Review of methods for connecting electrical wires. Wire connectors: types and purpose. Rules for connecting wires Rules for connecting wires and cables

Knowledge of modern technologies and methods of working with electrical fittings, is it really necessary? Yes, you need to know how to connect electrical wires correctly.

This can be useful during installation and installation of any power supply systems. Is the wiring burned out, does the lighting fixture need to be replaced, or new equipment needs to be installed. Such knowledge may not be necessary, but it would be better to know all the common methods of connecting electrical wires

Application in terminal block circuits

Terminal blocks are electrical products made of non-conducting material, inside of which a conductive sleeve is inserted, which has a pair of screws at opposite ends. They serve to secure the wire. An excellent choice for implementing a modern way of connecting wires.

When choosing a reliable connection of wires, it is important to remember: terminal blocks are produced with different holes for many cross-sections.

This method is almost always used for connections in junction boxes of any type, during installation, installation of wall and other lamps. It is suitable for. It is easy to mount a network using such fittings; you just need to insert the bare ends into the holes and, using moderate force, securely tighten the screws. The wire itself should not be crushed. Having figured out how to properly connect electrical wires using terminals, it is worth exploring other equally reliable methods.

Terminal method rating: Excellent fastening quality. Their prices are reasonable. Quite quick and easy installation. A good opportunity to connect different conductors, for example, aluminum and copper.

It is not recommended to connect aluminum and stranded circuits with blocks. This is due to the high fragility of aluminum wires and the great flexibility of the stranded wire conductors themselves. But overall a decent method.

Spring terminals

Quick installation of electrical networks is sometimes simply necessary. For example, install temporary lighting on a balcony, terrace, gazebo. Wago spring terminals are an excellent product for such work. A modern and of course reliable way to connect wires. Although they are new to the electrical accessories market, installation using spring terminals is quick and, importantly, convenient.

The main difference between the use of the Vago terminal blocks themselves: they are more convenient to connect any wires in electrical boxes than with twisting. Here, for high-quality installation, a unique clamping mechanism is used, rather than a simple screw. Manufacturers produce both disposable and reusable vagon systems.

1. In the usual version, this product is used for one-time use; during repair work in the future it cannot be restored. It is removed and a new one is installed in its place.
2. Wago reusable terminals are a little more expensive, but with their help you can disconnect the assembled contacts several times, rewiring the circuit to suit your needs. This speeds up the process of repairing or installing permanent and temporary networks. A simple lever-type mechanism provides the advantage that it is possible to carefully but efficiently fix any wire without damaging or squeezing it.

With the help of a vault, it’s easy to do the fastening yourself; you just need to strip the insulation and insert the required wires into the mounting hole. Press the lever. It's important to get it right.

Wago Clamp System Rating: A unique opportunity to combine any aluminum, copper and other conductors. There is an option for connecting multi-core cables simultaneously (two or more).

Wago universal clamps allow you to fix any thin stranded conductor without damaging it. Another plus is the compact size of the pads.

Wago self-clamping terminals

Excellent quality and durability. The Vago type block has a technological hole that provides access for a screwdriver with a voltage indicator. The operation of any power line can be checked at any time. Perhaps one drawback is the considerable cost of the terminals themselves. But this type of wire connection is the most modern and fastest.

Isolation with PPE caps

Deciphering the product is not difficult, connecting insulating clips (PPE). They are ordinary nylon or plastic caps with an internal lock.

The simplest type of connection of wires, it is carried out after twisting the conductors themselves, the cores. Caps are often used to connect wires in junction boxes and to mark connections with the desired color.

Evaluation of the use of such products: Quite low cost of PPE. The use of safe material prevents ignition of electrical wiring. Easy installation, put it on a twist of wires and you're done. These caps have a wide range of colors, which is convenient. Of course, if the wires are not color coded, colored PPE has the ability to determine or simply mark zero, phase and other necessary electrical routes.

There are also disadvantages: Insufficient level of fixation. Multicore wires can be installed only after soldering.

Installation of networks using sleeves

This option claims to be the most reliable connection method. Any load and quality of wires.

Crimping wires with sleeves

The conductive wires are inserted into a special tube - a sleeve, and crimped with a certain force. There is one thing, but... The cross-section of the wires should not exceed the cross-section of the mounted sleeves. Having inserted and crimped the clip, the sleeve is carefully insulated with heat-shrinkable tubing or other insulating materials.

Overall rating. A great way to securely connect wires. The direction of the conductors can be on different sides of the tube or on one side. The sleeves are quite inexpensive. A good way to reliably connect wires to each other.

There are also disadvantages. Disposable use of sleeves, they are not dismountable. To carry out such work you will need a tool: pressing pliers, which are also used as a special tool. They remove the insulation. They have a crimping device in their arsenal, and electrical installation work takes a little longer.

Soldering or welding wires

This method is reliable. Typically, this method of connection in a junction box involves first stripping and twisting the ends, after which they are dipped into heated solder. It is advisable to connect aluminum to aluminum wires by soldering. They are then insulated using a heat pipe or insulating tape.

Evaluation of the soldering method. It gives strong chain contacts and excellent quality, not expensive, it is the most reliable method of connecting electrical wires in a soldered box.

Technological disadvantage. You can't do this without a soldering iron. The speed of work is not high. The connection is naturally not detachable. It follows from this that soldering is done in extreme cases, using more modern connection methods. It has not been popular among masters for a long time because it takes more time.

There is also a less common method for connecting electrical wires, welding. The process is similar, but requires the use of a special welding machine, of course, and certain skills.

Contact twisting method

Not a new, one might say “old-fashioned” method, it consists of spiral twisting of the cores among themselves. The essence of all work is to twist the stripped conductors using pliers, and cover the twisted area with insulation. These are, perhaps, all the ways to twist wires.

Evaluation of this connection method. High speed of all installation work. The cost part is minimal.

Flaw. It is prohibited to connect together strands of different compositions, copper and aluminum wires., oxidation is inevitable. According to the regulatory framework, fastening wires with twists in a junction box is not recommended for use in rooms with flammable materials, high humidity, basements, or in any house built of wood. More details about the twisting method. I definitely recommend watching a video about which is better: twisting or Vago terminal blocks.

Wire clamp "walnut"

Such a device is simply a cable clamp that has two plates inside and several screws for tightening, usually in the corners. It is enough to screw the wires to the plate itself. Then put a carbolite shell on top.

Grade. An excellent option for connecting any electrical wires in a large and medium-sized junction box. Definitely, these types of products are quite convenient and have a high degree of protection. Makes it possible to quickly connect a wire to a thick gauge track without tearing it.

Flaws. Dimensions allow installation only in spacious distribution boxes and switchboards. Over time, the screws loosen.

Tip: When choosing fittings and method, remember the following:

• It is necessary to work only with isolated tools and use protective equipment.
• Be sure to post a “do not turn on” warning sign on the shutdown panel or meter.
• Connect electrical appliances according to the attached instructions.

Having considered the main types of wire connections, you can easily select the right option. And having a simple tool and a diagram at hand, you can mount it yourself. In details

When doing DIY repairs of household appliances or electrical wiring maintenance, any craftsman is faced with the issue of safely creating electrical circuits by connecting wires to each other or connecting them to output terminal blocks.

At the same time, even experienced electricians can make mistakes in ensuring the reliable formation of electrical contacts, which will not appear at the initial moment of operation, but will create a malfunction over time.

The metal of the wire is made for the ideal flow of electric current through it. For this purpose, it is cast from a homogeneous composition of copper or aluminum alloy with a standard cross-section along its entire length.

To create contact, simply touching the surfaces without any effort is enough. The photo below shows that if you place the exposed core of a second wire on one bare section, an electrical connection is formed between them. Through it, a 4-volt battery can make a light bulb from a flashlight glow.

Home wiring is much larger - 220 volts. An erroneous conclusion is drawn from this fact: it is easy to create contact between electrical wires.

Novice electricians simply forget the issue of providing reliable contact resistance for long-term operation of such a connection.

When installing wires, the home master is faced with the need to process:

1. conductor;
2. insulation layer.

These are two interrelated processes that ensure the final result - the optimal flow of electric current through the created circuit.

How to work with wire insulation layer

The dielectric coating protects the metal core from unexpected circuits. When it is violated, leakage currents immediately appear, leading to malfunctions.

The wire insulation layer may be damaged:

• under mechanical influence;
• overheating;
• from solar radiation.

Protection is required from all these destructive factors. Moreover, if necessary, removing the insulation layer to connect the wire, you must not damage the surface of the metal core.

To do this job safely, many tools with cutting edges have been created. Let's consider their use at home.

Electrician's knife

Trade provides a wide range of their designs. Some workers prefer to use knives made by themselves from materials selected according to individual characteristics.

When choosing the right model for your needs, pay attention to them, eliminating the possibility of accidental cuts.

The main condition for proper operation is the orientation of the blade relative to the axis of the wire. The angle formed should be acute. Then the knife will cut off the dielectric layer and at the same time slide along the metal without touching it.

Installing a knife perpendicular to the wire will cut not only the insulation, but also the surface of the metal core. This means it will reduce its cross-section, break the connection, increase the electrical resistance to the passing current, which will cause excessive heating and aging of the dielectric layer.

Deep penetration of a sharp blade into the metal leads to rapid breakage when the wire bends. Such scratches can be identified by careful visual inspection. But who does this?

A lineman's knife is a common tool for every electrician, but not all home craftsmen have good practical skills in removing insulation with it. And experienced specialists can accidentally cut metal and not notice the mistake.

Therefore, industry has long been producing tools adapted for these purposes.

Stripping pliers

Their industrial designs have been produced for quite some time, and the design is constantly being improved. Let's look at them with examples.

Rare sample

Combined pliers were produced for the Soviet electrician's tool kit, allowing:

• Safely cut through and remove insulation from wires with typical cross-sections of 1.5 and 2.5 mm square;
• bite copper wires;
• bend neat rings;
• perform other operations.

They cope with their tasks normally even now, despite their unsightly appearance, slight wear and heavy weight. To strip the insulation from the ends of the wire, it is enough:

• insert it into the corresponding slot;
• squeeze the handles to cut the insulation;
• ensure axial movement of the pliers to the end of the wire.

The surface of the metal core is not damaged and remains in its original condition.

The increased compression force of the handles is compensated by the design of the pliers and does not create malfunctions.

Modern models

They have significantly greater technical capabilities, allowing them to work with wires of small and large cross-sections, both monolithic and stranded conductors.

The case, made of high-strength plastic, has dielectric properties and is lighter in weight. Various regulators and devices are installed on it.

Before work, such a tool must not only be studied, but also correctly adjusted for each cross-section. Otherwise he will create problems.

Pliers and side cutters

Among electricians, there is a category of workers who remove insulation in a similar way. The error of this method is the uncontrolled squeezing force of the handles, leading to squeezing of the metal wire, deformation and destruction of its surface.

This error may occur periodically in a random pattern. It depends on the employee’s experience, condition, attentiveness and other factors.

Removing insulation in this way is dangerous, and the places where it is removed must be carefully checked. Particular attention should be paid to stranded strands.

How to work with metal core wires

Methods for creating electrical contacts through wire are based on the use of:

• screw terminals;
• twists;
• soldering or welding;
• spring compression.

Screw connections

The connection can be made:

• pressing the ring;
• by pressing the core with a screw directly or through washers.

Making rings

When screwing in the screw, the ring of wires should work to compress, not unwind. They must be separated with wide washers on each side of the surface. A wire that is incorrectly clamped into a ring may come out of the fastening during operation.

This method is considered the most reliable and is widely used in energy enterprises.

Using terminal blocks

The metal core is inserted into a special socket and held in it by the tightening force of a screw through the surface of a spring steel washer or its threaded end.

With this method, it is important to maintain the nominal value of screw screwing force. Weak twisting leads to the wire being pulled out of the terminal (you need to check it with your hand), and excessive twisting crushes the wire.

Twisting wires

The created contact surface between the cores must cover the cross-sectional area with a margin.

To do this, the twisted ends with the insulation removed are made of a large length, about 10 cm, and they are twisted using pliers quite tightly with an even distribution of turns.

When twisting, the wires should be well crimped and stretched to ensure reliable contact of the surfaces.

Ways to Create an Improved Twist

The contact resistance of the surface layer can be reduced by:

• welding the final section of the connection;
• soldering twisted surface.

Not every home master can use this technology. It requires special equipment - a welding transformer for copper or aluminum, or. Therefore, in home wiring, the twists are immediately covered with electrical tape or insulated with heat-shrinkable tubes.

Typical twist errors

Often, electricians make short ends of the wire, which, under heavy loads, cause increased heating of the contact connection being created.

Insulating caps for connecting wires

The contact is created by compressing the surfaces of each wire with the force of a spiral spring built inside the housing.

Metal wires of the appropriate diameter, stripped of insulation, are screwed into a spiral, creating a twist. The steel spring straightens a little when the ends of the wire are inserted and compresses them into the socket.

Errors in installing wires with PPE caps

Poor connection contact quality occurs from:

• incompetent work of electricians;
• the use of low-quality counterfeits of branded products;
• incorrect calculation or installation of electrical wiring;
• incorrect and protective shutdown devices.

To prevent possible malfunctions, individual craftsmen increase the surface of the twist, having first removed a larger layer of insulation than required and twist it on it. After screwing in the PPE cap, the exposed area is wrapped with electrical tape or covered with heat-shrink tubing, which creates additional compression.

However, such technology is not provided by manufacturers and requires additional actions and time.

Wago terminal blocks

When using them, the electrical contact of the circuit is created by a spring clamp controlled by a special lever.

The wire is inserted with a metal core into the terminal block socket until it stops with the lever retracted, and then fixed in it with a simple action. The created contact connection has an acceptable contact resistance and works well at rated loads. You should not count on its reliable operation under long-term overloads of more than 16 amperes.

The advantage of Vago terminal blocks is the ability to quickly rewire the circuit for its reconstruction. The wires from them in most designs can be quickly and easily removed. However, there are disposable models on sale that do not provide the function of re-breaking the created chain.

This connection method is common among our western neighbors. It is well suited for the DIYer who does everything with his own hands, but does not have sufficient practice in reliably connecting cores in other ways.

Features of connecting a flexible wire

Stranded strands are designed for use in mobile electrical appliances. They withstand bending and twisting well, but do not work well when installed in terminal blocks to create a screw or spring contact.

Under the created compression force, individual wires are deformed, and their overall twist spreads so that the total cross-sectional area of ​​the wire can decrease.

To prevent this process, metal tips with a dielectric insert of appropriate diameters are used. After installing the bare core in them, a small crimp is made, creating electrical contact.

When a stranded wire with such a tip is inserted into the terminal block, it is additionally compressed by fastening a screw or by spring force. As a result, a normal electrical contact is created from all the wires.

Only properly configured protection can prevent the consequences of undetected installation errors when switching on under load:

• circuit breakers,

To supplement the material on reliable connection of wires, in relation to home wiring conditions, the owner’s video “Tips from an Electrician” “Pros and Cons” provides information. We recommend viewing.

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.

When installing electrical wiring in a house or apartment, connecting the wires is the most important point. For trouble-free and safe power supply, you will need a reliable and high-quality connection of wires.

A careless attitude towards connecting wires and cables can lead to very bad consequences. It would seem that there is nothing complicated in connecting the wires, twist them, wrap them with electrical tape and everything is ready, but everything is not so simple... as popular wisdom says "Electrics is the science of contacts", and the connection of wires and cables must be carried out with all responsibility, since the percentage of accidents and damage in power supply systems due to poor-quality connection of wires is very high. No matter how good the electrical contact between the wires is, wire connections have higher resistance, which means they heat up more. And the worse the contact, the more it heats up, which will ultimately lead to melting of the insulation, a short circuit, and then a fire.

In practice, several methods of connecting wires are used, I will tell you about the most common ones.

Connecting wires by twisting

Connecting wires twisted, widespreadeverywhere, but if we turn to the main book of electricians PUE, then according to:

clause 2.1.21 “Connection, branching and termination of cables and wire cores must be done by soldering, welding, crimping or clamping (screw, bolt, etc.)”

As we can see, there is no twisted connection of wires at this point, which means twisting of wires is prohibited. But twists have always been, are and will be used to connect wires when installing electrical wiring. Yes, and well-made twisting can last for decades, but the connection of wires by twisting must be done efficiently. The technology for connecting wires and cables by twisting is quite simple:

• the length of the twist must be at least 4-5 cm;
• The connected wires, stripped of insulation, must be cleaned of the oxidized film, for example, with an ordinary knife or sandpaper;
• It is necessary that the connected wires wrap around each other evenly and tightly, ensuring sufficiently reliable contact.

One “but”, problems may arise when handing over the electrical installation to the fire inspectorate, because... Connecting wires by twisting according to the PUE is prohibited. However, this applies mainly to industrial consumers, retail premises, etc.; a fire inspector will not come to your apartment or private house to inspect it.

Connecting wires by twisting- This necessary measure, when there is nothing else left, it is better to use wire connections using the methods described below.

Connecting wires by soldering

If solder twisted wires, then we get the connection of wires soldering, which guarantees reliable and high-quality contact, which has a fairly low contact resistance, high conductivity and mechanical strength. But it is important to solder the wire connection correctly; for this you need:

• tin the connected wires with rosin (flux);
• the solder should flow into the twist;
• After the solder has cooled, you can sand it with sandpaper, because sharp edges of the solder can pierce the insulation;
• insulate the wire connection.

But such connection of wires by soldering is very labor-intensive and requires certain skills. TO negative sides of soldering wire connections, I would classify:

• need for isolation;
• complexity (not everyone knows how to solder well), and even for those who are good at soldering, doing this, for example, while standing on a stepladder or ladder, to put it mildly, is not very convenient;
• if a mistake was made when connecting the wires, it will not be easy to separate them after soldering, so it is better to leave a larger supply of wires and cables;
• high time consumption.

Connecting wires by welding

Connecting wires welding provides even better electrical contact between wires. But here everything is even more confusing than with soldering wires, since you need to have:

• welding transformer;
• welding skills;
• masks (goggles) for welding, special gloves, electrodes;
• construction hair dryer for heat shrink tube.

Wire connection by welding, you can perform only from homogeneous metals. Such a connection of wires can be found infrequently, our people do not really like difficulties, and many electricians do not like this method of connecting wires due to the large investment of time, but it is worth noting that connecting wires by welding is faster than soldering.

Connecting wires by crimping

Connecting wires crimping, consists of compressing the connecting sleeve (aluminum or copper tube) into which the wires are inserted with special press pliers. The wires are first stripped of insulation to the length of the sleeve, then we place the wires inside the sleeve and crimp it in two or three places for reliability. If the sleeve is much larger than the wires that need to be crimped, then you can stuff the sleeve with additional wires. We insulate the resulting wire connection using crimping tape, or better yet, heat-shrink tubing + hair dryer.

Sleeves for connecting wires by crimping, there are copper, aluminum and copper-aluminum, i.e. Crimping can be used to connect copper and aluminum wires.

Connecting wires using crimping is quite reliable if done correctly. Skills in connecting wires using crimping will also be useful to you when, for crimping NShVI bushings.

The disadvantages include the cost of pressing pliers for connecting wires by crimping and sleeves, the inseparability of connecting wires by crimping, i.e. they crimped the wire in the sleeve and “forgot” about it.

Bolted connection of wires and cables

Bolted connection wires, as a rule, are used when connecting wires made of different metals, that is, if we have one wire made of copper and the second of aluminum, a steel washer must be placed between them.

This connection of wires turns out to be very cumbersome, it is inconvenient to place it in junction boxes and insulate it. Periodic broaching is required.

Connecting wires with screw terminals

Connecting wires screw terminal blocks, as well as bolted, can be used to connect wires made of different metals. This wire connection meets the requirements of the PUE, but requires periodic tightening of screws in terminals that weaken over time, which means the contact itself weakens, which can close over time.

Periodic pulling the screw connection of wires involves, What connection access in the box should always be open, which will not look very nice in an apartment or private house. Also, when tightening the screw, you can damage the wire itself, especially the softer aluminum one. And if you need to connect a stranded wire, then you need to either solder the stripped ends of the wire or crimp it with tubular lugs.

Connecting wires with PPE caps

Connecting wires PPE caps(Connection Insulating Clamps). PPE are plastic caps with a conical spring inside, which, when twisted, compresses and fixes the wires, and the plastic PPE cap itself insulates the connection of the wires and is fire and mechanical protection.

This wire connection is quick and simple; to perform it correctly you need:

• strip the insulation from wires and cables to a length slightly shorter than the length of the PPE cap itself;
• fold them into a bundle, precisely into a bundle, and not twist them;
• use your hands to twist the PPE clockwise onto the bundle of wires;
• tighten the PPE using pliers.

The advantages of such a connection wires and cables are obvious (no special tools required, no need for additional insulation, quick and easy), but there are also disadvantages:

• Do not connect multi-wire wires;
• the quality of such a connection will be worse than those listed above, so I would recommend using these clamps for small loads, for example, in lighting circuits.

PPE caps are divided according to the total cross-section of the wires to be twisted and are designated by numbers from 1 to 5, which indicate the number of wires to be twisted and their cross-section.

Connecting wires with self-clamping (spring) terminals

Well, in conclusion, let’s consider the simplest, most effective, convenient, and most importantly fast connection of wires - self-clamping (spring) terminals. Spring terminals from Wago are widely used, which allow you to connect wires:

• without having any special skills;
• there is no need to purchase special tools (soldering iron, welding transformer, press pliers);
• some Wago terminals have a special paste that allows you to connect copper and aluminum wires and prevents oxidation;
• no additional insulation required;
• quick disconnection of the connection (press the lever and pull out the desired wire).

Wago terminals are produced for connecting wires and cables from 0.75 to 4 sq. mm, the number of connected wires is from 2 to 8. Wago terminals

Wago terminal blocks were invented in Germany. Perhaps the most significant disadvantage is their price, the average cost of a Wago terminal block for 3 wires will be approximately 11-12 rubles, so if there are a lot of distribution boxes, then the total cost of Wago terminal blocks will be considerable. You should not use Wago terminals when installing wiring with loads of more than 16 A. In general, it is better to use them maximum on the lighting line for electrical wiring in a private house or apartment, and choose Wago terminal blocks with a margin of at least a step higher.

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 - a simple and fairly reliable connection;
• soldering - works well if the currents do not exceed the norm and the connection does not heat up to temperatures above the norm (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 are doing it “for yourself” and know how to handle a welding machine well, 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. It is necessary to pack the wires according to certain rules, measure the size of the resulting bundle, and 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. There are sockets of different sizes - for different sizes of conductors, with different numbers of 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 the ability to use a screwdriver. Another important advantage is that you can easily connect wires of 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 joint, 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 of this method of connecting wires. 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 the low mechanical strength of soldering. 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 quick 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 and lighting fixtures, two types of wire clamps are used: series 222 (detachable) with the ability to reconnect or change the connection, and series 773 and 273 - which are called permanent.

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. The maximum cross-section is 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 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 this case, the number immediately following the letters indicates the type of case. “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. With its help, you can connect two conductors with a cross section of at least 0.5 mm 2 (in total they give 1 mm, which meets the minimum requirements - see the table). This cap contains a maximum of conductors, the total cross-section of which should not be more than 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 in 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 used mainly 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, and 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.