Proper twisting of wago wires. Correct twisting of wires

During installation work, twisting of wires is used to create reliable contacts in electrical circuits.

An electrical wiring device for any purpose - in the domestic sphere and in industry - is carried out according to certain rules.

These rules require that there is no additional resistance to the flow of current at the junction of the wires. If the resistance is higher than normal, then the contact point is constantly heated.

To make a connection meet this requirement, the following methods are used:

• twist;
• welding;
• soldering;
• screw clamp;
• terminal blocks and blocks;
• self-clamping express terminals;
• PPE caps.

Wiring Requirements

If we conduct a retrospective analysis of the processes that took place in the electrical industry, we can highlight several characteristic points.

Half a century ago, twisting was used everywhere. The main tool that the installer needed was a special knife, a screwdriver and pliers.

This set was enough to connect the ends of the wires in the junction box. Electricians had to do such operations constantly for many years.

Experience has shown that properly performed stranding will serve reliably for many years and even decades.

However, it is necessary to take into account the operating conditions and loads that the networks mounted in this way can withstand. The load on them was minimal.

If we compare it with modern values, then the growth amounts to hundreds of percent. Then the apartment had a minimum of electrical appliances - only light bulbs and a radio.

For this reason, the use of aluminum wire is limited by specifications, and the use of copper is strongly recommended.

Selecting the connection method

Over time, the tool with which the wiring is carried out has become different. If in the recent past it was possible to get by with good pliers, today this is not enough.

Welding wires requires a special apparatus. Soldering the ends without a minimum set of equipment is also impossible.

The connecting insulating clip, which is briefly called PPE, was also invented not so long ago. One method is used to connect aluminum wires, and another is used to connect copper wires.

In each case, you need to choose the right connection method, and do it according to the rules of electrical equipment devices - PUE.

Twisting

You can make a twist in one of three ways:

• simple twist;
• bandage;
• groove twist.

The first method is most often used in everyday life. Properly chosen tool, the use of PPE caps allows you to get good contact.

In this way, the ends are connected in the junction box.

Bandage twist is used to make large diameter wire connections. To ensure a strong connection of aluminum conductors, twisting with a groove is used.

If the connection technology in the junction box is performed accurately, then the contact can serve for a long time and reliably.

All of the listed types of twisting require a certain skill in work.

Simple twisting takes up very little space in the junction box. For better contact, you can “wind up” the PPE cap.

With a wire cross section of 6 squares and above, PPE caps in the junction box are not used.

To strengthen the bandage twist, soldering is used. Technological instructions do not allow simple twisting of aluminum and copper wires.

Such connections can be made after preliminary tinning of copper.

All of the above methods are used to connect multicore cables and wires. All operations in the junction box must be done carefully. Especially in the case when there are more than three cores in the cable.

If you want to make an additional tap on a certain section of the line, then all actions are performed according to a standard and familiar pattern.

The only difference is that the stripping of the supply wire must be done in the middle, and not at the end. The tool will need the same - pliers and a knife, which removes the insulation.

To make a reliable twist of aluminum wires, the electrician requires theoretical training and practical skills.

With enough experience, he can quickly complete any connection. In this case, the place of twisting must be cleaned. Aluminum oxide has insulating properties.

If the contact at the place of twisting heats up, then it is most likely that the stripping of the aluminum wire was not done well. It's no secret that you need to do all the operations correctly.

This law is strictly applied in electrical engineering. The fitter must have a good tool and an exam on the rules for the operation of electrical installations - he must pass it within a certain time frame.

Connection by welding

Practice shows that wire welding, as a technology, as a tool for connecting wires, is used in combination with other methods.

Most often, welding is used as one of the options for processing twists. A correctly “twisted” contact does not heat up and can serve reliably and for a long time.

However, during operation, there is always the possibility of weakening the twist.

This should not be allowed, especially in the junction box, which is located in an apartment or a private house.

Welding quickly and at minimal cost gives the contact the necessary parameters.

The state fire control requires that welded joints be made.

One of the three popular ways to improve the quality of the strand is soldering.

This technology does not require a special transformer or other complex tool.

Here you need a hundred-watt soldering iron and the right solder.

The desoldering of the ends is done in the junction box before putting PPE caps on them.

When connecting stranded wires, soldering is used more often than other methods. The most common soldering flux is rosin.

It should be emphasized that soldering is used to connect copper wires.

For aluminum products, other technologies are used.

Screw terminal and terminal blocks

If the connection of copper and aluminum wires by twisting is not allowed, then this problem has to be solved in other ways.

Can't help here and welding. In this case, screw terminals and terminal blocks are used.

When solving any technical issue, it is very important to correctly assess the operating conditions of wires and contacts.

In circuits with a load of more than 100 watts, the contact of the aluminum wire with copper heats up intensely.

To avoid this effect, terminal blocks of various designs are used.

It is advisable to purchase a device of this type from a heat-resistant material that will not react to how the contact heats up.

Self-clamping devices

The main argument given by opponents of the use of twisting is that the contact obtained in this way is heated.

Which can lead, and sometimes leads, to serious incidents.

Connectors with spring-loaded insulated clamps do not have this disadvantage. They started making such a device in Europe a few years ago.

If such a clamp is correctly applied, then the electrical circuit will serve without interruption. In practice, welding is still more often used, although there are more and more supporters of the clamping device over time.

The connection of stranded wires using self-clamping connectors is performed better.

PPE connecting caps are made specifically to improve the twisting of wires.

In fact, this is a tool that is designed to perform two functions - to isolate the contact and make it better.

When using a PPE cap, no tape is needed.

The design of this product is not as simple as it might seem. Inside it is a conical spring.

The correct selection of the number and cross-section of the wires to be connected ensures reliable contact.

Contact with such protection is practically not heated.

When screwing the PPE cap onto the place of twisting, the edges of the spring remove the layer of oxides from the surface of the wire.

This article has a somewhat provocative title. I am sure that there will immediately be people who will write instructively, saying that twisting is illegal and wire twisting is prohibited according to the PUE.

Nobody argues with this. If it were not for the fact that, despite everything that is written in the PUE, the vast majority of wire connections in the territory of the former large Soviet country are still made on twists.

I won't claim that it's very good wire twist- this is the most reliable and high-quality way to connect wires, although they constantly try to prove it to me. It seems that someone even measured and compared the voltage drop on the twist and on the whole piece of wire, so it turned out to be less on the twist. Perhaps this is something from the field of mythology among electricians. We will simply proceed from the fact that good twisting can be called one of the stages and a very important element of such methods of connecting wires, such as soldering or welding.

Before discussing further about the correct twist, let's dwell on what will happen if the wires are connected just like that, without technology, "how it happened." In this case, at the point of contact of the two wires occurs. There are two reasons for this - a decrease in the cross-sectional area of ​​\u200b\u200bthe wire at the point of contact (mainly due to microprotrusions during connection) and the presence of an oxide film on the conductors of the wire.

oxide film- the result of the interaction of the atoms of the metal of which the core consists with oxygen in the air. Such an oxide film has a very decent resistivity. The oxide film is absent only in noble metals - gold, platinum, etc. (that's why they are "noble", that they do not react with anyone). In silver, the resistivity of the oxide film is the same as that of the metal itself, so silver is actively used in the contacts of various electrical devices.

When the wire is heated by the current passing through it, the transient contact resistance increases even more, because. the generated heat is not completely removed to the environment, but also heats up the wire itself, including the twist.

As a result, all this can lead to an avalanche-like process, when the place of twisting heats up more and more. Here you have one of the causes of fires due to the so-called "malfunctions in the wiring."

I met one case when an aluminum twist in a neighbor's dacha stood for only one day. The reason for this is not only the presence of poor-quality twisting, but also the material of the conductive core of the wire. already posted on the site.

The most interesting thing is that no circuit breakers and fuses in the electrical panel will help in this case, because. they respond to an increase in current in the circuit. In our case, the current does not change, it just heats up the place of contact between the two wires more and more.

Based on this, we can conclude that a good twist of wires is necessary, first of all, so that the contact contact resistance always remains stable and does not change over time.

So, what does it take to make a good twist of wires?

First you need to remove the insulation without damaging the wire strands. We clean the bare area of ​​\u200b\u200bthe core from dirt with a clean rag soaked in acetone or white spirit. Then we clean the wires with a metal brush or sandpaper to a metallic sheen.

Next, we twist the stripped veins with two pliers. To do this, we bend the ends of the cores at an angle of 90 ° at a distance equal to 7-10 diameters of the core from the insulation cut, and wind them up for each other. We wind 5-7 turns of one core onto another with pliers.

We wind 5-7 turns of another core and seal the connection with pliers, i.e. we tighten the coils of cores with two pliers in opposite directions. Then tightly bend the ends of the wires.

In order to make a branch, it is necessary to wind 10-15 turns of the branch core around the main core. Seal the branch with two pliers, tightening the turns of the core by moving them in opposite directions. Then tightly bend the end of the branch core. After all these operations, the twisting will be mechanically strong and reliable.

There are many other ways to connect wires with a twist. All these methods are given even characteristic names.

For example, here are the methods shown in one well-known book for young electricians:

The option that I described in this article, using two pliers, has been tested by practice and has never failed itself.

After creating a high-quality twist, the wires can be soldered (little used due to labor intensity), welded (in one of the articles on the site it was somehow proved that).

A good twist is also needed, for example, for a more modern and less time-consuming method of connecting wires - when used, which is a good alternative to electrical tape.

In appearance, it looks like a regular cambric, which is put on for twisting with a margin in both directions. Then the heat shrink tube heats up (for this you can use a regular lighter, but it is better to use an electric hair dryer), tightly wraps around the cable and insulates it securely.

Do your twists right!

If you have your favorite wire connection options - share and tell us about it in the comments to the article!

According to paragraph 2.1.21. PUE, connections of wires and cables must be carried out in one of the following ways: by welding, crimping, using screw or bolted connections, or by soldering in accordance with the current instructions approved in the prescribed manner. As you can see, "twisting" is not mentioned at all here. We can safely conclude: twisting is practically prohibited by the PUE.

However, let's see why the official attitude to twisting is so unambiguous, what may be the reason for its exclusion from the list of allowed methods of connecting wires, because it is quite clear that this was done for a reason. Allowed: crimping, soldering, welding and screw connection. To begin with, we will consider what are the features of the allowed connection methods, and how they differ from twisting.

Soldering and welding

Soldering and welding assume solidity and the maximum possible conductivity of the permanent connection being created. During soldering, the permanent connection formed is formed by interatomic bonds, because when the metals to be joined are heated below their melting point, the solder is already melted, it immediately wets them and flows into the gap, after which it crystallizes.

Welding also involves the establishment of interatomic bonds between the parts to be welded, but here the metals themselves melt or undergo plastic deformation (or undergo simultaneous melting and deformation).

One way or another, it is now clear to us that both soldering and welding of wires make their pairing as complete and high-quality as possible, because the wires are combined at the atomic level, which means that for current they are turned into a single wire, when there are no air gaps at the transition between the parts to be combined, there are no unnecessary intermediate elements that could somehow worsen the conductivity.

Crimping and screw connection

With regard to crimping and screw connection, this implies such a strong pressing of the mating conductors to each other that the quality of the connection is almost identical in terms of conductivity to a welded joint or solder.

Yes, the tensile strength of such a connection may be less than that achievable by welding or soldering, however, the achievable joint conductivity turns out to be almost the maximum possible, since the wires can be said to flow into each other, their metals diffuse. There is not even an intermediate element here - solder, the resistivity of which, in principle, can be greater than the resistivity of the metals of the combined wires.

If the purpose of the connected wires is such that the wires will not carry a significant mechanical load, then crimping or screw connection in terms of conductivity will not yield to welding and soldering.

Why is the twist heated

What about twist? Twisting will not only not allow you to create a reliable, well-conducting contact, it will also not provide strength and will heat up more than the rest of the wire when any significant current passes through it.

This will happen because at the place of twisting the wires are not connected at the atomic level, they only contact with part of their surfaces, and in some places between them there are air gaps in which oxides will necessarily form over time.

In addition, mechanically, the twist will still unwind over time, which will further aggravate the formation of oxidation products.

In the end, due to the combined action of these factors, the contact of the wires in the twist will deteriorate so much that it will be fraught with the formation of sparks and even ignition of the wire insulation.

Of course, if we are talking about a temporary connection of wires, for example, when testing a circuit for switching on some kind of load or when checking a part of some device being repaired, then in these cases no one will forbid you to carefully use elementary detachable connections - twists.

However, one should be aware of the obvious disadvantages of such a solution as twisting and the inevitable long-term consequences of its use. Therefore, please make permanent connections only in the ways permitted by the PUE.

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

Connection is carried out in accordance with electrical safety standards using the following methods:

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

Connecting wires with a twist implies the advantages and disadvantages of the method. There is a PUE regulation to prohibit such an operation. But despite it, twisting is often used.

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

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

Upon completion of the preliminary work, the fully assembled circuit is tested for functionality. In case of incorrect operation of the equipment, lack of electricity find out the cause and site of damage. You have to change faulty nodes, twist the wires correctly.

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

• The finished combination remains.
• Improving.
• It changes to a new one, with a different way of connecting the cores.
• An elementary set of tools for wire manipulation. It is easy to perform work in the field in the absence of powerful consumers.

Therefore, it is worth considering the maximum number of connected devices, deciding how to properly twist the wires, calculate the appropriate cable cross-section, and further develop the power system in the event of an increase in the number of consumers. Then the mounted soldering will serve reliably for more than one year.

The twisting of cable cores to connect pieces of wiring to each other appeared immediately after the discovery of electricity. At first, this approach suited everyone. But time does not stand still new electrical equipment has appeared, the need for development has increased power networks with increased power and current strength. The question arose of how to twist the wires in the more complicated realities. Twisting ceased to guarantee uninterrupted operation in such conditions. But at the household level, it is widely used and meets the requirements of networks with a low load.

Pros and cons of twists

The advantages of a braided connection are:

• twisting speed;
• long service life 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 point can be additionally stretched or soldered;
• is inexpensive;
• the tap contains two - four branches at the same time;
• connection is repeated in case of error or inaccurate 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, galvanized . The contact is broken. With increasing load in the chain, solder erosion accelerates. Connecting in such conditions leads to sad results:

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

Occurrence of oxide

The influence of air on the conductors oxidizes the junction. For copper and aluminum conductors, such an aggressive environment reduces the service life. The use of expensive metals like silver or gold in conventional schemes it is not economically feasible. The problem is solved by isolating the twists with a quality dielectric material with the correct execution methods. Such measures prolong the trouble-free operation of the soldering point and the entire circuit.

Resistance at the junction of the wires

The result of weak contact between the cable cores is an increase in resistance in this place. There is heating in the transition space and the destruction of the entire connecting circuit. Tight wire bonding will reduce these risks.

Types of connections in electrical circuits

Twisting is classified according to the material of manufacture of the cores participating in the operation, their types, and the method of twisting. The cross-sectional areas, the permissible load must be identical.

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

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

For arranging temporary or mobile wiring, a more reusable twisted soft cord is chosen. The stationary and final electrical circuit is made up of a monolithic residential.

Connection of multi-wire cables is allowed. The directories contain data for all types. Materials are selected according to the numbers for mounting from wires with various combinations lived. It is necessary to take into account the cross section according to the current rating. The ways of weaving such endings do not differ.

The connection of wires will last more than one year if the exact order of manufacture is followed during execution.

So we do with the following veins.

TU cambric is displaced to the junction and heated to a monolithic overlay on the area of ​​twisting. In the absence of a tube, insulating tape is used. It is applied in three to four layers in 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 the bare ends through the hairs. Manipulation is performed with each contact.

Serial connection is carried out by combining opposing beams one into the other, so that wires are intertwined. The twist is made from two sides in opposite directions.

When mounted in parallel, the manipulations are close. The wires fit like a house and the fluffy corollas are braided into a braid. The connections are sealed with pliers and insulated.

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

To build up by a simple sequential interlacing, the bare wires are bent, shifted towards the intersection and twisted with a screw in opposite directions.

When one wire before connection is bent and twisted around the second in 2 places (near the insulation and in the area of ​​its folded edge), the cable is spliced ​​in a way of parallel crossing with the gutter.

Similar consistent twisting is done with a braid of both strands. Two twisted places are formed at the base of the insulating layer.

A brace-assisted connection is required when working with heavy gauge wire or cable. A similar technique also has parallel and sequential versions. The core is pre-prepared from a monolithic wire of a thinner section, soft and from a material similar to the main cable. The stripped ends are bent at a right angle, brought to each other. The prepared shroud core is wrapped around them in uniform turns.

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

With the intensive development of electronic technology, the load on electrical networks increases. The requirements for the reliability of soldering branches of the current supply are also growing. The twist connection is gradually becoming a thing of the past. This is clearly seen in production areas, where installation is carried out in progressive ways, and obsolete splices are replaced.

In the process of installing electrical wiring, especially in residential premises, it is necessary to use technologies for connecting wires and cables. This process requires some skills and knowledge. After all, an incorrect connection can lead to irreversible processes. There may be a disruption of the general power supply, as well as fires. The fact is that a carelessly made connection of stranded wires can lead to a fire, which in turn leads to a threat to life and health of people. The requirements for wiring in residential buildings are prescribed in the Rules for Electrical Installations, abbreviated as PUE. The PUE allows the use of electrical wiring in residential premises made only with copper wires. The connection of stranded and solid wires is allowed only by crimping, welding, soldering or using crimps. In clamps, the connection is made mechanically, using screws or bolts and clamps.

Various twist options

non-professional connection. This is a twisting of a stranded wire with a single-core. This type of connection is not provided for by the rules, and if such a connection of wires is discovered by the selection committee, then the facility will simply not be accepted for operation.

The twisting of a stranded copper wire in a steamed box is used as an intermediate operation before soldering or welding the joint, and soldering or crimping is required.

However, twisting is still used, and here you need to know how the correct twisting of stranded wires is performed. It is often used in emergency cases when it is not possible to professionally make a connection, and the service life of such a connection will be short. And yet, twisting can temporarily be used only for open wiring, so that you can always inspect the junction.

Bad wire connection

There are several types of twists. When twisting, it is necessary to achieve good electrical contact, as well as the creation of mechanical tensile strength. Before proceeding with the connection of wires, they should be prepared. Wire preparation is carried out in the following sequence:

• from the wire, the insulation is removed at the junction. The insulation is removed in such a way as not to damage the wire core. If a notch appears on the wire core, then it may break in this place;
• the exposed area of ​​the wire is degreased. To do this, it is wiped with a cloth dipped in acetone;
• to create a good contact, the fat-free section of the wire is cleaned with sandpaper to a metallic sheen;
• after connection, the insulation of the wire must be restored. To do this, an insulating tape or a heat-shrinkable tube can be used.

In practice, several types of twists are used:

Connecting the wire to the main

Connection of stranded and solid copper wire

• other various connection options.

In detail, about the methods of connecting single-core wires

Professional Connection

Consider various options for a reliable connection according to technology: soldering, crimping, welding and terminal connection of wires. You will refuse unreliable twisting when installing unsoldered boxes and other connections.

Soldering wires

The connection of copper stranded and solid wires by soldering is one of the reliable methods. With this connection, a good electrical contact is created, and the junction is mechanically resistant to tensile loads. This method can be used for: splicing two damaged wires, lengthening wires, moving sockets or switches. The wires connected in this way can be used in hidden wiring. If the junction is well insulated, then such a wire is not inferior to a solid section.

The technology of such a connection is as follows:

• preparation of wires is carried out in the same sequence as before the start of twisting;
• cleaning to a metallic sheen of wire sections;
• solder coating of joints (tinning);
• wires are connected by one of the types of twisting;
• twisted wires are soldered with solder;
• the place of soldering is processed with an emery cloth. There should be no burrs at the soldering point that could damage the insulation;
• the junction is carefully isolated.

The wires connected in this way can be placed under the plaster. For reliability, the junction should be placed in a PVC tube.

welding method

Welding belongs to the category of permanent connections. This type is the most reliable. It is with this method that the connection site acquires solidity. The contact resistance and mechanical strength of the connection section is no different from that of a solid wire. Welding is carried out both on direct and alternating current.

For professional welding of wires, various types of welding machines are used, but inverter current devices are most widely used. These devices are mobile, they are easily carried on the shoulder of an electrician, they are small in size.

Inverter devices are distinguished by a wide range of operating current regulation. The welding arc easily ignites even at low operating currents, and is stable during the entire welding period.

In addition to a welding machine for welding copper wires, it is also necessary to have copper-coated carbon electrodes.

Welding technology consists of several simple operations. First, the insulation is removed from the wire. Then, according to the technology described above, the wires are twisted. Twisted wires are aligned by trimming their ends. In order not to overheat the wires and their insulation, it is necessary to remove heat during the soldering process. For this, a special clamp is used, which is connected to one of the poles of the welding machine. Welding is carried out by touching the ends of the wires of the working electrode, which is held in a welding holder connected to the other pole of the welding machine.

Crimping

When crimping, the wires are placed in special mounting sleeves, which are made of the same material as the wires. In this case, copper. Then the sleeves are compressed with a special tool. When the sleeve is compressed, the wires are deformed. Deforming, the wires are tightly compressed with each other. With local indentation, the wires are deformed in such a way that their individual points penetrate each other's body. Thus, a reliable electrical contact is created, and the junction becomes mechanically strong. Crimping connects wires that are placed in junction boxes and electrical cabinets.

To perform crimping, special mounting pliers are used. Crimping pliers model PK-16 have gained wide popularity for connecting wires during installation of wiring in residential premises. To connect copper wires, connecting copper sleeves of the GM type are used. They are made of copper and have a red color.

In order for the junction to not come into contact with oxygen, it is preserved with special technical vaseline. Thus, the junction is isolated from the harmful effects of the environment. The wires will not oxidize and the connection will last a long time. The connection point can also be sealed with a heat shrink tube.

Threaded connection

Stranding of stranded wires using the method of braiding and clamping with a bolt

This type of connection, the connection of single-core and stranded wires, belongs to the category of detachable connections. For this, special terminal blocks are used, consisting of housings and devices built into them, designed for screw clamping of the wire. It is imperative for a reliable connection to communicate or tin the wire. The most widely used are when connecting end consumers. (lamps and chandeliers)

Self-clamping terminal block Vago

It is used to connect wires with a cross section of not more than 2.5 mm 2. With this type of terminal block, up to 8 wires can be connected simultaneously. They are used to connect wires in electrical cabinets. Mainly used for lighting. In the outlet group for heavy loads, use more reliable connection options.