Connect two different wires. Reliable ways to connect electrical wires. Some brands of power cables

Electricity is an area in which everything must be done correctly and thoroughly. In this regard, many people prefer to figure it out on their own, rather than trust strangers. One of the key points is the connection of the wires in the junction box. The quality of the work depends, firstly, on the correctness of the system, and secondly on the safety - electrical and fire.

What is a junction box

From the electrical panel, the wires diverge through the rooms in the house or apartment. In each room, as a rule, there is more than one connection point: there are several outlets and a switch for sure. To standardize the methods of connecting wires and collect them in one place, junction boxes are used (they are also sometimes called branching or junction boxes). They lead cables from all connected devices, the connection of which takes place inside the hollow case.

In order not to look for wiring during the next repair, it is laid according to certain rules, which are spelled out in the PUE - Rules for the Arrangement of Electrical Installations.

One of the recommendations is to route all connections and branching wires in the junction box. Therefore, the wires are run along the top of the wall, at a distance of 15 cm from the ceiling level. Having reached the branch point, the cable is lowered vertically downward. A junction box is installed at the branch point. In it, all the wires are connected according to the required scheme.

According to the type of installation, junction boxes are internal (for concealed installation) and external. A hole is made under the inner ones in the wall, into which the box is built. With this installation, the cover is flush with the finishing material. Sometimes, during the renovation process, it is covered with finishing materials. However, such installation is not always possible: the thickness of the walls or finishes does not allow. Then an external box is used, which is fixed directly to the wall surface.

The junction box can be round or rectangular in shape. There are usually four conclusions, but there may be more. The terminals have threads or fittings, to which it is convenient to attach the corrugated hose. After all, it is in a corrugated hose or a plastic pipe that it is more convenient to lay wires. In this case, it will be very easy to replace the damaged cable. First disconnect it in the junction box, then from the consumer (socket or switch), pull and pull it out. Tighten a new one in its place. If it is laid in the old fashioned way - in a gutter, which is then covered with plaster - to replace the cable, you will have to hammer the wall. So this is the recommendation of the PUE, which is definitely worth listening to.

What junction boxes generally give:

Increased maintainability of the power supply system. Since all connections are accessible, it is easy to locate the damaged area. If the conductors are laid in cable channels (corrugated hoses or pipes), it will be easy to replace the damaged area.
Most electrical problems arise in the connections, and in this installation option, they can be periodically inspected.
The installation of junction boxes increases the level of fire safety: all potentially dangerous places are located in certain places.
Requires less money and labor than cable routing to each outlet.

Ways to connect wires

In the box, the conductors can be connected in different ways. Some of them are more difficult, they are implemented, others are easier, but if they are executed correctly, they all provide the required reliability.

Twisting

The most popular method among folk craftsmen, but the most unreliable. It is not recommended by PUE for use, as it does not provide proper contact, which can lead to overheating and fire. This method can be used as a temporary one, for example, to check the functionality of the assembled circuit, with a mandatory subsequent replacement with a more reliable one.

Even if the connection is temporary, everything must be done according to the rules. The methods of twisting stranded and solid conductors are similar, but have some differences.

When twisting stranded wires, the procedure is as follows:

the insulation is stripped 4 cm;
conductors are untwisted by 2 cm (item 1 in the photo);
are connected to the junction of non-untwisted conductors (position 2);
the veins are twisted with your fingers (position 3);
twisting is tightened with pliers or pliers (position 4 in the photo);
insulated (electrical tape or a heat-shrinkable tube put on before the connection).

It is easier to twist the wires in a single-core junction box. The stripped conductors are crossed and twisted by fingers along the entire length. Then take a tool (pliers and pliers, for example). In one, the conductors are clamped near the insulation, the second is strenuously twisted, increasing the number of turns. The junction is insulated.

Twist with pliers or pliers

Twist with mounting caps

Twisting is made even easier using special caps. With their use, the connection is more reliably insulated, the contact is better. The outer part of such a cap is molded from a plastic that does not support combustion; a metal conical part with a thread is inserted inside. This insert provides a larger contact surface, improving the electrical performance of the connection. This is a great way to connect two (or more) wires without soldering.

Twisting the wires with the caps is even easier: the insulation is removed by 2 cm, the wires are slightly twisted. A cap is put on them, with effort it is turned several times, until the metal is inside the cap. That's it, the connection is ready.

Caps are selected depending on the cross-section and the number of conductors that need to be connected. This method is more convenient: it takes up less space than ordinary twisting, everything fits more compactly.

Soldering

If there is a soldering iron in the house, and you know how to handle it at least a little, it is better to use soldering. Before twisting the wires, they are tinned: a layer of rosin or soldering flux is applied. A heated soldering iron is dipped in rosin, and carried out several times over the part stripped of insulation. A characteristic reddish bloom appears on it.

After that, the wires are twisted as described above (twisting), then they take the tin on a soldering iron, heat the twist until the molten tin begins to flow between the turns, enveloping the connection and ensuring good contact.

Installers do not like this method: it takes a lot of time, but if you make the connection of the wires in the junction box for yourself, take the time and effort, but you will sleep peacefully.

Wire welding

If available, a weld connection can be used. This is done on top of the twist. Set the welding current on the machine:

for a cross section of 1.5 mm 2 of the order of 30 A,
for a section of 2.5 mm 2 - 50 A.

A graphite electrode is used (this is for copper welding). Using grounding pliers, we gently cling to the upper part of the twist, bring the electrode to it from below, touch it briefly, trying to ignite the arc, and remove it. Welding takes place in a split second. After cooling, the junction is insulated. See the video for welding wires in the junction box.

Terminal blocks

Another connection of wires in the junction box is using terminal blocks - terminal blocks, as they are also called. There are different types of pads: with clamps and screw, but, in general, the principle of their device is the same. There is a copper sleeve / plate and a wire fastening system. They are designed so that by inserting two / three / four conductors in the right place, you connect them securely. Installation is very simple.

The screw terminal blocks have a plastic housing in which a contact plate is secured. They are of two types: with hidden contacts (new) and with open ones - of the old model. In any of them, a conductor stripped of insulation (length up to 1 cm) is inserted into the socket and clamped using a screw and a screwdriver.

Their disadvantage is that it is not very convenient to connect a large number of wires in them. The contacts are arranged in pairs, and if you need to connect three or more wires, you have to squeeze two wires into one socket, which is difficult. But they can be used in branches with significant current consumption.

Another type of blocks is Vago terminal blocks. These are quick assembly pads. Two types are mainly used:

The peculiarity of these terminal blocks is that they can only be operated at low currents: up to 24 A with a copper wire cross-section of 1.5 mm, and up to 32 A with a cross-section of 2.5 mm. When connecting loads with high current consumption, the wiring in the junction box must be connected in a different way.

Crimping

This method is possible with special pliers and a metal sleeve. A sleeve is put on the twist, it is inserted into the pliers and clamped - pressed. This method is just right for lines with high amperage (like welding or soldering). See the video for details. It even contains a junction box model so it will be useful.

Basic wiring schemes

Knowing how to connect the wires in the junction box is not all. It is necessary to figure out which conductors to connect.

How to connect sockets

As a rule, the socket group goes on a separate line. In this case, everything is clear: you have three cables in the box, three (or two) conductors each. Coloring can be the same as in the photo. In this case, usually brown is the phase wire, blue is neutral (neutral), and yellow-green is ground.

In another standard, colors can be red, black and blue. In this case, the phase is red, blue is neutral, green is ground. In any case, the wires are collected by color: all of the same color in one group.

Then they are folded, stretched, cut to the same length. Do not cut short, leave a margin of at least 10 cm so that you can reseal the connection if necessary. Then the conductors are connected using the selected method.

If only two wires are used (in old buildings there is no grounding), everything is exactly the same, only there are two connections: phase and neutral. By the way, if the wires are of the same color, first find the phase (with a probe or multimeter) and mark it, at least by winding a piece of electrical tape around the insulation.

Connecting a one-button switch

With a switch, things are more complicated. There are also three groups, but their connection is different. There is

entrance - from another junction box or from a panel;
from the chandelier;
from the switch.

How should the circuit work? Power - "phase" - goes to the switch key. From its exit it is fed to the chandelier. In this case, the chandelier will only light when the switch contacts are closed ("on" position). This type of connection is shown in the photo below.

If you look closely, it turns out that the phase goes to the switch with a light wire. It leaves another contact, but already blue (do not confuse) and connects to the phase wire that goes to the chandelier. Neutral (blue) and ground (if mains) are twisted directly.

Connecting a two-button switch

Connecting wires in a junction box with a two-button switch is a little more complicated. The peculiarity of this circuit is that a three-core cable must be laid to the switch for two groups of lamps (in a circuit without grounding). One wire is connected to the common contact of the switch, the other two - to the key outputs. In this case, it is necessary to remember what color the conductor is connected to the common contact.

In this case, the phase that has come is connected to the common contact of the switch. The blue wires (neutral) from the input and the two lamps are simply twisted all three together. Remaining wires - phase from the lamps and two wires from the switch. So we connect them in pairs: one wire from the switch to the phase of one lamp, the second output to another lamp.

Once again about the connection of wires in the junction box with a two-button switch in video format.

When installing an additional outlet, connecting a new chandelier or eliminating a malfunction in the electrical wiring, you will have to do electrical work. Without practical experience, it is difficult to ensure reliable contact between conductors made of different materials with different cross-sections or completely different numbers of cores.

In our proposed article, all methods of connecting electrical wires that are used in the construction of electrical wiring are described in detail. We have analyzed the technical and technological features of each option. With our advice, you can successfully repair or upgrade your power grid.

Any electrical work should be done competently. It is important to remember that the safety and life of all people and animals living in a house, apartment or in the country depends on the correctness of their implementation. An oversight is unacceptable - at best, there will be no good contact. And these are non-working electric points.

In the worst case, a family member, friend, or acquaintance who drops by for a visit could be electrocuted from an improperly insulated connection. Or the wiring will catch fire, which threatens a fire.

For high-quality and correct execution of electrical wire connections, you need:

knowledge of the basic types and principles of connection;
availability of special tools for performing electrical work;
the presence of all consumables that will come in handy when performing a specific type of connection;
preliminary training on separate sections of wires.

When everything you need is available, you should carefully prepare the future place of work. To do this, you need to de-energize all the wires with which you have to deal. This is a very important step that cannot be ignored!

Without knowledge of electrical installation, it is better to entrust the replacement of electrical wiring to a professional electrician.

In order not to get an electric shock, it is better to make sure once again that the apartment or house is really de-energized. In this case, it is convenient to use an indicator screwdriver - this is an inexpensive tool that can be purchased even in the online store.

It is convenient when, in addition to the desire to do everything with your own hands, there is also the necessary tool - with it, electrical installation work is much easier and faster to perform

In a situation where there are serious concerns about the advisability of carrying out electrical work with your own hands, it is better to contact an electrician. Moreover, you should invite only an experienced craftsman who has not only experience in carrying out such work, but also a special education.

The services of an electrician will be especially relevant if you have to / at home. You cannot save on this - as a result, you can pay double or triple the price, or even pay with your property.

Overview of popular connection types

The main types of compounds used for domestic needs, there are about 10 options. Among them, there are both simple ones, which can be performed without having many years of experience, and more complex methods, which require not only experience, but also special tools and skills to work with them.

Complex connection options

The connection of two or more wires is carried out in order to obtain a high-quality contact. It is he who will ensure the operability of all electrical points in a particular house or apartment.

You can establish reliable contact between the conductors on your own or invite a specialist. It all depends on the type of connection chosen, the availability of tools and skills for carrying out such work.

Complex types of connections include:

soldering;
welding;
crimping.

These options will be quite difficult for a beginner to cope with. The fact is that soldering a node of two or more conductors will require a special tool, the skills to work with it are one awkward movement, and instead of reliable contact, you can get the opposite result.

For soldering, you need to take solder from a tin-lead alloy, rosin and a brush for applying it, a soldering iron and sandpaper for stripping the core

The essence of this method is to remove the insulation from the conductors of the connected conductors and clean them with sandpaper to a shine. Then you need to apply rosin to each vein with a brush and warm it up well with a soldering iron - the cleaned metal should be covered with a uniform layer of rosin on all sides.

When all the conductor veins are prepared, it remains to twist them well and heat the solder with a soldering iron, and also heat the resulting twist until the rosin boils. Now you need to apply solder with a soldering iron to the heated conductor assembly and ensure its uniform flow between the individual veins.

By using welding, brazing and pressing tongs, a strong and incredibly reliable connection is obtained. In such nodes, contact will not be lost even after 30 years.

As soon as it was possible to obtain a full distribution of the liquid solder over the entire surface to be soldered, the soldering can be completed. Now it remains to wait until the resulting knot cools naturally.

Welding is an even more complex type of connection. To complete it you will need:

welding machine;
carbon electrode;
flux, which will protect the melt from oxygen exposure;
face shield and special heat-resistant gloves for hands.

And the most important thing when working with welding is the ability to use the device. In the hands of an amateur, instead of a reliable contact that can last 30-50 years, a molten conductor and damaged insulation will come out from under the welding machine.

Before starting welding, you need to twist, as before soldering, to a shine. The essence of welding is to obtain a monolithic metal connection. To do this, pour flux into the recess of the carbon electrode, turn on the welding machine and lower the end of the twist into the same recess.

The ball at the ends of the strands of the conductors to be connected will provide reliable contact. Moreover, this method is excellent for stranded wires.

As a result of welding, the ends will melt and a metal ball is formed on them. You need to wait for it to cool, clean it from the flux and varnish it.

For crimping, you will also need special equipment - press tongs, also called crimper, and a metal sleeve made of copper, aluminum, combined alloy or insulated.

To get a high-quality contact in this way, you need to prepare the conductor cores in the same way as before soldering. For stripping it is better, as a last resort, side cutters. Then take a sleeve and place the prepared cores of one conductor on one side and the second conductor on the other.

The distance to which you need to strip the insulation from the conductor cores depends on the selected connection method.

Now you have to crimp the joint on both sides with press pliers. It is important that the sleeve or other type fits the diameter of the cross-section of the wires to be connected - the cores must freely enter inside.

After compression with a crimper, you should check the quality of the crimping - you need to pull one and the second wire. If they are tightly clamped and do not fall out of the sleeve, then the contact is successful.

All joints obtained as a result of soldering, welding or crimping must be insulated. For this, electrical tape or heat shrink tubing is used.

The second option is more convenient and is now used by both professional electricians and home craftsmen. Moreover, when creating a contact using crimping, the heat shrink tube must be put on before inserting the cores into the sleeve.

Image gallery

Select a sleeve of the correct material and with the correct inner diameter

Select a shrink tubing of the required diameter. It is important to put it on the wire before crimping with a crimper.

Press pliers to crimp the connection on one and the other side, trying to create a reliable contact

Put a heat-shrinkable tube on top of the resulting assembly and heat it with a construction hairdryer or a lighter so that it tightly wraps around and insulates the contact

Step 1: Select the required sleeve diameter

Step 2: Pick up the heat shrink tubing

Step 3: crimp the connection with a press pliers

Step 4: Put the tube on top

Easy ways to create contacts

In addition to time-consuming and complex options for creating a contact, requiring skill and the presence of special tools, there are simpler ones that can be mastered with your own hands. Such methods are acceptable for connecting two or more wires with different cross-sections or with the same. And the material of the veins can be different - copper, aluminum or steel.

The simple methods most often used in a domestic environment include the following compounds:

twisting;
bolted;
screw;
self-tightening.

There are two options for twisting at home. The first - they simply twist the strands stripped to a shine and wind them over with electrical tape or heat shrink tubing. The second option - a PPE cap is screwed over the twist.

It is extremely inconvenient to use insulating tape, especially in hard-to-reach places. Better to buy a shrink tubing of the correct diameter. Moreover, the price is quite affordable.

The first option is a relic of the past. Such connections are unreliable, they can disintegrate and contact disappears. In the second case, reliability is opposed by the high price for one cap. It is not worth buying cheaper products - they do not withstand the inclusion of a powerful heater in the network or other electrical appliances.

For a bolted connection, you have to prepare a bolt, washers one more than the number of conductors to be connected, and a nut. When creating a contact, the cores are prepared in the same way as before welding or soldering. One condition is that the length of the stripped core should be enough for 3-4 single windings around the bolt.

First, a washer is put on, then the conductor core is wound, then the washer again, the second conductor again, the washer again, etc. When the veins of all the conductors are wound, the last washer is put on and all this is fixed with a nut. The key will have to tighten the connection well to ensure a good contact. Be sure to isolate the resulting node.

Another simple and inexpensive way is with screw connections. They are made using terminal blocks. Moreover, the length of the section to be cleaned from insulation to shine depends on the model of the device and the cross-section of the conductor.

Image gallery

The PPE cap is easy to put on, as if it is screwed over the twisted wires. It is important to buy an original analogue, not to be flattered by a cheap fake

A bolted connection allows you to create a contact of conductors from different materials, and the diameter does not play a fundamental difference here.

Screw terminal blocks are inexpensive and can be cut into the required number of cells, but they are not suitable for stranded conductors

PPE cap is easy to put on

Bolted connection

Screw terminal blocks are inexpensive

Terminal block with pressure plate

The simplest option is self-clamping devices or. They create reliable contact and are easy to use. Another advantage is their reusability. Even a person who is very far from electrical installation can remove and reinstall WAGO.

Which option should you give preference to?

In order to choose the right method of execution, you should take into account the peculiarities of your situation, evaluate the volume of future work and your skills. If we are talking about replacing a chandelier, then there is no point in studying the intricacies of welding and buying a welding machine. Here you can spend money on the purchase of original German WAGO terminal blocks.

When a full-scale renovation of an apartment or house with replacement of wiring is to be done, it is more expedient to use the welding method here. If you do not have the skills to work with this equipment, then you can practice doing high-quality crimping and create all the contacts yourself.

Junction boxes often use screw or. But here is one caveat - they should be tightened periodically. Therefore, you need to arrange the boxes in such a way as to provide easy access to them for auditing.

Non-detachable, disposable clamps. If you need to break the connection and create a new one, you will have to cut off the old contact node

It is extremely dangerous to use a regular twist and, as before, wind electrical tape on top. Moreover, this option is prohibited by electrical rules.

Technical nuances of the main types of connections

Each of the popular types of contact creation has its own characteristics. So, only single-core conductors from the same material can be twisted.

If you have to create contact with stranded wires, then you need to use special tips - they will compress a bundle of small wires. After installing the ferrule, the conductor can be connected to the terminal block without a clamping plate.

To make a reliable connection, stranded wires must be compressed with a special ferrule.

When performing electrical wiring, you inevitably face the need to connect sections of wires to each other. The connections are made in junction boxes that are mounted in the wall or on the wall. Usually, in such a box, wires are connected leading to the machine in the switchboard, and wires going to the outlet, lamp, switch. Another wire can transit from our box to the next. All connections, of course, are made in accordance with the scheme.

Wall Mounted Junction Box

So, before running and connecting the wires, let's remember what the main types of connections exist:

twisting wires and their further soldering or welding;
connection using terminal blocks;
connection using "nuts";
connection of neutral wires using connecting buses;
spring terminals of the WAGO type;
using a bolted connection.
connection using sleeves.

The good old way of joining is twisting

To twist the wires and insulate the twisting place, you do not need anything except pliers and electrical tape. Qualitatively and accurately made strands of copper veins live for several decades. Do not forget to clean the bare sections of the conductive core (TPV) before twisting them.

For greater reliability, the twist can be soldered using standard tin-lead solder and rosin or other flux. It is even better to pass a short-time welding current through the connection. At the end of the twist, an influx (drop) of copper is formed, such a connection will last until the insulation collapses. Only copper conductors can be welded and soldered. But if we look at the PUE, we will see that twisting is forbidden, especially in wooden houses and baths, therefore, twisting is done with soldering or welding.

stranding with soldering and stranding by welding

In general, it is much more difficult to achieve a reliable connection of aluminum conductors than the same for copper. When twisting aluminum wires, due to the mechanical properties of the material, it is very easy to break or break the bare part of the TPG. Using screw and, in general, threaded connections for an aluminum wire, it is necessary to periodically stretch the contacts, since the material "floats" over time, the contact resistance gradually deteriorates, and as a result, the contact may burn out and, in the worst case, fire.

The main problem that can arise when performing conventional twisting is electrochemical corrosion when trying to connect conductors of different materials, it is especially dangerous to try to twist wires from copper and aluminum. In practice, more than one case is known when such connections had to be redone.

PPE (connecting insulating clamp) is widely used to perform twists of uniform material. The PPE cap is screwed onto the cores connected together, ensuring their twisting and squeezing the exposed sections of the TPG. The insulation of such a connection is quite reliable, and definitely not worse than when using electrical tape. When using PPE, it is necessary to very carefully monitor the compliance of the standard sizes of the cap and the wires to be connected.

Terminal blocks

Terminal block connections are common. The plastic housing of the shoe contains contact sleeves (usually brass) with an internal thread. Reliable contact is ensured by screws clamping the wire inserted into the sleeve.

Branch cable clamps

For reliable connection of wires made of different materials and for branching wires from the main (main) line without breaking it, cable clamps ("nuts") are used. The nut core consists of two clamping dies and a dividing center plate. This whole structure is bolted together. The main feature of the cable clamp is that the wires to be connected are in contact with each other only through the steel separation plate. Often "nuts" are used when entering a house or apartment to switch from the main aluminum wire to copper internal wiring.

Clamp "Nut" without cover

"Nut" fully assembled

Connecting busbars

Busbars are widely used to connect a large number of conductors of working neutral or protective grounding in distribution boards. The zero bus is attached to the panel structure or mounted on a DIN rail through an insulating support, the "earth" bus is attached directly to the case. And that, the other bus has several holes with clamping screws for connecting the cores.

Grounding bar

When using screw terminals, the force with which the core is pressed against the contact weakens over time, especially in the case of contact with aluminum. Contact deteriorates, the junction begins to warm up. This leads to the need for periodic revision and broaching of the threaded contacts.

Spring terminals

Spring-loaded screwless terminals significantly speed up the installation process. Their design was developed in the German company WAGO in the fifties of the twentieth century. Clamps for building installation on the basis of flat-spring clamps allow you to reliably connect any copper and single-core aluminum wires in any combination without the use of special tools.

WAGO 222 Series

The main advantage of spring terminals is that the spring itself is always movable; during the entire service life of the terminal, spring steel clamps create a given clamping force. It automatically matches the cross-section of the conductor, the force is applied to the surface of the core without deforming it. This ensures constant contact.

Wire installation in WAGO 222 series

The use of spring terminals allows you to reduce the wiring time (this is especially important for large volumes of work), there is a separate terminal place for each conductor, the conductors are not damaged, reliable protection against accidental contact with bare contacts is provided, all connections look aesthetically pleasing and compact.

There are spring-loaded terminals with plug-in contacts (for example, WAGO terminals 773, 2273 series). These terminals can only be used for solid conductors. The bare end of the core is simply inserted into such a terminal block with little effort. To disconnect the contact, the wire is also unscrewed from the terminal block with little effort.

Even more convenient are the universal terminals - "latches" (for example, the WAGO terminals of the 222, 221 series). They can be used when assembling temporary circuits, since the establishment and disconnection of the contact takes a few seconds. Such terminals allow you to connect wires of different materials and different cross-sections.

The tinned busbar provides a permanently reliable and gastight connection. For example, 221 series performance is 32A / 450V and maximum temperature 105 ° C. The 221 series can be used for ambient temperatures up to 85 ° C.

It is recommended to fill the terminal with a special contact paste before connecting the aluminum wire, which removes the oxide film and prevents further oxidation of the core. WAGO's nomenclature includes terminals filled with such a paste during manufacture.

There are special spring terminals for connecting luminaires. Typical parameters of such terminals - from the mounting side, it is possible to connect one or two copper or aluminum single-core wires with a cross section of up to 2.5 sq. mm; from the side of the luminaire - any copper wire of the same section. Rated current for copper wires 24 A, for aluminum - 16 A.

Bolt connections of different materials

When connecting copper and aluminum wires, it is necessary to exclude direct contact of these metals. For this you can use branch cable clamps ("nuts"). Spring cage connectors can be used. You can use a regular steel bolt onto which insulated wire ends of different materials are wound. Between the wires, it is imperative to put a steel washer on the bolt, it is advisable to spring it with a Grover washer for the durability of the connection.

The final view of the connection of wires from different metals

Sleeve connections

The most reliable connection method is sleeve. It is necessary to select the sleeve itself for the cross-section of the wires. Place wires on one side and the other, and a sleeve with wires is crimped with special pliers.

Crimping the liner with a special press

After that, the sleeve is insulated with electrical tape or heat shrink tubing. Of course, the connection quality is good, but the work increases significantly. Moreover, it is difficult to pick up and buy liners in the store.

The article will discuss the types of connection of electrical wires to each other. The connection method is selected based on environmental conditions, number of conductors, material and cross-section of cores.

The easiest way to connect in an electrician is twisting two wires together. The usual twisting is not provided by the Rules for the Installation of Electrical Equipment, as a connection method due to its unreliability, but it is often found today. For twisting, you need to take 2 wires, remove the insulating layer by 5 centimeters, twist the bare cables, cut to one level and secure with insulating tape.

To connect wires using soldering, you need the following:

soldering iron;
rosin;
sandpaper;
solder.

Algorithm of actions:

We remove the insulating layer from the cables.
We sand the wires to a metallic shine.
We twist the cables.
We heat the twist with a soldering iron (it is better to do this from the end of the twist, so as not to damage the insulating layer).
We dip the twist into the molten rosin.
Using a blowtorch, we solder the twist with solder.

This method has the following advantages:

the connection of wires is more reliable than in most other options;
soldering can be done at home.

However, soldering cables also has disadvantages:

takes a lot of time. This is rather inconvenient when connecting electrical cables on an industrial scale;
if the connection needs to be disassembled, then the soldering point is cut off and a certain part of the cable is lost.

This method is considered the most reliable, but it requires special skills. Welding is often used in the installation of high-voltage power grids. List of required when welding wires:

welding machine;
individual protection means;
flux for cleaning from oxidation welding place;
metal brush;
electrodes.

Wire welding

To carry out welding, the following sequence of actions is performed:

Strip the cores from insulation (4-5 centimeters).
Twisting the cable. As with soldering, it is recommended to bite off the wires with pliers to the same length.
Pour flux into the electrode.
Press the twist against the electrode.
Weld the contact with a welding machine.
Retract the electrode.
Clean the resulting weld with a wire brush.
Secure the welding with insulation.

The disadvantage of welding is the aforementioned complexity of the process and the inconvenience of using it at home.

Terminal blocks

Convenient and modern way of connecting wires. Currently, there are several types of terminal blocks.

Polyethylene terminal blocks

One of the most common terminal blocks, as they are sold in every store. In this case, the cables are connected using two screws, which are located inside the terminal block.

The advantages of such a connection are ease of use, low cost. But polyethylene terminals have a lot of disadvantages:

you cannot connect aluminum cables, since the screws of the terminal block compress the metal and, due to its structure, it begins to deform under pressure, which leads to a deterioration in contact;
it is impossible to connect stranded wires (this is due to the design of the terminal block);
fragility of the material (brass, which is used in this case, tends to deform easily if the screws are tightened strongly).

Plastic screw terminal blocks

They have a similar clamping mechanism, but are of higher quality and more reliable due to the materials used.

Self-clamping terminal blocks

The most common terminal blocks are Vago. To connect the cables in this way, it is enough to strip the cables to the required length and insert them into the special connector of the terminal block. A metal plate inside the mechanism will press the cable, thus securing it securely.

you can connect from 2 to 8 cables to each other (depending on the type of terminal block);
you can connect aluminum cables, since the metal plate gently presses them and does not deform at the same time;
ease of use.

The disadvantage of self-clamping terminal blocks is that it is quite problematic to get the cable without damaging the terminal block. But you can still do this if you start turning the cable along its axis and slowly pull it out.

Vago lever terminal blocks

Terminal blocks consist of a plastic case on the outside, levers and internal metal clamping plates. To create a contact, you just need to strip the cores to the required length, insert into the terminal block connector and clamp the lever.

The main advantages of such a terminal block:

the ability to use different types of cores (copper and aluminum);
reusable (opened the lever, took out the cable and inserted a new one).

Of the shortcomings, it can be pointed out that when installing networks, such terminal blocks take up a relatively large amount of space.

They consist of a transparent plastic body and several pointed metal teeth with a plate. In this version, the cable is simply inserted into the terminal block (without removing the insulating cover) and it is clamped with pliers. Thus, metal cutters pierce the insulation of the wires and create contact between them.

This connection method is simple and does not require any special skills. However, such terminal blocks have several disadvantages:

can only be used to connect conductors with low current (telephone wires, cables for lighting);
one-time use. To disconnect the contact, you must cut the wires at the base of the terminal block. Thus, part of the wire is also lost.

PPE (twist caps)

Connecting insulating caps (PPE) are a simple and reliable connection method. They consist of two parts - a cone-shaped outer cap made of non-flammable plastic and an inner metal spring.

To connect using PPE, you must:

Strip insulation from conductors.
Twist the cores together in a screw-like manner.
Insert into the cap.
Turn clockwise a couple of times.

Pros of PPE:

you can connect from 2 to 8 cores, depending on the type of PPE;
ease of use;
if necessary, you can disassemble the connection without damaging the wire;
withstand large temperature drops. However, before industrial use of PPE it is strongly recommended to test it for contact overheating.

Disadvantages of PPE:

aluminum and copper conductors must not be connected together due to their different structure. In this case, oxidation of the wires and weakening or complete loss of contact (at best) or short circuit of the network (at worst) are possible, which can lead to a fire;
if you pick up the caps of the wrong diameter, then they can fly off the connection or, on the contrary, transfer it.

Connecting sleeves

To use such a sleeve, you need to strip the wires, insert them inside and squeeze the sleeve with pliers. The advantage of such a connection is that the sleeve does not reduce the resistance in the veins and, as a result, can serve for a long time. There are also special sleeves for connecting copper wires with aluminum ones. The disadvantages include one-time use.

This type of connection can be made at home. Its advantage is that aluminum and copper conductors can be twisted together. To connect, you need the following:

insulating tape;
a bolt with a nut and three washers;
pliers or wrenches to tighten the bolt.

Procedure:

We clean the wires.
We twist the loops at the ends. This is best done with a bolt.
We put on the bolt: 1 - washer, 2 - wire, 3 - washer, 4 - wire, 5 - washer. Then we screw the nut on top of all this and tighten the resulting connection.
We wrap the contact with insulating tape.

The undoubted advantage of this design is that it is possible to connect conductors from different metals.

The disadvantages include the fact that this method is more time-consuming than using PPE or terminal blocks.

This method is different from all those described above. The clamps are not used to connect wires, but to branch off from an existing electrical network. In this case, for the connection, the insulating layer is removed from the cable according to the size of the clamp, the terminal block is put on the wire, the branch cable is inserted and the clamp is twisted.

The advantages of such a connection:

there is no need to cut wire cores for subsequent connection;
reusable clamp;
the ability to connect together aluminum and copper wires.

The disadvantages can be attributed only to the fact that such clamps are most often used in trunk power grids and at home will be simply impractical.

In contact with

How to connect a single-core and stranded wire so that in the future this does not lead to problems, and the contact connection has served us for more than one year? And in general, how to correctly make connections of various types of wires?

We will try to answer all these questions in our article, as well as analyze what such rules are associated with, and what dangers are hidden behind an incorrect connection.

First of all, let's look at what the requirements for the high-quality performance of contact connections are related to. After all, it is not without reason that clause 2.1.21 of the PUE separately stipulates the methods of connecting wires, and only allows screw or bolt clamps, crimping, welding or soldering.

This is primarily due to the fact that these types of connections can provide the proper level of durability and reliability of the connection. After all, any electrician will tell you that more than 90% of all damage occurs precisely on contact connections, and therefore they are given such great attention.
After all, what is a poor-quality contact connection is a connection that has a large contact resistance. And since we have resistance, it means heating.

As we remember from the physics course, any conductor in a heated state has a greater resistance than a conductor with a lower temperature. Therefore, an avalanche-like process turns out. From a poor-quality contact connection, the conductor heats up, and its resistance increases even more. As a result, it heats up even more - until the point comes at which it simply melts.
As a result, our main concern is to ensure the minimum resistance between the two conductors to be connected. This is achieved by ensuring the proper contact area of the two conductors, as well as due to the maximum possible contact between them.
Let's immediately analyze why we will not consider the question of how to twist single-core wires or their multi-core counterparts. Indeed, with the right approach, and due to twisting, it is possible to provide a sufficient area of contact and compression of the conductors with each other.

The fact is that in any case, the contact connection will be exposed to temperature effects. That is, it will heat up and cool down. And as we know, heating leads to expansion of materials, and cooling, accordingly, to contraction. As a result, our contact connection, which is not fixed by any third element, can quickly become of insufficient quality.

Note! Surely each of you can cite dozens and hundreds of examples when twisting has stood for decades, and even now looks better than screw or bolted connections. But, as they say, exceptions to the rule only confirm the rule itself. According to statistics, twisted joints are damaged much more often than other types of joints.

Correct connection of conductors

Now you can talk about how to properly connect a solid and stranded wire, two solid or two stranded wires. And also what type of connection for each of these types will be optimal, and which should be used only with certain restrictions.

Compression connection

By the method of compression, PUE means a screw or bolted connection of conductors. The Wago terminals, which are now so popular now, can be attributed to the same type of connection, which use the compression method through the use of springs or special mechanisms.

At the moment, the compression method is one of the most popular joining methods. After all, the price of terminals based on this method is one of the lowest. The installation process is simple and does not require additional equipment, and the method itself is quite reliable.

For wires of small cross-section, the screw connection method is mainly used - or the compression method using a special mechanism. The essence of the screw method is that two conductors are installed in a brass tube, which are then clamped each with their own screw.
This method is well suited for connecting two solid copper conductors. If aluminum is used, then this material is softer, and when you clamp it with a screw, you can either critically reduce its cross section, or even transfer it. Therefore, for aluminum wires, the use of this method is undesirable, or it should be used with extreme caution.

In the photo - a lug for a stranded wire

The use of a screw clamp to connect stranded wires is also associated with the likelihood of breaking off individual wires that make up the conductor in whole or in part during the screw tightening process. To protect the wires from mechanical stress, special tips should be used.
Using special lugs, stranded wires can be connected both between themselves and between single-core wires - using screw clamps.

There are screw terminals with a special clamping pad that provides clamping over the entire section of the brass tube. In this case, the use of special lugs for stranded wires is optional.

As for the Wago terminals and the like. Until now, there are disputes among electricians about their reliability and durability. Some argue that the use of springs in the terminals is not the best option, others that it is very convenient and the springs are quite reliable.