When installing or repairing electrical wiring, when connecting household appliances and a host of other works, it is necessary to connect conductors. In order for the connection of wires to be reliable and safe, it is necessary to know the features of each of them, where and when, under what conditions they can be used.

Existing methods of connecting conductors

Connecting wires can be done in several ways:

• welding is the most reliable method, ensuring high reliability of the connection, but requiring skills and the presence of a welding machine;
• terminal blocks - easy to do and quite reliable connection;
• soldering - works well if the currents do not exceed standard values ​​and the connection does not heat up to temperatures above normal (65°C);
• crimping with sleeves - requires knowledge of technology, special pliers, but the connection is reliable;
• use of spring clamps - wago, PPE - are quickly installed and, subject to operating conditions, ensure good contact;
• bolted connection - easy to perform, usually used in difficult cases - when it is necessary to switch from aluminum to copper and vice versa.

The specific type of connection is selected based on many factors. It is necessary to take into account the material of the conductor, its cross-section, the number of cores, the type of insulation, the number of conductors that will be connected, as well as operating conditions. Based on these factors, we will consider each type of connection.

Welding – high reliability in any conditions

When connecting wires by welding, the conductors are twisted and their ends are welded. As a result, a metal ball is formed, which provides a stable and very reliable connection in any conditions. Moreover, it is reliable not only in terms of electrical characteristics, but also mechanically - the metal of the connected wires after melting forms a monolith and it is impossible to isolate a separate conductor.

Welding - it is important to heat the metal, but not melt the insulation

The disadvantage of this type of wire connection is that the connection is 100% permanent. If you need to change something, you need to cut off the fused piece and do it all over again. Therefore, for such connections, a certain supply of wires is left in case of possible alterations.

Other disadvantages include the need for a welding machine, appropriate electrodes, flux and operating skills. In addition, welding takes a lot of time, it is necessary to protect surrounding objects, and it is also inconvenient to work with a welder at height. Therefore, electricians practice this type of connection in exceptional cases. If you do it “for yourself” and know how to handle things well welding machine, you can practice on scraps. The main trick is to not melt the insulation, but to weld the metal.

After cooling, the welding site is isolated. You can use electrical tape, you can use heat shrink tubing.

Connecting wires by crimping

To crimp wires, a special aluminum or copper sleeve is required - it is selected based on the size of the twist (bundle diameter), and the material is the same as for the conductors. The bare wires, stripped to a shine, are twisted, a tube-sleeve is put on them, which is clamped with special pliers.

Both sleeves and pliers are different, there are several types. Each of them has its own rules of use (the number of wires that can be packed in a sleeve), which you need to be well versed in. Wires must be packaged according to certain rules, measure the size of the resulting bundle, adjust it to the requirements. In general, a rather dreary task. Therefore, this type of wire connection is mainly used by professional electricians, and more and more often they are switching to spring clamps.

Terminal blocks

One of the simplest and most reliable wire connections is through terminal blocks. There are several types, but almost all of them use a screw connection. Available with sockets different sizes- for different sizes of conductors, with different amounts pairs - from 2 to 20 or more.

The terminal block itself is a plastic case in which a metal socket or plate is sealed. A bare conductor is inserted into this socket or between the plates and clamped with a screw. After the screw is tightened, you need to give the conductor a good tug to make sure it is tightly clamped. Due to the fact that the connection points remain uninsulated, the terminal blocks are used in rooms with normal humidity.

The disadvantage of such a connection: due to the ductility of metals - especially aluminum - the contact weakens over time, which can lead to an increase in the degree of heating and accelerated oxidation, which again leads to a decrease in contact. In general, the connection of wires in screw terminal boxes must be tightened periodically.

Advantages: speed, simplicity, low cost, does not require any skills, except perhaps the ability to use a screwdriver. Another important advantage is that you can connect wires without any problems different diameters, single-core and stranded, copper and aluminum. There is no direct contact, so there are no risks.

Soldering

First, about soldering technology. The connected conductors are stripped of insulation, cleared of the oxide film to bare metal, twisted, and then tinned. To do this, the conductors are heated with a soldering iron and applied to rosin. It should cover the joint completely. Tinned wires are twisted first with your fingers, then pressed using pliers. Instead of tinning, you can use soldering flux. They wet the wires well, but after twisting.

Then, in fact, the soldering process begins: the joint is heated with a soldering iron or narrow torch. When rosin or flux begins to boil, take some of the solder onto the soldering iron tip and bring it into the soldering zone, pressing the tip against the conductors. The solder flows to fill the gaps between the wires, making a good connection. When using a torch, solder is simply added little by little into the torch.

Next, after the soldering area has cooled, according to the technology, it is necessary to wash off the remaining flux (they accelerate oxidation), dry the connection, cover it with a special protective varnish, and then insulate it with electrical tape and/or heat-shrinkable tubes.

Now about the advantages and disadvantages this method wire connections. In low-current systems, soldering is one of the most reliable methods of connecting wires. But, when installing electrical wiring in a house or apartment, it is criticized mercilessly. The thing is that solder has a low melting point. When large currents periodically pass through the connection (this happens if the circuit breakers are incorrectly selected or faulty), the solder gradually melts and evaporates. Over and over again, the contact becomes worse and the connection heats up more and more. If this process is not detected, the matter may well end in a fire.

The second negative point is low mechanical strength rations. It's the tin again - it's soft. If there are a lot of wires in a soldered joint, and if they are also rigid, when you try to pack them, the conductors often fall out of the solder joint - the elastic force is too great, which pulls them out. That is why it is not recommended to use soldering connections when wiring electricity: it is inconvenient, time-consuming and risky.

Spring clamps for connecting wires

One of the most controversial ways to connect wires is using spring clamps. There are several types, but the two most common are wago terminal blocks and PPE caps. Externally and in terms of installation method, they are very different, but both designs are based on a spring, which creates strong contact with the wire.

There is controversy about this spring. Opponents of using wago say that the spring will weaken over time, the contact will become worse, the connection will begin to heat up more and more, which, again, leads to an even more rapid decrease in the degree of elasticity of the spring. After some time, the temperature may rise so much that the body (plastic) will melt, but what can happen next is known.

Spring clamps for electrical wiring - popular connections for wires

In defense of using spring clamps to connect wires, if they are used according to manufacturers' recommendations, problems are very, very rare. Although there are many fakes of both wago and PPE, as well as a sufficient number of photographs of them in melted form. But, at the same time, many people use them, and, under normal operating conditions, they work for years without complaints.

wago wire clamps

They appeared on our market several years ago and made a lot of noise: with their help, the connection is very fast and easy, and at the same time has high reliability. The manufacturer has specific recommendations for using this product:

Inside these devices there is a metal plate, which ensures the proper degree of contact. The shape and its parameters of the plates were specially developed and tested. The tests were carried out on a vibration stand for many hours, then heated and cooled. After which the electrical parameters of the connection were checked. All tests were passed “excellent” and branded products always perform “five”.

In general, the range of Wago products is very wide, but for installing electrical wiring or connecting home appliances, lighting fixtures, use two types of wire clamps: series 222 (detachable) with the ability to re-close or change the connection and series 773 and 273 - which are called one-piece.

Detachable

Spring clamps for electrical wiring Wago 222 series have a certain number of contact pads - from two to five - and the same number of locking flags. Before starting the connection, the flags are raised up, the conductors stripped of insulation are inserted into them (all the way), after which the flag is lowered. At this point the connection is considered complete.

Wago wire connectors - connection methods

If necessary, you can reconnect the connection - lift the locking flag and remove the conductor. Convenient, fast and reliable.

The 222 Vago series can be used to connect two or three, even five conductors made of copper or aluminum (you can connect different metals in one terminal). Wires can be single-core or multi-core, but with rigid wires. Maximum cross section- 2.5 mm 2. Soft stranded wires can be connected with a cross-section from 0.08 mm 2 to 4 mm 2.

One-piece

There is another type of clamps that does not provide the ability to redo the connection of wires - series 773 and 273. When using these terminals, the work is generally done in seconds: the stripped wire is inserted into the appropriate socket. The spring present there clamps it, ensuring contact with the plate. All.

These spring loaded wire clamps can be used to connect solid aluminum or copper wires with a cross-sectional area from 0.75 mm 2 to 2.5 mm 2, stranded with rigid wires - from 1.5 mm 2 to 2.5 mm 2. Soft stranded conductors cannot be connected using such connectors.

To improve contact, the wires must be cleaned of oxide film before connecting. To prevent oxidation from continuing, wago manufacturers also produce contact paste. The inside of the clamp is filled with it and it itself corrodes the oxide film, and then protects the wires from oxidation in the future. In this case, only heavily oxidized, dark conductors need preliminary stripping, and the clamp body is filled with paste.

By the way, manufacturers say that, if desired, the wire can be pulled out of the clamp. To do this, grab the wire with one hand, hold the terminal box with the other and rotate them back and forth with a small range, in opposite directions, stretching them in different directions.

Clamps for lamps (construction and installation terminals for lamps)

For quick and convenient connection of lamps or sconces, wago has special 224 series terminals. With their help, you can connect aluminum or copper wires of different sections and types (single-core or stranded with rigid wires). The rated voltage of this connection is 400 V, rated current:

• for copper conductors - 24 A
• 16 A for aluminum.

Cross-section of connected conductors from the installation side:

• copper 1.0 ÷ 2.5 mm2 – single-core;
• aluminum 2.5 mm2 – single-core.

Cross-section of connected conductors on the side of the chandelier/sconce: copper 0.5 ÷ 2.5 mm2 – single-core, stranded, tinned, crimped.

When connecting copper wires, it is necessary to use contact paste, and aluminum wires must be stripped by hand to bare metal.

This product has two disadvantages. The first is that the price of original terminals is high. Secondly, there are a lot of fakes at a lower price, but their quality is much lower and they burn and melt. Therefore, despite the high cost, it is better to buy original products.

PPE caps

PPE caps (which stands for “connector insulating clips”) are very easy to use devices. This is a plastic case, inside of which there is a spring that has a conical shape. The conductors, stripped of insulation, are inserted into the cap, and the cap is turned clockwise several times. You will feel that it has stopped scrolling, which means the connection is ready.

How to make a wire connection using PPE

These conductor connectors are produced by many manufacturers; they are available in different sizes, for different diameters and the number of connected conductors. In order for the wire connection to be reliable, the size must be selected correctly, and for this you need to understand the markings.

After the letters PPE there are several numbers. Depending on the manufacturer, the number of numbers varies, but they mean the same things. For example, there is this type of marking: SIZ-1 1.5-3.5 or SIZ-2 4.5-12. IN in this case The number immediately following the letters indicates the type of housing. “1” is set if the body is a regular cone, on the surface of which grooves can be applied for better grip. If there is a SIZ-2, then there are small protrusions on the body that are convenient to grasp with your fingers and twist.

All other numbers reflect the total cross-section of all conductors that can be connected using this particular PPE cap.

For example, PPE-1 2.0-4.0. This means that the body of the connecting cap is ordinary, cone-shaped. It can be used to connect two conductors with cross section not less than 0.5 mm 2 (in total they give 1 mm, which corresponds to minimum requirements- see table). This cap contains a maximum of conductors whose total cross-section should not exceed 4 mm 2 .

Connecting wires using PPE caps

In the second version of marking, after the abbreviation PPE there is only a number from 1 to 5. In this case, you just need to remember which of them is useful for which cross-section of wires. The data is in another table.

PPE caps and their parameters

By the way, only copper wires can be connected with PPE caps - aluminum wires, as a rule, are thicker than the maximum allowable for these connectors.

Bolted connection

This connection is assembled from a bolt of any diameter, a suitable nut and one, or better yet, three washers. It is assembled quickly and easily, serves quite a long time and reliably.

First, the conductors are stripped of insulation and, if necessary, the top oxidized layer is removed. Next, a loop is formed from the stripped part, the internal diameter of which is equal to the diameter of the bolt. To make it easier, you can wrap the wire around the bolt and tighten it ( middle option on the right picture). Afterwards it all comes together in this order:

• A washer is placed on the bolt.
• One of the conductors.
• Second puck.
• Another conductor.
• Third puck.
• Screw.

The connection is tightened first with your hands, then with the help of keys (you can take pliers). That's all, the connection is ready. It is mainly used if it is necessary to make a connection between wires made of copper and aluminum; it can also be used when connecting conductors of different diameters.

How to connect aluminum and copper conductors

By the way, let us remind you why you cannot directly connect copper and aluminum wires. There are two reasons:

• This connection gets very hot, which in itself is very bad.
• Over time, the contact weakens. This happens because aluminum has a lower electrical conductivity than copper, as a result, when the same currents pass through, it heats up more. When heated, it expands more, squeezing out the copper conductor - the connection becomes worse and gets hotter.

To avoid such troubles, copper and aluminum conductors are connected using:

• terminal blocks;
• wago;
• bolted connection;
• branch clamps (make connections of wires on the street).

Other types of connectors cannot be used.

How to connect wires of different diameters

If it is necessary to connect conductors of different diameters, twisting should not be present to obtain good contact. This means you can use the following types:

• terminal blocks;
• wago;
• bolted connection.

Connecting wires made of dissimilar metals (a particular and most common case is copper and aluminum) is most often necessary in cases where the home wiring is made of copper conductor, and the entry into the house is made of aluminum.

It happens the other way around. The main thing here is the contact of dissimilar metals. Copper and aluminum cannot be combined directly.

The reasons lie in the electrochemical properties of metals. Most metals, when combined with each other in the presence of an electrolyte (water is a universal electrolyte), form something like a regular battery. For different metals, the potential difference upon contact is different.

For copper and aluminum this difference is 0.65 mV. It is established by the standard that the maximum permissible difference should be no more than 0.6 mV.

If there is a higher potential, the conductor material begins to deteriorate and become covered with oxide films. The contact will soon lose reliability.

For example, the electrochemical potential difference of some other pairs of metals is:

• copper - lead-tin solder 25 mV;
• aluminum - lead-tin solder 40 mV;
• copper – steel 40 mV;
• aluminum – steel 20 mV;
• copper – zinc 85 mV;

Twisting wires

The simplest, but least reliable way to connect conductors. As mentioned above, you cannot directly twist copper and aluminum wires. The only one possible option contact of such materials - tinning one of the conductors with lead-tin solder.

It is very difficult to tin the aluminum at home, but there will be no problems with copper. Enough powerful, a piece of solder and a little rosin, or another flux for soldering copper and copper alloys. Tinned copper and pure aluminum conductors are tightly twisted together using pliers or pliers so that the wires wrap tightly and evenly around each other.

It is unacceptable for one conductor to be straight and the other to wrap around it. The number of turns must be at least 3-5. The thicker the conductors, the fewer the number of turns you can make. For reliability, the twisted area can be wrapped in a bandage made of thinner tinned copper wire and additionally soldered. The twisting area must be carefully insulated.

Threaded connection

The most reliable connection of wires is threaded (bolted). The conductors are pressed against each other using a bolt and nut. To make such a connection, it is necessary to make rings at the ends of the connected wires with an internal diameter equal to the diameter of the bolt.

Just like for twisting, the copper core must be tinned. Multicore wire must be serviced (even if wires of the same metal are connected).

The resulting compound looks like a sandwich:

• bolt head;
• washer (with an outer diameter no less than the diameter of the ring on the wire);
• one of the connected wires;
• second wire;
• washer similar to the first one;
• screw;

The copper core does not need to be tinned, but in this case a steel washer must be placed between the conductors.

A significant disadvantage of this method is its large dimensions and, as a consequence, difficulties with insulation.

Terminal blocks

The most technologically advanced way to connect wires is to use special terminal blocks.

And finally, a few tips that you should take into account in order to protect yourself in the future and not redo the work:

1. For stripping conductors You should not use side cutters, pliers or other tools with a similar operating principle. In order to cut the insulation without affecting the body of the wire, considerable experience is required and still in most cases the integrity of the wire will be compromised. Aluminum is a soft metal, but it does not tolerate bending very well, especially if the integrity of the surface is damaged. It is possible that the wire may break during installation. And it’s much worse if this happens a little later. It is necessary to remove the insulation sharp knife, moving it along the conductor, like stripping a pencil. Even if the tip of a knife removes some layer of metal, a scratch along the wire is not terrible.
2. For tinning copper conductors Under no circumstances should you use acid-containing fluxes (zinc chloride, etched hydrochloric acid, etc.). Even thorough cleaning of the connection will not save it from destruction for some time.
3. Stranded conductors Before installation, it is necessary to irradiate it to obtain a monolithic conductor. The only exceptions are spring clamps and terminal blocks with clamping plates.
4. Washers, nuts and bolts for detachable or permanent connections should not be made of galvanized metal. The potential difference between copper and zinc is 0.85 mV, which is significantly greater than the difference when copper and aluminum are directly connected.
5. For the same reason, you should not purchase overly cheap terminal blocks. unknown manufacturer. Practice shows that metal elements These pads are often zinc coated.
6. You can't use advice protect the direct connection of copper and aluminum conductors with various water-repellent coatings (grease, paraffin). Machine oil is difficult to remove from leather alone. Sun, air, negative temperatures will destroy protective coating much faster than we would like. In addition, some lubricants (especially grease oil) initially contain up to 3% water.

How to connect two aluminum wires to each other? It would seem like a rather banal question, but even here the first answer that comes to mind is not always correct. After all, twisting of wires is prohibited according to the PUE standards, and any wires can be connected only by crimping, soldering, welding and using screw clamps. And we’ll talk about how to do it correctly in our article.

But we propose to start our conversation with a quick analysis of the properties of aluminum wire. This will reveal problem areas and understand possible problems during its installation.

• Let's start with the advantages of aluminum wire. The main one is the price, which is an order of magnitude lower than that of its main competitor - copper.
• Another advantage of this material is its lightness. This conditioned him wide application in power lines where weight is very important.
• Well, the last advantage is its resistance to corrosion. Aluminum is almost instantly coated with a persistent oxide film, which prevents further oxidation. At the same time, this film also has negative aspects - it is a very poor conductor of electric current.

• Then there were only continuous shortcomings. And the first of them is the low electrical conductivity of aluminum. For this material it is 38×106 S/m. For comparison, for copper this parameter is 59.5 × 106 S/m. This results in the fact that, for example, a copper wire with a cross-section of 1 mm2 is capable of passing a current almost 2 times greater than a similar aluminum wire.

• The next significant disadvantage is that aluminum wires have very low flexibility. In this regard, they cannot be used in places where the wiring is subject to repeated bending or other mechanical stress during operation.
• Well, and finally, the instructions say that aluminum has such a bad property as fluidity. As a result of thermal and mechanical influences, it can lose its shape, which has an extremely negative effect on contact connections.

Pay attention! According to the PUE standards, since 2001 it has been prohibited to use aluminum wire for installing electrical wiring in residential premises. This ban significantly reduced the use of aluminum electrical wiring in everyday life.

Methods for connecting aluminum wires

As we said above, aluminum wires can be connected in four main ways - screw or bolt clamps, pressing, welding and soldering. Let's look at the features of each of these types of connections.

Connecting aluminum wires using the compression method

Let's start with the most common connection method - compression. It can be of several types - bolted, screw or using a pressure spring, which is used in Wago terminals.

	Compound aluminum wires each other with the help of this type connection carries with it one drawback. If you use conventional screw terminals, then using a screw you can completely or partially press down the soft aluminum core. This will either reduce or completely destroy contact.
	To exclude this option, the connection should be made through special contact nozzles made of brass. Brass has less elasticity and is more difficult to bend. Therefore, such attachments provide reliable contact and eliminate the possibility of damage to the wire.
	For bolted connections aluminum wire, you should also use special tips. They are attached to a wire or cable using the crimping method and then these lugs are connected using a bolted method.
	As for Wago terminals, everything is much simpler here. This type of connection cannot damage the wire, so such terminal blocks can be used without additional attachments. This somewhat compensates for their higher price.

Connecting aluminum wires using the pressing method

Recently, connecting aluminum wires with a sleeve has become increasingly popular. This is partly due to the widespread use of crimpers or, as they are also called, crimping pliers. This tool allows you to crimp wires of different sections, ensuring fairly reliable contact.

• The connection of wires by crimping is carried out using special sleeves. These sleeves are available in different diameters and materials. To connect aluminum wires, either aluminum or brass sleeves should be used. Copper should not be used under any circumstances, since the connection of these two materials can lead to the formation of galvanic isolation and ultimately the complete destruction of the aluminum conductor.

There are still a considerable number of premises where electrical wiring made of aluminum. At the same time modern systems based on the use of copper as a conductor. That is why the problem of joining wires made of these dissimilar materials is relevant. How to connect copper and aluminum wires will be discussed below.

Electrochemical corrosion

You can often come across statements that it is undesirable to combine copper and aluminum into one whole. From the point of view of material compatibility, these are fair statements. What about combining copper and galvanized or steel and silver? There are many options for metal pairs, and it is difficult to remember which ones are compatible with each other and which ones are not. To simplify the task, there are special tables, one of which is presented below.

Table of electrochemical potentials (mV) arising between connected conductors.

To understand the issue, you need to know what processes occur when different conductors of electricity touch each other. If there is no humidity, the contacts will be reliable in any case. However, in practice, such a situation is impossible, since there is always moisture in the atmosphere, which disrupts the connections.

Every conductor of electricity has some electrochemical potential. This circumstance is used by humans for practical purposes, for example, accumulators and batteries operate on the basis of different potentials.

When moisture gets on contacting metal surfaces, a short-circuited galvanic environment occurs and one of the electrodes is deformed. One of the two metals is destroyed in the same way. Thus, to determine the compatibility of metals, it is necessary to have information about the electrochemical potential of all materials involved in the reaction.

What happens if copper is combined directly with aluminum?

According to technical regulations, mechanical joining of metals is permitted if the electrochemical voltage between the two materials is not higher than 0.6 mV. For example, from the table above, it can be established that in the case of joining aluminum and copper, the electrochemical potential is 0.65 mV, which is significantly higher than when joining the same copper with duralumin (0.20 mV).

And, nevertheless, if you really need it, you can also combine materials that are not entirely compatible, such as copper and aluminum. How to connect copper and aluminum wires will be discussed below.

Overview of connection methods

Several methods are used to connect aluminum and copper wires. Moreover, in each of the described cases, special devices will be needed. Let's consider each type of docking separately.

This type of connection is the most common because it is simple and cheap. If done correctly, a wire connection using nuts and bolts will ensure reliable contact for the entire life of the wiring and electrical appliances. In addition, you can always disassemble the connection, connect additional conductors, etc. Thanks to threaded connection, the relevance of the electrochemical incompatibility of metals is lost, it becomes possible to join aluminum and copper, thick and thin wires, multi-core and single-core. It is important to avoid direct contact between dissimilar materials by making gaskets from spring washers.

To do the job you will need a bolt and nut, as well as a washer (it must be made of anodized steel).

The connection is made as follows:

1. We remove the insulating layer from the wires to a short length (about four bolt diameters). We also strip the conductor, especially if its cores have been oxidized. We form rings from the veins.
2. First, an aluminum conductor is screwed to the bolt in one girth.
3. We put on the puck.
4. Now it’s the turn of the copper conductor. We also screw it in one turn.
5. Next, screw the nut in such a way as to achieve a reliable connection.

Pay attention! If the docking is carried out for use indoors, where technical specifications There is vibration, for a high-quality result you will need an additional nut.

Terminals

There are several options for terminal connections. One option is the so-called “nuts”. Such an unusual name for terminal blocks is due to their external resemblance to nuts. Several types of “nut” terminals are available.

The most primitive model in its design has three demarcation plates inside. The conductors are located between the plates. In this way, direct contact between dissimilar materials is avoided. At the same time, the “nuts” allow you to maintain the supply circuit of the electrical circuit.

To achieve the integrity of the circuit, it is necessary to strip the supply conductor from the insulating layer, unscrew a couple of bolts, install the bare wire between the plates and tighten the bolts again. The insulator must be removed from the outlet ends, and then the wires must be directed into holes located perpendicular to the inlet channel. Next, the conductors are fixed between other delimiting plates.

There is also a more complex model on the market, the design of which is designed in such a way that there is no need for cutting conductors. The fact is that the plates of the device contain teeth, which, when squeezed by bolts, simply tear the insulating layer. The described docking option is considered very reliable.

There is another option for terminal blocks - ordinary blocks. The device is a strip with terminals. To connect two dissimilar materials, you need to strip their ends and route the wires into the terminals. The ends are secured with bolts that are located on top of the terminal holes.

Wago terminal blocks

Connecting copper and aluminum wires can be done using Wago terminal blocks. This device refers to the above-mentioned terminals, however, we should talk about the Wago pads in a little more detail due to their popularity among buyers.

Wago comes in two versions: disposable with a non-removable wire and reusable - with a lever that allows repeated installation and removal of the conductor.

Wago is used for all types of single-core wires whose cross-section is between 1.5 and 2.5 square millimeters. The block can be used in distribution boxes with a current strength of up to 24 amperes. However, in practice it is believed that 10 amperes is more than enough and higher values ​​will lead to overheating.

To connect the conductors, you need to force one of them into the block hole, as a result of which it will be securely fixed there. To remove the conductor from the hole, you will also need to apply force. It should be borne in mind that as a result of removing the wire from the disposable terminal block, the contact may be deformed, so the next time reliable contact is not guaranteed.

It is much more convenient to use a reusable Wago device. Feature such a terminal block - the presence of an orange lever. Using such a device, you can connect or disconnect all types of wires with a cross-section from 0.08 to 4 square millimeters. Acceptable level current - 34 amperes.

To create a connection, you need to remove 8-12 millimeters of insulation from the wire, lift the lever upward, and direct the wire into the hole in the terminal block. Next, return the lever to reverse position, thereby fixing the wire in the terminal.

The only one significant drawback Wago - higher cost compared to traditional terminals.

Rivets

This method of joining dissimilar conductors resembles a bolted one. However, instead of a nut and bolt, a rivet is used, forming permanent connection. In other words, once fixed, it is no longer possible to remove the rivet without damaging it.

To make the connection, we strip both conductors from insulating material, and also bend the wires into rings. Next, we string one of the rings onto the rivet, after that we put on a steel washer, then we string the ring again, but with the second conductor.

The rivet has a head on one side. Now you need to flatten the second side, thereby forming a second cap, which will act as a fastener. The rivet is deformed either with a hammer or special tool, similar to pliers. The method of joining with rivets allows you to obtain a very high-quality connection.

Soldering iron

If desired, you can solder two dissimilar metals. However, this will require compliance with some technological nuances.

As for copper, there will be no problems with soldering, but with aluminum the situation is more complicated. The fact is that as a result of soldering and under the influence of oxygen, an amalgam appears on the metal surface. This alloy film is incredibly chemically stable, which is why it does not form adhesion to solder. To remove the film you will need a solution of copper sulfate, a Krona battery and a piece of copper wire.

On the aluminum wire, we clean the area for soldering, and after that we apply a little vitriol there. We fix the aluminum wire on the negative pole of the battery, and we fix the copper wire with one end on the positive pole, and put the other end in copper sulfate. After some time, the aluminum will be covered with a copper layer, onto which a copper conductor can be soldered.

Connection quality

In most of the previously discussed cases, rigid fastening of conductors stripped of the insulating layer is used. However, when joining copper and aluminum, one important technological nuance must be taken into account: aluminum under the influence of load acquires plasticity, as experts say, it begins to “flow”. As a result of this process, the connection weakens, and therefore the bolts need to be tightened regularly. If you do not tighten the bolts in time, the terminal may simply catch fire due to severe overheating.

There are a number of rules that you can follow to achieve a quality connection:

1. Conductors with multiple cores should not be clamped too tightly. The wires in such wires are too thin, they easily break under pressure. The consequence of ruptures is an overload on the remaining wires, which can lead to a fire.
2. It is important to choose the right terminal taking into account the cross-section of the conductor. If the channel is too narrow, the conductor will not fit, and if it is wide, it will fall out.
3. Brass sleeves and terminals are very fragile, so do not clamp them too hard.
4. You should pay close attention to the markings, which indicate the maximum possible current strength. Moreover, it is better not to achieve this indicator, limiting yourself to no more than 50% load.

Pay attention! It is not recommended to buy unnamed products made in China. Connectors - too much important detail to save on them. It is best to give preference to products from well-known companies (for example, the Swiss company ABB).

Stranded wires

As mentioned earlier, conductors with many cores should not be overly pinched. To connect stranded wires, sleeves or ordinary twists are most often used. We'll talk about these methods in a little more detail below.

Sleeves

The sleeve is a protective cap made of plastic, under which there is a hollow metal tip. First of all, it is necessary to remove the insulating layer from the conductor. Next, the strands are twisted into one whole, and the resulting “pigtail” is directed into the sleeve. Next, the sleeve is crimped (pliers are suitable for this operation). The tip of the sleeve is inserted into the terminal. To increase the reliability of the connection, the sleeve can be treated with solder.

Twist

Among professional electricians, twisting is not respected. However, there are situations when twisting is the most convenient way way out of the situation (for example, to create a temporary connection or in the absence of the necessary materials).

So, twisting of copper and aluminum is permitted only after thorough cleaning of the aluminum surface. If the copper conductor has many cores, all existing wires must be collected into one “pigtail”. The copper also needs to be coated with solder - this will improve contact.

When twisting, it is important to prevent the wires from breaking. It is best to cover the ends with insulating protective caps, which can be purchased at any hardware store.

Pay attention! Twisting is not allowed in rooms with humid air.

So, there is nothing complicated in connecting copper and aluminum conductors. You just need to remember the cost of a mistake: incorrectly connected wires can cause not only failure electrical appliances, but also fire.

Most often, the need to connect aluminum and copper wires arises in the process of replacing or repairing existing electrical wiring. Also, the ability to do this will be very useful if the power cord of any electrical appliance is damaged.

There are several ways to solve this problem. Check out the presented options, choose the method that is most suitable for your case and get to work, observing the requirements of the technology.

We connect the wires by twisting

An additional advantage This option is the ability to simultaneously connect several conductors, the number of which is limited only by the length of the screw.

The method is suitable for connecting cables of different diameters and with different numbers lived You just need to make sure that between the wires different materials there was no direct contact. To eliminate this, a spring washer is included in the connection. Additionally, such washers must be installed to prevent contact of the conductors with the nut and screw head.

The order of connecting the conductors is as follows.

First step. We remove the insulation from the cables. We calculate the required length by multiplying the diameter of the screw used by 4.

Second step. We study the condition of the veins. If they have oxidized, we clean the material until it shines, and then form rings according to the diameter of the screw.

Third step. We alternately put a spring washer, a ring of wire, a washer, a ring of the next conductor and finally a nut on our screw. Screw the nut until the washers are straight.

Useful advice! You can first tin the end of the copper cable with solder. This will eliminate the need to place a spring washer between the conductors.

We make the connection using a terminal block

The method of connecting conductors with special terminal blocks is gaining increasing popularity. In terms of reliability, this option is inferior to the previous one, but it also has its advantages.

Terminals make it possible to connect wires as quickly, simply and efficiently as possible. In this case, there is no need to form rings or insulate connections - the terminals are designed in such a way that the possibility of contact between bare parts of the cables is eliminated.

The connection is made as follows.

First step. We remove the insulation from the connected ends of the wires by about 0.5 cm.

Second step. We insert the cables into the terminal block and secure them with a screw. We tighten it with a little force - aluminum is a fairly soft and brittle metal, so it does not need extra mechanical stress.

Terminal blocks are very often used when connecting lighting fixtures to aluminum wires. Repeated twisting leads to rapid breakage of such conductors, as a result of which practically nothing remains of their length. In such situations, the block comes in handy, because to connect with it, just a centimeter length of cable is enough.

The terminals are also very suitable for connections when laying new wiring is impractical and the remaining length of the conductors is not enough to make connections using other methods.

Important note! The pads can be plastered only if they are installed in a junction box.

Not long on the market electrical equipment and components, modified terminals equipped with spring clamps were presented. Disposable (conductors are inserted without the possibility of their further removal) and reusable (equipped with a lever that allows you to remove and insert cables) terminals are available.

Disposable terminal blocks allow you to connect single-core conductors with a cross-section within the range of 1.5-2.5 mm 2. According to the manufacturers, such terminals can be used to connect cables in systems with currents up to 24 A. However, professional electricians are skeptical about this statement and do not recommend applying loads higher than 10 A to the terminals.

Reusable blocks are equipped with a special lever (usually painted orange) and allow you to connect cables with any number of cores. Allowable conductors to be connected are 0.08-4 mm2. Maximum current – ​​34A.

To make a connection using these terminals, do the following:

• remove 1 cm of insulation from the conductors;
• lift the terminal lever up;
• insert the wires into the terminal;
• lower the lever.

Terminals without levers simply snap into place.

As a result, the cables will be securely fixed in the block. The costs of making such a connection will be more significant, but you will spend much less time on the work and save yourself from the need to use any additional tools.

Making a permanent connection of wires

The main difference between this option and the previously discussed threaded method is the inability to disassemble the connection without destroying the wires. In addition, you will have to buy or rent a special device - a riveter.

Actually, the wires are connected using rivets. Durability, affordable cost, simplicity and high speed getting the job done - these are the main advantages of a permanent connection.

The riveter works on an extremely simple principle: a steel rod is pulled through the rivet and cut. There is some thickening along the length of such a rod. As the rod is pulled through the rivet, the rivet will expand. Rivets available in the market various diameters and lengths, which allows you to select a device for connecting cables of almost any cross-section.

We work in the following order.

First step. We clean the insulating material from the conductors.

Second step. We make rings at the ends of the cables slightly larger than the diameter of the rivet used.

Third step. We alternately place a ring of aluminum wire, a spring washer, then a ring of copper cable and a flat washer onto the rivet.

Fourth step. We insert the steel rod into our rivet gun and forcefully squeeze the handles of the tool until there is a click, which will indicate that the excess length of the steel rod has been trimmed. At this point the connection is ready.

You have become familiar with the basic methods self connection aluminum and copper wires. Each method has its own characteristics, disadvantages, advantages and preferred areas of application. Choose the most suitable option, follow the instructions and very soon all the necessary connections will be ready.

Good luck!

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Video - Connecting aluminum and copper wires