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Correct twisting of wires. How to connect wires in a junction box. Connecting tinsel wire by twisting with a single-core or stranded conductor

The topic of connecting wires seems quite interesting to consider. For those who are just learning the basics of electrical engineering, this information will be very useful and necessary. After all, you don’t have to be a professional electrician to understand that all wire connections are a serious danger zone. As a rule, 90% of all problems and accidents occur in contacts and cable twists.

The connection of wires can be of several types: twisting, using terminal blocks, using contact clamps, etc.

As you understand, there are quite a lot of types of wire connections, but only those connection methods that can be made by ordinary consumers at home will be considered.

Let's start with some general information.

When laying or repairing electrical wiring, quite often you have to make all kinds of branches and splices of wires. During this operation, you should always strive to obtain a high-quality connection and good contact. This is really very important because in places of poor contact due to increased resistance conductors heat up, and this can lead to a fire in the insulation of your conductor and, in some cases, to serious consequences (as we have already mentioned above).

There are several ways to connect wires and cables:

1. Twisted.
2. Screw terminal blocks.
3. Contact clamps.
4. Electric welding.
5. By contact heating method.
6. Soldering in a twist or in a sleeve.
7. By crimping in sleeves.

Some of these connection methods require special equipment; at home, contact clamps, screw terminal blocks, and, as a last resort, twisting without soldering are the best options for connecting wires yourself.

All methods of connecting conductors, which will be discussed below, are almost equivalent. Each of them has its own pros and cons. If all your connections are made correctly and conscientiously, then there should be no problems with them in the future, no matter how you make this connection.
Next, we will consider the most common methods of connecting wires that are applicable at home.

Twisting wires

This method of connecting wires today is used only in the absence of special tools and devices. In most cases, the wires are simply twisted and wrapped with electrical tape. In some cases, such a connection is not reliable, but when certain conditions Such connections show amazing reliability. To do this, you need to remember a couple of rules: you need to twist copper with copper, aluminum with aluminum and provide a relatively small current to power your chandelier.

In this case, the entire length of your twist should be approximately 3-4 cm. As you already understood from the above, in no case should aluminum and copper wires be twisted together. At the places of such connections, there is always a process of electrolysis (with the participation of water contained in the air), during which these metals are destroyed. This mainly applies to aluminum. In this process, there is always one rule: the greater the current, the faster the process occurs.

The type of twist depends mainly on the type and functional purpose connection, diameter and material of twisted wires. Below, to help you understand this issue, a table of types of twists is provided.

Modern twisting of wires is carried out without the use of pliers. To create it, special connecting polymer caps with a metal spiral inside are used. There are both imported and domestic caps on the market.

The cap (twist) is the simplest way TPG connections of small cross-section. Used when you need to connect several ends of a wire. The connection is made very simply, the straight ends of the wires are stripped to a length of approximately 15 mm, inserted inside the cap until it stops and the housing is rotated using the wings on the housing until a strong connection is obtained. You can check the resulting connection using conventional instrumentation, since at the top of the caps there is a control recess for the probe of the device.

The connection can be screwed on and, in some cases, unscrewed if the ends of the wires are the same length. But here you should always remember that spring caps are designed for a certain number of wires (this information should be on the cap body or on the packaging in which the caps were located), so when performing this type of work you should always have a set of different sizes.

When choosing the cap size you need, you can focus on color scheme. Just when buying caps, carefully study their range presented in the store. Pay attention to the color and technical characteristics that should be written on the introductory sheet, and if you need to, remember all this information. In most cases, you can get by with buying red caps - with their help you can twist wires from 0.5 to 12.5 mm².

The next type of wire connection to consider is the connection using terminal blocks.

Connection with terminal blocks

Terminal blocks are a fairly convenient way to connect wires, especially when you have a lot of them.

The block is a dielectric housing with screw contacts inside.

Terminal blocks, as you have already seen, have quite a lot of sockets isolated from each other (usually there are two screws per terminal block). Here all connections are made quite simply. You just need to strip the ends of the wires, insert them into the corresponding hole (towards each other) and tighten the fastening screws. But do not overdo it, so as not to cut off these same veins. The terminal blocks are designed to operate in an alternating current network with a rated voltage of 220-230 V and a frequency of 50 Hz.

The pads have holes in the middle of their body. Through these holes you can attach the terminal blocks to any surface. If you do not need the entire block, you can cut off the extra terminal strips based on the holes.

You can also this type The terminal blocks can also be used as a dead-end terminal. That is, you put all the wires that you need to connect on one side and strip the wires so that they can be tightened with not one, but two screws. It is better to do this so that the ends of the tightened wires do not stick out from opposite side terminal block. Then take the electrical tape and try to insulate the end so that you yourself do not get an electric shock in the future.

Although there are dead-end terminal blocks on sale, buying them is not always profitable. It is unlikely that you will purchase a large electrical product.

And one more point that should be taken into account when working with terminal blocks. If you are trying to connect a stranded wire, then always try to crimp the lugs onto the ends of the strand, since when tightening this wire with screws, there is a high probability that you can cut off a large number of individual strands and thereby reduce its cross-section, and this can lead to further unpredictable consequences. One piece of advice is appropriate here: when purchasing terminal blocks, always inspect them carefully and try to buy ones that have pressure plates inside.

Terminal connection

The next type of wire connection, which should be considered in more detail, is connection with contact clamps (in other words, the use of WAGO terminal blocks, they are also called flat-spring contact clamps).

Nowadays, wires are increasingly connected using spring clamps. In this case, you do not have to twist or solder anything; you just need to strip the ends of the cores by about 12 mm and insert them into the holes of the clamp.

Scheme of connecting wires with contact clamps: a – connection of an aluminum single-core wire with a pin output: 1 – nut; 2 – split spring washer; 3 – shaped washer; 4 – steel washer; 5 – pin terminal; b – connection of a two-core wire with a flat contact screw clamp; c – connection of the core with a clamp-type terminal; g – contact spring clamp.

This is what this design will look like.

These terminals are filled with a special contact paste, which, when connecting an aluminum conductor, removes the oxide film from it and prevents re-oxidation. That is, during installation you can safely connect both a copper and an aluminum conductor to one terminal block.

Many experts criticize this type of connection for one reason or another. But still, it is quite reliable and has a number of advantages:

1. The conductors are not damaged.
2. Reliable protection against accidental contact with live connections.
3. Each conductor has a separate terminal location.
4. Connecting both copper and aluminum conductors together.
5. It is possible to measure the electrical parameters of the circuit without damaging the insulation.
6. Safety and order when using these terminal blocks in electrical boxes.
7. Short circuit and heating at the connection point are completely eliminated.
8. This series clamps are the best option for connecting wires at currents up to 25 A.
9. Instant installation of conductors.

There are terminal blocks of this type for multi-core wires.

There are also connection methods, less popular, that you can do yourself.

Diagram of the contact clamp device: 1 - screw; 2 - spring washer; 3 - washer or contact clamp base; 4 - current-carrying core; 5 - stop that limits the spreading of the aluminum conductor.

Screw terminals are contacts in which the wire is secured with screws. The clamp itself is mounted on the underlying surface using screws. In some cases, screw terminals may look like this:

Cable clamps - these devices help connect wire strands without cutting the TPG. Used to branch wires from the main line.

This type of compression is a bit outdated. Now they are trying to use a slightly different design, which does not need to be disassembled and when using which there is no need to strip a section of the main line from insulation, since they are self-piercing. That is, when tightening the nut, which is located on top of the clamp, special teeth pierce the conductor insulation and thereby ensure reliable contact. You can insert another conductor into another hole and thereby make a branch.

Panel terminal blocks or busbars – this connection method is used when you need to connect several conductors. For example, when connecting suitable neutral wires to the common.

Soldering is the joining of wires using a soldering iron and special solders.

Whatever connection you choose, try to do it thoroughly and without haste, so as not to blame yourself in the future if the unexpected happens.

During installation electrical wiring Special attention is given to electrical contacts, since the quality and reliability of the entire electrical network as a whole depends on this. An integral part of such contacts is the connection of wires. For this, both modern technologies and old methods are used. Each method has its own disadvantages and advantages. What type of wire twisting to use depends on the conditions and possibilities.

Requirements for twisting wires

Twisting wires together is the most popular and simplest method, but at the same time it is also the most unreliable. To understand how to twist wires correctly, it is necessary to imagine what processes can take place at the junction. Over time, as a result of temperature exposure, the clamp weakens. This is caused by linear expansion of the conductor during the passage of large amounts of current. The contact at the junction weakens, its resistance increases, and accordingly the twisted area heats up. The wires oxidize and overheat, contact is lost or insulation breakdown occurs, which can lead to a short circuit and fire.

Requirements for twisting wires are regulated by the rules for installing electrical equipment (PUE). The basic rules for any method of connecting wires are to ensure contact without additional resistance. That is, this value is at the place of twist should not exceed the minimum resistance value of the wires themselves. This is also true for the requirements of mechanical strength; the contact point should not be less strong than the strength value of the wires themselves.

Therefore, according to the PUE, simply made connections in the form of twisting when installing electrical wiring are prohibited. After twisting, additional operations are required to increase its reliability. This can be soldering, welding, crimping, mechanical clamping.

It is important to note that twisting is applicable only if the connected conductors are made of the same material. Otherwise it will be formed chemical compound due to oxidation, which quickly destroys the twist.

Exist Various types twist:

• parallel simple;
• sequential simple;
• parallel to the groove;
• consistent groove;
• bandage

Before starting the connection, you need to prepare the wires. To do this, you will need to remove the insulation over a length of at least 50 mm, clean the exposed wire with fine sandpaper, and only then start twisting. Parallel connection is applied when it becomes necessary to connect the ends of the wires together, for example, in junction boxes. Consistent twisting when making branches.

Parallel connection method

Parallel connection is a simple operation that involves a method in which two wires, stripped to the same length, are applied parallel to each other. Next, the bare ends are crossed so that the edges touch each other. Then, with a rotational movement, they begin to twist. You need to twist in one direction, which one doesn’t matter.

The insulated parts of the conductors must not be twisted together. First, the conductors are twisted by hand, forming a direction, and then tightened with pliers. In this case, the ends of the wires are taken with pliers to give the twisting uniformity. The “parallel to the groove” method means that when twisting, one core is motionless, and the second braids it. To do this, starting from the end of the insulation, one wire makes three to four turns around the second. We lay the first one with a tight touch parallel to the second one and at the end we perform three to four turns again.

Description of the sequential method

A simple serial connection is accomplished in a different way. The stripped ends of the wires are not applied to each other, but are arranged oppositely, overlapping. Centers of stripped cores are applied to each other, and then braided in one direction and the other. In this case, it is necessary that the stripped conductors do not come into contact with the insulation of the opposite wire. When twisting with a groove, each core is braided with the other only at the end of the insulation, and in the middle it passes with a tight touch.

Cable banding

Executed as parallel , and sequential method. In the first method, the wires are pressed against each other with an insulating layer, and a third conductor is wound around the stripped conductors in a spiral motion. To do this, one end of the additional wire is held with your fingers, and the other is wrapped around with pliers, tightly squeezing the connected wires together. In the second method, the stripped wires are applied parallel, but opposite each other, not reaching one or two millimeters from the insulation of the opposite wire. Then they are tightly rolled with an additional conductor.

Twisting a multi-core cable

There are small nuances with this connection. To increase the contact area, the same methods are used, but with preliminary separation of the cores in each wire. After removing the insulation, the conductors are separated in each wire, and two to four pigtails are created from them with an equal number of conductors in each. Then they are laid one on top of the other, and the wires are twisted, one pigtail from each wire. At the end, the resulting braids are woven together. This way it will turn out correct twist wires with strong mechanical strength and low resistance.

The number of turns that is obtained during operation should be more than six. The types of wire connections do not depend on the material used and are performed in the same way for both aluminum and copper wire. It is important to understand what to twist different types wires cannot be connected to each other, and aluminum wire If tightened too much, it may break off. If you need to twist more than two wires, the process technology will not change.

Additional technological operations

Since the PUE prohibits twisting alone, and it is impossible to connect different materials, the twisting process must end with a terminal block or soldering. To make the connection reliable, the following technological operations are used:

• soldering;
• welding;
• screw terminals;
• crimping in special spring devices;
• crimping.

Soldering and welding when connecting

The only drawback of this operation is the labor intensity of the work. For soldering you will need tin and flux. When working with copper, rosin is used as a flux, while for aluminum, highly active fluxes containing oleic acid and lithium iodide. If a soldering iron with a power of up to 100 W is enough for soldering copper, then aluminum is welded using a gas heater, the heating temperature should be 400-500 degrees. Solder for copper is lead-tin. And for aluminum containing zinc.

The technology itself is simple, since the thermal conductivity of twisting is greater than that of solder, when melted it transfers to the joint, creating a thin layer. When soldering, large amounts of solder are not allowed; it should be distributed evenly over the entire surface.

Application of screw terminals

Screw clamps, in their operating principle, involve mechanical compression of twisted surfaces using a bolted connection. For this, steel pads are used. The finished twist or individual wire strands are placed under a steel washer and compressed by screwing in a screw. In this case, the clamping is carried out both by the washer itself and only by the screw. The first method is better, since the contact surface is larger.

The terminal block itself looks like a plate on an insulator with a group of contacts. Using terminal blocks, both copper and aluminum wires of different sections are connected.

Using spring devices

Allows for the fastest connections without the use of tools. Wago terminal blocks are widely used. They are produced not only different sizes, but also under different quantities connected wires. With their help, single-core and multi-core wires of different sections and types are connected. The wires are combined both individually and with each other. For this purpose, the terminal blocks have a latch-flag, which allows you to lay the wire and clamp it inside after latching. Or use a device in the form of clips.

Using the Wago terminal, you can connect aluminum and copper to each other. But for this, a special paste is used to prevent air from entering, and the wire strands are separated into separate cells.

Crimping of connected cords

If it is necessary to connect large cross-section wires, lugs (sleeves) are used. The wires are stripped and inserted into the sleeves, then the sleeve is compressed using press pliers and the wire is crimped. This connection is considered reliable, but requires specialized tools.

Connecting insulating clamps (PPE) are also considered a kind of crimping. After twisting the wire, depending on the diameter, the caps are screwed on top of the connection, pressing the contact and insulating it.

The last final step after making the connection is to carefully isolate it. Dielectric tape or thermal tube is used as an insulator. The insulation should be 2-3 cm larger than the junction itself. The insulation must be carried out efficiently, otherwise there is the possibility of a breakdown between the wires, which will lead to a short circuit.

Twisting of wires is used to provide connections and branches during electrical installation operations. Contacts with this method of switching must be reliable. Carrying out work on wiring of all types - in everyday life or in industry - is subject to a collection of requirements and rules on how to properly twist wires. They say that it is impossible for additional resistance to appear at the points of contact between the cores. Neglecting this rule will lead to heating of the contact point.

The connection is made in accordance with electrical safety standards using similar methods:

• Twists.
• Welding.
• Soldering.
• Screw clamp.
• Terminal blocks and blocks.
• Self-clamping express terminals.
• PPE caps.

Connecting wires by twisting implies the advantages and disadvantages of the method. There is a PUE regulation prohibiting such an operation. But despite this, twisting is often used.

Twisting of contacts occurs during rough installation. This is explained by the need to establish the correct operation of already installed connections. Check the integrity of electrical lines, make the necessary corrections, install additional devices:

• switching structures;
• simple and special sockets;
• equipment for voltage conversion and stabilization;
• rectifiers;
• metering devices.

At the end preliminary work fully assembled circuit passes the functionality test. In case of incorrect operation of equipment, lack of electricity determine the cause and area of ​​damage. We have to replace faulty components and twist the wires correctly.

Correct twisting of the wires makes it possible to quickly restore the power supply. Depending on the situation, they decide what to do with the elements of annexation:

• The finished combination remains.
• Improves.
• It is replaced with a new one, with a different way of tying the cores.
• A basic set of tools for wire manipulation. It is easy to carry out the work in the field in the absence of powerful consumers.

Therefore, it is worth considering the maximum number of connected devices, deciding how to twist the wires correctly, calculating the appropriate cable cross-section, further development energy systems in the event of an increase in the number of consumers. Then the mounted solder will serve reliably for more than one year.

Twisting cable strands to connect pieces of wiring to each other appeared immediately after the discovery of electricity. At first, this method suited everyone. But time does not stand still, new electrical equipment has appeared, the need for development has increased energy networks with increased power and current. The question arose of how to properly twist the wires in the increasingly complex realities. The twists no longer guarantee uninterrupted operation under such conditions. But at the household level it is widely used and meets the requirements of networks with low load.

Pros and cons of twists

The advantages of a braided connection are:

• twisting speed;
• long lifespan with high-quality installation;
• does not require the use of complex tools;
• ideally serves signaling networks where there is no powerful electrical equipment;
• if necessary, the contact area can be additionally stretched or soldered;
• is inexpensive;
• the tap contains two to four branches simultaneously;
• connection is repeated if there is an error or careless execution.

There are also many disadvantages:

• high-quality insulation;
• not intended for use in power networks;
• inconvenient way to assemble wires;
• when heated, a fire occurs;
• voltage drop associated with feeder overloads.

Twisting wires with different cores

Such combinations are strictly prohibited for use. It is unacceptable to combine copper and aluminum wire! When touched, these metals enter into a chemical oxidation reaction and are galvanized . The contact connection is destroyed. As the load on the chain increases, weld erosion accelerates. Connecting in such conditions leads to sad results:

• heating, sparking and, as a result, fire;
• weakening of contact at the adhesion point;
• the size of the contact space is reduced;
• power surges in a section of the chain disrupt thermal equilibrium and destroy twisting.

Oxide appearance

The influence of air on the conductors oxidizes the junction. For copper and aluminum conductors, such an aggressive environment shortens their service life. The use of expensive metals such as silver or gold in conventional schemes it is not economically feasible. The problem is solved by insulating the strands with high-quality dielectric material with using the right methods execution. Such measures prolong the trouble-free operation of the soldering point and the entire circuit.

Resistance at the place where the wires are combined

The result of weak contact between the cable cores is an increase in resistance in this place. Heating appears in the transition space and destruction of the entire connecting circuit. Tight connection of the wires will reduce such risks.

Types of connections in electrical circuits

Twists are classified according to the material of manufacture of the veins involved in the operation, their types, and the method of twisting. The cross-sectional areas and permissible load must be identical.

Wires with copper conductors allow repeated, up to ten times, torsion without compromising strength and contact. They easily also suitable for triple-quadruple connections. Aluminum cable is not as resistant to mechanical stress. One or two attempts at gossip - and he breaks off.

Cable cores can be single or multi-wire. The twisting method must be found taking this feature into account.

For temporary or mobile wiring, choose a more reusable twisted soft cord. The stationary and final electrical circuit consists of a monolithic core.

Connecting multi-wire cables is allowed. The directories contain data for all types. Following the numbers, materials are selected for installation from wires with different combinations lived It is necessary to take into account the cross section according to the current rating. The methods of weaving such endings do not differ.

The connection of wires will last for many years if the exact manufacturing procedure is followed.

We do this with the following veins.

The TU cambric is moved to the joint and heated until it is monolithically applied to the twisted area. In the absence of a tube, insulating tape is used. It is applied in three to four layers with a full overlap.

In the absence of special devices for splicing cables, we use twisting. The main requirement is the maximum contact area of ​​the cores at the point of alignment. After stripping, we twist each wire at the sheath by one centimeter. We fluff out the bare ends into the hairs. Manipulation is performed with each contact.

Serial connection is made by combining counter beams one into another so that the wiring of the cores got mixed up with each other. Twisting is done from both sides in opposite directions.

When installed in parallel, the manipulations are close. The wires are arranged like a house and the fluffy corollas are braided. The connections are sealed with pliers and insulated.

Most easy method soldering of single-wire conductors is called parallel. The wires are brought together at an arbitrary angle, the stripped areas are twisted away from the point of adhesion.

To build up using a simple sequential interweaving method, the bare wires are bent, moved towards each other until they intersect and twisted with a screw in opposite directions.

When one wire, before connection, is bent and curled around the second in 2 places (at the insulation and in the area of ​​its bent edge), the cable is spliced ​​by parallel intersection with the gutter.

Similar consistent Twisting is done with braiding of both cores. Two twisted spots are formed at the base of the insulating layer.

Connection with the assistance of a bandage is required when working with a rigid wire or cable with a large cross-section. This technique also has parallel and sequential versions. A core is pre-prepared from a monolithic wire of a thinner cross-section, soft and made of a material similar to the main cable. The stripped ends are bent at right angles and brought closer to each other. The prepared bandage core wraps around them in uniform turns.

The connection of an additional wire and branch for each option occurs in a parallel way. The branching of the bandage differs in that, that only the attached process is wrapped.

With the intensive development of electronic technology, the load on electrical networks increases. Requirements for the reliability of soldering of current supply branches are also growing. The twisting method is gradually becoming a thing of the past. This is clearly noticeable in production areas, where installation is carried out using progressive methods, and outdated joints are replaced.

Laying electrical wiring in a house involves connecting wires; from the main network you will need to make branches necessary to provide power to electrical appliances.

How to make a wiring connection correctly

Connecting wires is required everywhere in rooms, in cars, devices and mechanisms, wherever there are wires. Today the following methods are used:

• Twisting;
• Welding;
• Soldering;
• Using special blocks, terminal blocks;
• Using self-clamping terminal blocks;
• Using PPE caps.

What you need to know about twisting

Take a close look at the photo of twisting wires, you will see that it can be done in different ways. You will need to prepare tools: a knife to strip the insulation, pliers to make the connection reliable, and you will also need electrical tape to insulate the twisted area.

Method - twisting wiring with protected ends

Expose the wires by at least 5 cm, cross the ends not protected by insulation, clamp the resulting cross with pliers and twist them together using a rotational movement.

A common method is groove twisting

First, familiarize yourself with the sequence of steps on how to twist wires with your own hands. Bend the ends of the wire into small hooks, hook them together, and wind one wire around the other.

Insulate the resulting twist to ensure human safety, reliable contact, prevent current leakage and prevent short circuits.

Professionals say that these types of wire twisting can be made more durable by using the following recommendations:

Twisted contacts are additionally connected by soldering or welding, as a result the contact acquires maximum reliability and is almost impossible to break. It is preferable to use soldering when both wires of the connection have a large cross-section.

WAGO terminals greatly facilitate connection, making it more efficient; they are needed when you have to figure out how to twist copper wires with aluminum ones. The whole procedure will go quite quickly, while the “wags” allow you to connect wires that have different section, the contact will be reliable and durable.

If a home handyman is faced with the task of connecting wires in an electrical outlet or lamp, use WAGO terminal blocks.

Thanks to PPE clamps, the reliability of the connection increases significantly, making it as safe as possible. These products have a low price, so they are available at any electrical store.

Wires twisted together should not be immediately closed using a junction box. It is better to observe how the electrical network works for several hours, after which it is recommended to check the temperature at the mounting location. If the connection gets very hot, you need to do everything again: most likely, the contacts are unreliable.

The twist itself is not waterproof, so it is better to take a box to connect the wires inside the wall; if without it, then the twist wires will need to be insulated using cambrics.

All you have to do is determine for yourself which twisting method is better and consider methods for isolating nodes.

What a DIYer should know about soldering and welding

Soldering is considered simply an improvement on twisting; the wires are first twisted and then soldered using a soldering iron with solder. Advantages of soldering:

• Increased twist strength;
• Reduced resistance, which means the twisting area will not heat up.

Multi-core copper wiring can be easily soldered, but this method is not suitable for all wires, with the exception of twisting aluminum wires. Since soldering is fragile, you cannot be careless when performing it, otherwise you will end up with a poor-quality connection.

Welding is another method that improves twisting and increases reliability, but is also not suitable for aluminum wires. It is used for multi-core copper cables with a large cross-section; welding reliability is considered higher than soldering.

When using welding, the possibility of weakening of the twist cannot be ruled out; under the influence of high temperatures, the performance characteristics of the metal can change.

Insulation methods

Insulation of wires is carried out using various types of electrical tape; it is necessary to insulate the twisted area and a section of insulated wires equal to at least 2 or 3 cm. Then it will be possible to make high-quality insulation that protects against unwanted contact with moisture; also, for this purpose, special thermal tubes are additionally used.

Insulation with thermotube

A tube of the required length is put on one core before twisting.

Twisting is performed, after which the thermotube is moved to the junction of the contacts.

It is necessary that the tube adheres to the wiring as tightly as possible, so it is heated a little with a lighter. Under influence high temperature the heat tube will shrink and it will be possible to ensure a tight grip on the wiring.

The advantages of all kinds of twists lie in the simplicity of their execution; despite the minimal equipment, they have proven themselves to be quite reliable connections.

When high-quality insulation is made, for which good electrical tape is used, the service life of the twist will be quite long. This connection is convenient to use: it is detachable, which means that if necessary, the wires can simply be twisted again.

Twisting is used in loose electrical wiring that sag; this method has been adopted by motorists, since the wiring in the car is constantly exposed to vibration.

Among the disadvantages of twisting, the following should be noted:

It is not possible to connect wires having different cross-sections; in such a connection, as a rule, there is a very high resistance, which causes constant heating of the wires and melting of their insulating layer.

It is difficult to twist together multi-core cables, which are soft and may break under any tension.

When there are several insulated wires in the wiring, due to the fact that each core is insulated separately, the total thickness can be very large.

Twisting is not suitable when it is necessary to connect wires made of different materials - copper and aluminum.

When choosing a method, it is important to take into account all sorts of nuances; only then will you be able to get a high-quality connection with your own hands. Twisting must be done after turning off the power supply for safety reasons.

Photo of wire twisting

It would seem that it could be easier connections wires? After all, there are several ways to connect wires. This includes twisting wires, soldering wires, welding wires, crimping and connecting wires using a terminal block. Even a schoolchild knows the easiest way to twist conductors. You need to put the ends of the metal wires, called strands, together and twist them into one “pigtail”, and then wrap them with electrical tape. There is no need for a soldering iron, terminal block, connecting caps and other “unnecessaries”.
Any “own electrician” has mastered this operation. And, when the need arises, he applies this method in his daily practice. For example, splices the wires of a power cord household appliance, tablet or computer adapter after a break.
Russian “technicians” use this technology for fastening wires everywhere. It’s just that the rules for constructing electrical installations of PES do not provide for “twisting”, all kinds of “bends” and “rivets”. There are no such electrical installation methods in other regulatory documents. Why?

We often don’t think about the consequences of such a “simplification”. Meanwhile, an unreliable contact will fail at the most inopportune moment; the power supply to consumers/power receivers can always be cut off. Voltage “surges” cause breakdown of the elements of the power cascades of complex SBT household appliances. Even special protection devices used in the most “sophisticated” models of foreign manufacturers cannot save you from breakdown.

The induction of short electromagnetic pulses with a voltage of several thousand volts onto the electronic filling causes “harmless” sparking at the joints. At the same time, the standard protection equipment with which apartments are now equipped (RCDs, circuit breakers, fuses) do not “see” such short low-current pulses, so they simply do not trigger them, and we do not accept installing special devices for this. Uninterruptible power supplies for computers also did not become a panacea for transient impulses. The occurrence of “poke” causes malfunctions in the operation of electronic equipment and computer equipment, leading to failure of electrical components and expensive functional modules.
Overheating at the site of a poor connection leads to even more catastrophic consequences; when current passes, the weakened connecting node becomes red-hot. This often causes fires and fires, causing enormous damage to the owners of the premises. Statistics show that 90% of all electrical wiring faults occur due to twists and poor contact connections of conductors. In turn, the very malfunction of electrical wiring and equipment, according to the Ministry of Emergency Situations, is the cause of one third of the fires that occur in Russia.

However, historically it happened that several decades ago, in conditions of shortage of electrical accessories/copper conductors, twisting of aluminum wires was considered the main method used in electrical installation work. Twisting as a connection can be used in electrical engineering when carrying out repair and restoration work.

How to connect wires correctly

How to connect the wires: we start by removing the insulation. Correct connection conductors must satisfy three basic requirements:

1. Ensure reliable contact with a minimum transition resistance between each other, close to the resistance of a single piece of wire.
2. Maintain tensile strength, fracture resistance and vibration resistance.
3. Connect only homogeneous metals (copper to copper, aluminum to aluminum).

There are several connection methods that satisfy these requirements. Depending on the wiring requirements and capabilities practical application, the following types of wire connections are used:

All these methods require preliminary preparation wire or cable - stripping the insulation to expose the connected cores. Traditionally, rubber, polystyrene, and fluoroplastic are used as insulating shell materials. Additionally, polyethylene, silk and varnish serve as insulation inside. Depending on the structure of the conductive part, the wire can be single-core or multi-core.
By single-core is meant a wire whose cross-section is formed by an insulating sheath with a metal core or wiring inside.

IN stranded wire metal core formed by several thin wires. They are usually intertwined and represent a lay, surrounded on the outside by an insulator. Often, individual wires are coated with polyurethane varnish, and nylon threads are added to the structure between them to increase the strength of the wire. These materials, like the fabric braid on the outside, complicate the process of removing the insulation.

Depending on the type of connection, 0.2–5.0 cm of insulation is removed from each end of the wire. Several types of tools are used for this.
Using a 5-point system, you can evaluate the quality of insulation removal and the degree of protection against cutting - damage to cores by each device:

Damage to insulation/core

Monter (kitchen) knife – 3/3
Side cutters (nippers) - 4/3
Stripper - 5/4
Soldering iron or electric loop burner - 4/4

In low-current television/computer networks, coaxial cables are used. During the cutting process, it is important to carefully cut and remove the insulating jacket without damaging the shielding braid. To access the central vein, it is fluffed up and removed, exposing the trunk. After which the polyethylene insulation is cut with a knife or a special device, the trim is removed from the core.
The bifilar in the screen consists of a pair of wires in the screen, which, in order to access the conductors, is also pre-fluffed into wires, allowing access to each core.

Important! To remove the insulating material of an enameled wire with a cross-section of less than 0.2 mm², a soldering iron should be used. The enamel is carefully removed using sandpaper and moving the paper along the wires.

How to twist wires correctly

Most often, twisting is used in the repair of electrical wiring, cords and adapters (including low-current ones) of household appliances and equipment. If we are talking about the home electrical network, then the standards provide for the use in homes of wires with a current-carrying core cross-section of 1.5–2.0 mm made of copper and 2.5–4.0 mm made of aluminum. Typically, wires of the VVG and PV brands in a polyvinyl chloride sheath are used for wiring. Power cords of the ShVL and ShTB brands with rubber or PVC insulation have a cross-section of 0.5 - 0.75 mm.
You can splice the wires together step by step as follows:

1. Degrease the bare ends of the wires by wiping with acetone/alcohol.
2. We remove the varnish layer or oxide film by sanding the conductors with sandpaper.
3. Apply the ends so that they intersect. We wind clockwise at least 5 turns of one core onto another. To make the twist tight, use pliers.
4. We insulate the open current-carrying parts of the wires using electrical tape, or screw on an insulating cap. They should extend beyond the insulation for 1.5–2.0 s to cover the exposed areas of the conductors.

To splice a stranded stripped wire with a single-core wire, another winding technique is used:

1. A single wire is wrapped with a stranded wire, leaving the end free without winding.
2. The end of the single-core wire is bent 180° so that it presses the twist, then pressed with pliers.
3. The connection point must be firmly fixed with electrical tape. For best performance, an insulated heat pipe should be used. To do this, a piece of cambric of the required length is pulled over the connection. To make it grip the wiring more tightly, the tube should be heated, for example, with a hair dryer or lighter.

With a bandage connection, the free ends are placed next to each other and wrapped on top with an existing piece of wire (bandage) made of a homogeneous material.
Coupling with a groove provides that before mutual twisting, small hooks are configured from the ends of the wire, they are interconnected, then the edges are wrapped.
There are more complex varieties of parallel/serial connections. Connecting wires using the twisting method is used by professional electrical repairmen when carrying out restoration work.

Important! Copper and aluminum have different ohmic resistances; when they interact, they actively oxidize; due to different hardnesses, the connection turns out to be fragile, so the connection of these metals is undesirable. In case of emergency, the ends to be connected should be prepared - tinned with tin-lead solder (PLS) using a soldering iron.

Why is it better to crimp (crimp) wires?

Wire crimping is one of the most reliable and high-quality methods of mechanical connections currently used. With this technology, loops of wires and cables are crimped into a connecting sleeve using press pliers, ensuring tight contact along the entire length.

The sleeve is a hollow tube and can be made independently. For liner sizes up to 120 mm², mechanical pliers are used. For large sections, products with a hydraulic punch are used.

When compressed, the sleeve usually takes the shape of a hexagon; sometimes local indentation is made in certain parts of the tube. In crimping, sleeves made of electrical copper GM and aluminum tubes GA are used. This method allows crimping of conductors from different metals. This is largely facilitated by the treatment of the constituent components with quartz-vaseline lubricant, which prevents subsequent oxidation. For sharing There are combined aluminum-copper sleeves or tinned copper sleeves GAM and GML. Wire connections using the crimp method are used for conductor bundles with a total cross-sectional diameter between 10 mm² and 3 cm².

Soldering as a reliable alternative to twisting

The closest alternative to twisting, which is prohibited for electrical installation, is to connect wires using the soldering method. It requires special tools and Supplies, but provides absolute electrical contact.

Advice! Overlapping wire soldering is considered the most unreliable in technology. During operation, the solder crumbles and the connection opens. Therefore, before soldering, apply a bandage, wrap a piece of wire of a smaller diameter around the parts being connected, or twist the conductors together.

You will need an electric soldering iron with a power of 60–100 W, a stand and tweezers (pliers). The soldering iron tip should be cleaned of scale, sharpened, having first selected the most suitable shape of the tip in the form of a spatula, and the body of the device should be connected to the ground wire. Among the “consumables” you will need POS-40, POS-60 solder from tin and lead, rosin as a flux. You can use solder wire with rosin placed inside the structure.

If you need to solder steel, brass or aluminum, you will need a special soldering acid.

Important! Do not overheat the junction points. To prevent the insulation from melting when soldering, be sure to use a heat sink. To do this, hold the bare wire between the heating point and the insulation with tweezers or needle-nose pliers.

1. The wires stripped of insulation should be tinned, for which the tips heated with a soldering iron are placed in a piece of rosin; they should be covered with a brown-transparent layer of flux.
2. We place the tip of the soldering iron tip into the solder, grab a drop of molten solder and evenly process the wires one by one, turning and moving along the tip blade.
3. Attach or twist the wires together, securing them motionless. Warm up with the tip for 2–5 s. Treat the areas to be soldered with a layer of solder, allowing the drop to spread over the surfaces. Turn over the wires to be connected and repeat the operation on the reverse side.
4. After cooling, the soldering joints are insulated in the same way as twisting. In some compounds, they are pre-treated with a brush dipped in alcohol and coated with varnish.

Advice! During and after soldering for 5–8 s. The wires cannot be pulled or moved, they must be in a stationary position. A signal that the structure has hardened is when the solder surface acquires a matte tint (it shines in the molten state).

But welding is still preferable

In terms of connection strength and contact quality, welding surpasses all other technologies. Recently, portable welding inverters, which can be transferred to the most inaccessible places. Such devices are easily held on the welder's shoulder using a belt. This allows you to work in hard-to-reach places, for example, welding from a stepladder in a distribution box. For welding metal cores into a holder welding machine carbon pencils or copper-plated electrodes are inserted.

The main disadvantage of welding technology - overheating of the parts being welded and melting of the insulation - is eliminated using:

• Correct adjustment of the welding current 70–120 A without overheating (depending on the number of welded wires with a cross-section from 1.5 to 2.0 mm).
• The duration of the welding process is no more than 1–2 seconds.
• Tightly pre-twist the wires and install a copper heat sink clamp.

When connecting wires by welding, the twisted wires should be bent and the cut side must be turned upward. An electrode is brought to the end of the wires connected to ground and the electric arc is ignited. The molten copper flows down in a ball and covers the twisted wire with a sheath. During the cooling process, an insulating belt made from a piece of cambric or other insulating material is put on the warm structure. Lacquered fabric is also suitable as an insulating material.

Terminal blocks are the most ergonomic electrical installation products

The PUE rules, clause 2.1.21 provide for the type of connections using clamps (screws, bolts). There is a connection directly using hanging fasteners, when a screw and washer are threaded through the loops of each wire and secured with a nut on the reverse side.

This installation is wrapped with several turns of electrical tape and is considered quite practical and reliable.
Electrical installation products called screw terminal blocks are more ergonomic. They represent contact group, placed in a housing made of insulating material (plastic, porcelain). The most common way to connect wires using terminal blocks is in junction boxes and electrical panels. To connect the wire, you need to insert it into the socket and tighten the screw; the clamping bar will securely fasten the wire to the seat. Another connecting wire is connected to the mating socket, short-circuited with the first one.

In self-clamping terminal blocks of the WAGO type, the wire is snapped into the socket; for better contact, a special paste or gel is used.

Branch clamps are a permanent version of a screw terminal block with several short-circuited taps; they are used mainly outdoors and in places with unfavorable environmental conditions.

The connecting clamps are an insulating cap with a thread inside; it is screwed onto the twist, simultaneously compressing and protecting from mechanical stress.