and melting of the cable insulation.

How to connect wires of different sizes?

1.By twisting with soldering or welding

This is the most common way. You can twist wires of adjacent cross-sections, for example, 4 mm 2 and 2.5 mm 2. Now, if the diameters of the wires are very different, then good twisting will no longer work. During twisting, you need to make sure that both cores are twisted around each other. A thin wire should not be allowed to twist on a thick one. This can lead to poor electrical contact. Do not forget about further soldering or welding. Only then will your connection work for many years without any complaints.

2.Using screw clamps ZVI

I already wrote about them in detail in the article: Ways to connect wires. Such terminal blocks allow, on the one hand, to start a wire of one section, and on the other side of a different section. Here, each core is clamped with a separate screw. Below is a table according to which you can choose the right screw terminal for your wires.

Screw terminal type		Permissible continuous current, A
ZVI-3	1 - 2,5	3
ZVI-5	1,5 - 4	5
ZVI-10	2,5 - 6	10
ZVI-15	4 - 10	15
ZVI-20	4 - 10	20
ZVI-30	6 - 16	30
ZVI-60	6 - 16	60
ZVI-80	10 - 25	80
ZVI-100	10 - 25	100
ZVI-150	16 - 35	150

As you can see, with the help of ZVI, you can connect wires of neighboring cross-sections. Also remember to look at their current load. Last digit in the type of screw terminal, it indicates the amount of permissible continuous current that can flow through this terminal.

We clean the cores to the middle of the terminal ...

We insert them and tighten the screws ...

3.Using Wago universal self-clamping terminals.

Wago terminal blocks have the ability to connect wires of different cross-sections. They have special nests where each core is "stuck". For example, you can connect a 1.5 mm 2 wire to one hole of the clamp, and 4 mm 2 to the other, and everything will work properly.

According to the manufacturer's markings, terminals of different series can be used to connect wires of different cross-sections. See the table below:

Wago Terminal Series	Cross-section of the connected conductors, mm 2	Permissible continuous current, A
243	0.6 to 0.8	6
222	0,8 - 4,0	32
773-3	0.75 to 2.5 mm 2	24
273	1.5 to 4.0	24
773-173	2.5 to 6.0 mm 2	32

Here's an example with the 222 series ...

4. Using a bolted connection.

A bolted connection of wires is a composite connection consisting of 2 or more wires, a bolt, a nut and several washers. It is considered reliable and durable.

Here it goes like this:

1. we clean the vein by 2-3 centimeters so that it is enough for one full turn around the bolt;
2. we make a ring from a core according to the diameter of the bolt;
3. we take a bolt and put it on a washer;
4. we put a ring from a conductor of the same section on the bolt;
5. then we put on the intermediate washer;
6. we put on a ring from a conductor of a different section;
7. put the last washer and tighten the whole thing with a nut.

In this way, you can simultaneously connect several cores of different cross-sections. Their number is limited by the length of the bolt.

5. Using the junction nut clamp.

I wrote about this connection in detail with photos and the corresponding comments in the article: Connecting wires using "nut" type clamps. Let me not repeat myself here.

6. Using tinned copper lugs through the bolt and nut.

This method is well suited for connecting large cable sizes. For this connection, it is necessary to have not only TML tips, but also crimping press pliers or Hydraulic Press... This connection will be a little cumbersome (long), it may not fit into some small junction box, but it still has the right to life.

It's easy to connect here. A tip is put on each core, they are crimped and connected with a bolt with a nut and washers. Then this place is insulated with insulating tape or heat-shrinkable tubing (it must be put on the wire before connecting).

Unfortunately, I didn't have a thick wire and the necessary terminals at hand, so I made a photo from what was. I think you can still understand the essence of the connection from it.

It seems that I have listed everything. If you know other ways to connect wires of different cross-sections, then write in the comments.

Let's smile:

There are two sitting in the cell:
- What are you sitting for?
- For murder.
- How much did you give?
- 7 years. What are you for?
- For poaching.
- How many?
- Fifteen.
- Who are you hunting ?!
“I’m walking, so I’m hunting, I see a telegraph pole, an eagle is sitting on the pole. Well, I'm a doublet ...
- And what ?! For the eagle for 15 years? Did you even kill him?
- Yeah ... shot, claws in one direction, pliers in the other.

To date, a bunch of the most diverse ways to connect have been invented. But, for some reason, the method of "bite off, twist and rewind with electrical tape" is not inferior to its position.

But it also happens that it is fundamentally wrong.

The reason is that twisting two wires from different material, for example, copper and aluminum, is categorically wrong. The fact is that when the aluminum wire is oxidized, galvanic vapor is released, which will eventually break the connection. And the more current passes through this connection, the sooner it collapses. And, if the load on the wires is not constant, then constant heating-cooling will only worsen the condition of the wiring.
This wiring connection can be dangerous. As sparks in the compound can cause a fire.

Fortunately, there is a sure way out of the situation.

For example, here's a thing called a polyethylene terminal block:

You can buy such an uncomplicated contraption in any hardware store... And if you pull out a brass sleeve from it, you can clearly see how the wiring is connected:

You need to shove the ends into it and tighten the screws:

When folded, that is, in normal form, it looks like this:

And by the way, each insulating segment can be detached from each other. So, at first glance, everything is perfect and simple, but no. And here there were some drawbacks.

If you pinch the aluminum wire, then you need to make sure that it does not work out like this:

This is a clear example of the fact that aluminum cannot be clamped, and if this has happened, then the terminals need to be changed once a year. Otherwise, the contact will heat up and this will lead to a fire.

Do not clamp stranded wires in the sleeve. You may not get lucky and something that you already know will happen.

It is important to choose right size sleeves for the diameter of the wire, otherwise it may fall out or break if pinched.

When buying a terminal block, do not get fooled by the inscription on it. They are lying. It is better to divide the current into 2 or 3 sleeves.

And as practice says, it is better not to buy such terminals at all. And if used, then only to connect something small, a light bulb, for example.

The same goes for unnamed Chinese gizmos. Better overdoing than underdoing. Therefore, buy terminals from normal trusted manufacturers, such as: Tridonik, ABB, Legrand, Verit

Terminal Blocks TB Series

Made of hard black plastic, with a lid. This one is already much better than the previous one.

Inside consists of two screws and a plate:

Here you need to screw it around the screw and press it with a plate:

A good thing, because here the wires are clamped by an iron plate, and not by the screw itself, which is undoubtedly a big plus.

.
The surface is such that it does not increase the clamping surface by much, which means that both multi-core and single-core ones can be clamped. But, nevertheless, aluminum should be checked from time to time. The bad thing about these terminals is that they don't share. And less than 6 pieces are unlikely to be found.

Self-clamping terminals (WAGO, REXANT 773 series)

They look like this:

Extremely comfortable clamps. What you need is so simple to strip the wire and push it all the way:

Inside that terminal there is such a thing, where the pressure plate is indicated by the blue arrow, and the orange small bus made of tinned copper:

Here's what happens when a wire is pushed into it:

That is, the wire is pressed tightly by the plate to the tire and holds it so constantly, does not allow it to fall out.

Even an aluminum wire can be pushed into this terminal without fear.

These are exactly the same but transparent terminals:

Their plus is that through the illuminated walls you can see how deep the wires are pushed. This terminal is suitable for 4KW. However, there is one big BUT. This means that only original WAGO terminals have such capabilities. For the rest, the maximum current is limited to a lower value.

WAGO 222 Series Terminals

Such terminals will be indispensable if there are wires of different diameters and from different materials.

These terminals have levers:

When the lever is raised, then you need to insert the wires and fix by lowering the lever:

You can replace the wire by lifting the lever and pulling it out. Smart thing, conducts current up to 32A.

When wiring or repairing electrical wiring, when connecting household appliances and a lot of other work is required to connect the conductors. In order for the connection of wires to be reliable and safe, it is necessary to know the characteristics of each of them, where and when, under what conditions they can be used.

Existing ways of connecting conductors

To connect wires can be done in several ways:

• welding is the most reliable method that provides high reliability of the connection, but requires skills and the presence of a welding machine;
• terminal blocks are simple doable and pretty reliable connection;
• soldering - works well if the currents do not exceed the standard and the connection does not heat up to temperatures above normal (65 ° C);
• crimping with sleeves - requires knowledge of technology, special pliers, but the connection is reliable;
• the use of spring clips - wago, PPE - are quickly installed, provided that the operating conditions are observed, they provide good contact;
• bolted connection - simple to perform, usually used in difficult cases - when it is necessary to switch from aluminum to copper and vice versa.

The specific type of connection is selected based on many factors. It is necessary to take into account the material of the conductor, its cross-section, the number of cores, the type of insulation, the number of conductors that will be connected, as well as the operating conditions. Based on these factors, we will consider each of the types of connections.

Welding - high reliability in all conditions

When connecting wires by welding, the conductors are twisted, and their end is welded. As a result, a metal ball is formed, which ensures a stable and very reliable connection in all conditions. Moreover, it is reliable not only in terms of electrical characteristics, but also mechanically too - the metal of the connected wires after melting forms a monolith and it is impossible to isolate a separate conductor.

Welding - it is important to heat the metal, but not melt the insulation

The disadvantage of this type of wire connection is that the connection is 100% one-piece. If you need to change something, you need to cut off the fused piece and redo it all over again. Therefore, for such connections, a certain supply of wires is left - in case of possible rework.

Other disadvantages include a welding machine, appropriate electrodes, flux and work skill. In addition, welding takes a lot of time, it is required to protect the surrounding objects, and it is also inconvenient to work with the welder at a height. Because electricians given type connections are practiced in exceptional cases. If you do "for yourself" and know how to handle well welding machine, you can practice on scraps. The main trick is not to melt the insulation, but to weld the metal.

After cooling, the welding site is insulated. You can use electrical tape, you can use heat shrink tubing.

Crimping wire connection

For crimping wires, a special aluminum or copper sleeve is required - it is selected based on the size of the twist (diameter of the bundle), and the material is taken the same as for the conductors. Bare and shine-stripped wires are twisted, a sleeve tube is put on them, which is clamped with special pliers.

Both sleeves and pliers are different, there are several types. Each of them has its own rules of use (the number of wires that can be packed in a sleeve), in which you need to navigate well. Wires should be packed according to certain rules, measure the size of the resulting bundle, customize it to your requirements. In general, a rather dreary task. Therefore, this type of wire connection is mainly used by professional electricians, and more and more often they are switching to spring clamps.

Terminal blocks

One of the simplest and most reliable wire connections is through terminal blocks. There are several types of them, but a screw connection is used almost everywhere. Eat with nests different sizes- for different sizes of conductors, with different amounts pairs - from 2 to 20 and more.

The terminal block itself is a plastic case in which a metal socket or plate is soldered. A bare conductor is inserted into this socket or between the plates, clamped with a screw. After the screw is tightened, you need to tug the conductor well - make sure that it is tightly clamped. Due to the fact that the connection points remain uninsulated, the area of ​​application of the terminal blocks is in rooms with normal humidity.

The disadvantage of such a connection: due to the plasticity of metals - especially aluminum - contact weakens over time, which can lead to an increase in the degree of heating and accelerated oxidation, and this again leads to a decrease in contact. In general, periodically the wire connection in screw terminal boxes must be tightened.

Advantages - speed, simplicity, low cost, does not require any skills, except that the ability to use a screwdriver. Another important advantage is that you can easily connect wires of different diameters, single and multi-core, copper and aluminum. There is no direct contact, therefore there are no risks.

Soldering

First, about the soldering technology. The connected conductors are cleaned of insulation, cleaned from oxide film to pure metal, twisted, then tinned. For this, the conductors are heated with a soldering iron and applied to the rosin. It should cover the joint completely. Tinned wires are twisted first with your fingers, then squeezed using pliers. Soldering flux can be used instead of tinning. They wet the wires well, but after twisting.

Then, in fact, the soldering process begins: the joint is heated with a soldering iron or a narrow-torch torch. When the rosin or flux begins to boil, they take some of the solder on the tip of the soldering iron, bring it into the soldering zone, pressing the tip to the conductors. The solder flows to fill the gaps between the wires, providing good connection... When using a torch, the solder is simply applied a little to the torch.

Further, after the soldering point has cooled down, according to the technology, it is necessary to wash off the flux residues (they accelerate oxidation), dry the connection, cover it with a special protective varnish, and then isolate it with electrical tape and / or heat shrink tubes.

Now about the advantages and disadvantages this method wire connections. In low current systems, soldering is one of the most reliable ways to connect wires. But, when wiring electrical wiring in a house or apartment, it is criticized mercilessly. The thing is that the solder has a low melting point. With the periodic passage of large currents through the connection (it happens if the circuit breakers are incorrectly selected or faulty), the solder gradually melts and evaporates. Over and over again, the contact gets worse, the connection heats up more and more. If this process will not be found, it may well end in fire.

The second negative point is the low mechanical strength of the soldering. It's about tin again - it's soft. If there are a lot of wires in the soldered joint, and if they are still rigid, when trying to pack them, the conductors often fall out of the solder - the elastic force is too great, which pulls them out. Therefore, it is not recommended to use the connection of conductors by soldering when wiring electricity: it is inconvenient, long and risky.

Spring clamps for connecting wires

One of the more controversial ways to connect wires is with spring clips. There are several types of them, but the most common two are wago (wago) terminal blocks and PPE caps. Outwardly and in the way of installation, they are very different, but at the heart of both designs is a spring that creates strong contact with the wire.

This spring is under debate. Opponents of wago use say that the spring will weaken over time, the contact will get worse, the connection will start to get hotter, which, again, leads to even more rapid decline the degree of spring elasticity. After some time, the temperature may rise so much that the body (plastic) will melt, but what can happen next is known.

Spring loaded wiring clamps - popular wire connection

In defense of the use of spring clips to connect wires, it can be said that if they are used in accordance with the manufacturer's recommendations, problems are very, very rare. Although there are many fakes and wago, and PPE, as well as an abundance of photos of them in molten form. But, at the same time, many use them, and, under normal operating conditions, they work for years without any complaints.

Wago wire clips

They appeared on our market several years ago and made a lot of noise: with their help, the connection is very fast and easy, and at the same time has high reliability. The manufacturer has specific recommendations for the use of these products:

There is a metal plate inside these devices, which ensures the proper degree of contact. The shape and its parameters of the plates were specially developed and tested. The tests were carried out on a vibration stand for many hours, then heated and cooled. Then we checked electrical parameters connections. All tests were passed with "excellent" and branded products always show themselves "five".

In general, the range of Wago products is very wide, but for wiring or connecting household appliances, lighting fixtures, use two options for wire clamps: series 222 (detachable) with the ability to reseal or change the connection and series 773 and 273 - which are called one-piece.

Detachable

Spring clips for wiring Wago 222 series has a number of contact pads - from two to five - and the same number of flag-clips. Before starting the connection, the flags go up, the conductors stripped from insulation are inserted into them (all the way), after which the flag is lowered. At this point, the connection is considered complete.

Wago wire connectors - connection methods

If necessary, you can reseal the connection - raise the locking flag and remove the conductor. Convenient, fast and reliable.

The 222 Vago series can be used to connect two or three, even five conductors made of copper or aluminum (you can connect different metals in one terminal). Wires can be solid or stranded, but with stiff wires. The maximum section is 2.5 mm 2. Soft stranded wires can be connected with a cross section of 0.08 mm 2 to 4 mm 2.

One-piece

There is another type of clamps, which does not provide for the possibility of redoing the wire connection - the 773 and 273 series. When using these terminals, the work is generally a second: the stripped wire is inserted into the corresponding socket. There is a spring clamping it, ensuring contact with the plate. Everything.

These spring loaded wire clamps can be used to connect solid aluminum or copper wires with a cross-sectional area of ​​0.75 mm 2 to 2.5 mm 2, stranded with rigid wires from 1.5 mm 2 to 2.5 mm 2. Soft stranded conductors you cannot connect with such connectors.

To improve contact, the wires must be cleaned of oxide film before connecting. To prevent further oxidation from continuing, wago manufacturers also produce contact paste. The inside of the clamp is filled with it and it itself corrodes the oxide film, and then protects the wires from oxidation in the future. In this case, only highly oxidized, dark conductors need preliminary stripping, and the clamp body is filled with paste.

By the way, manufacturers say that, if desired, the wire can be pulled out of the clamp. To do this, take the wire with one hand, hold the terminal box with the other and rotate them back and forth with a small range, in opposite directions, stretching in different directions.

Clamps for lamps (construction and installation clamps for luminaires)

For quick and convenient connection of lamps or sconces, wago has special 224 series terminals. With their help, it is possible to connect aluminum or copper wires of different cross-sections and types (single-core or stranded with rigid wires). The nominal voltage of this connection is 400 V, nominal current:

• for copper conductors - 24 A
• 16 A for aluminum.

Cross-section of the connected conductors from the mounting side:

• copper 1.0 ÷ 2.5 mm2 - single-core;
• aluminum 2.5 mm2 - single core.

Cross-section of the connected conductors from the side of the chandelier / sconce: copper 0.5 ÷ 2.5 mm2 - single-core, multicore, tinned, crimped.

When connecting copper wires, contact paste must be used, and aluminum wires must be manually stripped to bare metal.

This product has two drawbacks. First, the price of original terminals is high. Second - there are a lot of fakes at a lower price, but their quality is much lower and it is they who burn and melt. Therefore, despite the high cost, it is better to buy original products.

PPE caps

PPE caps (stands for “connecting insulating clamps”) are very easy-to-use devices. This is a plastic case, inside of which there is a conical spring. Conductors stripped of insulation are inserted into the cap; the cap is rotated clockwise several times. You will feel that it has stopped scrolling, which means the connection is ready.

How to make a wire connection using PPE

These conductor connectors are produced by many manufacturers, they are available in different sizes, for different diameters and the number of conductors to be connected. In order for the connection of the wires to be reliable, the size must be chosen correctly, and for this it is necessary to understand the marking.

After the letters PPE there are several numbers. Depending on the manufacturer, the number of digits changes, but they mean the same things. For example, there is this type of marking: SIZ-1 1.5-3.5 or SIZ-2 4.5-12. In this case, the number immediately following the letters indicates the type of case. "1" is set if the body is an ordinary cone, on the surface of which grooves can be applied - for a better grip. If there is a CIZ-2, then there are small protrusions on the body, which are convenient to grasp with your fingers and twist.

All other numbers reflect the total cross-section of all conductors that can be connected using this particular PPE cap.

For example, PPE-1 2.0-4.0. This means that the body of the connecting cap is conventional, tapered. It can be used to connect two conductors with a cross section of at least 0.5 mm 2 (they add up to 1 mm, which meets the minimum requirements - see the table). As much as possible, this cap contains conductors, general section which should not be more than 4 mm 2.

Connection of wires with PPE caps

In the second version of the marking, after the abbreviation PPE, there is only a number from 1 to 5. In this case, you just need to remember which one is useful for which wire cross-section. The data is in another table.

PPE caps and their parameters

By the way, PPE caps can only connect copper wires - aluminum conductors, as a rule, are thicker than the maximum allowable for these connectors.

Bolted connection

This connection is assembled from a bolt of any diameter, a suitable nut and one, or better - three, washers. It is assembled quickly and easily, it serves for a long time and reliably.

First, the conductors are stripped of insulation; if necessary, the upper oxidized layer is removed. Further, a loop is formed from the stripped part, the inner diameter of which is equal to the diameter of the bolt. To make it easier - you can wrap the wire around the bolt and tighten ( middle variant in the right figure). After that, all this is collected in this order:

• A washer is put on the bolt.
• One of the guides.
• The second washer.
• Another conductor.
• Third puck.
• Screw.

The connection is tightened first by hand, then using keys (you can take pliers). That's all, the connection is ready. It is mainly used if it is necessary to make a connection of wires from copper and aluminum, it can also be used when connecting conductors of different diameters.

How to connect aluminum and copper conductors

By the way, we recall why it is impossible to directly connect copper and aluminum wire... There are two reasons:

• Such a connection gets very hot, which in itself is very bad.
• Over time, the contact weakens. This is because aluminum has a lower electrical conductivity than copper, as a result, when passing the same currents, it heats up more. When heated, it expands more strongly, pressing copper conductor- the connection is getting worse, it gets hotter and hotter.

To avoid such troubles, copper and aluminum conductors are connected using:

• terminal blocks;
• wago;
• bolted connection;
• branch clamps (make wire connections on the street).

Other types of connectors cannot be used.

How to connect wires of different diameters

If you need to connect conductors that have different diameter, to receive good contact twisting should not be present. This means that you can use the following types:

• terminal blocks;
• wago;
• bolted connection.