In private construction, sooner or later there is a need for the installation of electrical networks. Some people turn to specialists for help, others want to do it on their own. The process itself is not very difficult if there are certain skills and knowledge of safety standards, but this mainly concerns the connection of wires of the same section.

But quite often situations arise when it is necessary to reliably connect three or more wires to each other, and all of them have a different cross section. In this regard, the question of how to correctly and safely connect wires of various sections is currently one of the most relevant in the installation of electrical networks.

Methods for connecting wires of various sections

Connecting copper wires of different thicknesses is not the most difficult process. However, for maximum reliability and safety, certain requirements must be observed here. There are several ways to connect three wires of different cross sections:

• welding or soldering;
• using screw terminals;
• using self-clamping terminals;
• bolted connection;
• branch clamp;
• using copper tips.

Three wires of different cross-sections can be securely connected by any of the listed methods, but it is important to remember that when installing sockets and switches, you cannot connect cables of different thicknesses to one contact. In this case, the thinnest of them will not be pressed tightly enough. And this, in turn, can adversely affect the safety of operation.

Connecting wires of different sections by welding or soldering

The simplest, but fairly reliable way to connect cables that have different thicknesses. In this case, three wires can be connected to each other by hard twisting with subsequent fixation. But here it should be remembered that a reliable connection is possible only between wires of approximately the same cross section. The twisting of wires whose diameters differ significantly cannot be reliable.

Twist three wires of different cross-sections with each other carefully. Each copper core should tightly wrap around the next one. The gaps between them should be minimal. Otherwise, it will affect the safety of subsequent operation.

Before proceeding directly to the twisting of the three wires, lay them out in front of you and sort by thickness. You can not wind a thin wire on a thick one - this will affect the quality of the contact. Such a connection will not last long.

Connection of three wires of different cross-sections using screw terminals

Three wires of different thicknesses can be securely connected to each other using special ZVI screw clamps. Clamps have a very convenient design and allow you to create contact between cables that have different sections. The strength of the connection is achieved by using separate screws for each clamp.

It is necessary to choose ZVI clamps taking into account the cross section of the wires that will be connected, as well as their current load. For reliable contact, it is recommended to connect three wires of adjacent sections. We conditionally designate the cross section of the connected conductors as SPP, and the permissible continuous current as DDT. Below are the parameters of clamps and wires:

• ZVI-3 - SPP 1 - 2.5; DDT - 3;
• ZVI-5 - SPP 1.5 - 4; DDT - 5;
• ZVI-10 - SPP 2.5 - 6; DDT - 10;
• ZVI-15 - SPP 4 - 10; DDT - 15;
• ZVI-20 - SPP 4 - 10; DDT - 20;
• ZVI-30 - SPP 6 - 16; DDT - 30;
• ZVI-60 - SPP 6 - 16; DDT - 60;
• ZVI-80 - SPP 10 - 25; DDT - 80;
• ZVI-100 - SPP 10 - 25; DDT - 100;
• ZVI-150 - SPP 16 - 35; DDT - 150.

With the right choice of screw terminal, you can create a really reliable connection that will ensure the uninterrupted operation of the electrical network.

Connect wires of different sections with bolts

Another way to connect wires of different sections to each other is to create a contact using bolts, washers and nuts. According to professional electricians, such a connection is the most durable and strong. The process itself is not too complicated, it takes a minimum of time. The procedure goes as follows:

• the copper conductors of the wire are carefully stripped (the length of the stripped section of the conductor depends on the diameter of the bolt);
• the stripped core is bent in the form of a loop;
• the loop is put on the bolt;
• an intermediate washer is installed on top;
• then a loop of wire of a different section is put on and fixed with an intermediate washer.

This continues until all the wires are connected to each other. After putting on the last loop and the last washer, the structure is firmly tightened with a nut.

Use of copper lugs to contact connections

Also, a very simple way to create a reliable connection is to use copper tips. They are recommended to be used for contacting wires of large diameter. Before proceeding with the procedure, it is necessary to prepare not only the tips themselves, but also special equipment - crimping pliers or a hydraulic press.

With all the obvious advantages, this type of connection has one (but significant) drawback - rather solid dimensions, due to which the resulting structure may not fit in every junction box. Nevertheless, experts actively use this method.

The process of creating a contact is as follows:

• wires of different sections are carefully straightened;
• the veins of each of them are cleaned by about two to three centimeters;
• a tip is put on each stripped core and clamped with a hydraulic press or crimping pliers;
• bolts are then put on, and the wires are connected with a nut.

After all the work has been done, it is necessary to carefully isolate the junction so that no dangerous situations arise during operation.

Self-wiring and creating contacts using terminals

Universal clamp terminals appeared on the market relatively recently, but almost immediately they began to be in serious demand not only among specialists, but also among potential customers who prefer to carry out all electrical work at home on their own.

With self-clamping terminals, you can create strong and reliable contacts between several wires ( three or more). The main advantage of such terminal blocks is their almost unlimited functionality - they can be used to connect wires whose sizes vary significantly.

The design of the terminals provides for the presence of holes into which pre-stripped conductors are inserted. For example, a wire with a cross section of 1.5 mm can be inserted into one hole, a wire with a diameter of 4 mm into another, a wire with a diameter of 4 mm into the third, and so on. And after their connection, the contact will be quite strong and reliable.

There are several more ways how to connect three or more wires of different diameters, but they are used quite rarely due to the complexity and length of the process itself. If you want to use one of them - consult first with a specialist who is competent in this particular area.

When connecting wires of different diameters in series, the maximum load current will be determined by the cross section of the wire with a smaller diameter. For example, copper wires with a diameter of 1.6 mm and 2 mm are connected. In this case, the maximum load current on the wiring, which is determined from the table, will be 10 A, and not 16 A, as for a wire with a diameter of 2 mm.

Twisting electrical wires

Until recently, twisting was the most common way to connect wires when making electrical wiring, due to availability, it was enough to have a knife and pliers from the tool. But, according to statistics, twisting is an unreliable way to connect conductors.

According to the rules for the installation of electrical installations (PUE), the connection of the type of twist during the installation of electrical wiring is prohibited. But, despite the noted shortcomings, the twisting method is currently widely used. The twisted connection of conductors of low-current circuits, subject to certain rules, is fully justified.

The photo on the left shows how it is unacceptable to twist. If one conductor is wrapped around another, then the mechanical strength of such a connection will be insufficient. When twisting wires, it is necessary to make at least three turns of wires around each other. In the middle photo, the twisting is done correctly, but the copper conductor is twisted with aluminum, which is not acceptable, since when copper contacts aluminum, an EMF of more than 0.6 mV occurs.

In the photo on the right, the twisting of copper and aluminum wires is done correctly, since the copper wire is tinned with solder before twisting. You can twist several wires together at once, in a junction box, it happens that up to 6 conductors are twisted, wires of different diameters and from different metals, a stranded wire with a single-core wire. Only the stranded wire must be made single-core, after being soldered with solder.

Connecting electrical wires by soldering

The connection of copper wires with high-quality soldering is the most reliable and is practically not inferior to a solid wire. All of the above examples of wire twists, except for aluminum and tinsel, when the conductors are tinned before twisting and then soldered with solder, will be reliable on a par with solid wires. The only downside is the extra work involved, but it's worth it.

If you need to connect a pair of wires and the conductors from the twist should be directed in different directions, then a slightly different type of twist is used.

By splicing two pairs of double wires in the manner described below, it is possible to obtain a compact and more beautiful connection by twisting both single-core and stranded pairs of conductors. This twisting method can be successfully used, for example, when splicing broken wires in a wall, extending a wire when moving a socket or switch from one place on the wall to another, when repairing or extending the length of the carrying cable.

To obtain a reliable and beautiful connection, it is necessary to adjust the lengths of the ends of the conductors with a shift of 2-3 cm.

Perform pairwise twisting of the conductors. With this type of twisting, two turns are enough for a single-core wire, and five for a stranded wire.

If you plan to hide the twist under plaster or in another inaccessible place, then the twist must be soldered. After soldering, you need to go over the solder with sandpaper to remove any sharp solder icicles that can pierce the insulation and stick out of it. You can do without soldering if the connection is accessible and there are not large currents flowing through the conductors, but the durability of the connection without soldering will be much lower.

Due to the shift of the twist points, it is not necessary to isolate each of the connections separately. We attach on both sides along the conductors along a strip of insulating tape. In conclusion, you need to wind three more layers of insulating tape. According to the requirements of the Electrical Safety Rules, there must be at least three layers.

Wires spliced ​​and soldered in the manner described above can be safely laid into the wall and plastered on top. Before laying, it is desirable to protect the connection with a vinyl chloride tube, dressed in advance on one of the pairs of wires. I have done this several times, and the reliability has been confirmed by time.

Connecting wires in junction boxes

When I moved into an apartment built in 1958 and began to make repairs, I immediately encountered the flashing of lighting bulbs in time with hammer blows on the walls. There was a primary task of repair, revision of junction boxes. Opening them showed the presence of poor contact in the twists of copper wires. To restore contact, it was necessary to disconnect the twists, clean the ends of the wires with sandpaper and twist again.

When trying to disconnect, I ran into a seemingly insurmountable obstacle. The ends of the wires broke off even without any effort. Over time, copper lost its elasticity and became brittle. When stripping the wire, the insulation was obviously cut with a knife blade in a circle and notches were made. In these places, the wire broke off. Copper hardened from temperature fluctuations.

To return copper elasticity, unlike ferrous metals, you can heat it to red and quickly cool it. But for this case, such an approach is unacceptable. The ends of the wires were no more than 4 cm long. There was no choice for the connection. Only solder.

I stripped the wires with a soldering iron, melted the insulation, tinned them with solder, tied them in groups with tinned copper wire and filled them with solder using a 60-watt soldering iron. The question immediately arises, how to solder the wires in the junction box if the wiring is de-energized? The answer is simple, using a battery powered soldering iron.

So I updated the connections in all junction boxes, spending no more than 1 hour on each. I am fully confident in the reliability of the connections made, and this has been confirmed by the 18 years that have passed since then. Here is a photo of one of my boxes.

When leveling the walls with Rotband in the hallway and installing a stretch ceiling, the junction boxes became a hindrance. I had to open them all, and the reliability of the solder joint was confirmed, they were in perfect condition. So I boldly hid all the boxes in the wall.

The connections currently practiced with the help of a Wago flat spring clamp terminal block greatly reduce the time spent on installation work, but are much inferior in reliability to solder connections. And in the absence of spring-loaded contacts in the block, they completely make connections in high-current circuits unreliable.

Mechanical connection of wires

Soldering is the most reliable type of connection of wires and contacts. But it has disadvantages - the inseparability of the obtained connections and the high labor intensity of the work. Therefore, the most common type of connection of wires with electrical contacts of devices is threaded, screws or nuts. For the reliability of this type of connection, it is necessary to perform them correctly.

The linear expansion from temperature changes is different for metals. Aluminum changes the linear dimensions especially strongly, then in descending order, brass, copper, iron. Therefore, over time, a gap is formed between the contact of the connected metals, which increases the resistance of the contact. As a result, to ensure the reliability of the connections, it is necessary to tighten the screws periodically.

In order to forget about maintenance, additional washers with a cut are installed under the screws, which are called split washers or Grover. The grower selects the resulting gaps and thus ensures a high contact reliability.

Often, electricians are lazy, and the end of the wire is not twisted into a ring. In this embodiment, the area of ​​contact of the wire with the contact pad of the electrical appliance will be many times smaller, which reduces the reliability of the contact.

If the formed wire ring is slightly flattened with a hammer on the anvil, then the contact area will increase several times. This is especially true when forming a ring of stranded wire soldered with solder. Instead of a hammer, flatness can be given with a needle file by grinding off a little ring at the points of contact with the contacts.

This is how it should be done ideal threaded connection of wires with contact pads of electrical appliances.

Sometimes it is required to connect copper and aluminum conductors to each other, or with a diameter of more than 3 mm. In this case, the most accessible is a threaded connection.

The insulation is removed from the wires for a length equal to four screw diameters. If the veins are covered with oxide, then it is removed with sandpaper and rings are formed. A spring washer, a simple washer, a ring of one conductor, a simple washer, a ring of another conductor, a washer and, finally, a nut are put on the screw, screwing the screw into which the entire package is tightened until the spring washer is straightened.

For conductors with a core diameter of up to 2 mm, an M4 screw is sufficient. The connection is ready. If the conductors are of the same metal or when connecting an aluminum wire to a copper wire, the end of which is tinned, then it is not necessary to lay a washer between the rings of the conductors. If the copper wire is stranded, then it must first be soldered.

Connecting wires with a terminal block

The connection of wires with a low current load can be performed using terminal blocks. Structurally, all terminal blocks are arranged in the same way. Thick-walled brass tubes with two threaded holes on the sides of each are inserted into the combs of the body made of plastic or carbolite. Connected wires are inserted into opposite ends of the tube and fixed.

The tubes come in different diameters and they are selected depending on the diameters of the connected conductors. As many wires can be inserted into one tube as its internal diameter allows.

Although the reliability of connecting wires in terminal blocks is lower than when connecting by soldering, much less time is spent on wiring. The indisputable advantage of terminal blocks is the ability to connect copper and aluminum wires in electrical wiring, as brass tubes are plated with chromium or nickel.

When choosing a terminal block, it is necessary to take into account the current that will pass through the switched wires of the electrical wiring and the required number of terminals in the comb. Long combs can be cut into several short ones.

Connecting wires using a terminal block
with flat spring clip Wago

Terminal blocks with a flat spring clip Wago (Vago) of a German manufacturer are widely used. Wago terminal blocks come in two designs. Disposable, when the wire is inserted without the possibility of removal, and with a lever that allows you to easily insert and remove the wires.

The photo shows a Wago disposable terminal block. It is designed to connect any type of single-core wires, including copper and aluminum wires with a cross section of 1.5 to 2.5 mm 2. According to the manufacturer, the block is designed to connect electrical wiring in junction and distribution boxes with a current of up to 24 A, but I doubt it. I think that it is not worth loading the Wago terminals with a current of more than 10 A.

Wago spring terminal blocks are very convenient for connecting chandeliers, connecting wires in junction boxes. It is enough just to force the wire into the hole in the block, and it will be securely fixed. In order to remove the wire from the block, considerable effort is required. After removing the wires, deformation of the spring contact may occur and a reliable connection of the wires when reconnecting is not guaranteed. This is a big disadvantage of a disposable terminal block.

A more convenient Wago reusable terminal block with an orange lever. Such terminal blocks allow you to connect and, if necessary, disconnect any electrical wiring wires, single-core, stranded, aluminum in any combination with a cross section from 0.08 to 4.0 mm 2. Designed for current up to 34 A.

It is enough to remove the insulation from the wire by 10 mm, lift the orange lever up, insert the wire into the terminal and return the lever to its original position. The wire is securely fixed in the terminal block.

The Wago terminal block is a modern, tool-free wire connection that is fast and reliable, but more expensive than traditional connection methods.

Permanent connection of wires

In some cases, when it is not supposed to switch the wires in the future, they can be connected in an integral way. This type of connection is highly reliable, and is advisable in hard-to-reach places, for example, connecting the ends of a nichrome spiral with copper current-carrying conductors in a soldering iron.

Connection of thin wires by crimping

A simple and reliable way to connect wire cores is crimping. Wire strands are inserted into a piece of copper or aluminum, depending on the metal of the wires being connected, and the tube is pressed in the middle with a tool called press tongs.

Crimping can connect both single-core and stranded wires in any combination. The diameter of the tube must be selected depending on the total cross section of the conductors. It is desirable that the conductors fit tightly. Then the reliability of the connection will be high. If in a stranded wire the conductors are interconnected, then it is necessary to develop and straighten them. It is not necessary to twist the wire strands together. The prepared conductors are inserted into the tube and crimped with press tongs. The connection is ready. It remains only to insulate the connection.

Crimping lugs are commercially available already equipped with an insulating cap. Crimping is performed by compressing the tube together with the cap. The connection is immediately isolated. Since the cap is made of polyethylene, it deforms during crimping and is securely held, providing reliable isolation of the connection.

The disadvantage of the connection by crimping should include the need for special press - tongs. Ticks can also be made independently from pliers with side cutters. It is necessary to round the side cutter blades and make a groove in the middle. After such refinement of the pliers, the edges of the side cutters will become blunt and will no longer be able to bite, but only squeeze.

Connection of wires of a larger cross-section by crimping

To connect electrical wires of a larger cross section, for example, in power shields of houses, special lugs are used, which are crimped using universal press tongs, such as PK, PKG, PMK and PKG.

For crimping each size of the tip or sleeve, its own die and punch are required, a set of which is usually included in the set of pliers.

To crimp the tip onto the wire, the insulation is first removed from the wire, the wire is threaded into the hole of the tip and wound between the matrix and the punch. For the long handles of the press tongs are compressed. The tip is deformed, compressing the wire.

In order to choose the right matrix and punch for the wire, they are usually marked and the branded press tongs on the matrix have an engraving for crimping which section of the wire the matrix is ​​intended for. The number 95 embossed on the tip means that this matrix is ​​designed for crimping in the tip of the wire with a cross section of 95 mm 2.

Connecting wires with a rivet

It is carried out using screw connection technology, only a rivet is used instead of a screw. The disadvantages include the impossibility of disassembly and the need for a special tool.

The photo shows an example for connecting copper and aluminum conductors. For more information about connecting copper and aluminum conductors, see the site article "Connecting aluminum wires". In order to connect the conductors with a rivet, you first need to put an aluminum conductor on the rivet, then a spring washer, then a copper and a flat washer. Insert the steel rod into the riveter and squeeze its handles until it clicks (this is cutting off the excess steel rod).

When connecting conductors made of the same metal, it is not necessary to lay a split washer (Grover) between them, but put the Grover on the rivet first or penultimate, the last must be an ordinary washer.

Connecting broken wires in the wall

Repairs should begin with a very careful removal of plaster in the area of ​​\u200b\u200bdamaged wires. This work is done with a chisel and a hammer. As a chisel when laying electrical wiring in the wall, I usually use the rod from a broken screwdriver with a sharply sharpened end of the blade.

Connection of copper wires interrupted in the wall

A piece of copper wire is taken, with a cross section not less than the cross section of the broken wire. This piece of wire is also covered with a layer of solder. The length of this insert should provide an overlap on the connected ends of the wires by at least 10 mm.

The insert is soldered with the connected ends. Solder should not be saved. Next, the insulating tube is shifted in such a way as to completely close the junction. If a sealed moisture-resistant connection is required, then before putting on the tube, the soldered connection must be coated with silicone.

Connection of aluminum wires interrupted in the wall

A prerequisite for obtaining a reliable mechanical connection of aluminum wires is the use of a washer type Grover. The assembly of the connection is performed as follows. A grover is put on the M4 screw, then an ordinary flat washer, rings of connected wires, then a simple washer and nut.

Step-by-step instructions for connecting broken wires in the wall are described in the article "Connecting broken wires in the wall"

Connecting wires with push-on terminals

Detachable connection of conductors with the help of captive terminals, which are put on contacts with a thickness of 0.8 and a width of 6.5 mm, are widely used in household appliances and cars. The reliability of fixing the terminal is ensured by the presence of a hole in the center of the contact, and a protrusion in the terminal.

Sometimes the conductors break off, and more often the terminal itself burns due to poor contact, and then it becomes necessary to replace it. Typically, the terminals are pressed onto the ends of the conductors using special pliers. Crimping can also be done with pliers, but there is not always a new replacement terminal on hand. You can successfully use a used one by mounting the terminal using the following technology.

First you need to prepare the old terminal for re-assembly. To do this, holding the terminal with pliers at the place of pressing, you need to spread the antennae that compress the insulation with an awl or a screwdriver with a thin sting. Further, the wire is repeatedly bent, until it breaks at the exit point from the pressing. To speed up, you can cut this place with a knife.

When the wire is separated from the terminal, a place is prepared with a needle file for soldering it. It is possible to completely grind off until the remaining wire is released, but this is not necessary. It turns out a flat area.

The resulting site breaks through with solder. The conductor is also cleaned and tinned with solder using a soldering iron.

It remains to attach the conductor to the prepared terminal site and heat it with a soldering iron. The antennae that fix the wire are bent after soldering the wire to the terminal, since if they are crimped before soldering, the antennae will melt the insulation.

It remains to pull on the insulating cap, put the terminal on the desired contact and check the reliability of fixation by pulling the wire. If the terminal jumped off, then it is necessary to tighten its contacts. A self-made soldered terminal on a wire is much more reliable than one obtained by crimping. Sometimes the cap is worn so tightly that it cannot be removed. Then it must be cut and, after mounting the terminal, cover it with insulating tape. You can also stretch a piece of vinyl chloride or heat-shrinkable tubing.

By the way, if you hold a PVC tube for five minutes in acetone, then it increases in size by one and a half times and becomes plastic, like rubber. After evaporation of acetone from its pores, the tube returns to its original size. In this way, about 30 years ago, I isolated the base of light bulbs in a Christmas tree garland. So far, the insulation is in excellent condition. I still hang this garland of 120 6.3 V bulbs on the Christmas tree every year.

Splicing stranded wires without twisting

You can splice stranded wires in the same way as single-core ones. But there is a more perfect way, in which the connection is more accurate. First you need to adjust the length of the wires with a shift of a couple of centimeters and strip the ends to a length of 5-8 mm.

Fluff the slightly cleaned areas of the pair to be joined and insert the resulting “panicles” into each other. In order for the conductors to take a neat shape, they must be pulled together with a thin wire before soldering. Then lubricate with soldering varnish and solder with solder.

All conductors are soldered. We clean the places of soldering with sandpaper and isolate. We attach on both sides along the conductors one strip of electrical tape and wind a couple more layers.

This is what the connection looks like after being covered with electrical tape. You can still improve the appearance if you sharpen the places of soldering with a needle file from the side of the insulation of adjacent conductors.

The strength of the connected stranded wires without soldering is very high, which is clearly demonstrated by the video. As you can see, the weight of the monitor is 15 kg, the connection can withstand without deformation.

Connecting wires with a diameter of less than 1 mm with a twist

We will consider the twisting of thin conductors using the example of splicing a twisted-pair cable for computer networks. For twisting, thin conductors are released from insulation for a length of thirty diameters with a shift relative to neighboring conductors and then twisted in the same way as thick ones. Conductors must wrap themselves around each other at least 5 times. Then the twists are bent in half with tweezers. This technique increases the mechanical strength and reduces the physical size of the twist.

As you can see, all eight conductors are connected with a sheared twist, which eliminates the need to insulate each of them individually.

It remains to fill the conductors in the cable sheath. Before refueling, to make it more convenient, you can pull the conductors with a coil of insulating tape.

It remains to fix the cable sheath with insulating tape and the twist connection is completed.

Connection of copper wires in any combination by soldering

When connecting and repairing electrical appliances, it is necessary to lengthen and connect wires with different cross-sections in almost any combination. Consider the case of connecting two stranded conductors with different cross sections and number of cores. One wire has 6 conductors with a diameter of 0.1 mm, and the second has 12 conductors with a diameter of 0.3 mm. Such thin wires cannot be reliably connected with a simple twist.

With a shift, you need to remove the insulation from the conductors. The wires are tinned with solder, and then the smaller wire is wound around the larger wire. It is enough to wind a few turns. The place of twisting is soldered with solder. If you want to get a direct connection of wires, then the thinner wire is bent and then the junction is insulated.

Using the same technology, a thin stranded wire is connected to a single-core wire with a larger cross section.

As is obvious from the technology described above, any copper wires of any electrical circuits can be connected. At the same time, one should not forget that the permissible current strength will be determined by the cross section of the thinnest wire.

TV coaxial cable connection

It is possible to extend or splice a coaxial television cable in three ways:
- TV extension cable, on sale are from 2 to 20 meters
– using an adapter TV F socket - F socket;
- soldering with a soldering iron.

Tinsel wire connection
stranded with solid or stranded conductor

If necessary, to give the cord a very high flexibility and at the same time greater durability, the wires are made using a special technology. Its essence lies in the winding of very thin copper ribbons on a cotton thread. Such a wire is called tinsel.

The name is borrowed from tailors. Gold tinsel is used to embroider the parade uniforms of high military ranks, coats of arms and much more. Copper tinsel wires are currently used in the production of high-quality products - headphones, landline telephones, that is, when the cord is subjected to intense bending during use of the product.

As a rule, there are several conductors of tinsel in the cord, and they are twisted together. Soldering such a conductor is almost impossible. To connect the tinsel to the contacts of the products, the ends of the conductors are crimped into the terminals with a special tool. To perform a reliable and mechanically strong connection by twisting without a tool, you can use the following technology.

10-15 mm tinsel conductors and conductors with which it is required to connect tinsel to a length of 20-25 mm with a shift with a knife in the manner described in the site article "Preparing wires for installation" are released from insulation. The tinsel thread is not removed.

Then the wires and the cord are applied to each other, the tinsel is bent along the conductor and the core of the wire is tightly wound onto the tinsel pressed against the insulation. It is enough to make three to five turns. Next, the second conductor is twisted. You will get a fairly strong twist with a shift. Several turns are wound with insulating tape and the connection of tinsel with a single-core wire is ready. Thanks to shear technology, the connections do not need to be insulated individually. If you have a heat-shrinkable or PVC tube of a suitable diameter, you can put on a piece of it instead of an insulating tape.

If you want to get a straight connection, then you need to turn the single-core wire by 180 ° before insulating. In this case, the mechanical strength of the twist will be greater. The connection of two cords with tinsel-type conductors to each other is carried out according to the technology described above, only for wrapping a piece of copper wire with a diameter of about 0.3-0.5 mm is taken and at least 8 turns must be made.

Any man strives to ensure that the power supply in his own house or apartment is of high quality, uninterrupted and reliable. Therefore, when carrying out electrical work during construction or repair, it is necessary to correctly connect the electrical wires. But in everyday life, you still have to face problems when light wire broken, the outlet stopped working. Of course, if you have basic knowledge of electrical engineering and the ability to carry out electrical work, it is easy to eliminate all these malfunctions on your own.

The connection of conductors made of different metals must be carried out with the obligatory consideration of all the properties of the material from which they are made. Currently, copper, aluminum and steel are used to transmit electrical energy. Each of these metals has different densities, electrical conductivity and resistance, which are taken into account when creating a good electrical contact. It is also necessary to take into account the magnitude of the electrochemical potential that occurs when a current is applied to a metal.

Therefore, if the aluminum and copper conductors are not connected correctly, there may be serious problems faced by many specialists who repair wiring in apartments. Previously used in homes copper wires, which, in terms of electrical performance, far exceeded aluminum ones. And at present use of copper conductors faded into the background.

Aluminum, having a high level of oxidation, forms a specific film when combined, which has a rather high electrical resistance. This property is manifested especially in a humid environment. The same film is formed in copper, only its resistance is much less. Therefore, due to this difference in resistance, the direct connection of these metals leads to difficulty in electrical conductivity. BUT oxidative processes lead to sparking, heating and ignition of wires.

Ways of safe contact

To create a reliable contact of electrical wires, there are several ways both with the use of special equipment and with the use of improvised means.

Types of wire connection:

1. Twisting (twisting) is the most common method, the use of which is desirable for a temporary connection.
2. Welding is the most reliable method that provides excellent conductor contact. Requires welding equipment and certain skills to carry out the work.
3. Soldering - has excellent connection performance, but requires compliance with the temperature regime (not higher than 65℃).
4. Terminal blocks are a fairly simple and reliable connection.
5. Connecting wires with clamps - subject to the operating conditions, allows you to get excellent contact. Installs very quickly.
6. Crimping with sleeves - requires special tongs and knowledge of installation technology, but the method is very reliable.
7. Bolted connection - used in difficult situations, easy to perform and does not require special devices.

When choosing the type of connection, it is necessary to take into account: the material of the conductive part; wire section; number of conductors; type of insulation; terms of Use. Most often, the selection of the type of connection is carried out at the place of work.

This technological operation is common to all methods of connecting conductors. Before combining the wires into a common electrical unit, it is necessary to strip them of the insulation layer.

The easiest way to do this work is with a fitter's knife, but in this case there is a possibility of damage to the conductive core. To avoid this, you need:

1. Lay the wire on the table surface.
2. Press it with the index finger of the left hand.
3. Holding the knife in your right hand, cut the insulation. In this case, it is necessary to direct the blade at an angle to the cut so as not to damage the core. Otherwise, the conductor may break.
4. With your left hand finger, twist the conductor one turn to cut the insulation.
5. Remove the cut piece of the insulating sheath.

Experienced electricians have a multifunctional tool in their arsenal - a stripper, which is designed for cutting cables and stripping insulation. This device does not damage the core when removing insulation from a conductor of any section, as it has a special calibrated recess for the desired wire diameter.

The length of the insulation stripping is selected in accordance with the method of connecting the conductors.

The simplest and most well-known method of connecting electrical wires is their twisting (twisting). Experienced electricians often call it the grandfather method.

Previously, this type of connection was used everywhere, but with an increase in the load in the electrical network modern apartment twisting has become prohibited. However, this connection method must be studied first of all, since it is the main step in soldering and welding wires.

The main advantage of twisting is the absence of any material costs, since you only need pliers and a stripping knife. And of course, the advantage of twisting is the simplicity of its execution. Any person holding pliers in their hands can do this job without any problems.

Over time, the twist weakens, which is its main disadvantage. This process is connected with the fact that in any veins there is a residual elastic deformation. Therefore, at the place of twisting, the contact resistance increases, which leads to a weakening of the contact and heating of the conductor. It is good if this defect is discovered in time and the docking point can be redone, but fire may occur.

But if for some reason you do not have the opportunity to use more reliable methods, then you definitely need to familiarize yourself with how to properly connect the wires to each other by twisting. To do this, you must first strip the wires from insulation by 70-80 mm. Then, holding both conductors in the place where the insulation ends, grab the ends of the cores with pliers and rotate them clockwise. chief the condition for reliable twisting is the simultaneous rotation of the conductors, and not alternately winding them on top of each other.

If the diameter of the wires is small, then the twisting can be done completely by hand. With your left hand, you need to hold the conductors along the cut of the insulation, and with your right hand, rotate the bend (10-15 mm) of the cores clockwise. For tighter contact at the end of the rotation, you can use pliers.

The next step is to isolate the junction of the wires. For this, insulating tape is used. To ensure reliability and protect contact from moisture, you need to wind the tape in several layers, while stepping on the wire insulation by 2-3 cm. A very good option for conducting insulation is the use of thermal pipes, the main thing is not to forget to put it on one of the cores.

Professional electricians advise not to stop at the stage of twisting the wires, but to strengthen the docking point by soldering or welding.

How to connect wires by soldering

The type of connection in which electrical wires are connected using molten solder is called soldering. This method is best applicable to wires with copper conductors, but the use of special fluxes allows you to get a high-quality joint and other metals.

The advantages of using soldering:

• in terms of reliability, this type of joining of wires is second only to welding;
• allows you to connect both single-core and multi-core wires, as well as cores with different sections;
• maintenance of the contact point for the entire period of operation is not required;
• low cost of work (flux and solder are inexpensive).

The disadvantage of soldering is considered to be a rather high labor intensity. The surfaces to be soldered must be pre-cleaned from oxides and tinned before twisting the wires.

An electrician must have a certain qualification and be able to use a soldering iron, because in the process of work it is necessary to strictly observe the temperature regime. A weakly heated or overheated contact point loses its reliability and strength.

The soldering process looks like this:

1. The insulation is removed from the conductors by 40-50 mm.
2. Areas of bare veins are cleaned well with sandpaper.
3. Wires are being tinned. To do this, a heated soldering iron is dipped into rosin and held several times with a sting over the cleaned surfaces.
4. The wires are twisted.
5. Soldered on the tip of the soldering iron, we warm up the twist. In this case, molten tin should fill all the gaps between the turns.
6. After cooling, the solder is wiped with alcohol and insulated.

To create the most reliable connection of conductors after twisting, they are additionally fixed by welding. The technology for making such a contact is very similar to soldering, only here a welding machine is used instead of a soldering iron.

In terms of quality and reliability, the welding method fully meets all regulatory requirements for creating electrical contact.

When creating a connection by welding, the conductors are twisted, and their tip is welded. The resulting ball of metal provides a very reliable joint of wires. At the same time, reliability is due not only to the creation of high electrical characteristics, but also mechanical ones.

The main disadvantage of this type of wire connection is the presence of a welding machine and devices for such work. In addition, it is required to strictly observe the rules of working at height and fire safety.

The sequence of welding wires:

1. We release the conductors from insulation by 60-70 mm.
2. We clean the veins mechanically (sandpaper).
3. We make twisting of wires, and its length should be at least 50 mm.
4. We fix the welding ground contact on top of the twist.
5. We lightly touch the twist from below with the electrode. Wire welding is very fast.
6. After the contact ball has cooled down, we insulate it.

As a result of such actions, an almost solid conductor is obtained, and the contact assembly will have the lowest contact resistance.

For such a connection of conductors, special copper or aluminum sleeves are required, which are selected in accordance with the size of the bundle diameter. The material of the sleeves is desirable to use the same as that of the conductor.

Wires are stripped to the length of the sleeve, twisted and placed in a tube. Then, with the help of special pliers, the connection is pressed and isolated.

There are sleeves-tubes for lengthening the conductors, that is, for their longitudinal fastening. Wires are inserted into such sleeves from different sides of the tube, then crimped separately.

bolt method

Such a connection is used in electrical circuits with increased voltage. Its use is suitable for switching almost any core.

• a washer is put on the bolt;
• first conductor;
• next puck;
• second conductor;
• puck again;
• screw.

Then the assembled knot is tightened by hand, and then pressed with a key or pliers.

Modern industry has mastered the production of special wire connectors, which have greatly facilitated work and accelerated switching work:

1. Caps with built-in compression spring. Stripped wires are inserted into such a cap and rotated clockwise. With this action, the wires are reliably squeezed inside.
2. Terminal blocks, which have tubular brass sleeves inside. Bare conductors are inserted into these sleeves and clamped with screws.
3. Self-clamping terminals automatically fix the stripped wire with a special plate.
4. Lever terminals are considered reusable devices. Fixation of the conductor is provided by raising and lowering the lever.

Remember that the connection of wires must always be made on de-energized electrical networks. Without knowledge of electrical engineering, it is better to entrust the work related to dangerous voltage to specialists.

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

Existing methods of connecting conductors

To connect the wires can be done in several ways:

• welding is the most reliable method, providing high reliability of the connection, but requiring skills and the presence of a welding machine;
• terminal blocks - a simple and fairly reliable connection;
• soldering - works well if the currents do not exceed the normative ones and the connection does not heat up to temperatures above the norm (65 ° C);
• crimping with sleeves - requires knowledge of technology, special pliers, but the connection is reliable;
• the use of spring clips - wago, PPE - quickly installed, subject to operating conditions provide good contact;
• bolted connection - easy to perform, usually used in difficult cases - if 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 to 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 ball of metal is formed, which provides a stable and very reliable connection under any 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 to 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 margin of wires is left - in case of a possible alteration.

Other disadvantages include a welding machine, appropriate electrodes, flux and work skills. In addition, welding takes a lot of time, it is necessary to protect surrounding objects, and it is also inconvenient to work with a welder at a height. Therefore, electricians practice this type of connection in exceptional cases. If you are doing “for yourself” and know how to handle a welding machine well, you can practice on scraps. The trick is not to melt the insulation, but to weld the metal.

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

Crimping connection of wires

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

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 into a sleeve), in which you need to be well versed. It is necessary to pack the wires according to certain rules, measure the size of the resulting bundle, and adjust it to the requirements. All in all, a pretty tedious job. Therefore, this type of wire connection is mainly used by professional electricians, and even more often they switch to spring clips.

Terminal blocks

One of the simplest and most reliable wire connections is through terminal blocks. There are several types, but almost everywhere a screw connection is used. There are sockets of different sizes - for different sizes of conductors, with a different number of pairs - from 2 to 20 or 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, it is necessary to pull the conductor well - make sure that it is well clamped. Due to the fact that the connection points remain uninsulated, the scope of the terminal blocks is rooms with normal humidity.

The disadvantage of this connection is that due to the plasticity of metals - especially aluminum - the 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, the connection of wires in screw terminal boxes must be tightened periodically.

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

Soldering

First, about soldering technology. The connected conductors are cleaned of insulation, cleaned of oxide film to bare metal, twisted, then tinned. To do this, the conductors are heated with a soldering iron, applied to rosin. It should cover the junction completely. Tinned wires are twisted first with 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 junction is heated with a soldering iron or a narrow-torch burner. When the rosin or flux begins to boil, take some of the solder on the soldering iron tip, bring it into the soldering area, pressing the tip against the conductors. The solder spreads out, filling the gaps between the wires, making a good connection. When using a torch, the solder is simply added little by little to the torch.

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

Now about the advantages and disadvantages of this method of connecting wires. 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 high currents through the connection (it happens if the circuit breakers are incorrectly selected or faulty), the solder gradually melts and evaporates. Time after time, the contact gets worse, the connection heats up more and more. If this process is not detected, it may well end in a fire.

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

Spring terminals for connecting wires

One of the most controversial ways to connect wires is with spring clamps. There are several types, but the most common two are wago terminal blocks and PPE caps. Externally and by the method of installation, they are very different, but both designs are based on a spring that creates a strong contact with the wire.

There is controversy about this spring. Opponents of using wago say that the spring will weaken over time, the contact will become worse, the connection will start to heat up more and more, which, again, leads to an even faster decrease in the degree of elasticity of the spring. After some time, the temperature may rise so much that the case (plastic) will melt, but what can happen next is known.

Spring clips for electrical wiring - popular wire connection

In defense of the use of spring clamps for connecting wires, if they are used in accordance with the manufacturer's recommendations, problems are very, very rare. Although there are many fakes of both wago and PPE, as well as an abundance of pictures of them in a melted form. But, at the same time, many use them, and, under normal operating conditions, they work for years without any complaints.

Clips for wires wago

They appeared on our market a few years ago and made a lot of noise: with their help, the connection is very fast and easy, while it has high reliability. The manufacturer has specific recommendations for the use of this product:

Inside these devices there is a metal plate, which provides the proper degree of contact. The shape and its parameters of the plates were developed and tested specifically. The tests were carried out on a vibration stand for many hours, then heated-cooled. After that, the electrical parameters of the connection were checked. All tests were passed as "excellent" and branded products always show themselves as "five".

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

Detachable

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

wago wire connectors - connection methods

If necessary, you can remake 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 rigid wires. The maximum section is 2.5 mm 2. Soft stranded wires can be connected with a cross section from 0.08 mm 2 to 4 mm 2.

One-piece

There is another type of clamps that does not provide for the possibility of redoing the connection of wires - the 773 and 273 series. When using these terminals, the work is generally seconds: the stripped wire is inserted into the appropriate socket. The spring present there clamps it, providing contact with the plate. All.

These spring-loaded wire clamps can be used to connect solid aluminum or copper wires with a cross-sectional area from 0.75 mm2 to 2.5 mm2, stranded wires with rigid wires from 1.5 mm2 to 2.5 mm2. Soft stranded conductors cannot be connected using such connectors.

To improve contact, before connecting the wires, it is necessary to clean the oxide film. To prevent further oxidation, wago manufacturers also produce contact paste. It fills the inside of the clamp and it itself corrodes the oxide film, and then protects the wires from further oxidation. In this case, only highly oxidized, dark conductors need to be pre-stripped, 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, they 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.

Clips for lamps (construction and installation terminals for lamps)

For quick and convenient connection of lamps or sconces, wago has special terminals of the 224 series. With their help, you can connect aluminum or copper wires of different sections and types (solid or stranded with rigid wires). Rated voltage of this connection is 400 V, rated current:

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

Cross-section of connected conductors on the mounting side:

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

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

When connecting copper wires, the use of contact paste is mandatory, and aluminum wires must be manually stripped to bare metal.

This product has two drawbacks. First, the price of original terminals is high. The 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 clips") are very easy to use devices. This is a plastic case, inside of which there is a spring that has a conical shape. Conductors stripped of insulation are inserted into the cap, the cap is scrolled 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, there are different sizes, for different diameters and the number of connected conductors. In order for the wire connection to be reliable, the size must be selected correctly, and for this it is necessary to understand the markings.

After the letters of the PPE comes a few numbers. Depending on the manufacturer, the number of digits varies, but they mean the same thing. For example, there is this type of marking: PPE-1 1.5-3.5 or PPE-2 4.5-12. In this case, the number immediately following the letters indicates the case type. "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 PPE-2, then there are small protrusions on the case, which are convenient to take with your fingers and twist.

All other figures 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 ordinary, cone-shaped. With it, you can connect two conductors with a cross section of at least 0.5 mm 2 (in total they give 1 mm, which corresponds to the minimum requirements - see table). Maximum conductors are included in this cap, the total cross section of which should not exceed 4 mm 2.

Connecting wires using PPE caps

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

PPE caps and their parameters

By the way, only copper wires can be connected with PPE caps - 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 assembles quickly and easily, serves quite a long time and is reliable.

First, the conductors are stripped of insulation, if necessary, the upper oxidized layer is removed. Further, a loop is formed from the cleaned 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 twist it (the middle option in the right picture). After all this is assembled in this order:

• A washer is put on the bolt.
• One of the conductors.
• Second puck.
• Another conductor.
• Third puck.
• Screw.

The connection is tightened first by hand, then with the help of keys (you can take pliers). That's all, the connection is ready. It is used mainly 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, let us recall why it is impossible to directly connect copper and aluminum wires. There are two reasons:

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

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 it is necessary to connect conductors having different diameters, twisting must not be present to obtain good contact. So you can use the following types:

• terminal blocks;
• wago;
• bolted connection.

To date, they have invented a bunch of a wide variety of ways to connect. But, for some reason, the way to "bite off, twist and rewind with tape" is not inferior to its position.

But there is also something that is fundamentally wrong.

The reason is that it is categorically wrong to twist two wires from different materials, for example, copper and aluminum, into a spiral. The fact is that during the oxidation of the aluminum wire, galvanic steam is released, which will eventually break the connection. And the more current passes through this connection, the sooner it will collapse. And, if the load on the wires is unstable, then constant heating-cooling will only worsen the condition of the wiring.
This connection of wires can be dangerous. Since sparks in the connection can cause a fire.

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

For example, here is such a thing called a polyethylene terminal block:

You can buy such a simple contraption at any hardware store. And if you pull a brass sleeve out of it, you can clearly see how the wires are connected:

You need to put 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 then there were shortcomings.

If you clamp 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 happens, then once a year the terminals need to be changed. Otherwise, the contact will heat up and this will lead to a fire.

Stranded wires must not be clamped in the sleeve. You may not be lucky and what you already know will happen.

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

When buying a terminal block, do not be fooled by the inscriptions 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 you use it, then only to connect something small, a light bulb, for example.

The same goes for unnamed Chinese gizmos. Better to be overdressed than underdressed. Therefore, buy terminals from normal proven manufacturers, such as: Tridonic, ABB, Legrand, Verit

TB Series Terminal Blocks

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

Inside consists of two screws and a plate:

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

A good thing, because here the wires are already 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 stranded and solid cores can be clamped. But, nevertheless, aluminum should be checked from time to time. What is bad about such terminals is that they do not 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 just to strip the wire and shove it all the way:

Inside that terminal there is such a thing, where the pressure plate is indicated by a blue arrow, and a small tinned copper bar is indicated by an orange one:

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

That is, the wire is pressed tightly with a plate to the tavern and keeps it so constantly, does not allow it to fall out.

You can, without fear, even push an aluminum wire into this terminal.

Here are exactly the same, but transparent terminals:

Their plus is that through the translucent walls you can see how deep the wires are inserted. This terminal is suitable for 4 kW. However, there is one big BUT. This means that only original WAGO terminals have such abilities. For the rest, the maximum current is limited by a lower indicator.

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 it by lowering the lever:

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