What should be the twist length of wires - Metals and their processing

Twisting wires: how to twist wires correctly

Whatever they say about the process and methods of twisting wires, this method remains very relevant to this day and will remain for a long time. Why is that? Let's consider this topic in more detail.

With this method of connecting electrical conductors, there are a large number of nuances, advantages and disadvantages, including a ban on performing such operations according to the PUE regulations. However, it is worth noting that twisted wire connections are most often used.

There are many reasons, let's look at the most common ones.

Firstly, twisted connections are often used when performing “rough” installation. This is due to the fact that during the initial work the main goal is to check the functionality of the installed units. The presence of signal/voltage is checked (depending on the type of manipulation performed), additional work is carried out on the secondary wiring of additional elements, contacts of devices are displayed, such as:

switches of various types;
built-in voltage stabilizers;
built-in voltage converters;
built-in step-down/step-up transformers;
regular sockets;
"smart" sockets;
power consumption monitoring devices;
specialized sockets with special outputs (RJ-45, for example).

After carrying out the “rough” installation, it is extremely important to check the functionality of the above devices. And in case of their incorrect operation or lack of electricity/signal, you have to re-deal with a certain section of the circuit or re-carry out wiring operations and troubleshoot problems.

Secondly, this type of contact of conductors allows you to quickly restore the operation of the area and obtain the necessary electricity/signal for certain manipulations. In the future, depending on what devices will be connected to this area, it will be possible to:

leave the completed twist;
improve connection;
replace this section with another one, with other connecting elements.

Thirdly, no special tools are required to twist the wires. Such manipulations can be performed even “in the field”, provided that no “gluttonous” electrical appliances are connected to the created area.

It is worth noting that twisted wires can provide fairly reliable contact for a long time, provided all necessary instructions are followed and the work is done correctly.

So, it is worth wisely taking into account the situation if you decide to resort to such a connecting method as twisting. It is necessary to take into account the connected load, select the optimal cross-section of wires and further calculate the circuit in case of a change in the number or power of consumers.

Advantages and disadvantages

Weaving wires together is probably the oldest method of merging conductors together. However, over time, the power of devices requiring high currents also increases. Twisting, as a rule, is not designed for them, but for home use it is very appropriate.

It is worth mentioning that this wiring option cannot be used with devices such as electric kettles, refrigerators, washing machines, heaters and fan heaters, electric stoves, and computers.

The main advantages of twisting are:

speed of creation;
durability (if done correctly);
the ability to weave wires without additional tools;
ideal for signal contact (in the absence of connecting high-current consumers);
the ability to improve the connection using soldering;
cheapness;
the ability to combine two, three, four wires simultaneously;
Possibility of reconnection.

Its disadvantages include the following:

the need for isolation;
operability only with low-current consumers;
inconvenient installation;
fire hazard if work is performed incorrectly;
a large number of nuances that MUST be taken into account when weaving wires;
“surges” of voltage and interference on electrical appliances when the area is overloaded.

As can be seen above, twisting has a limited range of use; it cannot be used with powerful devices, and when used with computers, modern televisions, audio equipment and other equipment of the 21st century, there is a problem with the occurrence of interference and “throws”. Therefore, it is advisable to weave wires when used with lighting devices (chandeliers, lamps, etc.), power adapters and other “weak” devices.

Connecting conductors from different materials

The most basic thing is that twisting is PROHIBITED with conductors made of different materials. It is PROHIBITED to weave copper and aluminum wires. This is due to the fact that when copper and aluminum come into contact, a galvanic couple appears, which destroys the created connection. The higher the current passing through the plexus, the faster its destruction will occur. Such contact of wires threatens with the following consequences:

heating, sparking and subsequent combustion;
deterioration in the quality of contact of such a “weave”;
reducing the contact area;
strong heating of the wires at the plexus;
rapid oxidation;
under temporary and powerful loads, “heating-cooling” cycles occur, which is fraught with severe
deterioration in connection quality.

The appearance of an oxide film

The film appears as a result of the interaction between the oxygen environment of the air and the conductor. The metal conductors used to make connections are usually made of aluminum or copper and are quite susceptible to oxide film if the connection is not insulated. More expensive materials that are rarely used in electrical circuits, such as gold and platinum, do not have this disadvantage, but their cost is extremely high. An oxide film on wires has the following consequences:

deterioration in the quality of twist contact;
intensification of the heating process when current passes.

Dealing with this drawback is quite simple - it is necessary to carry out high-quality insulation of the twist.

The appearance of transient contact resistance

This resistance appears as a result of poor contact between the wires, which causes the temperature to increase greatly at the point where the current passes from one part to another. Transient contact resistance serves as a catalyst for the rapid destruction of the wire tangle, especially in the absence of insulation. To minimize transient contact resistance, the tightest contact between the two conductors should be made.

Types of twists and connections of this type

One of the advantages of such a connection as twisting is the possibility of improving it by soldering or welding. When soldering, the connection becomes strong and is able to withstand high currents; when welding, special equipment is used, which makes it possible to give strength to the completed connection. Soldering and welding of both copper and aluminum wires is an excellent way to improve its performance: reduce the thermal load by improving contact at the welding or soldering points.

When carrying out work, twists can be divided into several types depending on the materials, type of wire, type of twist. It is extremely important that the cross-sectional area of each of the conductors matches each other, and is also suitable for the load used.

Conductors can be made of the following materials:

Aluminum braiding is less resistant to further unwinding, while copper conductors can be unbraided and rebraided several times, for example, to add a third contact. Aluminum can withstand 1-2 times the load of twisting and unwinding, copper can be twisted and untwisted 3-4 times without any damage.

In this case, conductors can be divided into 2 types:

with a monolithic core;
stranded.

When performing the twisting process, it is worth considering the type of conductor, since the options for the plexus may be different. Depending on the type of wire, one or another twisting method should be used.

A cord with a monolithic core is usually used for stationary wiring, when there is no need to move equipment. Stranded conductors are often used for “rough” installation or where there is a need to move devices.

The twisting of both copper wires and aluminum wires is the same and is shown in the tables for each type of cord (stranded/single-core). If it is necessary to weave more than two conductors, for example 3-4, then first the initial twisting is performed for the two ends (shaping the connection) - 1-2 turns, after which the required number of conductors is added and twisted according to one pattern or another.

It is allowed to connect two conductors of different types (stranded/solid), but it is important to take into account the cross-sectional area of each conductor.

We twist it ourselves

During professional installation, special clamps are used to make the connection - PPE (connecting insulating clamp); when using them, the final twisting is allowed from the point of view of the PUE, but it is worth remembering that such a device is not designed for high currents.

So, how to properly twist wires at home? To carry out this manipulation you need:

take into account all the nuances in advance (location, load of connected equipment, etc.);
acquire the necessary tools (pliers, knife, sandpaper, heat shrink, it is advisable to have a hot air gun and a device for removing insulation, a screwdriver if available).

Let's consider the situation with weaving from a cord with a monolithic core:

It is necessary to strip the ends of each wire by 3–4 cm using a special tool (stripper) or a construction knife. It is extremely important to remove the insulation and not leave deep cuts on the core.
Then we put heat shrink on one of the ends.
Then degrease the cleaned surfaces with alcohol/acetone/white spirit.
Then, taking sandpaper, we clean the wire strands.
We lay the wires parallel to each other and hold them with pliers.
We weave (in accordance with the diagram) clockwise, at least 5 turns for one core. The wires must fit tightly to each other.
We move the heat shrink to the contact point and warm it up with a hairdryer or lighter. It is important that the heat shrink fits tightly at the twisting site.

It is possible to hold one end of the cord with a screwdriver and slowly turn it, while weaving the other end onto the rotating end, creating tension with your hands, thereby making the connection tighter.

With a stranded cord the situation is a little different:

We strip the ends of each wire by 3–4 cm using a special tool (stripper) or a construction knife. It is extremely important to carefully remove the insulation and not damage/cut off the cord cores.
We put heat shrink on one end of the cord.
We unravel the strands of each cord into small “braids”.
We degrease the resulting “braids” with alcohol/acetone and so on.
We lay the cores on top of each other from each cord.
We weave together, making the connection tight (at least 5-6 turns per braid).
We move the heat shrink to the place of twisting, warm it up with a hairdryer/lighter. The heat shrink should fit tightly at the joint.

If it is necessary to create a “braid” from monocore and multicore cords, the algorithm also changes, and it is highly advisable to weave using the “Branching” method:

We strip the ends of each wire by 3–4 cm using a special tool (stripper) or a construction knife. We take care not to damage the cores of each cord.
We put heat shrink on one of the cords.
We degrease the cleaned areas with alcohol/acetone and so on.
We bend the single-core end 180 degrees, so that it then presses the twist.
We twist the multi-core cord around the single-core end in accordance with the diagram (clockwise), at least 5-6 turns, the more the better.
We clamp the pre-bent end of the single-core wire and press it against the twist made with pliers.
We move the heat shrink to the contact area and heat it with a hairdryer/lighter. We make sure that the heat shrink is well fixed at the twisting site.

At this point, we can consider the work done competently and efficiently. If you follow the instructions and take all necessary measures, you are guaranteed to get a high-quality connection for a long time.

Source: https://ProFazu.ru/provodka/montazh/skrutka-provodov.html

How to properly twist wires

The electrical network got its name for a reason. It covers all rooms like a web, ensuring the operation of the equipment. To distribute energy between individual connection points (sockets, switches), junction boxes are used. One cable goes into them, but several come out. A prerequisite for safe operation of the electrical network is to twist the wires correctly and accurately. To do this, you can use different methods.

To better understand how to do twisting correctly, let’s figure out what options exist, the order, and the features of their implementation. Electricity is considered one of the communications that “do not forgive” mistakes.

The result of illiterate actions is damage to the device, short circuit, or fire.

Beginning craftsmen often ask: is it possible to connect the wires in the junction box yourself? Of course, but before that you should take the time to study the rules and features of electrical work.

Wire connection methods

There are different ways of tightening wires in a junction box: crimping, welding, soldering, various clamps. Some require more time, special materials, and equipment. Others are easier to implement, but poor execution significantly reduces their reliability.

Twisting is popular among folk craftsmen. The PUE classifies it as an unreliable method that does not guarantee reliable contact. It is usually used as a temporary option, for example, when checking the functionality of a circuit. In addition, it is considered preferable for sagging, loose networks. Advantages:

ease of execution;
minimum tools;
Easy to disconnect if necessary.

One of the disadvantages is the difficulty of working with wires of different sections: the difference in resistance leads to heating of the insulation, its gradual melting. They try not to use this method for multi-core cables, since the probability of a circuit break is high.

Do not twist copper and aluminum wires: the result will be unreliable, the point of contact will become a source of increased resistance.

The easiest way to twist wires is by twisting the previously stripped ends together. The tools you will need are a knife and pliers. First, a section of the core 5 cm long is cleared of insulation. The bare ends are crossed, bringing the individual parts as close as possible. Then use pliers to rotate the crosshair, bend it in any direction parallel to the main line, and isolate it.

Types of wire connections

You can use another option, when the stripped ends are folded in the middle and interlocked. Then the wires are wrapped together. For reliability, they are crimped with pliers and insulated. Electricians know many methods of twisting: parallel or serial bandage, groove. Correct twisting should ensure the most complete fit of the cores.

Electrical tape is usually used for insulation. It is necessary that it extends at least 2-3 cm onto the insulation. You can use a thermotube. It is first put on the cable, then moved, covering the contact point. The tube should tightly grip the wiring, so it is heated a little.

For crimping, you will need a special sleeve, selected for the size of the bundle and the cable material. The stripped ends of the core are inserted into the sleeve, crimped with press pliers, and insulated.

In terms of reliability and quality, welding gives the best results. In fact, they get a one-piece structure that is protected from oxidation and rupture. To perform this you will need a welding machine, carbon electrode, and flux. Step-by-step implementation instructions:

strip the ends of the cable from insulation, bring them to a shine with sandpaper;
twist the wiring;
fill the recess of the electrode with flux;
weld the contact point.

Clean the resulting “ball” from flux and coat it with varnish. Similar actions are performed when soldering. Here the contact is provided by solder melted using a soldering iron.

Twists of copper and aluminum wires

A lot has been written about why copper and aluminum should not be combined with each other. The consequence of such contact is its heating, subsequent combustion. There are several reasons for this behavior of metals:

Difference in thermal expansion coefficients. Metals expand differently when heated and contract when cooled. Therefore, their connection gradually deteriorates.
Formation of an oxide film on aluminum. The film prevents the passage of current, the conductor heats up, and the connection is gradually destroyed.
Violation of the aluminum structure during electrolysis. Copper and aluminum form a galvanic couple. Under the influence of moisture, dissociation of ions begins, which leads to the destruction of the metal. The resulting shells and voids conduct current poorly and cause heating.

The presence of aluminum wiring in houses leads to the need to combine it with new copper conductors. Using simple rules, you can avoid heating the contact and ensure its reliability. When performing twisting, it is important to wrap the conductors around each other. The number of turns is more than 3 for a thick wire, at least 5 for a thin wire (less than 1 mm). The finished connection is sealed with a protective varnish that is resistant to water.

Maximum reliability is ensured by a method in which the copper is pre-coated with solder. This creates reliable contact between single and multi-core conductors. To do this, the multi-core wire must first be tinned with solder, it will become single-core.

To make the contact detachable, use a bolt, nuts, and spring washers. All elements are placed on the rod one by one, avoiding the combination of copper wires and aluminum. For example: a conductor with a diameter of less than 2 mm will fit perfectly on an M4 bolt.

The development of electrical engineering has brought new comfortable ways of working with different materials. An example is a terminal block. Its advantages:

comfortable;
reliable;
eliminates contact between bare areas.

The end of the core is stripped of insulation (approximately 5-10 mm), inserted into the hole, and clamped with a screw. The terminal box is indispensable when restoring a broken circuit or connecting a chandelier. It can only be placed in the wall in a junction box.

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The Wago terminal block is deservedly popular. It can be disposable or reusable (with a lever). The terminal block works simply: insert the cable with force, it is fixed. Disadvantage: more expensive than other traditional means.

The danger of twisting copper and aluminum wires

Twisting wires of different sections

Often the master is faced with the task of connecting wires of different diameters in a junction box. This can be done in several ways: twisting followed by soldering (welding), screw terminals, self-clamping terminals, bolts, nut-type couplers, tinned copper lugs.

The easiest way is to twist wires in a box that are similar in thickness (for example, 4 and 2.5). With a large difference, it is difficult to ensure high-quality contact. The wires must wrap tightly around each other, then they are welded or sealed. A strong connection will last for many years without complaints.

A reliable contract between conductors of adjacent cross-sections is created by the ZVI screw clamp. The cables are inserted from different sides, each clamped with a separate screw. The choice of clamp is made taking into account the characteristics of the conductors and the permissible current. Execution principle:

strip the ends by 2-3 cm;
insert them into the box;
tighten the screws.

If the wires have a large cross-section, you can twist them using a Wago self-clamping terminal. Its peculiarity is the presence of special sockets for each core. Marking the terminal body will help you figure out how many wires you can twist and what cross-section.

Long-lasting contact of the wires in the junction box is guaranteed by a bolted connection. It allows you to fasten two, three or more wires using nuts, washers, bolts. Step-by-step mounting instructions:

strip the core by 3 cm (you should get a full turn);
prepare a ring from the core according to the diameter;
put a washer on the bolt, a ring of one conductor, another washer, a ring of the second conductor;
Place the next washer and tighten with the nut.

This way you can connect several wires together. Their number is limited only by the length of the rod.

The question often arises: how to twist the wires together to branch from the main line in the distribution panel? The solution most often is a branch compression, in common parlance - a “nut”. It allows you to branch a line from it without cutting the main line.

To do this, the desired place in the main part is cleared of insulation, a clamp is attached, and an additional “branch” is inserted. It can also be used to connect two separate cables. When choosing a “nut”, you need to know the cross-section of the main cable and branches.

Using compression, you can connect a copper wire to an aluminum one.

The body of the “nut” is not sealed. To protect it from moisture, dust, and debris, it should be insulated.

The compression connection procedure is simple:

disassemble the housing by removing the retaining rings with a screwdriver;
strip the insulation (the length corresponds to the dimensions of the die);
loosen the fastening;
insert the cores into special grooves on the dies;
carefully (without overtightening) tighten the bolts;
place the die in the body;
close the housing, install retaining rings.

To work with a thick cable, you will need copper-tind lugs and crimping pliers. The connection turns out to be bulky, so you will need to provide enough space in the box for it. A ferrule is put on each core, crimped, secured with a bolt and nut, washer, and insulated (with electrical tape, heat pipe)

Reliable wire connection

Errors when twisting wires

A common mistake when twisting is to wrap one wire around another. This option does not provide the required mechanical strength. The conductors should wrap around each other evenly. It is unacceptable to screw a thin conductor onto a thick one; a tight fit will not be achieved.

The length of the twist depends on the cross-section of the wires. It should be at least 3-5 cm. Options for clutching in a ring, loose fit, or not twisted are unacceptable.

Direct connection of copper with aluminum leads to rapid destruction of the contact. Craftsmen often forget to install an intermediate plate, which will prevent direct contact of metals.

Source: https://uzotoka.ru/montazh-elektroprovodki/pravilnaj-skrutka-provodov.html

Correct twisting of wires

The electrical circuit is located over the area of virtually the entire frame, providing the room with electricity for household and industrial appliances, depending on the purpose of the building.

Essentially, a cable is supplied from the central network, which is subsequently placed in the switchboard, from which several more come out, are routed to different ends of the room and connected to the distribution box, from where the final wires come out, ultimately connected to sockets, switches, etc. . Precisely in the distribution.

boxes create the largest number of connections, and sometimes a soldering iron, welding, or connectors are not used there, but wire twisting is used, which does not require special devices or tools, but only those things that virtually everyone has (knife, pliers).
:

How to properly twist wires

In order to virtually reduce the possibility of short circuits and ignitions, the twists in distribution boxes must be made with high quality. If a person performs such an action for the first time, it is better to first carefully read the rules of such a connection, and only after that begin to perform the work. Let's figure out how to do twists correctly, what types there are, and what problems you may encounter when performing this work.

To begin with, it is worth saying that connecting two wires of different metals by twisting is not recommended. Many analytical articles and arguments have been written about this as to why this should not be done:

different coefficients of thermal expansion (metals react differently to heating and cooling, as a result of which the contact gradually deteriorates);
the appearance of an oxide film on the aluminum wire (it does not allow current to fully flow, the wire heats up and breaks down over time);
structural destruction of aluminum during electrolysis (these two metals form a galvanic couple, and after exposure to a humid environment, the metal ends are subject to heating and subsequent destruction).

Twisting of copper and aluminum wires

Copper and aluminum cannot be connected directly to each other. However, in many houses there are aluminum wires that need to be connected to copper wires, and twisting is sometimes the only way to connect. In this case, it is important to adhere to certain rules that will allow such fastening to last as long as possible.

To begin with, it is worth noting that the conductors must be tightly wrapped around each other. If their diameter is significant, there must be at least 3 turns, and if the diameter is up to 1 mm, in this case it will be necessary to wrap the wire around each other more than five times to ensure high-quality transmission of electrical flow. Also, after this it is very important to treat the bare surface with a special varnish that is resistant to water and moisture.
When connecting copper and aluminum wires, it is better to use a special steel plate placed between them. This will avoid their direct contact. Thus, the service life of such a connection will be much longer. If you don’t have such a component at hand, then you can resort to treating the bare copper wiring with solder, which will also avoid mechanical contacts of these two metals.
The ideal solution for connecting copper and aluminum conductors is to first apply solder to the copper core. Especially such pre-treatment is often used when connecting single- and multi-core wires, when in this way a wire consisting of several conductors is converted into a single-core one.

Twisting wires of different sections

This type of work implies the unambiguous use of additional means for connection. Such devices can be screw clamps, self-clamping terminals, bolts, tinned copper lugs, and walnut-type holes. Also, in order not to purchase additional components, you can use soldering or welding, or other methods of connecting wires.

If the difference in the diameter of the wires is insignificant, for example, 4 and 2.5 mm, then connecting them by twisting is not so difficult. To do this, you need to carefully wrap them around each other, after which you need to use welding or soldering. This fastening of two conductors will last for many years without complaints.

In other cases, twisting wires will not be reliable and durable. In such situations, you simply cannot do without additional components. In various situations, certain devices are used:

if the cross-section of the wires is large, it is best to use a self-clamping terminal;
for branching from the main line to the distribution. The shield uses a branch compressor, which among experts is also called “Nut”;
To connect wires with a large diameter, a copper-tind tip is used.

Errors when twisting wires

The most common problem with connecting conductors in this way is that one wire wraps around another. This is completely wrong. The wires must evenly wrap around each other, thereby ensuring reliable passage of electric current and creating mechanical strength so that such fastening will last for many years.

The length of the twist depends directly on the diameter of the conductors themselves. It is worth considering that the minimum threshold for this characteristic should be no less than 3 cm. Otherwise, everything depends on the diameter of the wires: the larger the diameter, the greater the length of the created twist should be, but there are no specifically prescribed standards in this regard, Each specialist decides for himself what this value should be in order for the connection to be reliable and of high quality.

Source: https://uelektrika.ru/soedinenie-yelektroprovodki/pravilnaya-skrutka-provodov/

Twisting wires - how to do it correctly

We will not prove to you that twisting wires is a good connection method. Yes, it can be done well and insulated. It is also perfect as a temporary option.

But according to the rules of electrical installations (PUE) in order to connect a wire or cable, ordinary twists are not recommended. Nevertheless, we will talk about it, and in very detail. Firstly, because, contrary to the PUE, most connections are made using this ancient “old-fashioned” method.

Secondly, because correct twisting is the main stage of the most reliable methods of connecting wires - welding and soldering.

Why do you need a good twist?

Imagine that the two wires being connected are twisted together just how. Those who are familiar with electrical engineering know that transition resistance occurs at the point of contact of two conductors. Its value depends on two factors:

surface area at the point of contact;
the presence of an oxide film on the conductors.

To perform twisting, the core is exposed, the metal interacts with oxygen in the air, as a result of which the surface of the conductor is covered with an oxide film, which has a decent resistivity value.

An example of poorly executed twisting: the twisting area heats up and the insulation melts

Accordingly, if the twisting is performed poorly, the contact resistance increases, which in turn will cause heating when an electric current passes through the joint. As a result, the twisted area may become so hot that the electrical wiring may catch fire. Surely everyone has heard the phrase in their life that a fire occurred due to a fault in the electrical network.

To prevent this from happening, the contact connection of the wires must be as strong, reliable and safe as possible. That is, the twisting must be performed so well that the contact resistance is stable and does not change over time.

Preparing wires for twisting

Remember! Never twist under voltage, even if you have a tool with insulated handles and dielectric gloves. First, de-energize your workplace by turning off the input circuit breaker for your apartment or house.

To get a good twist, you need to follow these steps exactly:

Strip the connected conductors of insulation, while avoiding damage to the metal surfaces of the conductors.
Soak a clean cloth in white spirit or acetone and wipe the exposed areas of the wires to remove any dirt.
Now, using sandpaper, sand the wires to a metallic shine.

And then you can start twisting.

Stranded wires

Twisting of stranded electrical wires can be done in different ways.

Parallel twist

The simplest method is parallel twisting, when both stripped wires are placed crosswise on top of each other at the place where the insulation was stripped and twisted at the same time. Such a connection provides reliable contact, but it will poorly tolerate the applied tensile force and vibration.

This method is best used for copper wires, when one of them is monolithic and the other is stranded. A monolithic wire needs to be stripped of insulation a little more than a stranded wire. After twisting, an additional bend is made from the remaining copper monolithic tail in the direction of twisting, due to this the connection is more reliable. This method is also suitable for twisting aluminum conductors with different cross-sections.

Another advantage of parallel twisting is that it can be used to connect more than two wires at the same time.

Serial twisting

With the sequential method, each connected wire is wound onto another. The reliability and contact of such a connection will be optimal, but this twist can only be used for two wires, no more.

Place the stripped wires crosswise on top of each other approximately in the middle of the exposed area and begin to twist. One wire goes around another wire, and wrap the second wire around the first in the same way.

Bandage twist

Stranded wires can be connected together using the bandage twist method. In this case, the connected conductors are stripped to the same length and applied parallel to each other. In this position, they are fixed with a third wire, which is tightly wound onto the bare surface of the connected conductors.

Please note that using such twisting you can connect hard stranded wires, but you must use a soft (flexible) wire as a fixing wire. The more tightly you wind the fixing wire, the more reliable the contact connection will be.

More than two conductors can be connected using bandage twisting.

Solid wires

All of the methods discussed above for twisting multi-core wires can also be used for single-core wires. But it is best in this case to use a parallel connection.

Remember the most important thing: before connecting single-core wires, the insulating layer on them should be stripped only along the conductor at an angle. This is especially true for aluminum conductors. If you run a knife at a 90 degree angle around the conductor, the insulation will, of course, be removed. But in further work, with the slightest movements at the place of the cut, the conductor will eventually bend and, ultimately, the core will break.

Strip the insulating layer by 3-4 cm on the wires to be connected. Place the wires on top of each other at an angle of 45 degrees, but not in the area of the bare wires, but 1.5-2 cm above the place where the insulation was cut. Hold this place firmly with your left hand, and with your right hand begin to twist both wires. First, they will be twisted together with the insulating layer, then the connection of purely bare conductors will begin.

No matter how strong your hands are, be sure to finish twisting with pliers at the end, especially when it comes to aluminum wires.

Another important tip! After you make the twist, do not rush to insulate it. Let the electrical circuit work for several hours, then turn off the input circuit breaker for the apartment and check the temperature at the place where it is twisted. If the node is hot, it means that the contact connection is unreliable and it is better to redo it. If no heating is detected, then the twisting is done well and can insulate it.

If you need to perform a large number of twists, you can use a screwdriver with a homemade device, as shown in the video below:

Methods for insulating twists

Twisting the wires is half the battle; it is very important to properly insulate this place. There are three ways to insulate a completed electrical assembly: using insulating tape, heat-shrinkable tubing, and PPE caps. Let's look at each of them in more detail.

Insulating tape

Insulating tape is a special material whose main purpose is to insulate the junction of electrical cables and wires. No matter what modern technologies appear, you can hardly meet an electrician who does not have a roll of electrical tape in his pocket. This is the most common and inexpensive insulating material.

There are many varieties of it. Tapes are made from mica and fiberglass, polyester and epoxy films, acetate fabric and paper. To insulate twists in a household electrical network, we recommend using PVC tape (it is based on polyvinyl chloride). To make it, take a polyvinyl chloride film and apply glue on top. The quality of the insulating tape itself, and, accordingly, the reliability of the insulated joint depends on the quality of these two components.

The best is considered to be insulating tape, for the production of which rubber-based glue and class A PVC film are used. This material is distinguished by such positive qualities as:

High adhesion (adhesion of dissimilar surfaces).
Increased elasticity (excellent stretch and adhesiveness).

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So be sure to keep this in mind when purchasing duct tape.

The insulating tape should be wrapped around the twisted section in at least two layers. Start winding 2-3 cm above the bare twist, the tape should be placed on top of the wire insulation. This will allow you to achieve maximum tightness and insulating reliability, and will protect the contact connection from moisture.

Next, wind it a little at an angle, moving towards the end of the twist. Having reached the end, bend the electrical tape around the tip of the twist and continue winding in the opposite direction. Having reached the place where you started winding, cut the insulating tape with a knife.

For efficiency, you can repeat the same thing again and make four layers of insulation.

It is recommended to use this tape to insulate strands installed in dry rooms.

Thermal tube

Heat-shrinkable tube (abbreviated as HERE) is made of thermopolymer materials that have the ability to change their geometric shape and dimensions (shrink or expand) under the influence of hot air, water or elevated temperature.

The main advantage of thermal tubes is that they can be attached to objects with a complex profile, which is exactly what twisted wires have. Heat-shrinkable tubing provides excellent electrical insulation and protects against mechanical damage. The tubes come in different diameters. The material from which they are made does not support combustion and is non-toxic.

Industrial hair dryers are used to apply heat to the tubes. This tool is not cheap and it is not economically profitable to buy it just to insulate the spliced wires. Therefore, at home, they often use an ordinary hairdryer or lighter.

It is important to remember that with this insulation method, the heat-shrinkable tube must be placed on one wire to be connected in advance (before twisting).

Cut the tube with a margin; when it is put on the bare area, it should extend onto the insulating layer of the conductor by at least 1 cm.

When the twisted connection of the electrical wires is completed, pull the tube over this place. Direct the heat jet of a hairdryer or the flame of a lighter at it; under the influence of hot air, the tube will instantly decrease in size and tightly seal the insulated area. Reliable, fast and inexpensive way.

Keep in mind that the connected wires, which are insulated with a heat pipe, can be used for laying in the ground or when immersed in water. This insulating material is recommended for use outdoors, in bathhouses and bathrooms, as it will reliably protect the twisting area from moisture.

How to use heat shrink tube is shown in this video:

PPE caps

When installing wiring in an apartment or house, you can use PPE caps (connecting insulating clamp) to insulate the connection points.

In this case, it is enough to make only high-quality twisting, without soldering. The tip must be cut off and put on with PPE force; the crimp springs inside the cap will expand and tightly grasp the unit being connected. To better fit the connection surface, rotate the cap clockwise.

Now you know how to twist wires correctly and what material is best to choose for insulating the connection. From the article it is clear that to perform twisting it is not at all necessary to be a professional electrician; such work can be done by anyone who knows how to hold pliers in their hands. Just do not forget that twisting is only an important stage that must be completed by welding or soldering.

Source: https://YaElectrik.ru/elektroprovodka/skrutka-provodov

Connection of wires. Twisting, soldering, welding, crimping, Wago terminal blocks

When installing electrical wiring in a house or apartment, connecting the wires is the most important point . For trouble-free and safe power supply, you will need a reliable and high-quality connection of wires.

A careless attitude towards connecting wires and cables can lead to very bad consequences. It would seem that there is nothing complicated in connecting the wires, twist them, wrap them with electrical tape and everything is ready, but everything is not as simple as the popular wisdom says “Electrics is the science of contacts” , and the connection of wires and cables must be done with all the care responsibility, because

The percentage of accidents and damage in power supply systems due to poor-quality wire connections is very high. No matter how high-quality the electrical contact between the wires is, the junctions of the wires have greater resistance , which means they heat up more.

And the worse the contact, the more it heats up, which will ultimately lead to melting of the insulation, a short circuit, and then a fire.

In practice, several methods of connecting wires are used, I will tell you about the most common ones.

Connecting wires by twisting

Connecting wires by twisting is common everywhere, but if we turn to the main book of electricians PUE, then according to:

“Connection, branching and termination of cables and wire cores must be done by soldering, welding, crimping or clamping (screw, bolt, etc.)”

As we can see, there is no twisted connection of wires at this point, which means twisting of wires is prohibited. But twists have always been, are and will be used to connect wires when installing electrical wiring. Yes, and well-made twisting can last for decades, but the connection of wires by twisting must be done efficiently. The technology for connecting wires and cables by twisting is quite simple:

the length of the twist must be at least 4-5 cm;
The connected wires, stripped of insulation, must be cleaned of the oxidized film, for example, with an ordinary knife or sandpaper;
It is necessary that the connected wires wrap around each other evenly and tightly, ensuring sufficiently reliable contact.

One “but”, problems may arise when handing over the electrical installation to the fire inspectorate, because... Connecting wires by twisting according to the PUE is prohibited. However, this applies mainly to industrial consumers, retail premises, etc.; a fire inspector will not come to your apartment or private house to inspect it.

Connecting wires by twisting is a necessary measure when there is nothing else left, and it is better to use connection of wires using the methods described below.

Connecting wires by soldering

If the twisted wires are soldered , we get a connection of wires by soldering , which guarantees reliable and high-quality contact, which has a fairly low contact resistance, high conductivity and mechanical strength. But it is important to solder the wire connection correctly; for this you need:

tin the connected wires with rosin (flux);
the solder should flow into the twist;
After the solder has cooled, you can sand it with sandpaper, because sharp edges of the solder can pierce the insulation;
insulate the wire connection.

But such connection of wires by soldering is very labor-intensive and requires certain skills. The negative aspects of soldering wire connections, I would include:

need for isolation;
complexity (not everyone knows how to solder well), and even for those who are good at soldering, doing this, for example, while standing on a stepladder or ladder, to put it mildly, is not very convenient;
if a mistake was made when connecting the wires, it will not be easy to separate them after soldering, so it is better to leave a larger supply of wires and cables;
high time consumption.

Connecting wires by welding

Connecting wires by welding provides even better electrical contact between the wires. But here everything is even more confusing than with soldering wires, since you need to have:

welding transformer;
welding skills;
masks (goggles) for welding, special gloves, electrodes;
construction hair dryer for heat shrink tube.

Wire connections by welding can only be made from homogeneous metals . Such a connection of wires can be found infrequently, our people do not really like difficulties, and many electricians do not like this method of connecting wires due to the large investment of time, but it is worth noting that connecting wires by welding is faster than soldering.

Connecting wires by crimping

Connecting wires by crimping consists of compressing the connecting sleeve (aluminum or copper tube) into which the wires are inserted with special press pliers.

The wires are first stripped of insulation to the length of the sleeve, then we place the wires inside the sleeve and crimp it in two or three places for reliability. If the sleeve is much larger than the wires that need to be crimped, then you can stuff the sleeve with additional wires.

We insulate the resulting wire connection using crimping tape, or better yet, heat-shrink tubing + hair dryer.

Sleeves for connecting wires by crimping are copper, aluminum and copper-aluminum , i.e. Crimping can be used to connect copper and aluminum wires.

Connecting wires using crimping is quite reliable if done correctly. The skills in connecting wires by crimping will also be useful to you when assembling an electrical panel for crimping NShVI bushings.

The disadvantages include the cost of pressing pliers for connecting wires by crimping and sleeves, the inseparability of connecting wires by crimping, i.e. they crimped the wire in the sleeve and “forgot” about it.

Bolted connection of wires and cables

Bolted connections of wires are usually used when connecting wires made of different metals, that is, if we have one wire made of copper and the other of aluminum, a steel washer must be placed between them.

This connection of wires turns out to be very cumbersome, it is inconvenient to place it in junction boxes and insulate it. Periodic broaching is required.

Connecting wires with screw terminals

Connecting wires with screw terminals , as well as bolted ones, can be used to connect wires made of different metals. This connection of wires satisfies the requirements of the PUE, but requires periodic tightening of the screws in the terminals, which weaken over time, which means the contact itself weakens, which can close over time.

Periodic pulling of screw connections of wires implies that access to the connection in the box must always be open , which will not look very nice in an apartment or private house. Also, when tightening the screw, you can damage the wire itself, especially the softer aluminum one. And if you need to connect a stranded wire, then you need to either solder the stripped ends of the wire or crimp it with tubular lugs.

Connecting wires with PPE caps

Connecting wires with PPE caps (Connection Insulating Clamps). PPE are plastic caps with a conical spring inside, which, when twisted, compresses and fixes the wires, and the plastic PPE cap itself insulates the connection of the wires and is fire and mechanical protection.

This wire connection is quick and simple; to perform it correctly you need:

strip the insulation from wires and cables to a length slightly shorter than the length of the PPE cap itself;
fold them into a bundle, precisely into a bundle, and not twist them;
use your hands to twist the PPE clockwise onto the bundle of wires;
tighten the PPE using pliers.

The advantages of such a connection of wires and cables are obvious (no special tools required, no need for additional insulation, speed and simplicity), but there are also disadvantages:

Do not connect multi-wire wires;
the quality of such a connection will be worse than those listed above, so I would recommend using these clamps for small loads, for example, in lighting circuits.

PPE caps are divided according to the total cross-section of the wires to be twisted and are designated by numbers from 1 to 5, which indicate the number of wires to be twisted and their cross-section.

Connecting wires with self-clamping (spring) terminals

Well, in conclusion, let’s consider the simplest, most effective, convenient, and most importantly quick connection of wires - self-clamping (spring) terminals . Spring terminals from Wago are widely used, which allow you to connect wires:

without having any special skills;
there is no need to purchase special tools (soldering iron, welding transformer, press pliers);
some Wago terminals have a special paste that allows you to connect copper and aluminum wires and prevents oxidation;
no additional insulation required;
quick disconnection of the connection (press the lever and pull out the desired wire).

Wago terminals are produced for connecting wires and cables from 0.75 to 4 sq. mm, the number of connected wires is from 2 to 8. Wago terminals

Wago terminal blocks were invented in Germany.

Perhaps the most significant disadvantage is their price, the average cost of a Wago terminal block for 3 wires will be approximately 11-12 rubles, so if there are a lot of distribution boxes, then the total cost of Wago terminal blocks will be considerable.

You should not use Wago terminals when installing wiring with loads of more than 16 A. In general, it is better to use them maximum on the lighting line for electrical wiring in a private house or apartment, and choose Wago terminal blocks with a margin of at least a step higher.

These are the main methods of connecting wires, each method has its own supporters and opponents who are ready to argue endlessly about the best way to connect wires. In my opinion, a lot depends on the situation, where and how it is necessary to connect the wires, the availability of time for electrical installation, and in some places you can get by with terminal blocks, and in others only with welding.

. Comparison of resistance of wire connections: twisted, welded and terminal blocks.

From the video we can draw the following conclusion that connecting wires by soldering and welding have the same resistance. That is, they are the same in physical properties , but connecting the wires by soldering or welding will slow down the chemical reaction of wire oxidation and preserve the integrity of the wire connection for many years. And if possible, then it is better, of course, to use soldering, welding or crimping to connect the wires.

It is important to remember that aluminum oxidizes faster than copper , and the oxide film on the surface of an aluminum wire has a higher contact resistance than that of copper wires. This impairs the conductivity of the connection (contact) and leads to its heating.

Thank you for your attention.

Source: https://elektroschyt.ru/soedinenie_provodov/

Correct twisting: features and types of connection of electrical wires

Perhaps the most cherished dream of any electrician is electrical wiring without intermediate breaks. So that a separate wire passes from the panel to each switch or socket without connections. But this is a pipe dream - not many people will like the fact that dozens of wires will be connected to the electrical panel. And it gets expensive - you need a lot of wire. That's why the wires branch and connect.

Typical wiring in an apartment can have over a hundred connections. And electrical wiring faults, as a rule, appear precisely in these connections. Therefore, great attention must be paid to the correct connection of wires.

Twist

Despite the contradiction of the PUE, twisting is considered the most popular type of connecting wires. The main disadvantage of twisting is the gradual weakening of the fastening due to residual elastic deformation of the cable core. Moreover, the transition resistance in the twist increases, the cable begins to overheat and the connection is broken. It's good if there is no fire.

But a properly made twist can last a very long time without any cause for concern. Therefore, if other connection options are not available to you, then twisting can be done at home. But only high quality!

Important! This option should only be used as a last resort. If possible, use other options.

Do not twist when the current in the circuit is more than 2-3 Amps.
Do not twist when laying wires over flammable materials.
Do not accept work from electricians if the connections are made by twisting without welding or soldering.
Do not use twists if you are engaged in electrical work as part of an individual business or official duties - this will entail liability, possibly even criminal liability.

wires made of different materials (aluminum and copper), as well as multi-core and single-core cables in one twist For high-quality twisting, the insulation is removed from two cables to a length of 70–90 mm, the wires are laid perpendicularly crosswise and twisted. If the cable diameter is small (up to one sq. mm), then this can be done manually. But it is advisable to twist it with pliers. The coils must be tight.

The remaining edges of the cable (4-6 mm) are removed with pliers using a screw rotation, while the cable material seems to be smeared together. When attaching three or more wires, the freed ends from the insulation are laid together, parallel to each other, as tightly as possible and twisted by the ends with pliers. After this, the remaining ends are bitten off in the same way. The total twist size must be at least 12–14 diameters of the twisted wires.

Then you need to insulate the twist. To do this, use insulating tape, heat-shrink or polyvinyl chloride tubing, or special caps. It is advisable to thread the heat shrink tube twice, and wind the insulating tape in at least four layers. The insulating material must capture all intact cable insulation - this will protect the twist from moisture and prevent slipping.

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Soldering

This is the most labor-intensive option for connecting wires, which requires some experience. Better quality twisting than poor soldering. Therefore, we will provide general information to those who have sufficient skills.

Before soldering, the cable is cleaned of oxides; if necessary, it is tinned, screwed (maybe not as tightly as when twisted), treated with flux and soldered. You can solder both aluminum and copper wires if you choose the right solder and flux.

There is no need to choose an acidic active flux - it will certainly remain on the wires and will destroy the connection over time. Soldering takes quite a lot of time, but the fastening is one of the most reliable.

Welding

The most durable option for twisting wires. Even with little experience, this connection option is relatively quick and simple. Welding is done with a current of any polarity with a voltage of 12-35 V. It is best to have the ability to regulate the welding current. For welding two copper wires with a diameter of 1.5 square meters.

mm 70 Amperes are enough, for 3 wires the voltage increases to 85-95 Amperes, for 3 wires 2.5 kW. mm, 95-110 Amperes are required, and 4-5 of these wires already require 110-130 Amps. With the correct current for welding, the electrode does not stick and the arc is kept quite stable.

Copper-carbon electrodes are used to connect copper conductors.

Insulation 60-70 mm long is removed from the wires and connected “for welding”. It differs from simple twisting in that the ends of the cores are not twisted by 6-7 mm. They are straightened and clamped parallel to each other. If three or more wires are screwed in, then there should still be only two wires at the end, the rest are cut to the length of the twist. This makes it easier for a melt bead to form when the welder is weak.

Important! Welding work must be carried out in compliance with all fire and electrical safety rules with the mandatory use of protective equipment (glasses with a thick filter or a welding mask, gloves, protective clothing).

Then the twist is placed in a welding clamp and the weld is made with an electrode. During welding, you need to melt the ends of the wires until a melt ball appears. For strong mechanical and electrical contact, the melting point must reach the main twisting area. After cooling, the wires are insulated in a way convenient for you.

For welding wires, you can choose different types of welding machines. inverter-type welding devices . Their advantages:

have low electricity consumption;
low weight and dimensions;
large range of welding current regulation;
provide a stable welding arc.

So, with a fairly large number of electrical installation works, purchasing a welding inverter can be considered the best choice; this device will be useful in many other works.

PPE connection

This is a plastic cap with a square metal wire inside, installed in a spiral cone. Often its cavity is filled with a special lubricant that protects the wires from moisture and prevents oxidation. When connecting wires using PPE, it is important to choose the size of the clamp correctly, taking into account the number and diameter of the wires being connected. As a rule, this information is located on the packaging.

For fastening, the insulation is removed from the wires to a size slightly smaller than the length of the cap, laid together and the PPE is screwed on top. Moreover, the edges of the square spring remove the layer of oxides from the surface of the core, its cone moves apart and, thanks to its elasticity, reliably clamps the wires together. For reliability, some electricians prefer to first do the usual twisting and then install the PPE.

The advantage of PPE is the simultaneous fastening of wires and insulation of their connection area. Disadvantages include weakening of the spring over time, which leads to increased contact resistance. It is not advisable to install PPE in high-current circuits.

Screw terminals

This fastening is very widely used when connecting switches, electrical sockets, lighting devices and other electrical fittings to wires. Screw clamps are often used when assembling electrical panels , as they make it possible to carry out neat and quick installation.

The obvious advantages of clamps include the absence of the need to isolate the fastening. Using these clamps, you can fasten wires made of various metals (copper and aluminum).

Of course, there are also disadvantages. It is not possible to install a multi-core cable into the clamps - it must first be crimped or soldered. In addition, screw terminals require maintenance - they need to be tightened from time to time to prevent the connection from loosening. In general, if there is a free approach to the connection areas, then screw terminals are an inexpensive and reliable solution.

WAGO terminals

This fairly new type of fastening is based on the installation of insulated spring clamps manufactured by the German company WAGO. These WAGO connectors are manufactured in a large assortment and include connectors of various designs, for various purposes, for a wide variety of cross-sections, types and numbers of wires. Therefore, it is advisable to buy WAGO connectors in a specialized store and always check the certificates.

The main advantages of these connectors include quick and easy installation without any special devices, as well as simultaneous insulation of the connection and fastening of the wires.

WAGO fasteners have all the necessary tests, are certified and are widely used both in our country and around the world. Therefore, there are no serious reasons not to trust them. All cases of any problems are due to the wrong choice of WAGO fastening for a certain load or the installation of fakes. It is these points that you need to pay great attention to when using for connection.

Crimping

This option means connecting the wires using crimping with a lug or tubular sleeve. Tips and sleeves are made for cables and wires with a core diameter of 2.6-250 square meters. mm.

Crimping is quite convenient for “set and forget” fastenings, but requires special equipment and the correct selection of sleeves for the specific diameter and number of wires being fastened.

The tools used are crimping presses, as well as manual hydraulic, electric and mechanical pliers.

For crimping, select the required sleeve; if necessary, adjust or select the working end of the tool. The insulation is removed from the wires, the conductors are cleaned and lubricated with a special paste, the sleeve is put on and clamped. A high-quality tool clamps the entire length of the sleeve in one pass; cheaper ones require several clamps at a certain distance from each other. After this, the sleeves are insulated with heat-shrinkable tubing or insulating tape.

Bolt fastenings

Used in circuits with high voltage . A washer of the required diameter is placed on the bolt, then the wires are wrapped around the bolt, another washer is put on and the whole thing is carefully clamped with a nut. If you install an additional metal washer between the cores, you can connect copper and aluminum wires together. In residential electrical wiring, this option is almost never used due to its bulkiness.

All completed installation connections of any type must be accessible for further maintenance and inspection. Correctly selected connection of wires is the main guarantee of the reliability of electrical wiring in an apartment or private house.

Source: https://stanok.guru/oborudovanie/raznoe/pravilnaya-skrutka-i-vidy-soedineniya-elektricheskih-provodov.html

How many wires can be twisted into one twist?

Every person has at least once encountered the need to twist wires. At first glance, there are no difficulties in this work, but in fact this is not entirely true.

In order to do this work efficiently and safely, it is necessary to take into account some points, since incorrect twisting often results in short circuits and fires. In this article we will tell you how to twist wires correctly and what you need to pay attention to.

Brief contents of the article:

What are the dangers of twisting the cable?

This connection method is considered the most dangerous for several reasons. The degree of contact between the conductors will depend on the quality of the work done, and loosely twisted wires will become even weaker over time and this can lead to loss of contact. All this is fraught with overheating of the cable, failure of insulation and short circuit of the wiring with subsequent fire, loss of housing and even death.

According to safety rules, this type of cable connection is prohibited, but despite this, it is used by electricians in their work.

According to experts, if you twist the wires very carefully and hide the twisted area with insulation, then no problems will arise during operation. This immediately begs the question: how to twist wires with your own hands reliably and for a long time?

Step-by-step twisting instructions

For example, let's take two single-core copper wires. So, in order to connect them you need to:

Using a sharp knife, expose the ends of the cable by at least 5 cm.
We degrease the exposed veins using a solvent.
Use sandpaper to clean the wires until they shine.
We cross the wires and carefully, slowly twist them together. For better twisting, use pliers. It is necessary to make at least 5 turns.
Next, you need to tightly wrap the joint with electrical tape.

Looking at the photo of the correct twisting of wires, you can see that this is not at all difficult even in the most difficult wire connections.

It is worth paying attention to the fact that it is undesirable to twist wires made of different materials - copper and aluminum, since the resistance indicators of these metals are different and, moreover, they oxidize during interaction, which leads to deterioration of contact and heating of the wiring.

To better understand how to do twisting correctly, let’s figure out what options exist, the order, and the features of their implementation. Electricity is considered one of the communications that “do not forgive” mistakes.

The result of illiterate actions is damage to the device, short circuit, or fire.

Twisted length of wires according to PUE - Fire safety

Working with electricity requires care. If you thoroughly understand the upcoming process, then you can do everything yourself.

Many home craftsmen do not know how to connect the wires in a box, because there are several ways to solve the problem.

It should be recognized that the performance of all wiring depends on the quality of the connection.

From the electrical panel, wires spread throughout the room. Each apartment must have several connection points - sockets and switches.

To collect all the wires in one place and thereby simplify wiring maintenance, distribution boxes are used.

Conductors from all connected devices are inserted into them and then connected.

It is necessary to connect the wires in the junction box in accordance with the PUE (Electrical Installation Rules).

In accordance with the requirements of this document, conductors must be located at a distance of 15 cm from the ceiling.

Junction boxes are installed at the branching points of the wires.

This is a simple electrical accessory that can be used for hidden and open wiring. Boxes have a round or rectangular shape. Thanks to their use, you can get the following benefits:

The maintainability of the wiring increases, since access to all conductor connections is open.
The level of fire safety is increasing.
Financial costs are reduced and electrical installation work is simplified.

Types of connections

To connect the wires in the junction box, you can use one of several methods. All of them allow you to ensure reliable contact of conductors and the home master has the right to choose the most convenient one.

Twisting and crimping

It should be said right away that now the use of twisting wires in a junction box is prohibited, since this method is recognized as the most unreliable.

By deciding to choose such a connection, the electrician accepts responsibility for the possible consequences. At the same time, the method of connecting conductors is extremely simple.

First, you need to remove a layer of insulation from the conductors for a length of about 1 cm, and then carefully twist the wires onto each other. When connecting wires with a cross-section of less than 1 mm, you need to make 5 or more turns.

If thicker cables are connected, the minimum number of turns is 3.

Crimping is very popular today. To make connections using this method, special sleeves are used, the diameter of which is selected in accordance with the size of the conductor bundle.

It is also important to use sleeves made of the same material as the current-carrying conductors. The sleeve is crimped using a special tool.

Some home craftsmen use ordinary pliers for this, but the quality of such a connection will be lower.

To carry out the work, you must first remove the insulation from the wires, then twist them and insert them into the connector.

The next step is to crimp the sleeve using press pliers and then insulate the contact area with electrical tape or heat shrink.

Soldering and welding

After connecting the conductors by welding, an almost complete wire is obtained. As a result, such a junction is not afraid of various negative environmental factors.

However, due to the need to use special equipment, this connection method is most popular among professional electricians.

You can create a welded joint using the following tools:

A welding machine with a power of at least 1 kW.
Flux.
Carbon electrode.

After removing the insulating layer from the wires, their bare areas need to be cleaned to a shine using sandpaper. At the next stage, normal twisting is performed.

Then flux is poured into the recess of the electrode and after turning on the welding machine, the electrode is pressed against the conductors. When a ball-shaped contact point appears at the junction, the force is released.

At the final stage, you need to clean the welding area from flux residues and coat it with varnish.

Although a solder connection is quite reliable and durable, it is not recommended for use in areas where the conductors may become very hot or subject to significant physical stress.

Screw clamps and bolted connections

The use of contact screw clamps allows you to reliably connect not only homogeneous current-carrying conductors, but also dissimilar wires.

Moreover, the cost of such clamps is low, which has made the method quite popular.

All work is carried out in two stages:

The insulation is removed from the conductors to a length of approximately 5 mm.
The exposed parts of the wires are inserted into the clamp and tightened with screws.

In order not to damage the integrity of the current-carrying conductors, it is necessary to control the clamping force. This primarily concerns work with aluminum wires.

Bolted connections are highly reliable, but at the same time they are cumbersome. If this method is used, then you need to choose the right junction box. Modern models most often have small dimensions.

It is also worth noting self-clamping connections, which have become very popular in recent years.

Such clamps are not only easy to use, but also contain a special composition inside that prevents oxidation of the conductors.

After the insulation has been removed from the wires, you need to lift the clip lever. When the bare end of the cable is inserted into it, the lever is lowered and the connection occurs.

Installation of boxes

To create high-quality wiring in a room, it is not enough to know how to properly connect the wires in the junction box. extremely important to be able to install the junction box itself .

In apartments and private houses, hidden wiring is most often used, since it does not spoil the interior of the room.

First, markings must be applied to the walls, indicating the installation points of electrical equipment and the paths of conductors.

As a result, you can easily calculate the required amount of materials. It is also advisable to draw up a wiring diagram to simplify the process of connecting electrical appliances.

At the next stage, grooves should be made in the surface of the walls using a special tool - a wall chaser. In addition, you need to cut niches for installing boxes, switches and sockets.

Most often, junction boxes for hidden wiring are installed on alabaster.

When all work on laying conductors and installing electrical equipment is completed, it is necessary to connect the wires in the boxes using one of the methods discussed. At the final stage, sockets and switches are connected, and then the functionality of the entire system is checked.

Knowing the features of installing junction boxes and the rules for connecting conductors in them, all work can be done independently. They are not very complex and problems should not arise.

Source: https://stz-irk.com/dlina-skrutki-provodov-po-pue/