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Two insulated wires connected together are called. Various options for connecting stranded wires. ScotchLok, mortise contact electrical connector

The answer seems to be simple, but nevertheless, often connecting wires, electricians and people who do electrical work on their own, violate the basic requirements for electrical contacts. What does this lead to? At best, to burning wires at the junction, at worst, to ignition and extensive fire. To prevent this from happening, further in the article the main methods of connecting wires during electrical work will be considered.

Connection methods: - twisting; - through the terminal; - through the clamp; - bolted connection; - soldering; - through the tips.

Twisting the wires. This is the fastest and easiest way to connect one or more wires, so it is used more often than others. If the wires are twisted correctly, then when used in a home network with a small load, they will last a long time without reminders of themselves. Common mistakes when connecting wires by twisting.

The most common mistake which installers allow is the twisting of conductors of different metals (copper with aluminum). With such a connection in the twist occurs difficult process electrolysis, which leads to the destruction of the metal itself. It is covered with oxides and ruts. All this leads to poor contact at the junction, and subsequently heating.

At the end, bend the excess onto this twist.

The copper is now in direct contact with the aluminum through the tinned wire. And this will prevent the occurrence of electrolysis on different conductors. Connection through the terminal. The presence of terminals can also facilitate this work and ensure a quality connection. There are a lot of types of terminals, but they have the same principle. The photo shows two types of terminals, which can often be seen in different devices.

For example, in fluorescent lamps, at the junction of the supply wires. Also, these terminals are freely available for sale and can be 10 pcs. and more in length. Having bought such a block, you can simply cut off the required number of elements with a knife. Connecting conductors of different metals in the terminal is not difficult. First you need to remove the insulation from the end of the wires by 3-4 mm so that the bare area does not go much beyond the terminal.

We unscrew the screws until the wires pass freely, and after inserting, we clamp them.

Do not apply too much force, otherwise the fragile thread will “break off”, which will require the terminal to be replaced. Such a connection is quite reliable. With a current of up to 1.5 kW, it is free to cope with its task. It all depends on which terminal to use. The weakest one is considered here, using a more powerful one, the flow current can be increased.

In addition to the option to connect wires from different materials, the terminals can be successfully used to increase the length. This can be useful when the wire in the box is so short that it is not enough to make a twist. This is where the clamp will help. The same applies to the broken wire coming from the ceiling to the lamp.

Then the problem with the connection can be solved with its help. How to do this is clear from the photo.

After the screws are securely clamped, this entire bare area must be insulated with adhesive PVC tape. Bolted connection. Bolts, nuts and washers will always be at hand. Therefore, in the absence of clamps and terminals, they will also fit. By the way, on bolts large sizes, make fairly high-quality connections of powerful large-section cables, and this method is still successfully used in industrial enterprises. So, you will need: - a bolt of the desired length; - a nut; - three wide washers.

You need to bend in the direction of the thread. That is, so that when the nut is tightened, the loop does not expand to the sides. The washer between the two conductors will prevent them from touching, and will prevent the electrolysis effect that destroys metals.

Soldering. The soldering connection is considered to be of the highest quality, since the resistance in this place becomes minimal. Some solder the twists in the boxes themselves, thus improving the connection. But it can be done with copper. Aluminum doesn't solder very well. Yes, you can use different acids and additives, but they, as a rule, destroy the connection over time.

Tips. If you find such tips, it will be very good. This is one of the most reliable types of connection. We insert the wires into the tips, and clamp them with pliers, and then we press them with a hammer and a bit.

Lugs must be tinned, or the aluminum conductor must be wrapped with tinned wire before being inserted into the hole of the lug. After that, the lugs should be compressed with a bolt and nut, and everything should be insulated with tape. Conclusion. Of course, now there are more advanced methods and devices for connecting wires, but they need to be bought and mastered, which takes extra money and time. The good old methods described above will be used for a long time, and will also serve faithfully for a long time. So why pay more?

Quite often it is necessary to connect wires with different cross-sections, this can be seen in switchboards residential buildings, when branches to each of the apartments depart from the supply core.

The difference in sections, and sometimes significant, primarily implies a very tight connection, in order to avoid heating in this place.

Just the most used method of connection in this case is precisely twisting. Despite the apparent backwardness of this method, many experts can confirm that if the twist is done with high quality, then it is able to withstand a much greater load and temperature than the clamp.

It is advisable to make twisting in the case when it is necessary to make a branch from the main line that does not have a break. In this case, in a dedicated area, the insulation layer is simply removed, and the end of the wire to be connected is wrapped around the core of the line.

When a wire break does occur, then mechanical clamps or terminal blocks can be used, and any other device where the possibility of connecting such cross-sectional sizes is structurally provided.

If, for example, you need to connect wires of different sections (also suitable for the same section) and one material (copper or aluminum), then in this case the special connecting blocks presented below are well suited.

They have a different number of inputs: in the figure, respectively: 2, 4, 6.

That is, this is a “kind of” twist for 2, 3, 4, 5 or 6 wires.

You need to understand that after connecting the wires in this way, they can no longer be removed from the block. Therefore, if you have never tried to work with such devices, buy a few of them in a store with a margin and practice at home. They cost pennies.

For a chandelier, the option of using wago-type terminals, especially if the wires coming from the ceiling are short, will not be very good, because, as already mentioned, in this case the wires can no longer be removed (for example, you need to change the chandelier or wash it) and you will have to cut them off. In the case of terminals with a screw connection, it will be enough just to unscrew the fixing screws and release the wires.

Connecting wires of different cross-sections requires care. However, by twisting or soldering, it is possible to connect conductors of only an adjacent section, for example, 4 sq. mm and 5 sq. mm.

  1. Connect conductors of different sizes using screw type clamps (ZVI). Such a device allows you to lead a core of one section into one entrance, and into another - a different section. A secure clamp ensures perfect electrical contact. Each wire is clamped with a separate screw.
  2. Wago universal clamps. This tool has been around for a long time. Differs in ease of use. Designed not only for connecting conductors with different cross-sections, but also create good contact between the cores of various raw materials.
  3. Bolted connection can be made from an unlimited number of conductors. Use both a different section, and not the same materials. The installation of washers in such a connection is mandatory. In addition, it is important to tighten the bolts tightly so that they do not quickly become loose.
  4. There is the use of copper-tinned tips in combination with a bolted connection. Tips alone are not enough, you need to buy more Hydraulic Press or special pliers. For achievement tight connection insulation must be removed in accordance with the PUE. Similar to the previous method, flat metal washers are used.

All types of wire connections described above are used when laying electrical wiring, but a specific type is selected based on several characteristics:

  • type and material of the core (copper/aluminum and solid/stranded);
  • the number of connected wires;
  • operating conditions (indoors, outdoors).

Removing the insulating layer from the wires

Immediately I would like to dwell on a question that will be common to any method. Before connecting the wires into a common electrical unit, they must be stripped from the upper insulating layer.

This can be done with a utility knife. This method is simple, but there is a high probability of damage to the conductive core. To do everything right, you must clearly follow the step-by-step instructions:

  1. Place the wire on some flat surface (like a table).
  2. Press it with the index finger of your left hand.
  3. Take the knife with your right hand and lightly press it into the insulating sheath of the wire. In order not to hook the metal core, position it towards the cut at an angle. If the angle is right, there is a possibility of a circular notch in the core, as a result of which it may subsequently break.
  4. Holding the knife in this position. With the index finger of your left hand, slowly rotate the conductor one full turn, thus notching the insulation around the entire circle.
  5. It remains only to pull off the cut piece of insulation.

Professional electricians now already have in their arsenal such a device as a stripper. This is a multifunctional tool, with it you can strip the insulation from the wire or cut the cable. It can be simple, semi-automatic and automatic. Most importantly, when stripping the insulation with a stripper, the conductive core is not damaged. For each standard core diameter, such a tool has a calibrated hole with a cutting edge.

The length to which it is necessary to strip the wire cores is different for each connection method.

Twisting

Let's start with the simplest and most well-known method - twisting. It can also be called the oldest, not for nothing that electricians among themselves call twisting the “grandfather method”.

Electricity is not the area where you need to save. It is advisable to do everything carefully, to select high-quality materials, to choose sizes / diameters / ratings carefully. Let's start with the fact that even the conductors must be connected correctly. And choosing how to connect wires is not as easy as it seems.

There are about a dozen ways to connect wires. In general, they can be divided into two groups: those that require special equipment or specific skills and those that any home master can successfully use - they do not require any special skills.

The first group includes:

  • Soldering. When connecting wires of small diameter in the amount of -2-3 pieces - a very reliable method. True, it requires a soldering iron and some skills in owning it.
  • Welding. We need a welding machine and special electrodes. But the contact is reliable - the conductors are fused into a monolith.
  • Crimping sleeves. Sleeves and special pliers are needed. Sleeves are selected according to certain rules that you need to know. The connection is reliable, but in order to remake it, it will have to be cut off.

All these methods of connecting wires are performed mainly by specialists. If you have experience with a soldering iron or welding machine, having trained on unnecessary scraps, you can do them yourself.

Some wiring methods are more popular, others less so.

Ways to connect wires that do not require any specific skills are becoming more and more popular. Their advantage is quick installation, reliable connection. The disadvantage is that “connectors” are needed - terminal blocks, clamps, bolts. Some of them cost quite decent money (Wago terminal blocks, for example), although there are inexpensive options- screw terminal blocks.

So here are the ways to connect wires, which are easy to perform:


Among professionals there are two opposite opinions. Some believe that new ways of connecting wires - clamps - the best way out, as they speed up installation without compromising the quality of the connection. Others say that the springs will someday weaken and the contact will deteriorate. In this matter, the choice is yours.

Technical nuances of different types of wire connections

All types of wire connections described above are used when laying electrical wiring, but a specific type is selected based on several characteristics:


Consider each connection method, the technology for its implementation and the appropriateness of use in various situations.

Soldering electrical wires

One of the oldest and most widespread types of connection. To work, you will need rosin, solder and a soldering iron. The soldering process is as follows:


Actually, on this soldering electrical wires finished. Not the most difficult process but requires certain skills. The main thing is to warm up the junction enough for the solder to flow between all the wires. In this case, you can not overheat, otherwise the insulation will melt. This is the art - not to burn the insulation, but to ensure reliable contact.

When can soldering be used? This method of connecting wires is excellent in low-current electrics. When connecting wires in a junction box, it is no longer very convenient. Especially if there are a lot of wires and / or they are of large diameter. Soldering such a twist is not a task for beginners. In addition, when trying to lay the connection in the junction box, the soldering begins to break down. To the point that some of the wires fall off. In general, the method is good for connecting conductors of small diameters.

Welding conductors in electrical connections

One of the most reliable ways wire connections - welding. During this process, the metal of individual conductors is brought to the melting point, mixed, after cooling it is a monolith. This method works very well on large diameters or when in large numbers connected conductors. It differs not only in excellent contact, which does not weaken over time and does not change its characteristics. It is also mechanically very strong - the fused part does not allow the connection to fall apart even under heavy loads.

The drop at the end of the twist is molten aluminum

Disadvantages are also present. The first one is just that the conductors are fused, that is, the connection turns out to be absolutely one-piece. If you need to remake it, you have to remove the fused part and start all over again. To be able to do this, you always need to leave a small backlog along the length of the wires. The second drawback is that you need a welding machine, skills in handling it, special electrodes for welding aluminum or copper. The main task in this case is not to burn the insulation, but to melt the conductors. To make this possible, they are stripped of insulation by about 10 cm, twisted tightly into a bundle, and then welded at the very end.

Another disadvantage of welding wires is a laborious process, which also requires jewelry precision in handling the welding machine. For the combination of these qualities, many professional electricians do not like this method. If you pull the wiring "for yourself" and know how to handle the equipment, you can spend some time. Just pre-practice on scraps, select the current strength and welding time. Only after several times you get everything perfect, you can start welding wires "in real life".

Crimping

Another method that requires special equipment is crimping wires with sleeves. Sleeves are copper and aluminum, different diameters. The material is selected depending on the material of the conductor, and the size is selected according to the diameter and number of wires in a particular connection. They should fill almost all the space inside the sleeve, but there should be free space. The quality of the contact depends on the correct choice of the sleeve size. This is the main difficulty of this method of connecting wires: the sleeve should not be too large or too small.

The technology of work is as follows:

  • The conductors are stripped of insulation (the length of the stripped section is slightly more than the length of the sleeve).
  • Each conductor is cleaned to bare metal (remove oxides with fine-grained sandpaper).
  • The wires are twisted, inserted into the sleeve.
  • Crimped with special pliers.

It seems that it is not difficult, but it is in the selection of the sleeve and the presence of ticks that the whole difficulty lies. You can, of course, try to compress with pliers or pliers. But it is impossible to guarantee normal contact in this case.

Twisting

In the first section of the article, we deliberately omitted the twisting of wires. According to the current standard, it cannot be used, since it does not provide proper contact and connection reliability. This method can replace any other methods of connecting wires.

Yes, they did wiring on the twists 20-30 years ago and everything worked fine. But what were the loads on the networks then, and what are they now ... Today, the number of equipment in ordinary apartment or a private house has increased significantly and most of the equipment is demanding on power supply. Some types simply will not work at reduced voltage.

Why is twisting so bad? Twisted wires do not make good enough contact. At first, everything is fine, but over time, the metal is covered with an oxide film, which significantly impairs contact. With insufficient contact, the junction begins to heat up, an increase in temperature causes a more active formation of an oxide film, which further worsens the contact. At some point, the twist heats up very much, which can lead to a fire. It is for this reason that it is better to choose any other method. There are some that are even faster and easier to do, but which are more reliable.

Connection isolation

All the methods of connecting wires described above - welding, soldering, crimping with a sleeve - provide for their insulation, since bare conductive conductors must be protected. For these purposes, electrical tape or heat shrink tubing is used.

Everyone probably knows how to use electrical tape, but we’ll tell you a little about heat shrink tubing. This is a hollow polymer tube, which significantly reduces its diameter when the temperature rises (by 2-6 times, depending on the type). The size is selected so that the pre-shrink volume is greater than the diameter of the insulated wires, and the post-shrink volume is less. In this case, a tight fit of the polymer is ensured, which guarantees a good degree of insulation.

Heat shrink tubing for insulation of conductors can be of different diameters and colors

In addition to size, heat shrink tubing is selected according to special characteristics. They are:

  • heat-resistant;
  • light-stabilized (for outdoor use);
  • oil-petrol resistant;
  • resistant to chemicals.

The cost of heat shrink tubing is not very high - from $ 0.5 to $ 0.75 per 1 meter. Their length should be slightly longer than the length of the bare conductors - so that one end of the tube is pulled over the insulation of the conductors by about 0.5 cm, and the second sticks out by 0.5-1 cm. After the tube is stretched, take a heat source (you can use a lighter) and heat the tube. Heating temperature can be different - from 60°C to +120°C. After the connection is covered, the heating stops, after which the polymer cools quickly.

It takes a little time to insulate the wires with a heat shrink tube - seconds count - and the quality of the insulation is high. Sometimes, for greater reliability, two tubes can be used - a slightly smaller and a slightly larger diameter. In this case, first put on and warm up one tube, then the second. Such connections can be operated even in water.

Terminal blocks

This method is also preferred by electricians, but it can be easily used by a person who can hold an ordinary screwdriver in his hands. This is one of the first ways to connect electrical wires without soldering. Today, on almost every electrical appliance, you can see a variant of this connection - this is the output block to which the power cord is connected.

Terminal blocks are a contact plate, which is soldered in a plastic (polymer) or carbolite housing. They cost very little, they are available in almost any store selling electrical goods.

Terminal blocks are convenient, inexpensive, allow you to connect copper and aluminum wires, conductors of different diameters, solid and stranded

The connection takes place literally in seconds. The insulation is removed from the conductor (by about 0.5-0.7 cm), the oxide film is removed. Two conductors are inserted into the socket - one opposite the other - and fixed with bolts. These bolts press the metal against the contact plate, making the connection.

The advantage of this connection method: it is possible to connect wires of various sections, single-core with multi-core. The disadvantage is that only a couple of wires are connected. Jumpers must be installed to connect three or more.

PPE caps

Another way to connect wires that does not require special skills is to install PPE caps. They are a plastic cone-shaped case, inside of which a spring is sealed. They come in different sizes - from 0 to 5. You can connect wires of different diameters - each package contains the minimum and maximum and minimum total cross-section of the connected wires. In addition, there are cases simply in the form of a cone, there are with stops "ears" that facilitate their installation. When choosing, pay attention to the quality of the plastic - it should not bend.

Connecting the wires with PPE is very simple: strip the insulation, collect the wires into a bundle, insert it inside the cap and start twisting. A spring inside the cap grips the conductors, helping to twist them. The result is a twist, which is wrapped around the outer side with spring wire. That is, the contact is very high quality and good. This method of connecting wires with PPE caps has been used for a long time in Europe and America, it came to us about 10 years ago.

If you need ways to connect wires without welding - consider PPE

There is another way: first, the wires are twisted, then caps are put on them. This method was invented by the Russian company that produces these wire connectors - KZT. But this technique requires more time, and the quality of the connection is no different.

There is one more point: how long to strip the wire from the insulation. Manufacturers give clear instructions on this matter - each size has its own length of bare conductors. It is designed so that all conductors without insulation are inside the case. If you do this, the connection does not require additional insulation, which greatly speeds up the process. In addition, the expanded lower part does not prevent heat removal and such a connection is heated less.

Practicing electricians advise to strip the wires by 5-10 cm, and insulate the twist left without insulation. This is argued by the fact that the contact area with this option is larger. It is true, but this option heats up more. And the standard solution has reliability. there are no problems with contact (with normal quality of PPE).

Wago clamps

The most heated debate flared up precisely about Vago. Some people absolutely love this product, others don't. And, no less emphatically. Opponents of using Wago do not like the fact that the contact is based on a spring. They talk about how she might weaken. This will lead to poor contact and overheating. And they bring photos with melted clamps. Supporters of this method conduct tests and comparisons, they say that a properly selected branded clip lasts for many years without signs of deterioration in contact. Yes, and manufacturers say that, subject to technology, Wago terminal blocks can be used for 25-35 years. It is important to choose the right type and parameters and not buy a fake (there are a lot of them).

There are two types of Vago clamps. The first series is slightly less expensive, called Wago. These clamps are suitable for connecting solid and stranded wires with a cross section of 0.5-4 mm2. For conductors of smaller or larger cross sections, there is another series - Cage Clamp. It has a very wide range of use - 0.08-35 mm2, but also a high cost. In any case, the contact is provided by a good copper contact plate. The special shape of the plate allows you to achieve reliable contact.

Detachable

In addition, Vago spring-loaded clamps are detachable (222 series) and one-piece (773 and 273 series). Detachable ones are convenient to install in those places where changes in the network configuration are possible. For example, in junction boxes. They have levers with which the wires are clamped or released. Detachable Wago terminal blocks can connect from 2 to 5 conductors. Moreover, they can be of different sections, types (single-core and multi-core). The order of connecting the wires is as follows:


We repeat the same operation with another (other) wires. All this takes a matter of seconds. Very fast and convenient. Not surprisingly, many professional electricians have forgotten other ways to connect wires.

One-piece

One-piece series differ in structure: there is a clamp body and a cap. The cap can be made of transparent polymer (773 series) or opaque plastic (223). There are holes in the case into which wires stripped of insulation are inserted.

To ensure normal contact, it is only necessary to remove the insulation correctly - exactly by 12-13 mm. These are the requirements of the manufacturer. After the conductor is inserted, the bare part of it should be in the terminal block, and the insulation should rest against the housing. Under such conditions, the contact will be reliable.

Bolted connection

Another type of connection of electrical wires with a solid experience is bolted. It is called so because a bolt, nut and several washers are used to connect the wires. Contact through the use of washers is good, but the whole structure takes up a lot of space and is inconvenient to install. It is mainly used if it is necessary to connect conductors from different metals - aluminum and copper.

The connection build order is as follows:

  • We clean the wires from insulation.
  • From the cleaned part we form a loop, the diameter of which is equal to the diameter of the bolt.
  • We put on the bolt in the following sequence
    • washer (it rests on the head of the bolt);
    • one of the conductors;
    • another puck;
    • second conductor;
    • third puck;
  • We tighten everything with a nut.

So you can connect not only two, but also three, and more wires. Please note that it is necessary to tighten the nut not only by hand. Must use spanners put in a solid effort.

The best ways to connect wires for different occasions

Since different wires can be connected, they can be operated in different conditions, then best way You have to choose taking into account all these nuances. Here are the most common situations:


These are the most common options for non-standard connections.


The fact is that it is by no means possible to connect copper and aluminum wires with a twist.
There are several reasons for this. The main problem is oxidation. aluminum wire in contact with copper, a galvanic couple is formed, which slowly but surely destroys the connection. And the faster, the more current goes through this twist.
Of course, after a couple of hours, such a connection will not fall apart, even if you turn on a heater or kettle through it. But over time, the resistance will slowly increase, which will cause the twist to heat up more and more. And if the load is not constant, but episodic, then constant heating-cooling cycles will worsen conductivity even more. Miscellaneous materials when heated, they expand in different ways, and turning the load on and off through such a twist will be tantamount to constantly pulling it back and forth. You understand, it will not lead to anything good.
Well, if it's just heating, it can usually be tracked by the characteristic smell of burnt insulation. But the sparking of the connection, especially next to the wallpaper or something flammable, can easily turn into a fire.
What solutions exist to solve this problem?
Polyethylene terminal blocks
Here is such a thing:

Sold in any hardware store, it costs a penny.
Inside is such a brass sleeve with two screws:


We push the wires into it, clamp it with screws:
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I pulled it out on purpose for clarity. Together with the insulation, it will look like this:


Each segment can be cut. It seemed like the perfect choice. But there is a nuance
Although these nuances and shortcomings are a wagon and a small cart, do not be fooled by simplicity.


In general, it is advisable not to use such terminal blocks. If you use it, then only with single-core wires and for connecting something small - a light bulb, a fan (not industrial). And no aluminum!
It is also advisable to buy not noname China, but terminal blocks from normal manufacturers: Tridonik, ABB, Legrand, Verit
Cost: from 10 to 50 rubles.
TB Series Terminal Blocks


Hard black plastic pads. Already better.
Removable cover:


And here is the internal structure:


We unscrew, we put the wire, we clamp it.


Pros - it is not a screw that clamps, but a metal plate. We press to the lower steel plate. In addition, the upper part is not flat, but with a characteristic surface, which increases the clamping surface:

.
As a result, stranded and aluminum wires can be clamped. Aluminum, however, it is advisable to at least occasionally check for weakening of the clamp. I saw the pads themselves for currents of 25A and 40A.
Inconvenience - it is not cut and not divided, or buy a bunch of small ones (I have not seen less than 6 pieces), or even put one big one on two wires.
Cost: from 30 to 80 rubles.
Self-clamping terminals (WAGO or REXANT series 773 and their copies)
Or they are also called express terminals. Like these ones:


Very handy stuff. I stripped the wire, put it inside to the end, you're done:
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Inside there is a pressure plate (blue arrow) and a small shank (orange) made of tinned copper:


When wires are shoved into it, this is what happens:


The plate presses the wire against the tire, maintaining pressure all the time. And the design of the pressing part does not allow the wire to fall out. And it's hard to pull it out. In general, they are disposable, but if you really want to, then gently rotating the wire around its axis, you can pull it out.


Since the copper contact is tinned, an aluminum wire can be inserted into such a terminal without fear of problems. At the same time, constant pressure will not allow the aluminum wire to fall out.
White paste (in the next photo you can see a white mass on the contact) is quartz sand with technical petroleum jelly, especially for aluminum wires. Quartz sand is an abrasive that cleans off the oxide film from the surface of aluminum, and petroleum jelly prevents it from re-forming.


The same terminals, but transparent:


They do not differ in anything, except for the dye. Well, in transparent terminals it is more convenient to see the wire - whether it is stuffed to the end or not.
Plastic is non-combustible, melts when the temperature rises, without releasing harmful substances into the air.
Designed for 25 A, which is approximately 4 kW. Attention! Currents are indicated only for original WAGO terminals.
Rexant terminals (manufacturer - SDS group) use a different spring steel, which relaxes when heated. Accordingly, the maximum current is limited, except for lighting it is not recommended.

Here is a test in which they held 50A and did not even melt. Well, this is in ideal conditions - in the air, the cooling was good. And the terminals are original, yes.
Cost: from 2 to 6 rubles, depending on the number of contacts

WAGO series 222 terminals with levers. I saw only vagovskie, others do not produce.
For particularly difficult cases, when there are several types of wires, different thicknesses, aluminum, copper, etc.


Raise the lever:


We push the wires, lower the lever:


If necessary, you can raise the lever, pull out the wire, insert another. And so many, many times. A great thing for those circuits whose wiring can change a bunch of times.
They eat everything. Current - up to 32A. Inside - a plate that presses against a common tire is connected to a lever.


Tricky design, in general.


Shank - tinned copper, as usual:


Cost: from 5 to 15 rubles.
Scotch locks, ScotchLok, electrical connector with mortise contact.
This is for low current (network, telephones, LED lamps, etc.).


The meaning is simple - several wires are stuffed into such a thing:


After that, it snaps into place with pliers or any pressing tool. No, there is of course a special tool, but I don’t see the point in it - it is a small pliers with flat jaws.
They are especially loved by installers of SCS and networks, for simplicity, cheapness, water resistance, and the absence of the need to remove insulation.


Inside - a hydrophobic gel that protects against corrosion, moisture, oxidation, etc. And a plate with a cutting-clamping surface:


Or two plates:


Here you can see what happens to the cable after termination:


Knives cut through the insulation, and firmly pressed against the wire. There is also a version for two cables at once, and the plates are a little thicker - quite suitable for lighting:


Of course, they are disposable and maintenance-free. It is necessary to replace - a piece of cable is bitten off with them, and a new one is put in.
Cost: from 1 to 4 rubles per piece.
For high currents
For such cases, there are sleeves:


Above - a sleeve-connector of an aluminum and copper cable, below - universal copper tinned:


A wire (or several) is inserted inside, the sleeve is crimped with a special tool. Unfortunately, some bad person stole my tongs, so I won't show them. I found this image on google:


And this is how the crimped sleeve looks like:


A huge plus is that with the right size and the right crimp, the resistance does not decrease compared to conventional wire. And maintenance-free, which is sometimes important. This means that it can be walled up (after normal insulation, of course) into the wall, buried in the ground (taking care of waterproofing), and so on.
Sleeves with a flat end and a hole are mainly used for grounding, when the wire must be connected to the body:


Sleeves with screw clamp - when you need to clamp the wire without a tool.


Currents - similar to currents for that section of the copper wire, which coincides with the inner diameter of the sleeve.
Cost: from 10 rubles for a sleeve, from 1000 for crimping.

About stranded wires

And there is also a situation when you need to connect a single-core wire to a multi-core one:


No, in general, you can irradiate and clamp already like a monocore. But there is an easier option:


They are called NShVI - Insulated Pin Sleeve Tip. The meaning is simple:


We select its diameter for the wire section, twist it gently so that it does not fluff, put on the tip and crimp along the entire length (well, at least 3-4 times). That's it, now this wire can be clamped into any connection, without fear that the cores will break off, the contact will be broken or something else. It is important to choose the correct tip diameter depending on the wire, otherwise the contact will be worse and the wire may slip out.

When connecting wires of different diameters in series, the maximum load current will be determined by the cross section of the wire with a smaller diameter. For example, copper wires with a diameter of 1.6 mm and 2 mm are connected. In this case, the maximum load current on the wiring, which is determined from the table, will be 10 A, and not 16 A, as for a wire with a diameter of 2 mm.

Twisting electrical wires

Until recently, twisting was the most common way to connect wires when performing electrical wiring, due to the availability, it was enough to have a knife and pliers from the tool. But, according to statistics, twisting is an unreliable way to connect conductors.

According to the rules for the installation of electrical installations (PUE), the connection of the type of twist during the installation of electrical wiring is prohibited. But, despite the noted shortcomings, the twisting method is currently widely used. The twisted connection of conductors of low-current circuits, subject to certain rules, is fully justified.

The photo on the left shows how it is unacceptable to twist. If one conductor is wrapped around another, then the mechanical strength of such a connection will be insufficient. When twisting wires, it is necessary to make at least three turns of wires around each other. In the middle photo, the twisting is done correctly, but the copper conductor is twisted with aluminum, which is not acceptable, since when copper contacts aluminum, an EMF of more than 0.6 mV occurs.

In the photo on the right, the twisting of copper and aluminum wires is done correctly, since the copper wire is tinned with solder before twisting. You can twist together several wires at once, in a junction box, it happens that up to 6 conductors are twisted, wires of different diameters and from different metals, a stranded wire with a single-core wire. Only the stranded wire must be made single-core, after being soldered with solder.

Connecting electrical wires by soldering

The connection of copper wires with high-quality soldering is the most reliable and is practically not inferior to a solid wire. All of the above examples of wire twists, except for aluminum and tinsel, when the conductors are tinned before twisting and then soldered with solder, will be reliable on a par with solid wires. The only downside is the extra work involved, but it's worth it.

If you need to connect a pair of wires and the conductors from the twist should be directed in different directions, then a slightly different type of twist is used.

By splicing two pairs of double wires in the manner described below, it is possible to obtain a compact and more beautiful connection by twisting both single-core and stranded pairs of conductors. This twisting method can be successfully applied, for example, when splicing broken wires in a wall, extending a wire when moving a socket or switch from one place on the wall to another, when repairing or extending the length of the carrying cable.

To obtain a reliable and beautiful connection, it is necessary to adjust the lengths of the ends of the conductors with a shift of 2-3 cm.

Perform pairwise twisting of the conductors. With this type of twisting, two turns are enough for a single-core wire, and five for a stranded wire.

If you plan to hide the twist under plaster or in another inaccessible place, then the twist must be soldered. After soldering, you need to go over the solder with sandpaper to remove any sharp solder icicles that can pierce the insulation and stick out of it. You can do without soldering if the connection is accessible and there are not large currents flowing through the conductors, but the durability of the connection without soldering will be much lower.

Due to the shift of the twist points, it is not necessary to isolate each of the connections separately. We attach on both sides along the conductors along a strip of insulating tape. In conclusion, you need to wind three more layers of insulating tape. According to the requirements of the Electrical Safety Rules, there must be at least three layers.

Wires spliced ​​and soldered in the manner described above can be safely laid into the wall and plastered on top. Before laying, it is desirable to protect the connection with a vinyl chloride tube, dressed in advance on one of the pairs of wires. I have done this several times, and the reliability has been confirmed by time.

Connecting wires in junction boxes

When I moved into an apartment built in 1958 and began to make repairs, I immediately encountered the flashing of lighting bulbs in time with hammer blows on the walls. There was a primary task of repair, revision of junction boxes. Opening them showed the presence of poor contact in the twists of copper wires. To restore contact, it was necessary to disconnect the twists, clean the ends of the wires with sandpaper and twist again.

When trying to disconnect, I ran into a seemingly insurmountable obstacle. The ends of the wires broke off even without any effort. Over time, copper lost its elasticity and became brittle. When stripping the wire, the insulation was obviously cut with a knife blade in a circle and notches were made. In these places, the wire broke off. Copper hardened from temperature fluctuations.

To return copper elasticity, unlike ferrous metals, you can heat it to red and quickly cool it. But for this case, such an approach is unacceptable. The ends of the wires were no more than 4 cm long. There was no choice for the connection. Only solder.

I stripped the wires with a soldering iron, melted the insulation, tinned them with solder, tied them in groups with tinned copper wire and filled them with solder using a 60-watt soldering iron. The question immediately arises, how to solder the wires in the junction box if the wiring is de-energized? The answer is simple, using a battery powered soldering iron.


So I updated the connections in all junction boxes, spending no more than 1 hour on each. I am fully confident in the reliability of the connections made, and this has been confirmed by the 18 years that have passed since then. Here is a photo of one of my boxes.

When leveling the walls with Rotband in the hallway and installing a stretch ceiling, the junction boxes became a hindrance. I had to open them all, and the reliability of the solder joint was confirmed, they were in perfect condition. So I boldly hid all the boxes in the wall.

The connections currently practiced with the help of a Wago flat spring clamp terminal block greatly reduce the time spent on installation work, but are much inferior in reliability to solder connections. And in the absence of spring-loaded contacts in the block, they completely make connections in high-current circuits unreliable.

Mechanical connection of wires

Soldering is the most reliable type of connection of wires and contacts. But it has disadvantages - the inseparability of the obtained connections and the high labor intensity of the work. Therefore, the most common type of connection of wires with electrical contacts of devices is threaded, screws or nuts. For the reliability of this type of connection, it is necessary to perform them correctly.

The linear expansion from temperature changes is different for metals. Aluminum changes the linear dimensions especially strongly, then in descending order, brass, copper, iron. Therefore, over time, a gap is formed between the contact of the connected metals, which increases the resistance of the contact. As a result, to ensure the reliability of the connections, it is necessary to tighten the screws periodically.

In order to forget about maintenance, additional washers with a cut are installed under the screws, which are called split washers or Grover. The grower selects the resulting gaps and thus ensures a high contact reliability.


Often, electricians are lazy, and the end of the wire is not twisted into a ring. In this embodiment, the area of ​​contact of the wire with the contact pad of the electrical appliance will be many times smaller, which reduces the reliability of the contact.

If the formed wire ring is slightly flattened with a hammer on the anvil, then the contact area will increase several times. This is especially true when forming a ring of stranded wire soldered with solder. Instead of a hammer, flatness can be given with a needle file by grinding off a little ring at the points of contact with the contacts.


This is how it should be done ideal threaded connection of wires with contact pads of electrical appliances.

Sometimes it is required to connect copper and aluminum conductors to each other, or with a diameter of more than 3 mm. In this case, the most accessible is a threaded connection.

The insulation is removed from the wires for a length equal to four screw diameters. If the veins are covered with oxide, then it is removed with sandpaper and rings are formed. A spring washer, a simple washer, a ring of one conductor, a simple washer, a ring of another conductor, a washer and, finally, a nut are put on the screw, screwing the screw into which the entire package is tightened until the spring washer is straightened.

For conductors with a core diameter of up to 2 mm, an M4 screw is sufficient. The connection is ready. If the conductors are of the same metal or when connecting an aluminum wire to a copper wire, the end of which is tinned, then it is not necessary to lay a washer between the rings of the conductors. If the copper wire is stranded, then it must first be soldered.

Connecting wires with a terminal block

The connection of wires with a low current load can be performed using terminal blocks. Structurally, all terminal blocks are arranged in the same way. Thick-walled brass tubes with two threaded holes on the sides of each are inserted into the combs of the body made of plastic or carbolite. Connected wires are inserted into opposite ends of the tube and fixed.

The tubes come in different diameters and they are selected depending on the diameters of the connected conductors. As many wires can be inserted into one tube as its internal diameter allows.


Although the reliability of connecting wires in terminal blocks is lower than when connecting by soldering, much less time is spent on wiring. The indisputable advantage of terminal blocks is the ability to connect copper and aluminum wires in electrical wiring, as brass tubes are plated with chromium or nickel.

When choosing a terminal block, it is necessary to take into account the current that will pass through the switched wires of the electrical wiring and the required number of terminals in the comb. Long combs can be cut into several short ones.

Connecting wires using a terminal block
with flat spring clip Wago

Terminal blocks with a flat spring clip Wago (Vago) of a German manufacturer are widely used. Wago terminal blocks come in two designs. Disposable, when the wire is inserted without the possibility of removal, and with a lever that allows you to easily insert and remove the wires.

The photo shows a Wago disposable terminal block. It is designed to connect any type of single-core wires, including copper and aluminum wires with a cross section of 1.5 to 2.5 mm 2. According to the manufacturer, the block is designed to connect electrical wiring in junction and distribution boxes with a current of up to 24 A, but I doubt it. I think that it is not worth loading the Wago terminals with a current of more than 10 A.

Wago spring terminal blocks are very convenient for connecting chandeliers, connecting wires in junction boxes. It is enough just to force the wire into the hole in the block, and it will be securely fixed. In order to remove the wire from the block, considerable effort is required. After removing the wires, deformation of the spring contact may occur and a reliable connection of the wires when reconnecting is not guaranteed. This is a big disadvantage of a disposable terminal block.

A more convenient Wago reusable terminal block with an orange lever. Such terminal blocks allow you to connect and, if necessary, disconnect any wires of electrical wiring, single-core, stranded, aluminum in any combination with a cross section from 0.08 to 4.0 mm 2. Designed for current up to 34 A.

It is enough to remove the insulation from the wire by 10 mm, lift the orange lever up, insert the wire into the terminal and return the lever to its original position. The wire is securely fixed in the terminal block.

The Wago terminal block is a modern means of connecting wires without tools quickly and reliably, but is more expensive than traditional connection methods.

Permanent connection of wires

In some cases, when it is not supposed to switch the wires in the future, they can be connected in an integral way. This type of connection is highly reliable, and is advisable in hard-to-reach places, for example, connecting the ends of a nichrome spiral with copper current-carrying conductors in a soldering iron.

Connection of thin wires by crimping

A simple and reliable way to connect wire cores is crimping. Wire strands are inserted into a piece of copper or aluminum, depending on the metal of the wires being connected, and the tube is pressed in the middle with a tool called press tongs.


Crimping can connect both single-core and stranded wires in any combination. The diameter of the tube must be selected depending on the total cross section of the conductors. It is desirable that the conductors fit tightly. Then the reliability of the connection will be high. If in a stranded wire the conductors are interconnected, then it is necessary to develop and straighten them. It is not necessary to twist the wire strands together. The prepared conductors are inserted into the tube and crimped with press tongs. The connection is ready. It remains only to insulate the connection.

Crimping lugs are commercially available already equipped with an insulating cap. Crimping is performed by compressing the tube together with the cap. The connection is immediately isolated. Since the cap is made of polyethylene, it deforms during crimping and is securely held, providing reliable isolation of the connection.

The disadvantage of the connection by crimping should include the need for special press - tongs. Ticks can also be made independently from pliers with side cutters. It is necessary to round the side cutter blades and make a groove in the middle. After such refinement of the pliers, the edges of the side cutters will become blunt and will no longer be able to bite, but only squeeze.

Connection of wires of a larger cross-section by crimping

To connect electrical wires of a larger cross section, for example, in power shields of houses, special lugs are used, which are crimped using universal press tongs, such as PK, PKG, PMK and PKG.


For crimping each size of the tip or sleeve, its own die and punch are required, a set of which is usually included in the set of pliers.

To crimp the tip onto the wire, the insulation is first removed from the wire, the wire is threaded into the hole of the tip and wound between the matrix and the punch. For the long handles of the press tongs are compressed. The tip is deformed, compressing the wire.

In order to choose the right die and punch for the wire, they are usually marked and branded press tongs on the die have an engraving for crimping which section of the wire the die is intended for. The number 95 embossed on the tip means that this matrix is ​​designed for crimping in the tip of the wire with a cross section of 95 mm 2.

Connecting wires with a rivet

It is carried out using screw connection technology, only a rivet is used instead of a screw. The disadvantages include the impossibility of disassembly and the need for a special tool.


The photo shows an example for connecting copper and aluminum conductors. For more information about connecting copper and aluminum conductors, see the site article "Connecting aluminum wires". In order to connect the conductors with a rivet, you first need to put an aluminum conductor on the rivet, then a spring washer, then a copper and a flat washer. Insert the steel rod into the riveter and squeeze its handles until it clicks (this is cutting off the excess steel rod).

When connecting conductors made of the same metal, it is not necessary to lay a split washer (Grover) between them, but put the Grover on the rivet first or penultimate, the last must be an ordinary washer.

Connecting broken wires in the wall

Repairs should begin with a very careful removal of plaster in the area of ​​\u200b\u200bdamaged wires. This work is done with a chisel and a hammer. As a chisel when laying electrical wiring in the wall, I usually use the rod from a broken screwdriver with a sharply sharpened end of the blade.

Connection of copper wires interrupted in the wall

A piece of copper wire is taken, with a cross section not less than the cross section of the broken wire. This piece of wire is also covered with a layer of solder. The length of this insert should provide an overlap on the connected ends of the wires by at least 10 mm.


The insert is soldered with the connected ends. Solder should not be saved. Next, the insulating tube is shifted in such a way as to completely close the junction. If a sealed moisture-resistant connection is required, then before putting on the tube, the soldered connection must be coated with silicone.

Connection of aluminum wires interrupted in the wall

A prerequisite for obtaining a reliable mechanical connection of aluminum wires is the use of a washer type Grover. The assembly of the connection is performed as follows. A grover is put on the M4 screw, then an ordinary flat washer, rings of connected wires, then a simple washer and nut.


Step-by-step instructions for connecting broken wires in the wall are described in the article "Connecting broken wires in the wall"

Connecting wires with push-on terminals

Detachable connection of conductors with the help of captive terminals, which are put on contacts with a thickness of 0.8 and a width of 6.5 mm, are widely used in household appliances and cars. The reliability of fixing the terminal is ensured by the presence of a hole in the center of the contact, and a protrusion in the terminal.


Sometimes the conductors break off, and more often the terminal itself burns due to poor contact, and then it becomes necessary to replace it. Typically, the terminals are pressed onto the ends of the conductors using special pliers. Crimping can also be done with pliers, but there is not always a new replacement terminal on hand. You can successfully use a used one by mounting the terminal using the following technology.

First you need to prepare the old terminal for re-assembly. To do this, holding the terminal with pliers at the place of pressing, you need to spread the antennae that compress the insulation with an awl or a screwdriver with a thin sting. Further, the wire is repeatedly bent, until it breaks at the exit point from the pressing. To speed up, you can cut this place with a knife.


When the wire is separated from the terminal, a place is prepared with a needle file for soldering it. It is possible to completely grind off until the remaining wire is released, but this is not necessary. It turns out a flat area.


The resulting site breaks through with solder. The conductor is also cleaned and tinned with solder using a soldering iron.


It remains to attach the conductor to the prepared terminal site and heat it with a soldering iron. The antennae that fix the wire are bent after soldering the wire to the terminal, since if they are crimped before soldering, the antennae will melt the insulation.


It remains to pull on the insulating cap, put the terminal on the desired contact and check the reliability of fixation by pulling the wire. If the terminal jumped off, then it is necessary to tighten its contacts. A self-made soldered terminal on a wire is much more reliable than one obtained by crimping. Sometimes the cap is worn so tightly that it cannot be removed. Then it must be cut and, after mounting the terminal, cover it with insulating tape. You can also stretch a piece of vinyl chloride or heat-shrinkable tubing.

By the way, if you hold a PVC tube for five minutes in acetone, then it increases in size by one and a half times and becomes plastic, like rubber. After evaporation of acetone from its pores, the tube returns to its original size. In this way, about 30 years ago, I isolated the base of light bulbs in a Christmas tree garland. So far, the insulation is in excellent condition. I still hang this garland of 120 6.3 V bulbs on the Christmas tree every year.

Splicing stranded wires without twisting

You can splice stranded wires in the same way as single-core ones. But there is a more perfect way, in which the connection is more accurate. First you need to adjust the length of the wires with a shift of a couple of centimeters and strip the ends to a length of 5-8 mm.

Fluff the slightly cleaned areas of the pair to be joined and insert the resulting “panicles” into each other. In order for the conductors to take a neat shape, they must be pulled together with a thin wire before soldering. Then lubricate with soldering varnish and solder with solder.

All conductors are soldered. We clean the places of soldering with sandpaper and isolate. We attach on both sides along the conductors one strip of electrical tape and wind a couple more layers.

This is what the connection looks like after being covered with electrical tape. You can still improve the appearance if you sharpen the places of soldering with a needle file from the side of the insulation of adjacent conductors.

The strength of the connected stranded wires without soldering is very high, which is clearly demonstrated by the video. As you can see, the weight of the monitor is 15 kg, the connection can withstand without deformation.

Connecting wires with a diameter of less than 1 mm with a twist

We will consider the twisting of thin conductors using the example of splicing a twisted-pair cable for computer networks. For twisting, thin conductors are released from insulation for a length of thirty diameters with a shift relative to neighboring conductors and then twisted in the same way as thick ones. Conductors must wrap themselves around each other at least 5 times. Then the twists are bent in half with tweezers. This technique increases the mechanical strength and reduces the physical size of the twist.


As you can see, all eight conductors are connected with a sheared twist, which eliminates the need to insulate each of them individually.


It remains to fill the conductors in the cable sheath. Before refueling, to make it more convenient, you can pull the conductors with a coil of insulating tape.


It remains to fix the cable sheath with insulating tape and the twist connection is completed.


Connection of copper wires in any combination by soldering

When connecting and repairing electrical appliances, it is necessary to lengthen and connect wires with different cross-sections in almost any combination. Consider the case of connecting two stranded conductors with different cross sections and number of cores. One wire has 6 conductors with a diameter of 0.1 mm, and the second has 12 conductors with a diameter of 0.3 mm. Such thin wires cannot be reliably connected with a simple twist.

With a shift, you need to remove the insulation from the conductors. The wires are tinned with solder, and then the smaller wire is wound around the larger wire. It is enough to wind a few turns. The place of twisting is soldered with solder. If you want to get a direct connection of wires, then the thinner wire is bent and then the junction is insulated.

Using the same technology, a thin stranded wire is connected to a single-core wire with a larger cross section.


As is obvious from the technology described above, any copper wires of any electrical circuits can be connected. At the same time, one should not forget that the permissible current strength will be determined by the cross section of the thinnest wire.

TV coaxial cable connection

It is possible to extend or splice a coaxial television cable in three ways:
- TV extension cable, on sale are from 2 to 20 meters
– using an adapter TV F socket - F socket;
- soldering with a soldering iron.


Tinsel wire connection
stranded with solid or stranded conductor

If necessary, to give the cord a very high flexibility and at the same time greater durability, the wires are made using a special technology. Its essence lies in the winding of very thin copper ribbons on a cotton thread. Such a wire is called tinsel.

The name is borrowed from tailors. Gold tinsel is used to embroider the parade uniforms of high military ranks, coats of arms and much more. Copper tinsel wires are currently used in the production of high-quality products - headphones, landline telephones, that is, when the cord is subjected to intense bending during use of the product.

As a rule, there are several conductors of tinsel in the cord, and they are twisted together. Soldering such a conductor is almost impossible. To connect the tinsel to the contacts of the products, the ends of the conductors are crimped into the terminals with a special tool. To perform a reliable and mechanically strong connection by twisting without a tool, you can use the following technology.

The conductors of tinsel 10-15 mm and the conductors with which it is required to connect the tinsel to a length of 20-25 mm with a shift with a knife in the manner described in the site article "Preparing wires for installation" are released from insulation. The tinsel thread is not removed.

Then the wires and the cord are applied to each other, the tinsel is bent along the conductor and the core of the wire is tightly wound onto the tinsel pressed against the insulation. It is enough to make three to five turns. Next, the second conductor is twisted. You will get a fairly strong twist with a shift. Several turns are wound with insulating tape and the connection of tinsel with a single-core wire is ready. Thanks to shear technology, the connections do not need to be insulated individually. If you have a heat-shrinkable or PVC tube of a suitable diameter, you can put on a piece of it instead of an insulating tape.

If you want to get a straight connection, then you need to turn the single-core wire by 180 ° before insulating. In this case, the mechanical strength of the twist will be greater. The connection of two cords with tinsel-type conductors to each other is carried out according to the technology described above, only for wrapping a piece of copper wire with a diameter of about 0.3-0.5 mm is taken and at least 8 turns must be made.

Electrical energy has firmly entered our lives. Without it, human existence is unthinkable, electricity will disappear - civilization will collapse. Factories, transport, the information network, in a word, everything rests on it dear. And one of the most important points of all electrical science is knowing how to connect wires reliably and correctly. It will seem to an ignorant person - well, what nonsense, twisted it somehow and it's ready. But no! So we'll talk about the correct connection of wires for different cases of installing electrical networks.

About the main types of wire connections

In this article, we will try to consider almost all types of wire connections that are encountered during the installation of an electric lighting network, when creating power and switching networks. All methods of connecting wires have both their advantages and disadvantages. The most important thing is that there should be reliable contact at the joints. If it turns out to be bad, then the junction will heat up and burn out over time, but this is not so bad. It can even start a fire! So the correct connection of the wires must be taken with all seriousness and responsibility.

So, what are the main ways of connecting wires:

  • twist;
  • soldering;
  • cap terminal;
  • threaded connection;
  • terminal blocks;
  • crimping;
  • rivets;
  • welding.

Let's consider each of them separately.

Twisted wire connection

Connecting wires by twisting a few years ago was almost the most important type when installing internal networks of buildings, and even now it is not abandoned.

Features of creating this connection:

  1. A knife and pliers are enough for the job.
  2. It is strictly forbidden to twist a copper wire with aluminum, as well as wrap one wire around another.
  3. When you still need to twist the copper wire with aluminum, then the copper core needs to be soldered. Use TOC as solder and rosin as flux. No acid-based fluxes!
  4. When installing internal networks in junction boxes, it is allowed to connect up to six wires in one twist and with different cross sections.
  5. When it is required to twist a stranded wire, then the place of its connection must also be tinned.
  6. It happens that there is a need to build up the wires, then they do this: they clean each one by two or three centimeters and twist it, wrapping it around one another. Each wire must have at least two turns. If possible, then you can solder the twist. And in the end, the whole thing is insulated with electrical tape in three layers.
  7. If you need to twist wires with a cross section of less than a millimeter (switching), then the ends are stripped by two or three centimeters and five or six turns are made on the twist. After twisting, it is bent in half to reduce dimensions and increase strength.

But at high power, the twisted wire connection does not hold loads. The twist will heat up, because of this, the wires will oxidize, and the contact on the twist will disappear.

Connecting wires by soldering

In the process of soldering, metals that are in a solid state are connected by solder, which, in molten form, flows into the gap between them. Connecting wires by soldering is considered one of the most reliable ways.

Consider soldering copper single-core wires:

  • The insulation is removed from the ends of the wire and the surface is cleaned of varnish, if the wire is covered with it.
  • Next, they make a simple twist, two wires wrap around one another or make a tap.
  • Then a flux is applied with a soldering iron and the joint is soldered with solder.
  • Use rosin or soldering oil as a flux, and TOC lead-tin solder or tretnik as solder.
  • If you solder stranded wires, then, having removed the insulation, they must be fluffed up, inserted one into the other and wrapped with thin wire, and then everything is exactly the same.
  • After soldering, insulation is applied.

The process of soldering aluminum wires is as follows:

  1. Soldering aluminum wires occurs after the ends of the wires are connected with a double twist. There should be a small gap between the wire strands.
  2. The wire connection is heated with a blowtorch or gas burner. The heating temperature should be such that the solder begins to melt.
  3. Solder is heated in a flame and rubbed into the wire joint, filling the gap with solder.
  4. Use F-64, FIM or FTBf - A as a flux, and TOC or Braze Tec as a solder.

Wire connections with push-on terminals

The connection with ring terminals is usually done on wires that have a cross section of less than one millimeter. This is a very common method. Almost all electrical wiring of transport is connected in this way. Yes, and in household appliances there are enough similar connections. Now on sale there are a lot of different cap clamps, such as "U" 3.7 - 4.75, "P" 2.8 - 6.4, "B" 2.8 - 6.4, "O" 3.7 - 5.

It is not difficult to fix the terminals on the wire:

  • It is necessary to strip the end of the wire - five to seven millimeters, put on it an insulator that comes with the terminal, and crimp the wire with special antennae.
  • There are two pairs of antennae on the terminal, the first one crimping the core of the wire, and the second one - the wire with insulation.
  • An insulating cap is put on the crimped terminal for connecting wires. If there is no special crimping, then pliers can be used.
  • For reinsurance, connecting the wire to the terminal can be soldered, but this is not necessary.

Ring terminals, only large sizes (1.25 - 3А.О, 1.25 - 3YS.U, etc.), are used to connect wires in industrial electrical installations. They are pressed with the help of special crimps. You can’t invent “gags” there, because poor-quality contact can create big troubles.

Wires on threaded connections

Although soldering is a reliable method of connection, it is laborious, so it is better to use threaded connections. In a similar way, wires are connected in sockets and switches. Making a screw connection of wires is simple: you need to remove the insulation from the wire, about a centimeter or one and a half, if necessary, make a ring, then twist the wire to the connection point with a screw with a washer and a grover.

If you have to connect two wires, then perform the following actions:

  1. First, remove the insulation from the ends of the wire and clean the metal core to a shine (you can scrape it with a knife).
  2. Then the rings are rolled up. They should be slightly larger in diameter than the diameter of the bolt that connects them.
  3. We put a washer on the bolt, then two rings and again a washer, then a grover and clamp it with a nut.
  4. So you can connect wires of different sizes.

And if you want to make a connection between copper and aluminum wire, then put a steel washer between the rings. Copper and aluminum oxidize when they come into contact. And if there is no steel washer, the twist contact will disappear.

This method also has a drawback. Bolted connections must be tightened from time to time. Especially if there is a wire with an aluminum core in the twist. Aluminum has a certain fluidity, and no matter how reliable the contact is, it will weaken over time, and if it is not tightened, the twist will heat up, the wire will oxidize and the contact will disappear.

Connection by terminal blocks

Connecting terminal blocks are mainly used in electrical installations where many wires must be connected at once. For example, you can easily connect aluminum and copper wires.

They are different types and sizes, made from various materials:

  • The base of the carbolite terminal block is made of insulating material - carbolite (does not burn, charred at high temperatures), and brass tires are inserted inside. The wires are fixed with steel bolts, and through the transparent cover you can always observe the quality of the connection.
  • There are terminal blocks with spring contact, they are used for wires of small sections, mainly for switching wire connections. When clamping the wires, the spring plate will prevent the thin core from breaking. The pad body is made of non-combustible polyamide material.
  • Terminal blocks for connecting wires, the body of which is made of polyethylene, are convenient for installation, they are easily cut into separate sections. True, they cannot be used where there is even a slight heating. Polyethylene begins to melt at low temperatures.

Terminal blocks have two types of fasteners: screw and DIN rail. Connecting wires through the terminal block is very simple:

  1. The insulation is removed from the ends of the wires - about ten millimeters.
  2. Unscrew the screws on the terminal block, insert the wires on both sides and tighten the screws back.
  3. When clamping the screws, you must work carefully so as not to transfer the wire with the screw and not to break the thread from the screw.

Crimped wire connection

There are cases when it is necessary to connect the wires in an integral way. Then they use pressure. The very essence of crimping lies in the fact that under the action of a compression force, the sleeve and the wire that is in it are simultaneously deformed. There are several types of crimping work - this is either local indentation or continuous compression.

The connection of wires by crimping is carried out as follows:

  • When it is required to crimp aluminum wires, due to the fact that they are covered with an oxide film, the wires are cleaned to a shine and treated with a special lubricant. You can use quartz-vaseline lubricant. It will not allow an oxide film to form, and the conductivity will be better.
  • Copper wires are lubricated only with technical vaseline. This is done so that the cores are not damaged during operation. During compression, the lubricant will be squeezed out, and there will be no increase in contact resistance due to the lubricant.
  • For crimping, special sleeves are used. Wires are inserted into the sleeve, and the joint should be in the middle. Making two indentations, we compress the sleeve on both sides.
  • It happens that it is necessary to connect the wires only on one side, then the wires are inserted into the sleeve and everyone does the same. After crimping, the connection is isolated.
  • If it is possible to connect copper and aluminum wires, then use a copper-aluminum sleeve.

For proper crimping, it is best to use hand-operated PMU pliers, and for a quality connection, use GA, GM, GAM, GML sleeves.

Connecting wires with rivets

The connection of wires with a rivet is very similar to the threaded one. Only if the bolt can be tightened or untwisted, then in the case of a rivet, the connection is one-time. Work with a riveted joint is done with a special tool - a riveter. There are different models of riveters: 001, 0050, 0400 reinforced, 004 with 90 degree rotation, two-handed Master 0710.

The rivet connection is done like this:

  1. Special rivets are used for connection.
  2. The insulation is removed from the wire, two or three centimeters, and rings are made.
  3. Then a grover, a washer and wire rings are put on the rivet, then a washer again.
  4. The whole thing is inserted into the riveter and the riveting process is performed.
  5. If aluminum and copper wires are connected, then a steel washer must be put between them.
  6. Always leave a spare wire so that in the event of a connection failure, it can be redone without any problems.

Connection of wires by welding

Every electrician with experience knows that the connection of wires by welding has the most reliable contact, or rather not even a contact - a single monolith. When melted, the wires become one whole.

Making the connection of two wires by welding is not particularly difficult:

  • First you need to remove the insulation from the ends of the wire, optimally - somewhere around five to seven centimeters. Then we twist the strands into a twist and bite off the end of it with side cutters.
  • Direct welding takes place with carbon electrodes. If you could not buy the original ones, then it is not difficult to make them from carbon-graphite brushes from a commutator motor.
  • Feed the mass to the twist (you can use the crocodile clip) and touch the end of the twist with the electrode. From touch, an electric arc will occur, which will fuse the wires into a single whole.
  • If a ball appears at the end of the twist as a result of reflow, then the connection is made with high quality.
  • The arc burning time should be no more than two seconds, otherwise the heating temperature will damage the wire insulation.
  • When choosing at what currents the welding will take place, consider the cross section of the wire and the thickness of the twist. The thicker the twist, then apply more current.
  • When welding wires, use a welding machine or an inverter. The latter is preferable, since the inverter has a fairly large range of smooth current adjustment.

Connecting wires by banding

The connection of wires by banding is used both in conjunction with other types of connections, and independently. The procedure for connecting the wires is simple. The insulation is removed from them and these sections are connected to each other. Next, the connection is tightly wrapped with a soft wire of the same material as the wires to be connected.

That, perhaps, is all about the basic wire connections. Let everyone choose what he likes. Some need to connect faster, others need to be more reliable. But remember one more thing: before you start working with the wires, make sure that they are disconnected and there is no voltage on them. Use proper tools and protective equipment when working!