home › Problems › Connection of three wires through a terminal block. Features of connecting the power cable to various elements of the electrical network. Connecting wires with a rivet

Connection of three wires through a terminal block. Features of connecting the power cable to various elements of the electrical network. Connecting wires with a rivet

Modern life cannot be imagined without electrical appliances: TV, computer, food processor, washing machine, iron, ironing unit, heater, fireplace, coffee grinder, kettle, refrigerator, etc. Well, it’s absolutely impossible to imagine our life without electric lamps, which help us live comfortably in the evening, morning and night.

When entering a house at night, our hand first reaches for the switch. We vaguely imagine how people used to live without electricity. But in order to use electricity in our apartments, houses, garages, offices, it is necessary to supply this same electricity.

Electrical installation

Electricity is supplied to consumers through wires. It is important to know how to connect wires for this purpose throughout the apartment. Electrical installation of wires in apartments and houses is done based on what and where will be placed in the apartment, where lamps, lamps, floor lamps and all kinds of electrical appliances will be needed.

In order to install sockets and switches so that life is trouble-free, electrical installation must be carried out competently. The most common damage caused by current flowing through wires is usually an open circuit. This trouble usually manifests itself at the places where the wires are connected (twists, terminals, clamps). With such a breakdown, the consequences can be disastrous. Let's look at how to connect the wires correctly. There are some peculiarities here. Failure to comply with certain rules can lead to malfunctions in the electrical system and even fire.

How to connect copper wires

Copper wires can be connected in any way - twisting, soldering, screwing, terminal blocks, etc. Switching from aluminum to copper wires improves the quality of connections. Since 2001, risers have been prescribed to be made only with copper wires and to switch to the same conductors everywhere. approved for use by consumers with a previously known, constant, guaranteed power. For sockets that provide operation of household appliances, where the load is constantly changing, only copper cables and wires are used. In construction, aluminum is used for external electrical wiring (underground cables, overhead lines, etc.) according to existing standards. Today, many houses are still equipped with aluminum wiring, and no one is going to convert it all to copper. But during renovations, for example, changes in the location of sockets occur in apartments. Here it is necessary to remember that contact of these two materials is unacceptable.

Branch squeezes

To branch from a whole wire, branch clamps are used. Electricians affectionately call them “nuts” because of their similarity to the walnut body.

They are arranged as follows: these are two steel plates in which there are grooves for conductors and they are compressed by four screws, and between them there is also a flat plate that separates the copper and aluminum wires. Such models are available for both home and outdoor use. They are mainly used for draining into apartments from an aluminum riser.

How to connect two wires?

The simplest thing is to twist the wires and fix them by soldering, but this takes a long time. It’s easier to use a terminal block where the twist is inserted and tightened with one or two screws. In this case, it is important to apply pressure with a flat plate so as not to cut the wires. When there is no such plate, it is necessary to solder or put a thin-walled tip on the twist - this prevents the destruction of the wires in the terminal. Soldering is carried out mainly on soft stranded conductors, and this leads to mechanical stress, displacement of the wire and breakage at the end of the tinned section.

Moving away from simple twisting

Anyone who wants to do something with electrical wiring on their own: install a socket, switch, asks themselves the question of how to connect the wires? Previously, they simply twisted two wires (or more) and insulated them, but this was often unsafe and clumsy.

The situation is changing for the better every year. When connecting rigid single-wire conductors, they are fixed with caps, soldering, spring terminals, welding, and screw clamps. In mass construction, connections were previously fixed with plastic caps. Now they are widely used and available to everyone. Inside the caps there is a special gel that prevents oxidation, or a conical spring that is screwed onto twisted connections, like a thread. Spring caps are used for a certain number of wires: two 4 sq. each. mm or four 1.5 sq. mm and no more.

Nowadays a newer three-wire circuit is used, and it is safer than a two-wire one. The new implemented scheme is when no current flows through the protective conductor in operating mode, and therefore the connections made do not experience stress.

Nowadays, for electrical installation work, flexible, multi-core PVA is preferred (“P” - wire; “B” - insulation and sheath of PVC plastic compound (vinyl); “C” - connecting), which is produced in accordance with GOST 7399-97. Designed for connecting electrical appliances, household and similar machines to electrical networks with rated alternating voltage up to 380 V and for 380/660 V systems).

Isolating connections

How to connect two wires, ensuring tightness? There is insulating tape for this. According to the PUE, insulation with tape must be done in at least three layers, both cotton and vinyl.

Cotton tape is more heat resistant. It can withstand 70-80 degrees, vinyl is less stable and flows at 50-60. But over time, cotton material loses its water-repellent properties and begins to absorb water. In this regard, for greater tightness and heat resistance, the inner layer of insulation is made of fabric, and the outer layer is made of vinyl.

Spring terminal connection

How to connect copper wires to aluminum? Spring terminals are very good for home use. The stripped wire is inserted into the hole and there it is secured with a spring. Such devices are available for soft and hard wires. In this device, it is easy to connect copper and aluminum wires because they do not contact each other, and this eliminates electrocorrosion. Moreover, the gel inside eats up the oxide film on the aluminum. You can connect wires of different diameters and only the number for which the terminals are designed. When connecting more than two wires (maybe of different cross-sections), not only spring terminals, but also ordinary terminal blocks are suitable.

Terminal block connections

Professional electricians most often use They have many insulated sockets with screws (usually two). We put a wire under one in the socket, and with the other we press the comb, which connects all the sockets of the block together. The required number of cells is cut off with a knife or hacksaw.

Very comfortable single clamp pads. The two wires inserted into the hole are secured with a screw. There are terminal blocks that use one screw to clamp two wires placed in parallel at once.

Another very convenient option involves fixing the wires not with a screw, but with a special lever. The terminal blocks are manufactured in such a way that they do not require additional insulation. It is impossible to touch live parts. Their degree of protection is high and equal to IP20. Another line of protection is the plastic housing of the junction box.

Connecting wires with terminal blocks

To connect several conductors (as many as you like), it is easier to work with a terminal block. This is a copper strip with holes and screw clamps. Such structures can be mounted in several units in distribution cabinets. With this design it is very easy to connect the wires in the junction box. This design is especially good for rigid conductors. But the terminal blocks must be firmly fixed in the junction box so that they do not touch each other.

How to connect wires during mixed installation, when they are hidden in wall grooves and behind plasterboard structures with built-in lamps? A flexible wire is used for such light sources. In this case, the quality of the connection of flexible wires should be treated especially carefully.

Junction box options

Wiring, disconnection is the connection of wires in order to distribute current flows. Twisting wires with their further desoldering, welding or without it, is desoldering. Connecting wires or cable cores to terminals and connectors is a disconnection.

Metal boxes must be grounded. These boxes are used only when laying electrical cables in metal pipes, for example, in wooden houses.

Connection of wires in the box

For ease of control of connections, they are made in junction boxes. Any craftsman knows how to connect the wires in a box. Typically, terminal blocks are located inside the distribution box. Box models are available with different numbers of inlet and outlet holes. The size of the box is selected according to the number of wires and their cross-section. Above in the text there are recommendations for choosing the method of connecting the wires. They are all equal and have their own advantages and disadvantages.

For example, a method such as soldering takes too much time to connect even two wires. Instant connection is provided by spring terminals. They are good for everyone: compact, reliable, but they are intended only for single-wire conductors (there are models for multi-wire conductors, but they are used to connect one rigid wire with one flexible one) and for a strictly defined number of them (it is impossible to make another branch when all the places are occupied ).

The wires in the box are connected according to their purpose: phase, common and ground. For installation, a three-core or two-core cable is used, in which the cores are marked with different insulation colors. As a rule, the purpose of the wires is tied to their color: phase - white, common - blue (blue), ground - yellow-green. In any case, how to connect 2 wires (by color) is decided by the master in a specific situation. The main thing is that he understands the issue well.

How to connect aluminum wires

You need to know that aluminum is not only fragile and can break after several bends, but also softens from the slight heating of the contacts when current flows, and flows out from under the screw. In this case, the pressure weakens significantly, and the temperature rises even more.

The ideal rule for an installer: assembled today, tightened tomorrow, and again a week later. In the future, another check with a tightening is arranged every six months. This is the answer to the question of how to connect aluminum wires. But it is advisable to inspect screw connections and copper wires at least once every two years. The wires in the junction box must be connected so that they are accessible for repair or inspection. These rules exist to avoid electric shock to people and eliminate the possibility of fire. Violations of them increase the likelihood of accidents, which can lead to death.

Headphone problem

How to connect headphone wires if they are broken? How to solve the problem correctly so that it is accurate and quality is not compromised? The wiring here is very thin. Simply twisting them together will ruin the quality of the perceived sound. Solder? But to do this, you need to get rid of the varnish that covers the wiring. It is necessary to remove it, but the wires are very thin and it is not easy to strip them with a knife - they break.

So, which wire connection method should you choose? Each method has its pros and cons. Each of the masters knows how to connect the wires correctly, and does it in a way that is more convenient, familiar and easier for him. There will be no problems if the work is done efficiently and conscientiously. It is not for nothing that it is believed that the safety of electrical wiring in the house depends on the decision of how to connect the wires correctly. Therefore, it would be useful to think through all the options and repeat again.

So how do you connect the wires? We take four-hundred-grit sandpaper, drip rosin onto it, place one wire at a time on the rosin, and with a soldering iron and solder we begin to carefully remove the varnish from the wire. After running it two or three times, we will see that it has come off and the wiring has become loose. Then we do the same with the rest of the wiring. That's it, the ends of the wires are prepared, they can be soldered, connecting to each other according to color.

Junction boxes perform a very important function. They ensure the distribution of electrical wires between points of consumption, i.e. switches, lighting fixtures and sockets.

Have you decided to install the devices listed above yourself? Then you need to thoroughly understand the features and order of connecting cables, as well as the basic methods of connecting them.

For a better understanding of the process, this event will be considered in several stages: from preparing the necessary materials to connecting electrical appliances using the example of an outlet, a two-key switch and light bulbs. First, you will learn about the basic methods of connecting cables and wiring features

Wire connection methods

There are several methods for connecting electrical wires. You can choose the most convenient and suitable option for your case.

Prices for cables and wires for construction and repair

Cables and wires for construction and repair

The first stage - getting ready for work

First of all, we prepare everything that is needed to connect electrical appliances to the box. Set includes:

cables 3x2.5, VVG;
cables 2x2.5, AVVG;
switch with 2 keys;
fastenings;
lighting;
socket;
round nose pliers;
roulette;
wire cutters;
pliers;
flat screwdriver;
hammer.

Second stage - make the markings

At this stage, we mark the installation locations of electrical appliances and the routes for wires. This way we can calculate the required amount of materials for installing the system.

The third stage - we begin installation

First turn off the electricity supply.

We connect the wires to the junction box. As a rule, cables are laid in grooves. Small nails or special plastic staples are used to secure the cables. If the work is carried out in a wooden house, the wires will be supplied through special mounting boxes.

Important note! You should try to lay the wiring so that the cables do not intersect. If intersections are unavoidable, such places must be isolated especially carefully.

The fourth stage - we connect electrical appliances and connect the wires

We insert approximately 10 cm of wire into a distribution box pre-built into the wall or fixed to the base (depending on the model). We remove the general sheath from the cables. Then we remove approximately 0.5 cm of insulation from each core. At this point, we focus on the situation - we remove enough insulation so that the cores can be connected in the chosen way.

The diagram shows an example of connecting electrical wires using terminal blocks.

In the example under consideration, the connection is made using a two-wire wire, in which one wire is a zero, the second is a phase. We connect the socket to zero and. We connect the phase supply wire to the socket and one core of the switch cable.

In our example, the switch is two-key. Each key is responsible for controlling a separate group of lighting fixtures. We connect the second wire of the switch cable to the first button, the third wire is connected to the second button.

The distribution box contains the neutral wires from the socket and light bulb sockets. The power cable is connected: zero is marked in blue, phase is marked in red. Wires are connected to connect each switch button to the light sockets.

Fifth stage - checking the functionality of the system

We turn on the power supply and check the operation of our outlet and. Everything works fine. We did a great job.

Now you know the order of connecting the wires in the junction box and the connection features of each main electrical appliance. Using the information received, you will be able to independently cope with all planned events.

Good luck!

Video - Connecting wires in a junction box

The fact is that in no case should you connect copper and aluminum wires by twisting.
There are several reasons for this. The main one is the problem of oxidation of the aluminum wire in contact with the copper wire - a galvanic couple is formed, which slowly but surely destroys the connection. And the faster the greater the current flows 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, causing the twist to heat up more and more. And if the load is not constant, but episodic, then constant heating-cooling cycles will further worsen the conductivity. Different materials expand differently when heated, and turning the load on and off through such a twist will be tantamount to constantly jerking it back and forth. You understand that this will not lead to anything good.
It’s good if it’s just heating, it can usually be tracked by the characteristic smell of burnt insulation. But a sparking connection, especially near wallpaper or something flammable, can easily develop into a fire.
What solutions exist to solve this problem?

Polyethylene terminal blocks

Here's a thing:

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

We push the wires into it and fasten it with screws:
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I pulled it out specifically for clarity. Together with the insulation it will look like this:

Each segment can be cut off. It would seem like an ideal option. But there is a nuance (c)
Although these nuances and shortcomings are a carriage and a small cart, do not be fooled by the simplicity.

In general, it is advisable not to use such terminal blocks. If you use it, then only with single-core wires and to connect 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

The pads are made of hard black plastic. Already better.
Have a removable cover:

And this is the internal structure:

Unscrew, insert the wire, clamp.

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

.
This allows stranded and aluminum wires to be clamped. However, it is advisable to check aluminum ones at least occasionally for looseness of the pressure. I saw the pads themselves for currents of 25A and 40A.
The inconvenience is that it can’t be cut or divided, either buy a bunch of small ones (I haven’t 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 773 series and their copies)

Or they are also called express terminals. Like these ones:

Very convenient things. I stripped the wire, pushed it all the way inside, and it was done:
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Inside there is a pressure plate (blue arrow) and a small tire (orange) made of tinned copper:

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

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

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

The same terminals, but transparent:

They are no different except for the dye. Well, in transparent terminals it is more convenient to see the wire - whether it is pushed in completely or not.
Plastic is non-flammable and 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 for original WAGO terminals only.
Rexant terminals (manufactured by SDS Group) use a different spring steel, which relaxes when heated. Accordingly, the maximum current is limited; it is not recommended to use it except for lighting.

Here's a test in which they held 50A and didn't 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 222 series terminals with levers. I have only seen the Vagov ones, they don’t produce others.

For particularly difficult cases, when there are several types of wires of different thicknesses, aluminum, copper, etc.

Raise the lever:

We push the wires in, lower the lever:

If necessary, you can lift the lever, pull out the wire, and insert another one. And so many, many times. An excellent thing for those circuits whose wiring can change a lot of times.
They eat everything. Current - up to 32A. Inside there is a plate that presses against the common bus and is connected to a lever.

Cunning design, in general.

The shank is tinned copper, as usual:

Cost: from 5 to 15 rubles.

Scotch-lock, ScotchLok, electrical connector with mortise contact.

This is for low current (network, phones, LED lights, etc.).

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

After which it is snapped into place with pliers or any pressure tool. No, of course there is a special tool, but I don’t see the point in it - it is small pliers with flat jaws.
SCS and network installers especially love them for their simplicity, cheapness, water resistance, and the absence of the need to remove insulation.

Inside there is 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:

The knives cut through the insulation and press firmly to the wire. There is also a version for two cables at once, and the plates are slightly thicker - quite suitable for lighting:

Of course, they are disposable and maintenance-free. It needs to be replaced - a piece of the cable with them is bitten off, and a new one is installed.
Cost: from 1 to 4 rubles per piece.

For high currents

For such cases there are sleeves:

At the top is a sleeve-connector for aluminum and copper cables, at the bottom is a universal tinned copper:

A wire (or several) is inserted inside, the sleeve is crimped with a special tool. Unfortunately, some bad person got his hands on my pincers, so I won’t show them. I found this image on Google:

And this is what the crimped sleeve looks like:

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

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

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

About stranded wires

There is also a situation when you need to connect a single-core wire to a stranded one:

No, in general you can tin it and clamp it like a single core. But there is an easier option:

They are called NSHVI - Insulated Pin Sleeve End. The meaning is simple:

We select its diameter to match the cross-section of the wire, twist it lightly so as not to frizz, 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 connections without fear that the wires will break off, the contact will be broken, or anything 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.

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

But there are also things that are fundamentally wrong.

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

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

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

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

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

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

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

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

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

Do not clamp multi-core wires in the sleeve. You may be unlucky and something you already know about will happen.

It is important to choose the correct sleeve size for the diameter of the wire, otherwise it may fall out or break if pinched.

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

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

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

TB Series Terminal Blocks

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

The inside consists of two screws and a plate:

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

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

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

Self-clamping terminals (WAGO, REXANT 773 series)

They look like this:

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

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

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

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

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

Here are exactly the same, but transparent terminals:

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

WAGO 222 Series Terminals

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

These terminals have levers:

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

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

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

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

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

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

WITH unifying

AND insulating

Z pressure

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

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

The cores are inserted into this cap and twisted together.

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

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

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

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

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

They can connect both monocores and stranded wires together.

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

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

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

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

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

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

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

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

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

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

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

Always choose the right terminal blocks for your car.

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

There is also a fairly old type of connection, such as terminal blocks. ZVI – insulated screw clamp.

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

Here are their technical characteristics (current, cross-section, dimensions, screw torque):

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

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

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

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

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

Surprisingly, the lowest value is obtained for screw terminals.

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

Copper and aluminum connection

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

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

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

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

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

GML sleeves are most often used for joining copper wires. Deciphered as:

G Ilsa

M single

L narrowed

For connecting pure aluminum - GA (aluminum sleeve):

To switch from copper to aluminum, special adapters GAM:

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

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

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

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

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

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

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

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

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

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

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

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

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

Welding and soldering

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

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

What if there is no voltage or generator nearby?

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