How to connect wires in a junction box. Reliable ways to connect electrical wires Connect 2 copper wires

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Old-fashioned methods of primitive twisting of wires with mandatory insulation with the notorious blue tape are long gone. requires a professional approach, which means that it is necessary to use materials and devices that meet not only the highest safety requirements, but also simplicity, reliability and attractive appearance. One of these devices is the terminals for connecting wires. Today we will talk about how to choose and use them correctly.

Small terminal - the solution to many problems in wiring

How two wires are connected depends on many factors. The metal of the conductor, the thickness of the wire, the number of strands and the type of insulating material should be taken into account. An important factor is the conditions under which the connection will be operated.

There are several main types of connections:

Let us consider in detail the main characteristics of all these compounds.

Features of professional twisting

Twisting is the simplest method of connecting wiring. No special tools are required for work, a knife and pliers are enough. To make the connection strong, experts recommend stripping the cores by at least 5 cm. To make the contact tight, the wires are clamped with pliers and twisted in a rotational motion. After the resulting connection is wrapped in one direction and tightly wrapped with electrical tape. This is the simplest version of such a connection.

Professional electricians have other ways to connect wires with a twist:

Important! If you are using electrical tape, do not skimp on the winding. The insulation should cover not only the twist itself, but also go onto the wires for at least a couple of centimeters.

Instead of electrical tape, you can use modern material - heat shrink tubing. Before connecting the conductors, heat shrink of the required length is put on one of the wires and then pulled onto the twist. It remains only for a moment to bring a match or a lighter to the tube, it will shrink and tightly fix and isolate the cores.

With reliable insulation, such a connection will last a long time. Its advantage is good vibration resistance, which is good for moving machinery. Electricians do not recommend using this method when connecting wires of different sizes. During operation, excessive resistance heats up the contact point so that the insulating layer can melt. Professionals do not recommend twisting wires with strands of different metals and cables with a large number of strands.

Soldering for perfect conductivity

Not only the flawless operation of the mechanism, but also the safety of its user depends on the reliability and strength of the connection of the conductors. Soldering is one of the most reliable types of connection.

There is a soldering iron in almost every home, and the procedure itself does not take much time.

Rosin is used for tinning, and tin or other fluxes are used as solder. Copper wires are recommended to be soldered with tin or lead, aluminum wires with zinc compounds with tin, aluminum or copper. Before soldering, the wires are stripped and twisted using one of the above methods. After that, rosin and flux are applied to the place of twisting with a soldering iron.

Important! The heated solder should fill in all the bumps and holes in the twist.

After soldering, the connection is insulated with tape or heat shrink. The hardest thing to solder is aluminum wiring. It oxidizes rapidly at high temperatures and does not form a strong bond with the solder material. For a strong connection, you need to use tinning.

If the soldering is done correctly, the contact should be good. The only drawback is the fragility of the connection; with vibration and mechanical loads, it will not last long.

For professionals: welding

Welding allows the metal of the conductors to merge and provide optimal resistance. This contact is strong and durable.

You can use arc, spot, torsion, plasma, ultrasonic and beam welding.

Such work requires experience and skill, so the welding method is a tool for professional electricians. They use graphite and carbon electrodes, operate stationary, and use high-precision, voltage-regulated inverters. This technique is not suitable for domestic conditions, only experienced welders know how to properly connect the wires to each other in such a complicated way.

Important! All welding work must be carried out in a protective helmet. It will be very difficult for a beginner to achieve a high-quality connection of conductors.

After welding, the contact point is also insulated with tape or heat shrink.

Crimping with sleeves

Returning to more accessible methods for connecting wiring for domestic use, it should be noted that crimping is a simple and affordable method that can be used without special skills.

The technique is very simple - wire strands are inserted into a metal sleeve and then the soft metal is crimped with pliers or a vice. It is best to use special pliers for this purpose. They can manually crimp sleeves with a cross section of up to 120 mm². If you need a larger sleeve, use hydraulics. The disadvantage of the sleeve connection is that it is final, and, if necessary, it will not be possible to fix the contact without cutting the wire.

Note! For crimping, sleeves of the appropriate material should be selected to ensure optimal contact. There are sleeves made of aluminum, copper and alloys. The diameter of the conductor section is also taken into account, the cores must fit tightly into the sleeve.

The use of terminal blocks for connecting wires

The easiest to use and at the same time reliable is the installation using terminal blocks.

Terminal clamps for wires can be used when mounting conductors made of different metals. At the same time, the design of the terminals makes it possible to avoid direct contact between aluminum and copper and the formation of corrosion, which is inevitable for such a connection.

Terminal blocks are divided into three main types: knife, screw and spring. As a rule, a brass alloy is used as the main material. Some models are filled with a gel that protects the contacts from corrosion.

Standard requirements for terminal blocks

Like any electrical component, the terminal block has developed standards of reliability and quality:

Requirement	Description
Thermal stability	The material of the terminal housing must be able to withstand high temperatures and not give any possibility of ignition. The body must not be deformed when heated, and the protective cover is not made of combustible material.
Strong fixation	Terminal blocks should be fixed without undue force and at the same time securely hold the wire strands. In this case, the conductors do not need to be somehow additionally processed or twisted.
Corrosion resistance	The contact plates in the terminals are of such length that direct contact between the conductors is excluded. In this case, even if the wires are made of different metals, there will be no electrochemical corrosion.
informative	Each connector for electrical wires contains information about the diameter of the cores and the allowable voltage in the mains.

Pros and cons of terminal switching

Like any device, terminal connections have their advantages and disadvantages. First about the benefits:

• Ease of connection. The terminals can connect two or more wires with different cross-sections and metal, while each core is placed in a separate socket and can be easily separated if necessary. If welding, jacket or soldering were used for switching, it would be necessary to remove the insulation, break or unwind the contacts and then repeat the switching procedure again.
• Security. The terminals are made of insulating material. Even if you accidentally touch the switching point, you will not receive an electric shock.
• There is no need to use a special tool. For screw connection, you only need a suitable screwdriver.
• Fastening reliability. The junction of the wires is resistant to mechanical and thermal stress, vibration and stretching.
• Aesthetics. Connecting wires with clamps looks much neater than winding electrical tape.

Disadvantages of clamp connections:

• Price. The price of a quality terminal is 10 ÷ 12 rubles apiece. If you just need to connect a couple of wires in a chandelier, this is not essential. But with a set of terminal contacts can cost a round sum. But this shortcoming is a matter of time. A lot of competition in this market and the development of new technologies will soon make these devices cheap.
• Some difficulties in installation in hard-to-reach places. If you need to install a terminal block in a place where it is difficult to reach your hand or fingers, the task may seem too complicated. On the other hand, it is not easy to perform any other switching in such a place.

How to choose terminals for connecting wires

To choose the right terminal, first of all, you should study the cable that you plan to connect. You need to find out, it is usually indicated in the wire marking.

The second selection criterion is the quality of the terminal material. It must be sufficiently rigid and have reliable insulation. It is better if the screw and bracket of the device are made of steel. Terminals must be compact. It is possible that you will have to place the contact group in a limited space, so the size of the connections will matter.

Another criterion for the right choice is ease of installation and maintenance. Particularly convenient in operation are terminals with a guide cone and a flag marking the conductor entry point.

Important! Terminals with a small cross section up to 16 mm² have insulation installed on one side, so you need to carefully monitor their installation, otherwise a short circuit may occur.

It is convenient if the terminal surface is suitable for marking. Sometimes it is necessary for the further operation of the connection.

Types of terminal contacts

Modern manufacturers offer a wide range of switches to perform connections of various purposes. Each model meets certain tasks and requirements, we will consider them in more detail.

Screw switches

These simple and reliable devices are great for installation in outlets and similar outlets. The cores are fixed in the terminal with screws.

Note! Lead and copper switches can be used to connect a car battery. Auto mechanics recommend giving preference to lead fasteners. They do not oxidize as much as copper, under the influence of acid.

Screw terminals are not used for aluminum wiring. This is due to the fact that the aluminum core is destroyed under the pressure of the screw fastener. If the switch is provided, the screw head is marked with green paint.

Terminal clamps for wires

The design of such switches provides for the use of a small spring that fixes the core in the desired position.

Such terminal blocks are installed in an instant: just insert the stripped wiring and fix it in one click.

Junction Box Switches

Such terminals are used to connect wires in junction boxes. The body of the switch is made of polycarbonate, and the contact point is made of copper. Springs are used to fix the cores.

For reliability, the terminals are treated with a special paste that protects the contacts from overheating.

Video on how to properly connect the wires in the junction box using terminals

Fuse terminals

A separate type of switches - with a built-in fuse. Such contact groups additionally protect the wiring from a short circuit.

Such wads for connecting wires take up more space than conventional terminal blocks and are used in cases where electrical appliances do not have built-in fuses in their design.

Connection blocks

Pads are a handy gadget for connecting multiple wires. In the case of such a device, brass tubes with threaded holes are placed. With the help of such small devices, it is possible to connect copper and aluminum wires to each other, as well as conductors of different sections.

Switching in the block occurs in such a way that the cores do not contact directly. The only thing you should pay attention to is the rated current indicator on the block itself.

Blade terminals

Such switches are also called crimp terminals for wires. They are used for power conductors with a small cross section up to 2.5 mm. The maximum voltage for such a connection is 5 kV. Such a connection will not withstand a more powerful current, so knife terminal blocks are not used in large power plants.

Which terminal blocks are better

In fact, the choice of a suitable terminal should be approached very seriously. Especially if there is a need to connect wires with conductors made of different metals. During operation, such contacts are very hot and deformed. This can lead to a complete loss of circuit integrity and even a short circuit. It is worth remembering that spring and screw terminals are not suitable for fastening aluminum and copper wiring.

A few words about switch manufacturers

On the shelves of electrical goods stores, products of European, Chinese and domestic manufacturers are presented. As a rule, few ordinary buyers are puzzled by the origin of switches. And in vain. The safety of your property can directly depend on these tiny devices the size of a fingertip. Do not blindly trust Chinese consumer goods. In most cases, the products of the Middle Kingdom do not meet the requirements of domestic standards.

Domestic products are more reliable, but less aesthetic and technologically advanced. European goods are more expensive, but I bought such a terminal and forgot about it. Manufacturers guarantee long-term and reliable operation of their products. Here are some of them:

LEGRAND

Screw switches from this manufacturer are the most popular product in this category. Brass products are nickel-plated and can reliably withstand powerful temperature changes. Such terminals are characterized by high strength and a wide range of sizes.

WAGO

The products of the French company guarantee a strong connection of wiring of various types and sections. The devices perfectly resist possible vibration and stretching and are installed without special tools. The main material of the French terminal blocks is tinned copper, which gives good contact with low resistance. Some models are filled with anti-corrosion gel.

PHOENIX CONTACT

The German manufacturer is distinguished by excellent product quality. It offers more than 200 kinds of different switches for different types of connections. Among the presented models there are resistant to high humidity and explosion hazard.

WIEDMULLER

Another European brand offers one and a half hundred terminal models. The range is based on screw connections made according to DIN technology.

Common problem: how to connect aluminum and copper wire

This problem is often faced by residents of Soviet-built houses. At that time, almost all wiring was carried out using aluminum conductors. Modern electricians mostly use copper wire. How to connect aluminum wire to copper? There are skeptics who argue that such a connection is impossible. You shouldn't believe them. If you correctly use the techniques that we will give below, switching will be reliable and durable.

As already mentioned, the usual twist for such a connection is not suitable. The contact of copper and aluminum is very hot and can damage the insulating layer.

Option 1 - Bolted

This is a simple and affordable method that uses a steel nut, bolt and washers. Due to the impressive dimensions of such fasteners, it is unlikely to be placed in a modern small junction box. But on the other hand, such switching allows you to combine wiring not only from different metals, but also with different cross sections. Such connections are easy to disassemble and assemble if necessary.

Option 2 - "nut" connection

The name of such a connection was invented by electricians because of the external similarity. For fasteners, a special crimp is used, which is sold in electrical stores. The device consists of two dies with grooves for conductors. After fixing the cores, the dies are wrapped with electrical tape.

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.

The need to fasten the wires together can arise for many reasons, and if you are interested in the question: “How to connect the wires correctly?”, We advise you to familiarize yourself with the materials in this article. To carry out work of this type, you need to figure out what the procedure and features of connecting wires are, carefully study what methods you can use to connect them.

Let's try to tell as much as possible about the main ways to solve this problem, consider the process of fastening cables in stages, show a photo of how to properly connect the wires on our own.

Connection methods

Today, there are several ways to connect electrical wires. The choice of this or that method is made based on your preferences: having learned about all the methods, you can choose the option that is most suitable and convenient for each specific case.

There are six main types of wire connections:

• twist;
• crimping;
• welding;
• soldering;
• screw terminals;
• self-locking connections.

Consider step-by-step instructions on how to connect cables in one way or another.

Twisting

Today, the connection of electrical wires to each other by twisting is prohibited, since it is considered the most unreliable and unsafe compared to other methods. By choosing the twisting option, all responsibility for the possible consequences will be assigned only to you.

The connection will be very simple: it is necessary to peel off about 10-15 mm of insulation from each cable and wind them neatly on top of each other. When fastening wires with a cross section of up to 1 mm, it must be made from 5 turns, with a large cross section - at least 3 turns.

Crimping

The connection is made using a special sleeve corresponding to the size of the wiring bundle. The sleeve must be made of a material similar to that of the cable.

For crimping the product, press tongs are used, with the help of which the sleeves are crimped. At home, some people clamp the sleeve with pliers, but it has been found that such a connection will be fragile and unreliable.

Instructions on how to connect the wires in this way:

• focusing on the length of the sleeve used to carry out the work, remove the insulating material from the cables;
• twist the wires into a common bundle and place in the sleeve;
• crimp the connector using press tongs;
• insulate the resulting connection with heat shrink or electrical tape.

Welding

Using this method, at the end of the work, you will receive an essentially one-piece cable. He will not be afraid of any oxidative processes, or any other negative impact characteristic of disconnected wires.

To complete the work, the following elements will be required:

• welding machine;
• sandpaper;
• flux;
• personal protective equipment - gloves, goggles;
• carbon electrode.

At the first stage, it is necessary to clean the cables from insulation and strip the wires until they shine with sandpaper. Then twist the wires together. The third step will be to fill the recess of the carbon electrode with flux.

After it is necessary to bring it into working condition, press the electrode to the place of cable twisting and hold it until a ball is formed, in other words - a contact point.

The resulting contact point must be cleaned of flux and coated with a special varnish. At the final stage, you need to isolate the connection.

Soldering

The sequence of actions will correspond to the previous method using a welding machine, the main difference is that the wires are connected to each other using solder, which is melted with a soldering iron.

The connection obtained as a result of soldering is considered reliable and durable, but you should not use this method in places where strong heating of the wires can occur. It is also not desirable to carry out soldering in places where there is a possibility of mechanical stress on the resulting joint.

Screw terminals

This method will allow you to quickly and easily connect the wiring, for example, in a junction box. Such clamps allow you to connect both homogeneous and dissimilar conductors.

The algorithm of actions will be as follows:

• peel the insulating layer from the cables (about 5-7 mm of insulation);
• insert their ends into the clamp and tighten the screw tightly.

Self-clamping connections

This method is the most popular and modern. Self-clamping devices are easy to use.

Also, inside these compounds is a paste, which completely eliminates the possibility of metal oxidation. This function allows you to place both homogeneous and dissimilar conductors in the clips.

Actions will be as follows:

• peel 10 mm of insulating material from each cable;
• lift the lever of the self-clamping device;
• place the conductor in the clip;
• lower the clip lever.

Clamps that do not have levers simply snap into place.

Do-it-yourself connection of wires is possible even for a person who does not have any experience with electrical wires.

Having studied all the possible methods, you can choose the one that seems most understandable and easy to you. And having studied the detailed instructions for each of the methods of connecting cables, a favorable outcome of the work can be guaranteed.

In stranded wires, the cross section is formed by several, sometimes intertwined with each other, cores. Knowing how to connect stranded wires to each other, you can quite easily do this work yourself and get a strong, absolutely safe contact during operation.

Where are stranded wires used?

Any stranded conductor contains at its base a large number of thin wires. The use of a multi-core cable is relevant in areas that require a large number of bends or, if necessary, pull the conductor through too narrow and long enough holes.

The scope of application of stranded conductors is presented:

• extended tees;
• mobile lighting devices;
• automotive wiring;
• connecting lighting fixtures to the electrical network;
• connecting switches or other types of leverage to the electrical network.

Flexible stranded conductors can be repeatedly and easily twisted, which does not negatively affect the functionality of the system. Among other things, it is this type of electrical wiring that is distinguished by plasticity, and greater flexibility and elasticity is given to the wire by weaving a special thread, which is a bit like nylon in strength and composition.

Methods for connecting stranded wires to each other

The methods used today for electrical connections of stranded conductors are distinguished by the ability to obtain not only strong, reliable and durable, but also completely safe contact of the cores.

Stranding stranded conductors

This option is the simplest and most intuitive, not requiring the use of special equipment or professional tools.

Twisting is the easiest way to connect stranded wires

The second method consists of the following steps:

Twisting wires by the third method:

There is also a fourth method, which is as follows:

Soldering method

Soldering conductors with a household soldering iron provides high-strength contact and good electrical conductivity. Tinning of stranded conductors is carried out using rosin (flux) and standard solder according to standard technology.

Terminal Type Connections

The use of terminals of various types is the most affordable way to connect stranded wires in everyday life. In most cases, the terminal blocks used are divided into a couple of basic types.

The principle of operation of the clamping terminals involves fixing the wire using a built-in spring mechanism.

Terminals are often used to connect wires.

The screw-type terminal block assumes reliable fixation of all connected stranded wires with a screw. To increase the area of ​​wired contact with a conductive surface, it is required to perform an additional bend of the core.

In the terminal block, the wires are fixed by tightening the screws.

Phased work:

Crimping method

The crimping method involves connecting wires or cables using a copper or aluminum sleeve using special hydraulic or manual crimping pliers.

In this case, the connection is made using a special sleeve

The pressing technology consists in stripping the insulation according to the length of the sleeve, and too thin wires should be connected by twisting. Then all the cables are folded together and placed inside the sleeve, after which a double crimping is performed along the entire length. The method allows to perform a reliable and safe connection of stranded wires made of different types of materials.

Bolted connection

The simplest, but not sufficiently reliable way to connect stranded wires is twisting followed by bolting. This type of plug-in connection is most often used in open wiring conditions.

Bolted connection is the simplest, but not very reliable

To increase the level of reliability of the connection of stranded wires, it is recommended to strip the ends of the insulation, then tin the cleaned sections and fasten them with a bolt.

Application of connecting insulating clamps

PPE elements are used when it is necessary to connect stranded wires with a small cross section (within 25 mm 2). The design feature of this clamp is a plastic housing with a built-in conical spring.

This method is suitable for connecting wires with a small cross section.

Stranded wires are first connected into one bundle using a twist, on which the clamping part is then wound. Among other things, the wire connection does not need additional insulation.

welding method

Permanent connection is the most reliable way when working with stranded wires. With properly performed welding, the general indicators of mechanical strength and contact resistance in terms of reliability do not differ from those of a solid conductor.

Welding wire connection is considered the most reliable

Welding can be performed on alternating and direct current. At the preparatory stage, the wires are stripped of insulation, after which they are twisted and aligned by trimming the ends. To ensure that the conductors do not overheat during the welding process, it is necessary to ensure high-quality heat removal.

Security measures

In order to ensure the safe operation of the connected stranded wires, it is essential to insulate all parts of the electrical wiring without fail. Proper insulation helps to prevent dangerous contact of conductive parts with each other or with the human body. When choosing an insulating material, it is necessary to take into account the operating conditions of the electrical circuit, but in most cases, insulating tape is used for this purpose, as well as a special vinyl or heat shrink tube.

If the connection area is exposed to the negative effects of high-temperature conditions, it is recommended to use varnished cloth or fabric insulating tape as an insulating material. Of no small importance is the correct execution of all stages of electrical installation. Only with a reliable connection and proper connection of all elements of the electrical network can it be possible to minimize the risk of areas with poor contact, as well as prevent local overheating and breaks in electrical wiring.

Multi-core cables are a popular and common option, widely used for arranging electrical wiring for various purposes. The general rules for the separate connection of stranded and solid conductors do not have any differences or features, therefore it is allowed to use twisting, screw clamping, PPE elements, welding and soldering for this purpose.

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 wire connection 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 (beam 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 acceleration of 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 clips. 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.