How to connect electrical wires to each other. Correct connection of electrical wires to each other

When repairing household appliances or maintaining electrical wiring with their own hands, any master is faced with the question of safely creating electrical circuits by connecting the wires to each other or connecting them to the output terminal blocks.

However, even experienced electricians can make mistakes in ensuring the reliable formation of electrical contacts, which will not appear at the initial moment of operation, but will create a malfunction over time.

The metal of the wire is made for the ideal flow of electric current through it. For this purpose, it is cast from a homogeneous composition of a copper or aluminum alloy with a standard cross section along the entire length.

To create a contact, a simple contact of the surfaces without any effort is enough. The photo below shows that if an open strand of the second wire is placed on one bare area, then an electrical connection is formed between them. Through it, a 4-volt battery can make a light bulb from a flashlight glow.

In home wiring much more - 220 volts. An erroneous conclusion is drawn from this fact: it is easy to create a contact of electrical wires.

Beginning electricians simply forget the issue of providing reliable transient resistance for long-term operation of such a connection.

When mounting the wires, the home master is faced with the need to process:

1. conductive core;
2. layer of insulation.

These are two interrelated processes that provide the final result - the optimal flow of electric current through the created circuit.

How to work with wire insulation layer

The dielectric coating protects the metal core from the occurrence of unforeseen chains. When it is violated, leakage currents immediately appear, leading to malfunctions.

The insulation layer of the wire may be broken:

• under mechanical influence;
• overheating;
• from solar radiation.

Protection from all these destructive factors is required. Moreover, removing, if necessary, a layer of insulation to connect the wire, it is impossible to damage the surface of the metal core.

To safely perform this job, many tools with cutting edges have been created. Consider their use for home conditions.

electrician's knife

Trade provides a wide range of their designs. Some workers prefer to use knives made with their own hands from materials selected according to their individual characteristics.

When choosing the right model for your needs, pay attention to them, eliminating the possibility of accidental cuts.

The main condition for proper operation is the orientation of the blade relative to the axis of the wire. The formed angle must be sharp. Then the knife will cut off the dielectric layer and at the same time slide over the metal without touching it.

Setting the knife perpendicular to the wire will cut through not only the insulation, but also the surface of the metal core. This means that it will reduce its cross section, break the connection, increase the electrical resistance to the passing current, which will cause excessive heating and aging of the dielectric layer.

Deep penetration of a sharp blade into the metal leads to rapid breakage when the wire is bent. Such scratches can be identified by careful visual inspection. But who does it?

A fitter's knife is a common tool for every electrician, but not all home craftsmen have good practical skills in stripping insulation. Yes, and experienced professionals can inadvertently cut the metal and not notice the error.

Therefore, the industry has long been producing tools adapted for these purposes.

Stripping pliers

Their industrial designs have been produced for quite a long time, and the design is constantly being improved. Let's look at them with examples.

rare sample

For the set of tools of the Soviet electrician, combined pliers were produced, allowing:

• safely cut and remove insulation from wires of standard sections 1.5 and 2.5 mm square;
• bite copper veins;
• bend neat rings;
• perform other operations.

They cope with their tasks normally even now, despite their unsightly appearance, slight wear, and heavy weight. To remove the insulation from the ends of the wire, it is enough:

• insert it into the appropriate slot;
• squeeze the handles to cut the insulation;
• ensure axial movement of the jaws towards the end of the wire.

The surface of the metal core is not damaged, it remains in its original state.

The increased gripping force of the handles is compensated by the design of the tongs, it does not create malfunctions.

Modern models

They have significantly greater technical capabilities that allow you to work with wires of small and increased cross-sections, both with monolithic and stranded conductors.

Made of high-strength plastic, the housing has dielectric properties and is lighter in weight. It is equipped with various controls and accessories.

Such a tool must not only be studied before work, but correctly adjusted for each cross section. Otherwise it will create problems.

Pliers and side cutters

Among electricians there is a category of workers who remove insulation in a similar way. The error of this method is the uncontrolled compressive force of the handles, which leads to squeezing of the metal of the wire, deformation and destruction of its surface.

This error may occur intermittently with a random sequence. It depends on the experience of the employee, his condition, attentiveness and other factors.

It is dangerous to remove insulation in this way, and the places of its removal must be carefully checked. Particular attention should be paid to stranded stranded conductors.

How to work with metal core wire

Methods for creating electrical contacts through wire are based on the use of:

• screw terminals;
• twists;
• soldering or welding;
• spring compression.

Screw connections

The connection can be made:

• pressing the ring;
• pressing the core with a screw directly or through washers.

Making rings

When screwing in the screw, the wire ring should work in compression, and not in spinning. They must be separated by wide washers on each side of the surface. Incorrectly clamped in the form of a ring, the wire may come out of the mount during operation.

This method is considered the most reliable and is widely used in energy enterprises.

Use of terminal blocks

The metal core is inserted into a special socket, held in it by the tightening force of the screw through the surface of the spring steel washer or its threaded end.

With this method, it is important to observe the nominal value of the screwing force. Weak twisting leads to pulling the wire out of the terminal (you need to check it by hand), and excessive twisting crushes the core.

Wire twisting

The contact surface created between the cores must cover the cross-sectional area with a margin.

For this, the twisted ends with the insulation removed are made of a large length of the order of 10 cm, and their twisting is performed with pliers quite tightly with a uniform distribution of turns.

When twisting, the wires should be well crimped and stretched for reliable contact of the surfaces.

Ways to create an improved twist

The contact resistance of the surface layer contact can be reduced by:

• welding of the terminal section of the connection;
• soldering twisted surface.

Not every home master can apply this technology. It requires special equipment - a welding transformer for copper or aluminum, or. Therefore, in home wiring, twists are immediately covered with electrical tape or insulated with heat shrink tubes.

Typical twist errors

Often, electricians make short ends of the wire, which, under heavy loads, cause increased heating of the contact connection being created.

Insulating caps for connecting wires

Contact is created by compressing the surfaces of each wire by the force of a spiral spring built into the housing.

The metal conductors of the appropriate diameter, cleaned of insulation, are screwed into a spiral, creating a twist. The steel spring expands slightly when the wire ends are inserted and compresses them in the socket.

Errors in wiring with PPE caps

The poor quality of the connection contact arises from:

• inept work of electricians;
• the use of low-quality fakes of branded products;
• erroneous calculation or installation of electrical wiring;
• incorrect and protective shutdown devices.

To prevent possible malfunctions, individual masters increase the surface of the twist, having previously removed a larger layer of insulation than required and make a twist on it. After screwing in the PPE cap, the exposed area is wrapped with electrical tape or covered with heat shrink tubing, which creates additional compression.

However, this technology is not provided by manufacturers and requires additional actions and time.

Wago terminal blocks

When using them, the electrical contact of the circuit is created by a spring clip controlled by a special lever.

The wire is inserted with a metal core into the socket of the terminal block until it stops with the lever retracted, and then fixed in it with a simple action. The created contact connection has an acceptable transient resistance, works well at rated loads. It is not worth counting on its reliable operation during prolonged overloads of more than 16 amperes.

The advantage of Vago terminal blocks is the ability to quickly rewire the circuit for its reconstruction. The wires from them in most designs are quickly and easily removed. However, there are disposable models on sale that do not provide the function of re-breaking the created chain.

This connection method is common among our western neighbors. It is well suited for the home craftsman who does everything with his own hands, but does not have enough practice to securely connect the wires in other ways.

Features of connecting a flexible wire

Stranded stranded conductors are designed for use in mobile electrical appliances. They withstand bending, twisting well, but do not work well when installed in terminal blocks to create screw or spring contact.

Under the generated compression force, the individual wires are deformed, and their total twist spreads so that the total cross-sectional area of ​​the wire can decrease.

To prevent this process, metal tips with a dielectric insert of the appropriate diameters are used. After installing a bare core in them, a small crimp is made, creating an electrical contact.

When a stranded wire with such a ferrule is inserted into the terminal block, it is additionally compressed by screw fastening or spring force. As a result, a normal electrical contact is created from all the wires.

Only properly configured protections can prevent the consequences of unnoticed installation errors when switching on under load:

• circuit breakers,

To supplement the material on a reliable connection of wires, in relation to the conditions of home wiring, provides the owner's video "Electrician's Tips" "Pros and Cons". Recommended for viewing.

How to connect the wires correctly? Every man asked this question at least once in his life, even without being an electrician. In everyday life, we often have to deal with such questions. The plug of the electric cable fell off, the wire of the chandelier broke off, the socket stopped working, the connection in the home telephone disappeared, there was no voltage in the on-board network of the car, etc. All these problems are easy to solve if you have elementary knowledge in the field of electrical engineering and observe safety when carrying out installation or repair work.

In this article, we will look at how to properly connect wires when installing electrical wiring, breaking an electrical circuit, or simply for the purpose of repairing electrical equipment.

Why you can not directly connect wires from different metals

Let's start with the fact that you can't just take and connect conductors without taking into account the properties of the material from which they are made. Each of the metals used to transmit electricity, and these are most often aluminum, copper and steel, has a different density, resistance and electrical conductivity. In addition, it is necessary to take into account such a factor as the electrochemical potential that occurs when a current is applied to a metal.

Serious problems, for example, can be caused by improper connection of copper and aluminum wires. This question is often faced by specialists involved in the repair of wiring in our homes. The fact is that most old houses and apartments are wired from copper wire. After all, 30 years ago, copper was cheap, and in terms of electrical performance, it significantly exceeds aluminum.

Today, copper wires are used quite rarely. Their place was taken by aluminum.

But what happens if you still combine copper with aluminum? The latter, being a metal with high oxidation rates, forms a specific film on its surface, which has a fairly high electrical resistance. This is especially true when exposed to moisture.

Copper also has a similar film, but its resistance is much less. Due to this difference, the direct connection of copper and aluminum wires causes difficult conduction, and mutual oxidation processes lead to the formation of shells on the conductors, heating, sparking and even fire.

But what about when it is necessary to connect wires from different metals? For this, there are special devices. We will now talk about them in the context of a review of existing types of compounds.

1. Twisting (twisting).
2. Banding.
3. Welding.
4. Soldering.
5. Crimping.
6. Riveting.
7. Terminal connection.
8. Connection using terminal strips and clamps (terminals).
9. Threaded connection.
10. Connection by piercing conductors.
11. Cable clamp.
12. Connection with a "nut".

Twisting

Twisting is the simplest connection of wires. It is enough to strip them of insulation, tightly twist them together with pliers - and you can test. Yes, such installation has the right to exist, but not for a long time, especially if we are dealing with different conductor materials. It can only be used as a temporary connection and, at the slightest opportunity, should be replaced by a more reliable one. By the way, in the rules for the installation of electrical installations (PUE), this installation is not mentioned at all, since it is considered unreliable and quite dangerous.

Such a connection of wires is categorically not recommended for the installation or repair of electrical networks, electrical wiring in a room and a car.

But there is also a reliable twist, or rather, an improved one. There are ZIS caps on sale, specially designed to increase the reliability of twisting. They are made of fireproof plastic, and inside they have a cone-shaped spring. Having placed an ordinary twist inside such a cap, it must be turned all the way. The coils of the spring will open under the influence of your force, and then securely fix the ends of the conductors together. In this case, the cap will get the role of a kind of electrical insulator. This method is often used to secure wiring in a distribution box in a residential or commercial building.

bandaging

Banding is also one of the varieties of twisting. It is not reliable and cannot be recommended for installation or repair of electrical wiring.

The essence of bandaging is that the bare ends of two, three or more conductors are folded together and wrapped with a softer wire with good electrical conductivity, such as copper with zinc coating, after which the contact point is carefully insulated.

Welding

Next, we will analyze more reliable types of wire connections. One of these installations is the welding of electrical conductors. It can be called an improved and legalized twist, because the ends of the wires are subject to welding after they are twisted. This process can be carried out in two ways: using electric arc welding and thermite. In the first case, metal electrodes are used, and in the second, a special combustible mixture is used.

If everything is clear with arc welding, then we will consider in more detail how the installation takes place using thermite powder.

There are special thermite cartridges of various diameters, inside of which there is a compressed combustible mixture. It consists of crushed aluminum, magnesium, calcium, silicon, titanium and other metals. This powder burns with the release of a huge amount of heat. Under its influence, the conductors, being placed in such a cartridge, are firmly welded to each other. To get such a connection of wires, you just need to strip them of insulation, twist them, place the twist inside the cartridge and set it on fire with a special match included in the kit. After welding, it is imperative to remove the slag deposits resulting from combustion.

Naturally, only large diameter wires and cables can be connected by welding. For domestic needs, this method is not intended.

Soldering

Another fairly common, but not particularly reliable mounting method is soldering. It is best suited for domestic use, unless it is electrical wiring. According to GOST R 50571.5.52-2011 and PUE, this connection method is not recommended for high voltage electrical circuits, since the solder has a rather low melting point. But for the repair of household electrical appliances, it is quite suitable.

It should be immediately indicated that this method can only be used to connect copper wires, since it is unlikely that aluminum can be soldered at home.

In order to carry out high-quality soldering, you will need:

• soldering iron with a power of 60-100 W;
• solder (tin-lead);
• flux (rosin);
• small brush (for applying flux);
• sandpaper.

We clean the wires by 3-4 cm, process them with sandpaper and twist them together. Now, using a brush, apply flux to the connection and solder the wires to each other, applying molten solder.

If our wires are stranded, we pre-twist each of them and cover them with solder.

Sometimes it becomes necessary to connect not two, but three, four or more conductors. Of course, one cannot do without special devices, however, for circuits using low voltage, installation called a “star” can be used. This is a kind of soldered twist of several conductors. The connection of wires with a star consists in winding a spiral on the main core of the taps, followed by coating the contact points with solder and insulation.

Crimping

Crimping is one of the most reliable types of connection and meets all the requirements of the rules for electrical installations. Its essence lies in the fact that the wires are placed in a special metal sleeve and crimped with a special tool.

To do this, it is enough to have:

• a sleeve of the appropriate size made of copper or aluminum (the material must match the material of the conductors);
• knife for removing insulation;
• special press tongs (pliers will not work);
• insulating tape.

We clean the wires to the length of the sleeve, twist and place in the sleeve. Next, with the help of pliers, we press our connection and isolate it for security purposes.

There are also special tube sleeves for longitudinal connection, i.e. extension of the conductor. In this case, the wires are inserted on both sides of the tube, after which each of them is crimped separately.

Such a connection of electrical wires is widely used in the installation of electrical wiring in residential and industrial premises.

riveting

This method cannot boast of its popularity, but its reliability is beyond doubt. Here, a special rivet is used as a connecting element, which, in fact, is needed in order to securely connect the conductors by riveting. Rivet material - copper or aluminum is selected according to the material of the wires.

Such a wire connection scheme is often used in the installation and repair of 380/220 V consumer electrical networks.

To connect the conductors by riveting, you will need:

• rivet (copper or aluminum);
• two steel washers (flat and spring);
• special tool - riveter.

First, the end of one wire, stripped and twisted into a ring, is put on the rivet, then the spring washer, after it, the end of the other wire and the flat washer, similarly processed and shaped, are put on.

Terminal connection

The terminal connection is most common in automotive on-board electrical circuits, where it is often necessary not only to connect the wires, but to connect them to some device, be it a relay, sensor, backlight, etc., which have special standardized contacts for this. Its essence lies in the fact that a terminal of the required size is put on the end of the wire stripped of insulation, after which its lower part is pressed with ordinary pliers. For more reliable contact, the junction can be soldered.

Terminal strips and clamps

Installation using "terminals" is probably the most common way to connect wires of household electrical wiring. There is no need for welding, soldering or special tools. It is enough to have special "terminals" for connecting wires, sold in any hardware store for a penny, and an ordinary screwdriver. Such installation is very reliable and durable.

"Terminals" for connecting wires are of two types:

• with bolt clamp;
• self-tightening with spring clamp.

The first option involves the use of a plastic terminal strip with contacts clamped with bolts. To carry out such an installation, you need to unscrew the screw with a screwdriver, insert the wire into the hole specially provided for it and clamp it in the same way.

Self-clamping terminal blocks are even easier to operate. Their design is equipped with a flat-spring mechanism, actuated by special levers on the body. It is enough to cock this lever, insert the end of the stripped wire under it and release it. The spring itself will clamp the wires and securely fix them.

These methods of connecting wires have practically no drawbacks, with the exception of one - the quality of the materials from which they are made. You probably remember the old Soviet terminal strips, made of hard non-combustible black plastic. Even today they are often found in old electrical wiring and are ready to serve for decades to come. Modern "terminals" cannot boast of this, so when buying, pay special attention to the case material and do not purchase cheap models.

Threaded connection

Threaded wire connections are most often used in various input and distribution devices of electrical installations. This installation is quite reliable and also does not require any special skills. An ordinary steel bolt is used here as a connecting element. The ends of the wires after stripping are formed into loops and put on the leg of the bolt mixed with steel washers so that there is a washer between them, as well as on both sides of the conductors. After that, the structure is clamped with a nut.

This installation is advantageous in that it allows both the connection of aluminum wires used in consumer power lines, and copper, as well as their combinations.

piercing

There is another type of installation that is used exclusively for power lines, various electrical installations and their switchgears. This is piercing. It is carried out using a special piercing clamp, which is put on the conductors and, compressing them, cuts off the insulation, forming a contact between the cores.

Its advantage over other methods is the possibility of installation without turning off the line power, because the master does not have direct contact with the conductor itself.

cable clamp

The cable clamp allows not only to connect two conductors of different metals, but also to create a side branch from them. It consists of two steel plates, flat or with special bulges for the diameter of the cable, connected with several bolts. Having unclenched these bolts, bare conductor strands are inserted between the plates in a certain order. Upon completion of the installation, the bolts are clamped, holding the wires securely. With the help of such plates, it is possible to compress ordinary twisting, significantly increasing its reliability.

Nut connection

"Nutlet" is an improved version of the cable clamp. Its design also provides for the use of two figured plates pressed against each other by bolts. However, the “nut”, among other things, has a collapsible body in the form of a plastic ball, which is put on the joint after installation is completed. This feature allows this connection to be used outdoors.

1. When connecting wires intended for high voltage transmission yourself, follow at least the first two of the three rules of an electrician: "Disconnect, check, ground."
2. Choosing the type of connection, stop at the most reliable and secure.
3. Never use rigs such as stranding or bundling to connect wires outdoors.
4. Each connection must be securely insulated.
5. Having no idea about electrical engineering, do not try to fix the electrical network or electrical appliance with your own hands, it is better to trust the specialists.

It is very important to know about connectors for electrical wires, because electrical contact depends on their quality. There are many ways to connect wires, you can do it the old way or use terminal blocks.

But not everything is so smooth, there are also disadvantages. Under room conditions, aluminum begins to flow under screw pressure. You will have to periodically revise the terminal blocks and tighten the contacts where the aluminum conductors are fixed.

If this is not done in a timely manner, the aluminum conductor in the terminal block will loosen, lose reliable contact, as a result, spark, heat up, which can result in a fire. With copper conductors, such problems do not arise, but it will not be superfluous to make a periodic revision of their contacts.

Terminal blocks are not intended for connecting stranded wires. If stranded wires are clamped into such connecting terminals, then during tightening under pressure of the screw, the thin veins may partially break, which will lead to overheating.

In the case when it becomes necessary to clamp stranded wires into the terminal block, then it is imperative to use auxiliary pin lugs.

It is very important to choose its diameter correctly so that the wire does not pop out later. The stranded wire must be inserted into the lug, crimped with pliers and fixed in the terminal block.

As a result of all of the above, the terminal block is ideal for solid copper wires. With aluminum and stranded, a number of additional measures and requirements will have to be observed.

They have a number of advantages:
• Ease of use.
• Ability to connect wires from dissimilar materials.
• Protection against corrosion and other external influences.
• Reliability, strength of connections.

Terminal blocks can have a different design. The most popular are 3 types of execution:
1. screw;
2. spring;
3. knife;

Another very convenient wire connector is a terminal on plastic pads. This option differs from terminal blocks by a smooth metal clamp. In the clamping surface there is a recess for the wire, so there is no pressure on the core from the twisting screw. Therefore, such terminals are suitable for connecting any wires in them.

In these clamps, everything is extremely simple. The ends of the wires are stripped and placed between the plates - contact and pressure.

Such terminals are additionally equipped with a transparent plastic cover, which can be removed if necessary.

Wiring using these terminals is simple and quick.

The wire must be pushed into the hole to the very end. There it is automatically fixed by means of a pressure plate, which presses the wire against the tinned busbar. Thanks to the material of which the pressure plate is made, the pressing force does not weaken and is maintained all the time.

The internal tinned bar is made in the form of a copper plate. Both copper and aluminum wires can be fixed in self-clamping terminals. These clamps are disposable.

And if you want clamps for connecting reusable wires, then use terminal blocks with levers. They lifted the lever and put the wire into the hole, then fixed it there by pressing it back. If necessary, the lever is raised again and the wire protrudes.

Try to choose clamps from a manufacturer that has proven itself well. WAGO clamps have especially positive characteristics and reviews.

Screw terminal blocks

Screw connectors are widespread in the electrical industry, in fact, they are a variation of a tubular (coupling) product. They are made in the form of a rectangular tube, but having a rounded (oval) bottom. On the upper plateau of such a tube there are threaded holes where the locking screws are screwed.

The entire structure is enclosed in kapron insulation. For access to the screws in the body of the insulation, passage channels are made. There are two types of such terminal blocks (connectors) for connecting wires - single and group.

Screw terminals for connecting wires are characterized by: pronounced mechanical strength; the ability to work with cables with a cross section of up to 25 mm; use in low current and power circuits. Working with this type of connector is easy.

The end parts of the wires are inserted inside the brass tube and the locking screws (usually two screws) are wrapped with a screwdriver. In turn, the screws press the conductor against the bottom of the metal tube.

Screw terminals- one of the most common types. They are a brass sleeve with two bolts in a plastic case. Contact is provided by bolt pressure. The case can be made of different materials - polyethylene, polyamide and polypropylene. With their help, you can connect wires with a cross section from 0.5 mm 2 to 35 mm 2.

The advantages of screw pads include:
• No special tool required (just a screwdriver).
• Possibility of repeated use.
• Ability to use the required number of segments.

Screw pads also have a number of disadvantages:
1. High transition resistance.
2. Low reliability (with vibration weaken).
3. Wire material restrictions.
4. Installation duration.
5. Requires some skill to tighten.
6. Annual maintenance required.

Such terminals are undesirable. They have increased "fluidity", the connection weakens over time. To avoid heating due to an increase in contact resistance, they must be regularly tightened. This creates inconvenience during operation.

Certain problems arise with stranded wires. It is possible to perform high-quality installation with screw connections only using special tips or pads with a pressure plate. Otherwise, there is a possibility of damage to the cores when tightening the screw.

Thus, solid copper wires are most suitable for this design.

Mounting with a screw connection is very simple:
• Cut off the required number of terminals from the block (with a regular knife).
• Strip the insulation of the connected wires (by 5-12 mm).
• Insert the stripped ends of the wires into the terminals.
• Tighten the screws.

Dealing with this is easy. The main thing is to be careful when tightening the screws and choose high-quality terminal blocks.

When choosing, special attention should be paid to the manufacturer of the product. Today, there are products of different brands on sale. It is better to use products from such well-known manufacturers as Legrand, ABB, Tridonic, Werit.

The most common blocks of this type are self-clamping terminal blocks from WAGO.

The WAGO series is available in 2 versions:
1. PUSH WIRE (one-piece disposable).
2. CAGE CLAMP (reusable).

It is impossible to remove the conductor from disposable terminals without damaging the terminal block. Reusable have a convenient lever to release the conductor.

This equipment is widely used not only in industrial production, but also in domestic conditions. They are especially popular for.

Clamping occurs with the help of a steel spring coated with a special chromium-nickel alloy. The intricately shaped spring provides a reliable, durable connection. The case, made of polycarbonate or polyamide, can withstand a wide range of temperatures, resistant to aggressive environments.

The terminal blocks themselves are made of tinned copper. This significantly increases the contact patch, reduces contact resistance, and protects against corrosion. In addition, WAGO can be filled with a special grease that provides additional protection against corrosion.

WAGO model. WAGO is able to connect 2-8 conductors with a diameter of 0.5-4 mm 2 . They are designed for a voltage of 220 V and a current of 32 A.

All springs come in 2 versions - for a DIN rail and a regular version.

Under the DIN-rail, terminal blocks are used in control panels and control cabinets, distribution boxes. They are used wherever there is increased vibration (for example, machine building, railway industry).

Phoniexcontact manufactures DIN rail terminal blocks for wires with and without ferrules up to 35 mm2. It is possible to connect up to 50 wires at the same time.

The main advantage of Phoniexcontact equipment is its versatility. You can do any assembly. All elements are easily docked with each other.

Installation is extremely simple and affordable:
• First you need to prepare the conductor - strip the insulation by about 10-13 mm.
• To connect the wire, it is enough to open the clamp with a conventional screwdriver, insert the conductor and remove the screwdriver. The contact will close automatically.

Advantages of spring connections:
1. The presence of a separate socket for each conductor.
2. Strong, high quality connection.
3. Low contact resistance.
4. Possibility of joining wires from different materials.
5. Protection against corrosion, as well as other external influences.
6. No special tools required.
7. No special skills required.
8. Possibility of multiple use.
9. Does not require annual maintenance.
10. Vibration resistant.
11. Free access for measuring instruments.
12. Potential distribution (if necessary) using jumpers.
13. The disadvantages include low allowable currents.

In addition to such well-known brands as WAGO, Phoniexcontact, similar equipment is produced by Legrand, ABB.

Blade terminal blocks

Such pads are used much less frequently. Mainly for grounding and grounding circuits when mounted with an inextricable conductive conductor. They are used to cut branches into a carrier conductor.

In addition, knife connections are widely used in audio technology. Blocks are produced with a width of 5 mm for conductors with a cross section of 0.2-1 mm 2, a width of 6 mm for conductors of 1-2.5 mm 2. A large contact area allows you to withstand currents up to 24 A. The color scheme is quite diverse: yellow-green, orange, gray, blue and red.

There are disposable and reusable pads. Disposable pads include Scotchlok pads, which are manufactured by 3M. In them, the joining of several wires is carried out by pressing with a special tool.

Their main distinguishing feature is that during installation, stripping of the conductor is not required. The wire, together with the insulation, is inserted into the terminal block and crimped until it is completely fixed. The insulation is cut through with contacts, providing a reliable one-piece connection.

Advantages of knife terminal blocks:
• Saving installation time.
• Wire stripping and crimping is not required.
• Secure connection due to snap lever.
• Reliability, compactness.
• No special tool required.
• No special skills required.
• Increased electrical safety.

The only downside is the high price.

Products are manufactured by such well-known manufacturers as Klemsan, Legrand, 3M, and many others.

Terminal clamps

Terminal blocks for connecting wires give one indisputable advantage, they can connect wires of different metals. Both here and in other articles, we have repeatedly reminded that it is forbidden to twist aluminum and copper wires together.

The formed galvanic couple as a result will lead to the occurrence of corrosive processes and the destruction of the connection. And it doesn't matter how much current flows at the junction. Sooner or later, the twist will still start to heat up. The way out of this situation is precisely the terminals.

Wago terminal blocks

In recent years, the market has been filled with foreign-made terminal blocks. We must pay tribute: technologically, foreign designs look more advanced than domestic products. It is more convenient to work with them - it is faster and easier to make connections.

But from the point of view of the reliability of the connections made by a foreign product, not everything is so simple. In this regard, the domestic product often looks preferable. However, let's look at some examples.

Noteworthy are the electrical terminals manufactured by WAGO. The company's engineers have invented several attractive designs, where an ordinary terminal turns into a convenient connection interface: Push wire, Power cage clamp, Cage clamp.

push wire

Push Wire technology is based on the use of the rigidity properties of an electrical conductor, due to which a completely reliable contact is obtained. This type of terminal block is the most suitable for working with solid wire. Indeed, the fast connection method Push Wire provides unconditionally.

It is enough just to strip the end of the wire (by 10-15 mm) and push the stripped end inside the terminal with a little effort. And in order to remove the conductor just as quickly, it must be pulled out while scrolling around its axis.

Two types of Push Wire connectors have been developed: For a single conductor. Under the group of conductors. The group connection configuration is designed to work with wires of less rigidity than in the case of a single option. A slightly different mechanical clamp design is used here.

To open access to the conductor entry holes, some force must be applied to the push button. There are also Push wire models without a button - under the pressure action with a screwdriver.

Universal Power cage clamp

This terminal block belongs to the category of universal developments. It is made for any type of electrical wire with a cross section of 6 - 95 mm. Structurally, the Power cage clamp is a so-called double cage, where there is a spring press and a current-carrying busbar.

The connection of electrical conductors to such terminals is carried out using a hex key. By turning the key, the spring is compressed, the end of the wire is inserted under the press, then the key is turned counterclockwise. As a result, the press lowers and securely presses the inserted end of the wire.

Stackable Cage clamp

This is a unique (WAGO patented) product that has received the characteristic of a wire terminal block. WAGO terminal blocks are designed for installation on wires with a cross section of 0.5-35 mm 2. They are well suited not only for working with single-core wire, but also with multi-core wires, regardless of the degree of thinness of individual cores.

The Cage clamp works simply: with a screwdriver (or a special lever in other modifications), the spring clamp is lifted, the wire is inserted under the current-carrying busbar, and then the clamp is lowered into place.

Despite the simplicity of the design, the manufacturer claims that the clamping force on the contact is automatically adjusted and directly depends on the cross section of the wire.

A variant of a wire connector that is practically the same as the product described above. But the design of Cage clamp S is still somewhat different. The peculiarity of the “S” modification is manifested by the ability to work with this type of terminal without the use of any electrician's tools.

Plus, the type-setting terminal block of the “S” modification is designed for conductors of sufficiently high rigidity - stranded and single-core. It is also permissible to connect wires with metal lugs to the terminal.

Working with Cage clamp S is very simple: the end (stripped) part of the conductor is inserted with some force until it stops, after which the connection is established.

Connecting terminals for wires from the Gage clamp S series found a place in almost all modifications of group multi-row terminal blocks. They are convenient to use on the installation of numerous low-current electrical lines. However, the successfully closed Cage clamp S design is also used in high current circuits.

There are two modifications of the “S” design, which is completely enclosed in insulation. One involves fixing the wire when pressing the plate in the frontal direction. The other is designed for lateral pressure with a screwdriver on a springy plate.

Connecting copper and aluminum wires at home

If you need to connect copper and aluminum wires, and terminal clamps and blocks are not at hand, you can do without them. Twisting the wires in this case is not a good way out, because sooner or later the place of twisting of copper and aluminum will oxidize and this will lead to loss of contact.

An effective solution to this problem is to use a conventional nut, bolt and washer.

The reliability of this connection is in no way inferior to the terminal blocks described above. The only disadvantage is bulkiness (for example, when used in a junction box) and a large amount of PVC insulating tape for reliable insulation.

Connecting wires with a terminal block

When choosing a connecting block, first of all, one should take into account the amount of current that will pass through the junction, as well as the required number of mounting terminals in the comb. As a rule, the process of connecting conductors does not cause any difficulties even for amateur electricians.

Installation is really very simple: take a block with the required cell size, cut off the required number of sections, insert the cores inside the terminal cell and clamp each of the connected conductors with screws.

Tighten the screws for fixing the cores with a fairly moderate force. Naturally, the insulation should first be removed from the ends of the connected conductors (it is quite enough to remove about 5 mm of insulation), and the surface of the conductive core itself should be carefully cleaned.

The big advantage of such blocks is that, depending on the installation conditions, each segment can be cut off. True, there is one caveat here: in such a block, I would not recommend clamping aluminum. When tightening, the aluminum core can be crushed by the screw itself.

If aluminum conductors are connected, the screws must be tightened with extreme care. This is due to the fact that, firstly, the aluminum core can simply break, and secondly, as you know, aluminum has a certain fluidity under the influence of significant pressure, which after some time can lead to deterioration or complete loss of contact.

And this, in turn, is fraught with overheating of the conductor and its ignition. By the way, according to the regulations, absolutely all connections in which there is aluminum must be tightened once a year.

How to connect stranded wires in a block

Also note that it is unacceptable to clamp stranded conductors in such a block. Stranded wire, like aluminum, can be crushed with a clamping screw.

The fact is that in the connecting block there is everything that the stranded wire does not really “like” - this is the uneven surface of the clamping screw, and point (uneven) pressure, and rotational movement.

Of course, the installation may turn out to be quite acceptable, but it may not work out - and only a very small number of cores will remain from the conductor.

The thin wires that make up such cores are quickly deformed and damaged under the action of the clamping screw of the block. As a result, the contact is unreliable - the connection is heated and melted.

The best solution to this problem is the use of special lugs for conductors. In household electrics, sleeve lugs with plastic cuffs are most often used, which are made in different colors for ease of installation.

The process of mounting tips is carried out in several stages:
1. The end of the conductor is trimmed with wire cutters (the ends of all "wires" of the core must be the same length).
2. The insulation is stripped in accordance with the length of the metal sleeve of the tip.
3. The parallelism of all wires is carefully formed (without twisting). If the wires are twisted, they are carefully straightened.
4. The tip is put on in such a way that the bundle of wires protrudes from the sleeve by about 0.5-1 mm. At the same time, make sure that the cuff covers the edge of the insulating coating of the conductor.
5. Then, using special press tongs, the tip is crimped (in the absence of this tool, crimping can be done using ordinary pliers).
6. After that, the conductor with the installed lug is inserted into the terminal connector and fixed with a clamping screw.

Junction boxes perform a very important function. It is they who ensure the distribution of electrical wires between consumption points, i.e. switches, lights and sockets.

Decided to install the devices listed above yourself? Then you need to thoroughly understand the features and order of connecting cables, as well as the basic methods of connecting them.

For a better understanding of the process, this event will be considered in several stages: from preparing the necessary materials to connecting electrical appliances using the example of a socket, a two-gang switch and light bulbs. Beforehand, you will learn about the main methods of connecting cables and the features of the connection.

Wire connection methods

There are several methods for connecting electrical wires. You can choose the most convenient and suitable option for your case.

Prices for cables and wires for construction and repair

Cables and wires for construction and repair

The first stage - getting ready for work

First of all, we prepare everything that is required to connect electrical appliances to the box. Set includes:

• cables 3x2.5, VVG;
• cables 2x2.5, AVVG;
• switch for 2 keys;
• fastenings;
• lighting;
• socket;
• round nose pliers;
• roulette;
• wire cutters;
• pliers;
• flat screwdriver;
• hammer.

The second stage - do the markup

At this stage, we mark the installation locations of electrical appliances and the paths for the passage of wires. So we can calculate the required amount of materials for the installation of the system.

The third stage - proceed to installation

First turn off the electricity supply.

We bring the wires to the junction box. As a rule, cables are laid in strobes. To fix the cables, small nails or special plastic clips are used. In the case of performing work in a wooden house, the wires will be supplied through special mounting boxes.

Important note! Wiring must be laid so that the cables do not intersect. In the event that intersections are inevitable, such places must be isolated especially carefully.

The fourth stage - we connect electrical appliances and connect the wires

We start in a junction box pre-built into the wall or fixed on the base (depending on the model) about 10 cm of wire. We remove the common sheath from the cables. Then we remove approximately 0.5 cm of insulation from each core. At this moment, we are guided by the situation - we clean off as much insulation so that the cores can be connected in the chosen way.

The diagram shows an example of connecting electrical wires using terminal blocks.

In this example, the connection is made using a two-wire wire, in which one core is zero, the second is a phase. We connect the socket to zero and. We connect the phase supply wire to the socket and one residential cable of the switch.

In our example, the switch is a two-button switch. Each key is responsible for controlling a separate group of lighting fixtures. The second wire of the switch cable is connected to the first button, the third wire is connected to the second key.

In the junction box, zero wires are connected from the socket and bulb holders. The power cable is connected: zero is marked in blue, phase is in red. Wires are connected to connect each switch button to the lamp sockets.

Fifth stage - check the performance of the system

We turn on the power supply and check the operation of our outlet and. Everything is working properly. We did a great job.

Now you know the order of connecting the wires in the junction box and the features of connecting each main electrical appliance. Using the information received, you will be able to independently cope with all the planned activities.

Successful work!

Video - Connecting wires in a junction box

When performing electrical wiring, you inevitably encounter the need to connect sections of wires to each other. Connections are made in junction boxes that are mounted in or on the wall. Usually, in such a box, the wires leading to the machine in the switchboard are connected, and the wires leading to the outlet, lamp, switch. Another wire can transit from our box to the next one. All connections, of course, are made in accordance with the scheme.

Wall Mounted Junction Box

So, before running and connecting the wires, let's remember what main types of connections exist:

• twisting wires and their further soldering or welding;
• connection using terminal blocks;
• connection using "nuts";
• connection of neutral wires using connecting tires;
• spring terminals type WAGO;
• use of a bolted connection.
• connection with sleeves.

The good old way of connecting - twisting

To twist the wires and insulate the place of twisting, you do not need anything but pliers and electrical tape. Qualitatively and accurately made twists of copper conductors live for several decades. Do not forget to strip the bare sections of the conductive core (TPZH) before twisting them.

For greater reliability, the twist can be soldered using standard tin-lead solder and rosin or other flux. It is even better to pass a short-term welding current through the junction. At the end of the twist, an influx (drop) of copper is formed, such a connection will last until the insulation is destroyed. Only copper conductors can be welded and soldered. But if we look at the PUE, we will see that twisting is prohibited, especially in wooden houses and baths, so they do twisting with soldering or welding.

soldering and welding stranding

In general, it is much more difficult to achieve a reliable connection of aluminum conductors than the same for copper. When twisting aluminum wires, due to the mechanical properties of the material, it is very easy to tear or break the bare part of the TPG. Using screw and generally threaded connections for aluminum wire, it is necessary to periodically stretch the contacts, since the material “floats” over time, the contact resistance gradually deteriorates, and as a result, the contact may burn and, in the worst case, a fire.

The main problem that can arise when performing conventional twisting is electrochemical corrosion when trying to connect strands of different materials, it is especially dangerous to try to twist copper and aluminum wires. In practice, more than one case is known when such connections had to be redone.

To perform twists of uniform material, PPE (connecting insulating clamp) is widely used. The PPE cap is screwed onto the cores connected together, ensuring their twisting and compressing the exposed areas of the TPG. The insulation of such a connection is quite reliable, and definitely no worse than when using electrical tape. When using PPE, it is necessary to carefully monitor the conformity of the sizes of the cap and the connected wires.

Terminal blocks

Connections using a terminal block are widespread. Contact sleeves (usually brass) with an internal thread are installed in the plastic case of the block. Reliable contact is ensured by screws clamping the wire inserted into the sleeve.

Branch cable clamps

For reliable connection of wires from different materials and for branching wires from the main (trunk) line without breaking it, cable clamps (“nuts”) are used. The "nut" core consists of two clamping dies and a separating central plate. The whole structure is bolted together. The main feature of the cable clamp is that the wires to be connected come into contact with each other only through the steel separating plate. Often, "nuts" are used when entering a house or apartment to switch from a main aluminum wire to a copper internal wiring.

Clamp "Nut" without cover "Nut" fully assembled

Connecting bars

Busbars are widely used to connect a large number of conductors of a working neutral or protective earth in switchboards. The neutral bus is attached to the shield structure or mounted on a DIN rail through an insulating stand, the ground bus is attached directly to the housing. And that, the other busbars have several holes with clamping screws for connecting the cores.

Ground bar

When using screw terminals, the force with which the core is pressed against the contact weakens over time, especially in the case of contact with aluminum. The contact deteriorates, the junction begins to warm up. This leads to the need for periodic revision and broaching of threaded contacts.

Spring terminals

Spring-loaded screwless terminals significantly speed up the installation process. Their design was developed by the German company WAGO in the fifties of the twentieth century. Terminal blocks for building installation based on flat spring clamps allow you to securely connect any copper and solid aluminum wires in any combination without the use of special tools.

WAGO Series 222

The main advantage of spring terminals is that the spring itself is always movable, during the entire service life of the terminal, spring steel clamps create a given clamping force. It is automatically consistent with the cross section of the conductor, the force is applied to the surface of the core without deforming it. This ensures constant contact.

Wire installation in WAGO series 222

The use of spring-loaded terminals allows you to reduce the time of wiring (this is especially important for large amounts of work), there is a separate terminal place for each conductor, the conductors are not damaged, reliable protection against accidental contact with bare contacts is provided, all connections look aesthetically pleasing and compact.

There are spring terminals with plug-in contacts (for example, WAGO terminals of series 773, 2273). These terminals can only be used for solid wires. The bare end of the core is simply inserted into such a terminal block with little effort. To disconnect the contact, the wire is also unscrewed from the terminal block with a little effort.

Even more convenient are universal terminals - “latches” (for example, WAGO terminals of the 222, 221 series). They can be used in the assembly of temporary circuits, since the establishment and separation of the contact takes several seconds. Such terminals allow you to connect wires from different materials and different sections.

The tinned busbar ensures a permanently reliable and gas-tight connection. For example, the performance of the 221 series is 32 A / 450 V and a maximum temperature of 105 ° C. The 221 series terminals can be used at ambient temperatures up to 85 °C.

It is recommended that before connecting the aluminum wire, fill the terminal with a special contact paste that removes the oxide film and prevents further oxidation of the core. The WAGO range includes terminals filled with such a paste during manufacture.

There are special spring terminals for connecting fixtures. Typical parameters of such terminals - on the mounting side, it is possible to connect one or two copper or aluminum single-core wires with a cross section of up to 2.5 square meters. mm; from the side of the lamp - any copper wire of the same section. Rated current for copper wires 24 A, for aluminum - 16 A.

Connections of different materials with a bolt

When connecting copper and aluminum wires, it is necessary to exclude direct contact between these metals. To do this, you can use branch cable clamps ("nuts"). Spring terminal connectors can be used. You can use an ordinary steel bolt, on which insulated wire ends of different materials are wound. Between the wires, it is imperative to put a steel washer on the bolt, it is advisable to spring it with a Grover washer for the durability of the connection.

The final view of the connection of wires from different metals

Sleeve connections

The most reliable connection method is sleeve. It is necessary to choose the sleeve itself for the cross section of the wires. Place the wires on one and the other side and the sleeve with the wires is crimped with special tongs.

Pressing the sleeve with a special press

After that, the sleeve is insulated with electrical tape or heat shrink tubing. Of course, the quality of the connection is good, but the work increases significantly. Moreover, it is difficult to pick up and buy sleeves in the store.