Expert overview of all existing wire connection options - from twisting to soldering and terminal clamping

Compact terminal block

Electrical appliances have long become an integral attribute of human life. It is no longer possible to imagine life without them.

Moreover, their number is constantly growing - dishwashers, toasters, microwave ovens, all kinds of gadgets and even sensors that also require power appear in apartments. In this regard, the load on electrical networks has increased significantly, so new, strict requirements are being imposed on it.

The weakest part of an electrical network is the wiring connections. Nowadays, wire clamps are actively used for switching. It is their use that ensures reliability and safety. This publication will talk about the variety of these devices.

When to connect cables

Cable connections will be required in case of poor-quality wiring performed earlier, or due to errors made during installation work. To restore power to the house, you need to connect the electrical wires. You can make a connection in ways that are divided into 2 groups:

1. For the first group, no special equipment is required.
2. The second group already requires certain skills and professional tools.

Work on connecting cables must be carried out in compliance with safety regulations.

Coupling Clamps

Take a tube, drill two holes at its ends, and cut threads into them. The wires are inserted and clamped with bolts. There are screw or screwless terminals.

You can do without bolts, these places are simply compressed strongly with pliers. Most often used for fastening single-core wires with a cross-section of up to seventeen millimeters.

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Types of cables for connection

The most common cable for home electrical wiring is a PVA connecting cable, consisting of two insulating layers.
Copper strands, stranded, twisted along the central axis. The wire is flexible, making it great for a variety of connections. The voltage of connected devices must be up to 380 Volts.

The cross section is selected depending on the load:

• for a current of 6 A, PVA with a cross section of 0.75 mm is used;
• for 10 Amperes - the cross-section is 1 mm;
• for currents of 16 A – 1.5 mm.

In addition to the PVS wire, for connection there are multi-core cables ShVVP, PUGNP, PRS, KG. They are used less frequently for home wiring than PVS.

Types of electrical clamps on terminal blocks

For now, let’s conditionally divide the product into two parts:

• electrical;
• electrical engineering

Different types of terminal clamps differ only in the current load, although it is minimal, it is there. It is worth remembering this when purchasing terminals for your own use. They are one of the components of the second of those named, without which the bonding of conductors will be defective.

Let's start our search for the best terminal connections with home analogues, time-tested and budget-friendly. Here are their names:

• sheath;
• ringed;
• pins;
• in the form of couplings.

In addition to terminals, there are types of wire connections: you can solder, fasten by welding, including the so-called cold welding. But terminals are the fastest and most convenient way to tie.

What is the best way to reliably connect two cables together?

Methods of connecting cables that require equipment and skills in the field of electrical engineering:

• soldering;
• welding;
• crimping with sleeves.

Simple connection methods that do not require tools or knowledge:

• connection using terminal blocks;
• spring clamps;
• PPE caps;
• bolted connection.

The choice of connection method depends on the characteristics of the wires. It is necessary to take into account the type and material of the core, the number of wires, and operating conditions.

With soldering

Soldering is a common method of connecting cables. To work you need a soldering iron, rosin, solder and sandpaper. How to connect wires by soldering:

• stripping of insulation;
• cleaning from oxides using sandpaper;
• the conductors need to be tinned - rosin is placed on the wire, it is heated with a soldering iron until the wire is covered with rosin;
• the conductors are assembled together, bubbling rosin must be applied to them and heated until the solder spreads;
• The soldering area is cooled.

The complexity of the process lies in the availability of professional skills. Do not overheat the solder area or twist it when heating, otherwise the insulation may melt. It is important to ensure high-quality and reliable contact of the wires. Soldering is used in low-current electrical applications.

No soldering

Wires are connected without soldering using special connecting elements. It is also possible to connect the wires by twisting. Twisting is the simplest method that does not require equipment, but this method is also the most unreliable.

It is prohibited to use only a twisted connection according to the rules of the PUE.

Copper

Copper wire can be connected using terminal blocks, Wago clamps (necessarily using special paste), using a bolt, or soldering.

Aluminum

Aluminum wires can also be connected using any method, but with some special features. When connecting, the metal must be manually stripped of insulation.

Copper and aluminum wires cannot be connected directly. The connection point becomes very hot and over time the contact weakens. Therefore, it is better to use terminal blocks, wago, bolt connection or special branch clamps.

How to make the switch correctly

To achieve high quality contacts, it is important not only to choose the right clamps, but also to perform the switching correctly. Follow the recommendations below to avoid common mistakes:

1. Strip the wires using a special tool that cannot damage the wire.
2. Do not forget to remove the oxide film from the surface.
3. Select the correct sleeve that allows you to perform high-quality compression.
4. Make sure to insert the wire into the terminal block - it should go all the way to the insulating layer.
5. Test the connection for strength.
6. Allow a small margin of wire length for convenient installation to avoid mechanical loads on the terminal block.
7. If you use a box with clamps, be sure to maintain a distance between them - this will help prevent a short circuit if they become heated.

Remember that, despite the fact that switching is a relatively safe and uncomplicated operation, work using wire clamps must be carried out exactly in accordance with the above rules. The reliability of switching will determine the level of characteristics of the electrical network, which, in turn, affect the stability of the operation of electrical appliances.

Is it possible to connect cables by twisting?

According to the rules of the PUE, twisting is prohibited, as it does not provide reliable contact. It can only be used in conjunction with another connection method. It is also unacceptable to use twisting to join two different metals.

Stranded and single-core

When connecting multi-core wires, the following rules should be followed:

• strip the insulation by 4 cm;
• unwind the conductors by 2 cm;
• connect to the junction of untwisted conductors;
• twist the wires only with your fingers;
• You can tighten the twist using pliers;
• bare wires are insulated with special tape or heat shrink tubing.

Twisting solid wires is much easier. They need to be stripped of insulation, twisted by hand along the entire length, then clamped with pliers and insulated.

Twisting methods

You can do twisting in different ways. It can be made by branch, parallel or series connection. Also, to improve the reliability of contact, caps and clamps are additionally used.

Correct twisting of electrical wiring in a junction box

When twisting, you need to follow the following procedure:

• cut off power to a house or apartment;
• clear the wiring of 4 cm or more of insulation;
• unwind the wires by 2 cm;
• connect untwisted wires to the junction;
• twist the veins with your fingers;
• tighten the twist with pliers;
• insulate exposed wires.

Both single-core and multi-core cables can be connected.

Twisting of different sections

Do not twist wires with very different diameters. Such contact is not reliable and stable. You can twist wires of adjacent sections - for example, 4 sq. mm and 2.5 sq. mm. When twisting, you need to make sure that both wires wrap around each other. A thin wire should not be wound onto a thick one, otherwise the contact will be unreliable. Then you need to solder or weld the joint.

Twist caps

The caps help to reliably insulate the contact point.
The cap is made of fire-resistant material, inside it there is a metal part with threads. Making twists using caps is quite simple - you need to remove 2 cm of insulation and lightly twist the wires. A cap is put on them and turned several times until the metal wires are inside.

With terminal clamps

The contact clamp consists of a screw, a spring washer, a base, a current-carrying core and a stop that limits the spreading of the aluminum conductor. Making a connection using a contact clamp is simple - just strip the ends of the wires by 12 mm and insert them into the hole in the clamp. Contact clamps are used for both solid and stranded conductors.

How to brew twist

After twisting, the wires need to be soldered. To do this, the wires are tinned and rosin is applied to them before twisting. The heated soldering iron is lowered into the rosin; it needs to be passed along the stripped part of the wiring. After twisting, take tin on a soldering iron and heat the joint until tin begins to flow between the turns. This method takes a lot of time, but it is reliable and of high quality.

Terminal clamps and their varieties

We return to various types of clamps, and we will even touch on mounting devices in a separate chapter. And we will start with terminal blocks, which in modern electrics have taken a leading place among the methods of connecting wires.

These devices are good because:

• Dielectric housing that does not require additional insulation;
• Reliable mechanical connection of cores;
• Convenient fixation mechanism (depending on the design);
• Possibility of connecting wires from different metals.

Screw terminal blocks

Wire clamp for chandelier

The photo shows the simplest and most inexpensive solution - a polyethylene terminal with a screw clamp. You can buy them at any hardware store, or find them together with a chandelier.

The one-piece block has several compartments designed for connecting wires. The structure of the cell is quite simple - it consists of a metal sleeve enclosed in a polymer casing.

There are two screws screwed into the sleeve on top, which are responsible for fixing the wires, which are inserted from different sides.

Wire terminal clamp

This product is quite reliable and, if installed correctly, will last a very long time, but there are also disadvantages:

1. Firstly , it is quite difficult to secure a stranded wire, since under the pressure of the screw the hairs move apart and only a certain part is pressed. In this case, some of the conductive wires may be damaged.
2. Secondly , these terminals are not very suitable for aluminum wires, which “flow” under the pressure of the screw, which requires periodic inspection of the connections. If the contacts are not tightened, over time the wire becomes loose, sparking appears, and the resistance and temperature of the connection increases.
3. Thirdly , it is difficult to work with such terminals at height, especially when you have to hang a chandelier, since you need to hold the device, guide the wires into the sleeves and tighten the screw.

Advice! Stranded wires in screw terminals are secured without problems if the ends are first crimped with metal pin lugs.

Screw terminal with clamping plate

There are no problems with fixing stranded wires with clamp terminals with contact pads. Here, the metal is pressed not by the screw itself, but by the plate on which it presses.

It becomes possible to press two wires at once with one screw, but on the condition that they are of the same cross-section.

Self-clamping terminals

Terminal Vago

Self-clamping terminals can be considered the pinnacle of terminal evolution. Wiring installation with their help is convenient and fast. The work can be carried out even by a person who does not have electrical knowledge.

The principle is this:

• The edge of the insulation is removed from the end of the wire, exposing the core by 1.5 cm;
• The desired lever is bent upward;
• The wire is inserted into the hole until it stops;
• The lever returns to its place.

There are other mechanisms that have no levers at all. Connections made with their help will be permanent.

The installation principle is somewhat different - the stripped wire is pushed into the channel, where the pressure plate tightly presses the conductor against the tinned contact plate. When you try to pull the wire back, the plate bites into the metal - the hook principle works.

Screw terminals

All versions of such terminals can be used to connect both aluminum and copper wires.

Attention! Let us remind you that recently the use of aluminum wiring has been prohibited at the regulatory level, however such wires can still be found in old houses and various buildings.

The world's most famous manufacturer of terminals of this type is Wago. The quality of its products is confirmed by many years of use and the most stringent tests on vibration and heat stands.

In all cases, the products turned out to be excellent. Therefore, when buying terminals, pay attention to these products.

Methods for clamping wires in Wago terminals

These switching devices appeared on the market not so long ago and immediately made a lot of noise. The price for them is quite reasonable (on average 25 rubles for a product with three contacts), and electricians were able to significantly simplify their work. At the same time, the reliability of all connections has increased many times over.

The manufacturer has a small instruction on the correct selection of connecting elements:

• The range of permissible cross-sections for single-core and stranded conductors is 0.5-4 mm2.
• The connection of multi-core wires of small cross-section must be done with Cage Clamp clamps - in the photo above it is on the far right.
• For installation of indoor wiring, only 3 types of terminals are used: 222, 273 and 773.

Pluggable terminal

• Wago 222 is a split clamp. Its body is equipped with 2 to 5 levers and the same number of contact channels. It is suitable for single- and multi-core wires, but provided that the metal is sufficiently rigid.

Permanent connection

• Model 273 is one-piece. As you can see, the case only has holes for installing wires. Working with such terminals is very simple and convenient - the connection is completed in a matter of seconds. Most of the time is spent stripping the wires. Only these terminals are disposable.

Self-clamping terminal

• The 773rd terminal is also non-separable. The model is only suitable for single-core wires from 0.75 to 2.5 mm2 and multi-core wires with rigid wires from 1.5 to 2.5 mm2 in cross section.

Optimal connection quality is achieved by removing the oxide film from the surface of the wire and the contact pad. This is done using a special paste that is placed inside the terminal. The composition will remove the existing film and prevent it from forming again.

Clamps for connecting lamps

To connect wires on chandeliers and other lighting fixtures, the company has developed a special series of 224 terminals, shown in the picture above. These clamps are suitable for a variety of metals and wire types. Provide maximum convenience and speed of installation under the ceiling.

These clamps are detachable and have a locking button on the body, designed in such a way that it can be used with one hand. The terminal has two terminals on different sides. The principle of operation of the spring can be seen in the following figure.

Clamping terminal Vago 224 in section

This product has one drawback - high cost. However, considering that connecting an apartment will take no more than two dozen terminals, you can spend money.

Attention! Today, Vago products are very often counterfeited. Buy electrical equipment only from trusted stores, and do not hesitate to ask the seller to present the original passport and quality certificate for the product.

PPE caps – connecting insulating clips

Now let’s look at the PPE spring caps in detail. These clamps have not gained such great popularity among electricians and ordinary people, and there are reasons for this.

Terminal clamp

This device will not be a block, but depending on the model, it can connect up to 8 conductors in one housing.

The outer material is plastic, which has a number of features:

• Does not support combustion even when exposed to open fire;
• Has a high melting point;
• Withstands voltages from 300 to 600 V, which indicates high insulating properties;
• It has high mechanical strength and reliably protects the connection from any damage.

The cap has a cone shape. The outside is corrugated or has two blades for ease of use.

A compression spring of the same shape is installed inside. As was written above, its edges are sharpened in a special way, which allows you to securely fix cores of different sizes.

If we compare PPE with Vago terminals, they will have a couple of obvious disadvantages:

1. Inability to simultaneously connect aluminum and copper wires.
2. Complicated installation that requires special processing of the wires - it is necessary to thoroughly clean the insulation without protruding even a millimeter of the bare part of the wire beyond the cap body.
3. An accurate selection of the cap model for the wire cross-section is required, since the best contact will be in the narrowest place, and if the wires are too thin, there will be increased resistance at the connection point, as when twisting the wires.
4. Sufficient force is required to ensure good contact between the conductors.
5. The cores must be strictly the same diameter.
6. For multi-core wires, this solution will not be the best, since partial damage to thin wires is possible.

PPE caps in distribution box

The cap is installed in the following sequence:

• The wires are exposed from insulation to a length corresponding to the length of the corrugation on the cap;
• Their ends are connected in parallel, without preliminary twisting.
• The cap is placed on top and rotated with force clockwise.
• When connecting three wires, a preliminary twist is made, after which its tip is bitten off.

Operating principle of PPE

The following video will show how to install PPE caps.

There are five types of PPE terminals in total, the difference between which can be seen in the following image.

The difference between PPE caps

Interesting to know! PPE 5 can be used to connect 8 cores with a cross section of 2.5 mm2.

The table also shows the color coding of the models. The majority of manufacturers adhere to it, but there is no single standard, so there may be differences, so be careful when purchasing.

Pay attention to the product labeling (PPE 1 1.0-3.0 and similar). It will help you accurately select the product for the cross-section of your wire.

The first digit of the marking indicates the type of housing, the rest indicate the permissible range of cross-sections.

Methods for connecting wires or cables to each other

The junction of two conductors must meet the following requirements:

• reliability;
• mechanical strength.

These conditions can also be met when connecting conductors without soldering.

Crimping

This method requires special equipment. Crimping of wires with sleeves is carried out for both copper and aluminum wires of different diameters. Depending on the cross-section and material, the sleeve is selected.

Crimping algorithm:

• stripping of insulation;
• stripping wires to bare metal;
• the wires need to be twisted and inserted into the sleeve;
• the conductors are crimped using special pliers.

Selection of a sleeve causes major difficulties. An incorrectly selected diameter will not ensure reliable contact.

Bolted connection

Bolts, nuts and several washers are used for contact.
The connection point turns out to be reliable, but the structure itself takes up a lot of space and is inconvenient to install. The connection order is as follows:

• stripping of insulation;
• the stripped part is laid in the form of a loop with a diameter equal to the cross-section of the bolt;
• a washer is put on the bolt, then one of the conductors, another washer, a second conductor and a third washer;
• the structure is tightened with a nut.

Using a bolt, you can connect several wires. The nut is tightened not only by hand, but also by a wrench.

Terminal blocks

The terminal block is a contact plate in a polymer or carbolite housing. With their help, any user can connect wires. The connection occurs in several stages:

• stripping the insulation by 5-7 mm;
• removal of oxide film;
• installing conductors in sockets opposite each other;
• fixation with bolts.

Pros - you can connect cables of different diameters. Disadvantages - you can only connect 2 wires.

Types of terminal blocks for multi-core and single-core cables

There are 5 main types of terminal blocks:

• knife and pin;
• screw;
• clamping and self-clamping;
• cap-shaped;
• "walnut" type clamps.

The first type is rarely used; they are not designed for high currents and have an open design. Screw terminals provide reliable contact but are not suitable for connecting multi-core cables. Clamp terminal blocks are the most convenient devices to use; their installation does not require special equipment. Cap-type devices are also often used, but unlike clamping devices, caps can be used repeatedly. "Nut" is practically not used.

Terminals in junction box (copper or metal)

Terminals are the most common connection method in a junction box. They are cheap, easy to install, provide reliable contact fixation and can be used to connect copper and aluminum. Flaws:

• cheap devices are of low quality;
• Only 2 wires can be connected;
• Not suitable for stranded wires.

Self-clamping terminal blocks WAGO

There are 2 types of Vago terminal blocks used:

• With a flat spring mechanism - they are also called disposable, since reuse is impossible. Inside there is a plate with spring petals. When installing the conductor, the petal is pressed out and the wire is clamped.
• With lever mechanism. This is the best connector option. The stripped conductor is inserted into the terminal and the lever is clamped. Re-installation is possible.

With proper use, Vago terminal blocks last 25-30 years.

Using Tips

For connection, 2 types of tips and sleeves are used:

• in the first, the connection is made inside the product;
• in the second, two electrical wires are terminated with different tips.

The connection inside the sleeve or tip is strong and reliable. There are also special sleeves for connecting copper and aluminum wires.

Soldering of electrical wiring lugs

The tips are connected to the wiring using a press.
If it is not there, contact can be ensured by soldering. The electrical wire and the tip inside are tinned, the stripped cable is inserted inside.

The entire structure on the contact must be wrapped with fiberglass tape and heated with a burner until the tin melts.

Products: advantages and features

Unlike the products of the French company described above, the German products do not require regular maintenance. Spring screwless terminal blocks from this company allow you to achieve the most reliable connection of wires, regardless of their type and diameter.

The Wago tip has a number of advantages:

1. The connection responds well to vibrations.
2. Due to the constant pressure of the spring on the conductors, it is possible to create a permanent electrical resistance of the connection.
3. Installing the products is simple and quick; no special tools are required.
4. If necessary, multiple reconnections are possible while maintaining the current-carrying core.
5. Open access of the tool taking measurements to the terminal block bus.

“Wago” terminal blocks are made from copper that has been tinned. This approach allows for an increase in the contact patch with a decrease in the electrical resistance of the connection and prevents oxidation of the conductor metals. Filling products with anti-corrosion lubricant is not excluded.

The design of Wago products can be presented in several versions:

1. PUSH WIRE - suitable for permanent connections, characterized by a high level of spring stiffness.
2. CAGE CLAMP - suitable for repeated connections, ideal for connecting flexible wires.

Mount the “Wago” terminal blocks on the wire in the following order:

1. The wires are stripped taking into account the recess in the terminal body. This is approximately 10-13 mm.
2. Install the conductor into the terminal block cavity using pliers.

The installation usually ends with testing the quality of the work.

Connectors for wires and cables

Connectors are special devices that facilitate the connection of two or more conductors. There are screw and clamping mechanisms.

Screw terminals

Used to connect wires of different materials and different diameters. An exception is multi-core electrical wires, which are crimped with special lugs. Also, screw clamps can damage aluminum wires, so it is better not to use them for such material.

Screw terminals

Allows you to connect aluminum and copper conductors together. They are easy to connect.

Power clamp

In such clamps, the stripped conductor is placed in the hole to the end. There it is automatically fixed by a pressure plate. Clamps can be used to secure copper and aluminum wires.

Clips

To install the wire, the clip clamp is placed in a vertical position, the wires are inserted inside, and then the clamp must be moved to a horizontal position. Plus, you can make adjustments.

Spring clamps

PPE caps are used as spring clips. Thanks to them, you can quickly make contact between two wires of similar diameters. It is important to choose the correct clamp, otherwise the contact will be unreliable.

Spring terminals

Wago spring terminals ensure reliable contact quickly and efficiently. However, over time, the spring may weaken or overheat.

Connection clamps

There are two types - electrical and electrical. The only difference is the current load. The connection takes place inside the device.

Couplings

It is made in the form of a metal tube. Used for conductors with a cross section of 0.25-16 mm. The wire is fixed by force crimping. Not used for single-core wires.

The time for twisting wires has passed, the time for terminals has come

Electrical engineering practice will no longer repeat cases where the primitive twisting of two or three wires instead of modern clamps served as a reason for tragedies in the form of fires in housing and at work. They were replaced by terminal clamps for wires.

Reliable single terminals or entire blocks make any circuit connections today durable and strong. Let's consider the domestic and imported assortment of terminals and some of their quality characteristics, methods of fastening wires of any cross-section made of copper or aluminum (duralumin).

Safety Tips and Rules

Only craftsmen with a qualification group are allowed to weld.
Persons who have skills in working with a soldering iron are also allowed to solder. Cables may only be connected in the manner permitted for them. Do not work with damaged wiring. All exposed parts must be insulated.

You can connect the cables in different ways. The choice of connection method is determined by the material, cross-section diameter and other parameters. For electrical equipment to operate correctly, the conductors need to be connected securely. In case of unreliable contact, there is a risk of fire.