How to connect a broken wire. How to connect wires in a junction box

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Almost everyone faces the need to connect wires. House master. During repairs, new wiring, or simply connecting a new device to the network, similar actions are required. They differ in scale and complexity.

On the way to the consumer, electrical networks have many branches. In these places they are installed connectors for wires. There are many types of them. Every electrician should know how to correctly select and use such elements of electrical networks before starting work.

Evolution of compounds

Previously, electricians never had a question. For this purpose, the same technology was used for all. The wires were stripped, twisted between soda and wrapped with electrical tape.

Previously, wiring in houses was made from copper wire. Today, a copper conductor is simply necessary for the arrangement. In recent decades, new, powerful technology has appeared in our homes and apartments. When using it, durable, high-quality wiring is required.

According to experts, malfunctions most often occur at the junctions of wires. Twisted conductors begin to heat up as the load increases. Electrical tape dries out over time. There is a high probability of a short circuit in this place. To avoid fire, it is necessary to use special wire connectors. Kinds and the features of the use of such products will be discussed further.

Wiring rules

To understand which wire connections are appropriate to make in a particular case, it is necessary to consider the rules for arranging electrical installations. They clearly indicate which methods are acceptable when arranging modern systems communications. Considering rules for connecting wires, conclusions can be drawn about the unacceptability of using twists. IN regulatory documentation It is clearly stated that all cores must be connected by welding, crimping, squeezing or soldering.

The wiring must be made from a cable with a copper core. In order for such a network to have high reliability indicators, the connections must be as strong as possible. The cross-section of the cores is selected in accordance with the total expected load. The more equipment is connected to the network, the thicker the conductor needs to be connected to the system.

Caps

Considering how to connect wires together, some unprofessional craftsmen still decide to give preference to twisting wires. This is acceptable if local wiring repairs are being made or a low-power device is being connected to the home network. In this case, the master can somewhat improve such a junction of the cores.

To ensure greater reliability, special caps are used. They are used instead of electrical tape. They are also called (PPE).

It is safer than the duct tape option. The connector looks like a plastic cup. It is built into it. It clamps the contacts and ensures reliable contact. High-quality clamps contain a special lubricant that prevents oxidation processes. When choosing, you must take into account what wires the product is intended for (multi-core or single-core). You should also evaluate the cross-section of the conductor for which the clamp is intended. PPE is not used to connect cores made of different materials.

Terminals

More often cable connector today it looks like terminals. They are made of brass. In this case, the connected ends of the cable do not contact each other directly. Therefore, using such structures, it is possible to switch identical conductors, cores of different cross-sectional sizes, made of different materials.

To be able to create the correct joint, you need to select the appropriate types of terminals. They differ in the nominal current rating, as well as the permissible diameter for the wire. All characteristics of the terminals are indicated on their housing.

Some commercially available terminals may contain a special filler. The gel prevents oxidation processes, increasing the reliability of the connection. Terminals can be knife, spring, or screw.

Spring varieties

Spring type are used for both simple and complex circuits. For several pairs of wires, a special block modification is made.

Fixation occurs due to straightening of the spring mechanism. This mount is considered one of the most reliable. This mechanism includes a special lubricant. It differs from previous materials that are used in fasteners. This is not a gel, but a lubricant of a certain consistency.

When producing a type, manufacturers indicate the scope of application of such products. Clamps are available for stranded and This must be taken into account when choosing. Most often, the presented type of fastening is used for branching zero and phase.

Blade terminals

Today another one is used electrical connector. It is called a knife terminal. This is a reliable, durable connection. These terminals are easy to install and operate. In this case, the wires are connected using a special conductive plate. When clamping wires, this structural element cuts the braid around the core. Therefore, when making such a connection, the wires do not need to be stripped.

Due to its features, the presented type of terminals is considered reliable and durable. When installing, the technician must apply force to secure the ends of the conductors well. This is considered the norm. Sometimes you have to use pliers to clamp.

The presented variety of terminal connectors is produced for permanent and detachable connection types. In the first option, the master must carefully consider all the nuances of organizing the electrical circuit. This process is carried out before installation work begins.

Connecting different materials

As you know, in modern wiring two types of conductors are used. The first category includes conductors made of copper, and the second - made of aluminum. According to the rules fire safety It is recommended to give preference to the first option. However, in some cases the master has to combine copper and aluminum conductors.

Normal configuration cannot guarantee High Quality at the docking point. This is due to a number of reasons. With temperature changes, linear expansion at various metals will not be identical. In this case, a gap may form between the directly joined aluminum and copper.

At the same time, the resistance increases at the point of their contact. The conductors begin to heat up. Also, a film of oxides appears on the stripped conductors. This also contributes to poor contact. This state of the network provokes various malfunctions and can cause a fire. Therefore, only special types of contactors are suitable for such connections.

Screw terminals

Electrical connector May be screw type. Such contactors have been used for a long time. This type of terminals has certain disadvantages and advantages. These are compact, easy-to-install devices. They allow you to connect wires various diameters. Moreover, they can be used for both single-core and multi-core conductors. In the second option, the end of the cable is stripped and crimped with brass lugs.

The disadvantage of the presented one is the inability of the terminals to connect more than three conductors at the same time. This complicates the work somewhat, forcing you to make more connections. Also, over time, such a connector loses its original characteristics. The wires no longer fit tightly together. Therefore, when using a screw connection, you periodically have to tighten the junction of the wires.

For wires large diameter compounds commonly known as “nut” are used. Such contactors are most often used when connecting wires from the carrier line to the house.

Modern connectors

Many electricians use male-female connector for wires. This type of connector has been known for a long time. This type of connector is divided into a “male” type with a plug or plug, and a “female” type with a socket or socket. Within the same series, such connectors are compatible with each other.

This is one of the most reliable modern types contactors. It will not be possible to connect the wires incorrectly with this connection. The male pins will completely match the internal configuration of the female sockets. In some cases, for accuracy of installation, painting of the connection points is used. This allows you to understand which consumer the connector is intended for and not confuse them.

Female-to-female and male-to-male connectors are available for sale. These are extension cords. Depending on the belonging to each category, contactors with a socket or plug are used.

Spring leads for dissimilar wires

Can be made from different materials spring type. They also help to eliminate direct contact between the cores. They can be detachable or non-detachable. One of the most famous and reliable ways to connect copper and aluminum cables is the Wago universal connector. The cross-section of the cores when using it can also be different.

One-piece wire connectors use the screw terminal principle. You can also use devices in which the metal plate is replaced by a special conductive rod. It is riveted to provide a secure connection. Exposed sections of the cable must be additionally insulated.

Having considered what exist wire connectors, as well as their characteristic differences, everyone will be able to choose the best option for connecting various devices or carrying out repair work.

First of all, you must understand that different conditions may be applied Various types connections. And their choice depends on the specific task at hand.

For example, it is much more convenient to connect small-section wires up to 2.5 mm2 in a compact junction box with terminal blocks or clamps. But if we're talking about about a groove or cable channel, then the sleeves come first here.

Let's consider the three most simple and at the same time reliable types of connections.

Let's start with the connection type PPE. It stands for:

WITH unifying

AND insulating

Z pressure

It looks like a simple cap. Comes in different colors.

Moreover, each color means that it belongs to specific sections of the cores.

The cores are inserted into this cap and twisted together.

How to do it correctly, first twist the wires and then put on the cap or twist them directly with the PPE itself, is discussed in detail in the article “.”

As a result, thanks to PPE, you get a good old twist, only immediately protected and insulated.

On top of that, it has a spring-loaded contact that prevents it from coming loose.

In addition, this process can be slightly automated by using an attachment for PPE for a screwdriver. This is also discussed in the above article.

The next type is Wago terminal blocks. They also come different sizes, and for different numbers of connected wires - two, three, five, eight.

They can connect both monocores and stranded wires together.

Moreover, this can be implemented both in different types of Vago, and in just one.

For stranded ones, the clamp must have a latch-flag, which, when open, easily allows you to insert the wire and clamp it inside after latching.

According to the manufacturer, these terminal blocks in home wiring can easily withstand loads of up to 24A (lights, sockets).

There are some compact specimens also available for 32A-41A.

Here are the most popular types of Wago clamps, their markings, characteristics and what cross-section they are designed for:

Series 2273 Series 221-222 Series 243 Series 773 Series 224

There is also an industrial series for cable cross-sections up to 95mm2. Their terminals are really large, but the principle of operation is almost the same as that of small ones.

When you measure the load on such terminals, with a current value of more than 200A, and at the same time you see that nothing is burning or heating, many doubts about Wago products disappear.

If you have original Vago clamps, and not a Chinese counterfeit, and the line is protected by a circuit breaker with a correctly selected setting, then this type of connection can rightfully be called the simplest, most modern and convenient to install.

Violate any of the above conditions and the result will be quite natural.

Therefore, there is no need to install wago at 24A and at the same time protect such wiring with a 25A automatic. In this case, the contact will burn out if overloaded.

Always choose the right terminal blocks for your car.

As a rule, you already have automatic machines, and they primarily protect the electrical wiring, and not the load and the end consumer.

There is also enough old look connections, such as terminal blocks. ZVI – insulated screw clamp.

In appearance, this is a very simple screw connection of wires to each other. Again, it comes in different sections and different shapes.

Here they are specifications(current, cross-section, dimensions, screw torque):

However, ZVI has a number of significant disadvantages, due to which it cannot be called the most successful and reliable connection.

Basically, you can only connect two wires to each other in this way. Unless, of course, you specifically choose large pads and shove several wires there. What to do is not recommended.

This screw connection works well for monocores, but not for stranded flexible wires.

For flexible wires, you will have to press them with NShVI lugs and incur additional costs.

You can find videos online where, as an experiment, transition resistances on different types of connections are measured with a microohmmeter.

Surprisingly smallest value obtained with screw terminals.

But we should not forget that this experiment refers to “fresh contacts.” Try making the same measurements after a year or two of intensive use. The results will be completely different.

Copper and aluminum connection

Often a situation arises when it is necessary to connect a copper conductor to an aluminum one. Because Chemical properties Copper and aluminum are different, then direct contact between them, with access to oxygen, leads to oxidation. Often even copper contacts on circuit breakers susceptible to this phenomenon.

An oxide film forms, resistance increases, and heating occurs. Here we recommend using 3 options to avoid this:

They remove direct contact between aluminum and copper. The connection occurs through steel.

The contacts are separated from each other in separate cells, plus the paste prevents the access of air and prevents the oxidation process from developing.

The third simple way to connect conductors is crimping with sleeves.

For docking copper wires GML sleeves are most often used. Deciphered as:

G Ilsa

M single

L narrowed

For connecting pure aluminum - GA (aluminum sleeve):

To switch from copper to aluminum, special adapters GAM:

What is the crimping method? Everything is quite simple. Take two conductors and strip them to the required distance.

After this, on each side of the sleeve, the conductors are inserted inside, and the whole thing is crimped with press pliers.

Despite its obvious simplicity, there are several rules and nuances in this procedure, if not followed, you can easily ruin a seemingly reliable contact. Read about these mistakes and rules on how to avoid them in the articles “” and “”.

To work with conductors of large sections 35mm2-240mm2, a hydraulic press is used.

Up to cross-sections of 35mm2, you can also use a mechanical one with a large span of handles.

The sleeve must be crimped two to four times, depending on the cross-section of the wire and the length of the tube.

The most important thing in this work is to choose the correct sleeve size.

For example, when connecting a monocore, the sleeve is usually taken to a smaller cross-sectional size.

And in this way you can connect several conductors at one point at the same time. In this case, only one sleeve will be used.

The main thing is to completely fill its internal space. If you are crimping three conductors at the same time, and you still have voids inside, then you need to “fill” this free space with additional pieces of the same wire, or with conductors of a smaller cross-section.

Sleeve crimping is one of the most versatile and reliable connections, especially when it is necessary to extend the cable, including the input cable.

In this case, the insulation turns out to be almost equivalent to the main one, when also using the outer tube HERE as a casing.

Of course, you won’t use either PPE or Wago for these purposes, but GML cartridges are just the thing! At the same time, everything comes out compact and can be easily reduced, either in a groove or in a cable channel.

Welding and soldering

In addition to all the above connection methods, there are two more types that experienced electricians rightfully consider the most reliable.

And even with its help it is not always possible to connect an aluminum monocore wire with a flexible copper stranded one. In addition, you are forever tied to an outlet or extension cord.

What if there is no voltage or generator nearby?

At the same time, on the contrary, 90% of electrical installers have elementary press pliers. It is not necessary to purchase the most expensive and sophisticated ones for this.

For example, batteries. It’s convenient, of course, just walk and press a button.

The Chinese counterparts also cope well with their task of crimping. Moreover, the entire process takes no more than 1 minute.

Connecting wires is probably the most critical area of work when installing electrical networks. The higher the load on the area, the higher the requirements for connecting wires will be - that’s why you need to use the most effective techniques, methods and devices.

We will analyze the most popular methods of connecting electrical conductors, paying attention to their advantages and disadvantages. In addition, I will give examples of the implementation of techniques most often used in the installation of electrical networks.

Overview of the main connection methods

Installation without the use of additional parts

The connection of electrical network wires must meet a number of requirements:

reliable mechanical fixation of two conductors;
ensuring conductivity between two conductors(the higher the conductivity, the better);
minimizing resistance at the joint area;
no increase in resistance during long-term operation.

Today, when installing electrical networks, the most different types wire connections that allow you to implement the above requirements on at different levels. They can also be classified in different ways, but for ease of analysis I will highlight only two large groups: connections with and without additional devices.

If we need to connect two wires, and we do not plan to use any other devices (except, of course, insulation), then the list of methods will be limited. Wires can be twisted, soldered or welded. These are the three methods we will analyze.

Without the use of special devices, conductors are mounted as follows:

Twist- the simplest, fastest and cheap way. The ends of the wires are stripped of insulation, then twisted together in a spiral, after which the exposed sections of the conductor are re-insulated.
Main disadvantage Such a connection consists in a gradual drop in conductivity. The contact point oxidizes over time, the heating of the conductors increases, and as a result, the reliability of the fixation decreases. The higher the current in the network, the higher the risk of fire at the twisting site, while the circuit breaker is almost guaranteed not to work.

In the modern “Rules for Electrical Installations” (PUE of 2009, Chapter 2, clause 2.1.21), such an installation method as fixing wires by twisting is absent in principle. If in earlier editions this method could be used for joining wires with a cross-section of up to 10 mm 2, then with an increase in the average load on the network, twisting was abandoned. Now it is used only as one of the stages of installation of soldered, welded or other connections.

Welding wires- according to the majority of electricians (I completely share!) the most reliable method. In welding, the conductors are first twisted to increase the contact area and then welded using alternating current.
Copper is very easy to work with, but when installing aluminum wires, it is advisable to use flux to remove the oxide film from the metal surface. The resistance at the welding site remains constant and does not increase over time, so the site will last a very long time.

Soldering- one more is enough effective method installation of connections. When soldering a copper wire, it is cleared of insulation, the junction is tinned, after which the conductors are twisted. The twisted section is soldered with solder and rosin, and you must try to solder the joint without gaps or sag.

From my point of view, soldering is less reliable compared to welding. On the other hand, when installing wiring yourself, a soldering iron is much easier to find than a welding machine. And the safety margin for household needs of a soldered connection is quite sufficient!

Connection using additional parts

To connect wires while maintaining maximum conductivity of the section, the most various devices. This includes both the simplest crimp sleeves and complex terminals that allow installation in literally seconds.

What parts can be used to connect wires?

Sleeves for crimping. The crimp sleeve is a hollow cylinder made of soft metal. During installation, the wires are stripped, brought together, and then a connecting sleeve is put on their ends. The part is clamped with a special tool, which allows you to tightly fix the conductors and prevent their displacement relative to each other.

Branch clamps. They are used to form taps from the main conductor with voltages up to 660 volts without violating its integrity. Contact is ensured by a clamping platform made of anodized steel, which is placed on the stripped section of the cable and secured with four screws. The connection of the wires is protected by a housing made of dielectric material (carbolite or analogues).

Self-insulating (PPE) caps. A popular device that is suitable only for low-current circuits. The PPE cap is a plastic cone with a clamping spring inside. When connecting, the conductors are twisted, after which a cap is screwed onto the twist. Despite the fact that the spring, in theory, should keep the twist from loosening the contact, it is not very reliable.

Terminal blocks. A fairly reliable and simple device, which consists of a plastic insulating body, copper contacts with screw fastenings. When connecting a wire to a terminal, its end is stripped, inserted into the hole in the block and pressed against the contact plate with a screw.

The quality of the connection directly depends on the condition of the terminal block itself. Some cheap varieties due to thermal expansion materials, the thread weakens over time, and the contact has to be “tightened”. Other pads have a risk of breaking the contact if the screw is over-tightened.

Spring terminals (WAGO and analogues). They are used to secure a section as quickly as possible: remove the insulation from the wire, insert the wire into the hole in the terminal - the spring fixes it with sufficient strength. There are also varieties with clamping levers that allow you to securely fix soft metal conductors - these are the ones I use most often.

The main disadvantage of such products is the relatively high price. A high-quality WAGO self-clamping terminal block costs from 7 to 25 rubles, depending on the configuration. If you need to make a lot of such connections, a decent amount will accumulate.

A few words about copper and aluminum

When describing methods for installing electrical networks, one cannot help but pay attention to such a delicate issue as twisting copper and aluminum wires. Probably everyone who is even remotely related to this area knows that these materials cannot be directly combined.

There are several reasons:

Temperature deformation. Aluminum and copper have different coefficients of thermal expansion. This means that when the current is turned on, they heat up differently, and cool down differently when turned off. As a result, periodic on-off switching leads to loosening of the connection and a decrease in contact density.
Oxidation. Over time, a film of oxides forms on the surface of aluminum, which is characterized by poor conductivity. As a result, resistance increases, and with it heating.

Yes, both of these factors can be compensated for: the first by tight clamps, the second by the use of special lubricants. But let's be honest: who does this and when when equipping the simplest twists?

Electroplating. Copper and aluminum are a galvanic pair. This means that when these metals combine, the resulting oxides will disintegrate into charged ions, and the higher the humidity in the room, the more active the process will be. As a result of electrolysis, the reliability of the connection will decrease - primarily due to the appearance of voids, and then due to the resulting heating.

Taking these arguments into account, I strongly do not advise connecting a copper wire to an aluminum one without the use of “intermediaries” - terminals, adapters, clamps and other devices.

Algorithms for installing basic connections

Method 1. Twisting with soldering and heat shrink tube

Different connection methods electrical wires require a different approach. In this section, I will provide step-by-step instructions for the most commonly used circuits.

Let's start with the simplest one - twisting. Yes, it is not very reliable, but it can be successfully used in low-current circuits. And if you solder the contact point, then you can use conductors almost everywhere.

Illustration	Execution technique
	Stripping conductors. Using a special tool or a sharp knife, remove the insulation from the ends of the conductor. We need to expose about 25mm of wire.
	Preparation of insulation. From heat shrink tube cut a fragment of the required diameter, the length of which will be approximately twice the length of the connected section. We put the tube on one of the conductors and move it to the side so that it does not interfere with us.
	Twisting. We twist the sections of the conductor, cleared of insulation, together. When installing single-core conductors, make sure that they are connected in a spiral, and not one wrapped around the other. First, we “fluff” the stranded wires, then weave the strands together and twist them in a spiral.
	Soldering. Using a soldering iron on medium heat, carefully solder the connection. When soldering, make sure that the solder evenly fills the voids between the individual cores in the twist.
	Insulation. We move the thermal insulation tube onto the soldered or twisted area so that it completely covers it and extends into isolated areas on both sides.
	Insulation seal. Using construction hair dryer(better) or a regular lighter (worse, but still possible), heat the heat-shrink tube until its diameter decreases and it crimps the entire length of the connection.

Method 2. Installation with crimping

Connection of conductors in distribution box can be done by crimping. To do this, we will need special crimp sleeves and a tool that allows us to fix them on the wires.

Installation instructions using crimp sleeves:

Illustration	Execution technique
	Removing general insulation. Using a sharp knife, we cut the insulating casing on the wires leading into the junction box. We remove the insulation and sort the wires by color, collecting them into groups. It will be much more convenient to work this way.
	Stripping conductors. Using a special tool or knife, remove the insulating layer of the conductors. It is advisable to remove a little less than can fit into the crimp sleeve - this will make it easier to insulate.
	Putting on the sleeve. Conductors that require connection into one group are assembled together without twisting. We put a sleeve on the conductors, pushing its edge onto the insulated area.
	Crimping. Using a special tool, we crimp the wires. We compress the sleeve in at least two places, and then check the strength of fixation.
	Connection of remaining conductors. We repeat the operations for the remaining groups of conductors.
	Insulation. We put a heat shrink tube on each group of wires with an installed crimp sleeve. We heat the insulation to compact it along its entire length.
	Installation of the second insulation circuit. We bend the free ends of the heat-shrinkable tubes. We put larger diameter tubes on top.
	Insulation seal. As in the first case, we warm up the heat-shrinkable tubes with a hairdryer. By contracting, they will fix the bent ends of the insulation, ensuring maximum tightness.

Method 3. Twisting with welding

The most reliable type of connection without additional parts is welded. It can be used where the contact point is subject to severe loads.

You can install wires in junction boxes using welding as follows::

Illustration	Execution technique
	Preparing the wires. We take the wires out into the junction box, after which we remove the outer insulation and disassemble them into cores. We clean the ends of the cores, forming sections 50–70 mm long that are free from insulation. We collect wires by color to facilitate the formation of twists.
	Formation of twists. We bring all the wires of the same color together, fold them parallel and bend the edge by about 1 cm. Holding the bent part, we twist the wires in a spiral. To increase the reliability and compaction of the twist, we make the last few turns using pliers.
	Preparation welding machine. You can weld wires using almost any household appliances- the power is quite enough. For welding, it is advisable to use graphite (special insert, brush from the engine, rod from the battery).
	Welding wires. We install one clamp on the twist at the top, and use the second clamp with a graphite insert to carry out welding, starting from the bottom of the twist. At the same time, we make sure that the connection does not overheat and begin to collapse. We thoroughly boil all connections.

After this, we just need to insulate all stripped sections of the wire. This is done using insulating tape, heat shrink tubing or special caps.

Method 4. Connecting copper and aluminum using a screw

Above, I noted that it is impossible to directly connect copper and aluminum. And yet, sometimes it is necessary to establish reliable contact between such conductors - for example, when “splicing” old and new wiring.

If we have two solid wires, the easiest way to connect them is using a clamp screw:

Illustration	Execution technique
	Formation of end rings. We strip the ends of both wires by about 30–40 mm. Using pliers, we make “ears” on both wires. The diameter of the ring should match the diameter of the screw that will be used for the connection.
	Installing the bolt. We use an M4 bolt as a connecting element. We put a washer of such a diameter on the rod under the cap that it completely covers the end ring of the wire. We put the wire with the ring on the bolt in such a way that when the fastening is tightened, the bent part does not open, but, on the contrary, bends even more.
	Forming a connection. Cover the first wire with a second washer of suitable diameter. Then we put a second wire on the rod - also with a ring. We cover it with the third washer, and install a grower (spring washer) on top, which will prevent the mount from unwinding.
	Tightening the fastening. We install the nut on top and tighten the fasteners, holding the screw head with a screwdriver. When fixing, you need to tighten the fastener tightly, but without excessive force, otherwise there is a risk of damaging the soft conductor. This is especially true for copper stranded wires.
	Insulation. We insulate the joint using either tape or large-diameter heat-shrink tubing. When using a heat-shrinkable tube, it is advisable to additionally secure its edges to the left and right of the contact point.

Method 5. Using terminal blocks

Using Terminal Blocks different types allows you not only to join wires made of copper and aluminum, but also makes it possible to create collapsible connections.

These parts are used as follows:

Illustration	Execution technique
Regular terminal block
	Stripping wires. We clean the ends of the connected wires. In this case, approximately 5–7 mm must be removed from the insulation - this is quite enough for reliable contact inside the terminal block.
	Preparing the terminal block. We cut off a fragment from the product with the required number of contacts. We loosen the mounting screws of the terminal block, opening the holes for installing the wires.
	Installation of the first wire. On one side, insert the stripped ends of the wire into the holes, pushing them so that they do not reach the middle. Use a screwdriver to tighten the mounting screws, clamping the wire inside the block.
	Installation of the second wire. We repeat the operations for the second wire. We make sure that the wires inside the block do not touch each other.
	Shutdown. We check the reliability of the connection, and then isolate the contact point, protecting it from moisture and dust.
Spring terminal block WAGO 222
	Preparation for installation. We clean the wires intended for installation in the same way as for installation using a terminal block. We lift the clamping lever on the terminal block, opening the hole for installing the conductor.
	Wire installation. We insert the conductor into the hole, pushing it all the way. Make sure that the wire inside the device is not bent.
	Fixation of the conductor. Lower the clamping lever. In this case, the contact plate inside the terminal block rises, clamping the conductor and securely fixing it inside the device due to spring action.

Conclusion

A reliable and safe connection of wires can be ensured in different ways. The options given above are quite sufficient to perform the most common types of work. If you need additional information, watch the video in this article or ask a question in the comments!

Any man strives to ensure that the power supply is own home or apartment was of high quality, uninterrupted and reliable. Therefore, when carrying out electrical installation work During construction or renovation, it is necessary to correctly connect electrical wires. But in Everyday life still have to face problems when the lamp wire broke, the socket stopped working. Of course, if you have basic knowledge of electrical engineering and the ability to carry out electrical installation work, it is easy to fix all these faults yourself.

The connection of conductors made of different metals must be made taking into account all the properties of the material from which they are made. Currently, copper, aluminum and steel are used to transmit electrical energy. Each of these metals has different densities, conductivities, and resistances that are taken into account when making good electrical contact. It is also necessary to take into account the magnitude of the electrochemical potential that arises when current is applied to the metal.

Therefore, if aluminum and copper conductors are connected incorrectly, problems may occur. serious problems problems that many specialists who repair wiring in apartments encounter. Previously used in homes copper wires , which were much superior to aluminum ones in terms of electrical performance. And currently use of copper conductors faded into the background.

Aluminum, having high level oxidation, forms a specific film when combined, which has quite high electrical resistance. This property manifests itself especially in humid environments. The same film is formed on copper, only its resistance is much lower. Therefore, due to this difference in resistance, direct connection of these metals results in difficult electrical conductivity. A oxidation processes lead to sparking, heating and fire of wires.

Methods for safe contact

To create reliable contact between electrical wires, there are several methods, both using special equipment, and when using improvised means.

Types of wire connections:

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

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

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

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

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

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

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

The simplest and known method connecting electrical wires is by twisting them (twisting). Experienced electricians often call it the old-fashioned method.

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

The main advantage of twisting is the absence of any material costs, since you only need pliers and a knife to remove the insulation. And of course, the advantage of twisting is the ease of its execution. Anyone who has held pliers in their hands can do this job without any problems.

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

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

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

The next step is to insulate the junction of the wires. Insulating tape is used for this. To ensure reliability and protect the contact from moisture, you need to wind the tape in several layers, while stepping 2-3 cm onto the wire insulation. Very good option Insulation is carried out using thermal tubes; the main thing is not to forget to put it on one of the cores.

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

How to connect wires by soldering

The type of connection in which electric wires joined using molten solder is called soldering. This method is best applicable to wires with copper conductors, but the use of special fluxes allows you to obtain high-quality joints of other metals.

Advantages of using soldering:

In terms of reliability, this type of connecting wires is second only to welding;
allows you to connect both single-core and stranded wires, as well as wires with different sections;
no maintenance of the contact point is required for the entire period of operation;
low cost of work (flux and solder are inexpensive).

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

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

The technological process for performing soldering looks like this:

The insulation is removed from the conductors by 40-50 mm.
Areas of exposed veins are well cleaned with sandpaper.
Tinning of wires is carried out. To do this, a heated soldering iron is dipped in rosin and the tip is passed several times over the cleaned surfaces.
The wires are twisted.
Place solder on the soldering iron tip and heat the twist. In this case, molten tin should fill all the gaps between the turns.
After cooling, the soldering is wiped with alcohol and insulated.

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

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

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

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

Sequence of welding wires:

We remove 60-70 mm of insulation from the conductors.
We strip the veins mechanically(sandpaper).
We twist the wires, and its length must be at least 50 mm.
We fix the welding grounding contact on top of the twist.
Lightly touch the bottom of the twist with the electrode. Wire welding occurs very quickly.
After the contact ball has cooled, we insulate it.

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

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

The wires are stripped to the length of the sleeve, rolled up and placed in a tube. Then, using special pliers, the connection is pressed and insulated.

There are tube sleeves for extending conductors, that is, for attaching them longitudinally. The wires are inserted into such sleeves from different sides of the tube, then crimped individually.

Bolt method

This connection is used in electrical circuits with high voltage. Its use is suitable for switching almost any conductors.

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

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

Modern industry has mastered the production of special wire connectors, which have made work much easier and have sped up switching work:

Caps with built-in crimp spring. The stripped wires are inserted into such a cap and turned clockwise. With this action, the wires are securely compressed inside.
Terminal blocks, which have tubular brass sleeves inside. Bare wires are inserted into these sleeves and clamped with screws.
Self-clamping terminals The stripped wire is automatically fixed with a special plate.
Lever terminal blocks are considered reusable devices. Fixation of the conductor is ensured by raising and lowering the lever.

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

Today, a bunch of different ways to connect have been invented. But, for some reason, the “bite off, twist and wrap with electrical tape” method does not give up its position.

But there are also things that are fundamentally wrong.

The reason is that twisting two wires from different materials, for example, copper and aluminum, is absolutely not correct. The fact is that when an aluminum wire oxidizes, galvanic steam is released, which will eventually break the connection. And the more current passes through this connection, the sooner it will fail. And, if the load on the wires is not constant, then constant heating and cooling will only worsen the condition of the wiring.
Connecting wires this way can be dangerous. So, sparks in a connection can lead to a fire.

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

For example, here’s a thing called a polyethylene terminal block:

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

You need to insert the ends into it and tighten the screws:

When folded, that is, in normal form, it looks like this:

And, by the way, each insulating segment can be disconnected from each other. So, at first glance everything is perfect and simple, but no. And here there were shortcomings.

If you hold aluminum wire, then you need to make sure that it doesn’t turn out like this:

This clear example that aluminum cannot be clamped, and if this happens, then the terminals need to be changed once a year. Otherwise, the contact will heat up and this will lead to a fire.

Cannot be clamped in a sleeve stranded wires. You may be unlucky and something you already know about will happen.

It's important to choose right size sleeves to match the diameter of the wire, otherwise it may fall out or break if pinched.

When buying a terminal block, do not be fooled by the inscriptions on it. They are lying. It is better to divide the current into 2 or 3 sleeves.

And as practice says, it is better not to buy such terminals at all. And if you use it, then only to connect something small, a light bulb, for example.

The same goes for unnamed Chinese gizmos. It's better to be safe than sorry. Therefore, buy terminals from normal, proven manufacturers, such as: Tridonik, ABB, Legrand, Verit

TB Series Terminal Blocks

Made of hard black plastic, they have a lid. This one is already much better than the previous one.

The inside consists of two screws and a plate:

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

It’s a good thing, because here the wires are clamped by an iron plate, and not by the screw itself, which is undoubtedly a big plus.

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The surface is such that it does not increase the clamping surface by much, which means that both stranded and single-core can be clamped. But still, aluminum ones should be checked from time to time. What's bad about these terminals is that they don't share. And there are hardly any less than 6 pieces.

Self-clamping terminals (WAGO, REXANT 773 series)

They look like this:

Extremely convenient clamps. What you need is to simply strip the wire and push it in until it stops:

Inside that terminal there is this thing, where the blue arrow indicates a pressure plate, and the orange arrow indicates a small bar made of tinned copper:

This is what happens when a wire is inserted into it:

That is, the wire is pressed tightly against the bar with a plate and holds it there constantly, preventing it from falling out.

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

Here are exactly the same, but transparent terminals:

The advantage of them is that through the translucent walls you can see how deep the wiring is inserted. This terminal is suitable for 4 kW. However, there is one big BUT. This means that only original WAGO terminals have such capabilities. For the rest, the maximum current is limited to a lower value.

WAGO 222 Series Terminals

Such terminals will be indispensable if there are wires different diameters and from different materials.

These terminals have levers:

When the lever is raised, you need to insert the wires and fix it by lowering the lever:

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

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