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

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.

Connecting sockets

Usually a separate line is allocated to the sockets. The box contains three cables of two or three conductors. Each wire is painted a different color. As a rule, brown is the phase, blue is the neutral conductor, and the yellow-green wire is ground. One way or another, in the box all the wires are connected by color, forming groups.

Once the conductors are separated by color, they are folded, stretched, and adjusted to the same length. Don't cut too short - leave a 100mm margin so that you can re-connect if necessary. Having chosen the appropriate connection method, you need to connect the wires.

In old houses there is no grounding, which means there will be only two wires. Sometimes the wires in the cable are the same color. To determine where the phase is and where the zero is, you need to use an indicator screwdriver to determine the phase.

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.

Soldering tips

Another way to use the tip is to solder it. To do this you need:

• stripped copper cable;
• tip designed for soldering. It is distinguished by a hole near the flat part and a thinner wall;
• bath of molten tin;
• a jar of phosphoric acid;
• a jar of soda solution.

Carefully! Wear protective glasses and gloves!

In order to solder the tip, the cable is cleared of insulation along the length of the tubular part and inserted into the tip. Then the tip is successively immersed in orthophosphoric acid, in molten tin for a time sufficient for the acid to boil away and the solder to flow into the tip. This is checked by periodically briefly removing it from the solder. After impregnating the tip and cable with solder, the tip is dipped in a soda solution. This is done to neutralize acid residues. The cooled tip is washed with clean water and is ready for further work. Such a tip can be connected to aluminum busbars and lugs without the use of adapter washers.

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.

Welding fastening

To create the most reliable connection of the conductors after twisting, they are additionally secured by welding. The technology for making such a contact is very similar to soldering, only here a welding machine is used instead of a soldering iron.

In terms of quality and reliability, the welding method fully meets all regulatory requirements for creating electrical contact.

When creating a connection by welding, the conductors are twisted and their tip is welded. The resulting metal ball provides a very reliable connection of the wires. At the same time, reliability is due not only to the creation of high electrical characteristics, but also mechanical ones.

The main disadvantage of this type of wire connection is the presence of a welding machine and devices for such work. In addition, it is necessary to strictly adhere to the rules of working at height and fire safety.

Sequence of welding wires:

1. We strip the conductors from insulation by 60-70 mm.
2. We clean the cores mechanically (sandpaper).
3. We twist the wires, and its length must be at least 50 mm.
4. We fix the welding grounding contact on top of the twist.
5. Lightly touch the bottom of the twist with the electrode. Wire welding occurs very quickly.
6. After the contact ball has cooled, we insulate it.

As a result of such actions, an almost solid conductor is obtained, and the contact node will have the lowest transition resistance.

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.

What is a junction box

Everyone knows that the wires from the panel do not run in a straight line, but are distributed among the rooms. Electrical wiring outlet points are mounted in each of them: socket, switch, light bulb.

To facilitate the distribution procedure, there are distribution boxes. Each wire in a wire connector is laid according to long-established rules. The wiring is laid under the ceiling, departing about 15 cm from it. The cable, which is led to a certain point, must extend perpendicularly from the main power line. A box will come in handy to hide all the connections.

There are two types of such boxes:

1. Internal - in this case, the entire device is hidden in the wall of the room and only the cover is brought to the surface, so that later an electrician can easily access the connected node.
2. The external type of boxes allows you to install it directly on the wall of the room.

Distribution boxes can be different in shape: rectangular or round, but still, each of them has four outlets. Sometimes there are devices with additional holes. Each outlet has a fitting or thread for attaching a corrugated hose. This state of affairs is excellent for repairing or replacing electrical wiring.

Distribution boxes come in different shapes. Source kogalym.kembrik.pro

Pros of using a junction box:

• Easy access to components in case of breakdown or for checking voltage;
• Most often, it is at the connection point that electricians make mistakes, but in the distribution box it is easiest to check all the nodes;
• Such boxes protect premises from possible fire;
• Boxes also help save money on purchasing multi-core cables.

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.

Crimping

The connection is made using a special sleeve corresponding to the size of the wiring bundle. The sleeve must be made of a material similar to the cable material.

To crimp the product, press pliers are used, with the help of which the sleeves are crimped. At home, some people clamp the sleeve with pliers, but it has been found that such a connection will be weak and unreliable.

Instructions on how to connect the wires this way:

• Based on the length of the sleeve used for the work, remove the insulating material from the cables;
• twist the wires into a common bundle and place in the sleeve;
• crimp the connector using press pliers;
• insulate the resulting connection with heat shrink or electrical tape.

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.

Self-clamping terminal blocks WAGO

In addition to terminal blocks with bolts, there are also terminal blocks with clamps. They are more expensive than usual, but they allow the connection to be made much faster, especially in connection with the new requirements of the PUE and the ban on twisting.

The most famous manufacturer of such terminal blocks is WAGO. Each terminal is a separate device with several holes for connecting wires, each of which is inserted into a separate wire. Depending on the version, it connects from 2 to 8 conductors. Some types are filled inside with conductive paste for better contact.

They are available for both detachable and permanent connections.

The stripped wire is simply inserted into the terminals for a permanent connection and spring tendrils fix the wire inside. Only hard (single-core) wire can be used.

In plug-in terminals, the wire is clamped using a folding lever and a spring clamp, making it easy to connect and disconnect wires.

Since the wires do not touch each other, the terminals allow you to connect wires of different sections, single-core to stranded, copper to aluminum.

This method of connecting conductors has proven to work best at low currents and is most widespread in lighting networks. These terminals are small in size and easily fit into adapter boxes.

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.

Removing insulation

Before connecting the wires in any of the eight known ways, the electrician will have to carry out preparatory work, namely, clean the core from the protective film. For the job you only need a mechanic's knife. Anyone can do this operation, but you need to be careful not to damage the wiring core. Therefore, you need to listen to the recommendations of experienced electricians and follow all their advice:

• The cable is placed on a table or flat board;
• Press firmly onto the board with your finger;
• The knife is pressed into the insulation at an angle;
• When removing the insulating ball, the wire should move, but not the knife;
• Having made a circular cut, the sheath is easily stretched and removed from the cable.

Electricians use strippers to strip insulation from cables.
Source yandex.ru Modern electricians use a stripper to remove the protective layer. This tool can be mechanical, semi-automatic or automatic. Its advantage is that the vein remains unharmed after the operation.

PPE

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

• C connecting

• And insulating

• Clip _

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 a cap or twist them directly with the PPE itself, is discussed in detail in the article “PPE cap for twisting wires.”

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.