Connecting wires is probably the most critical area of work during installation. electrical networks. The higher the load on the site, the higher the requirements for connecting wires will be - therefore, it is necessary to use the most effective methods, techniques and devices.
We will analyze the most popular ways to connect electrical conductors, paying attention to their advantages and disadvantages. In addition, I will give examples of the implementation of the techniques most commonly used in the installation of electrical networks.
Overview of the main connection methods
Installation without the use of additional parts
The connection of the wires of the electrical network must meet a number of requirements:
- reliable mechanical fixation of two conductors;
- ensuring conduction between two conductors(the higher the conductivity, the better);
- minimization of resistance at the joint;
- no increase in resistance during long-term operation.
Today, when installing electrical networks, a variety of types of wire connections are used, which allow you to implement the above requirements at different levels. They can also be classified in different ways, but for the convenience of analysis, I will highlight only two large groups: connections with and without accessories.
If we need to connect two wires, and we do not plan to use any other devices (except, of course, insulation), then the list of methods will be limited. Wires can be twisted, soldered or welded. These are the three methods we will analyze.
Without the use of special devices, the conductors are mounted as follows:
- Twisting- the easiest, fastest and cheapest way. The ends of the wires are cleaned of insulation, then twisted together in a spiral, after which the bare sections of the conductor are re-insulated.
Main disadvantage such a connection is a gradual drop in conductivity. The contact point oxidizes over time, the heating of the conductors increases, as a result, the reliability of fixation decreases. The greater the current in the network, the higher the risk of fire at the place of twisting, while the residual current circuit breaker is almost guaranteed not to work.
In the modern "Rules for the installation of electrical installations" (PUE of 2009, chapter 2, clause 2.1.21), such an installation method as fixing wires with a twist is absent in principle. If in earlier editions this method could be used for joining wires with a cross section of up to 10 mm 2, then with an increase in the average load on the network, twisting was abandoned. Now it is used only as one of the stages of mounting soldered, welded or other joints.
- wire welding- according to most electricians (I completely agree!) The most reliable method. In welding, the conductors are first twisted to increase the contact area, and then welded using alternating current.
It is very easy to work with copper, but when installing aluminum wires, it is advisable to use a flux to remove the oxide film from the metal surface. The resistance at the welding site remains constant and does not increase over time, so the site will last a very long time.
- Soldering- one more is enough effective method connection installation. When soldering a copper wire, it is cleaned of insulation, the junction is tinned, after which the conductors are twisted. The twisted section is soldered with solder and rosin, while trying to solder the joint without gaps and sagging.
From my point of view, soldering is less reliable than welding. On the other hand, when installing wiring with your own hands, a soldering iron is much easier to find than a welding machine. And the margin of safety for domestic needs at the soldered connection is quite sufficient!
Connection using additional parts
To connect the wires while maintaining the maximum conductivity of the site, a variety of devices can be used. This includes both the simplest crimp sleeves and complex terminals that allow installation in just seconds.
What parts can be used to connect wires?
- Sleeves for crimping. The crimp sleeve is a hollow cylinder made of soft metal. During installation, the wires are stripped, driven together, after which a connecting sleeve is put on their ends. The part is clamped with a special tool, which allows you to tightly fix the conductors and prevent their displacement relative to each other.
- Branch clamps. They are used to form taps from the main conductor with voltage up to 660 volts without violating its integrity. Contact is provided by an anodized steel clamping platform, which is put on the stripped cable section and secured with four screws. The wire connection is protected by a housing made of dielectric material (carbolite or analogues).
- Self-isolating (PPE) caps. A popular fixture that is only suitable for low-current circuits. The PPE cap is a plastic cone with a clamping spring inside. When connecting, the conductors are twisted, after which the cap is screwed onto the twist. Despite the fact that the spring, in theory, should keep the twist from loosening contact, it turns out not very reliable.
- Terminal blocks. A fairly reliable and simple device, which consists of a plastic insulating housing, copper contacts with screw fasteners. When connecting the wire to the terminal, its end is stripped, inserted into the hole in the block and pressed against the contact plate with a screw.
The quality of the connection directly depends on the condition of the terminal block itself. In some cheap varieties, due to the thermal expansion of materials, the thread weakens over time, and the contact has to be “tightened”. Other pads have a risk of breaking the contact if the screw is tightened too tightly.
- Spring terminals (WAGO and analogues). They are used to secure the section as quickly as possible: they removed the insulation from the wire, inserted the wire into the terminal hole - the spring fixed it with sufficient strength. There are also varieties with clamping levers that allow you to securely fix soft metal conductors - these are the ones I use most often.
The main disadvantage of such products is the relatively high price. A high-quality self-clamping WAGO terminal block costs from 7 to 25 rubles, depending on the configuration. If you need to make a lot of such connections, a decent amount runs up.
A few words about copper and aluminum
Describing the methods of installation of electrical networks, one cannot but pay attention to such a delicate issue as the twisting of copper and aluminum wires. Probably everyone who has at least a distant relation to this area knows that it is impossible to directly connect these materials.
There are several reasons:
- temperature deformation. Aluminum and copper have different coefficients of thermal expansion. This means that when the current is turned on, they heat up differently, and cool differently when turned off. As a result, periodic on-off leads to loosening of the connection and a decrease in the contact density.
- Oxidation. Over time, an oxide film forms on the surface of aluminum, which is characterized by poor conductivity. As a result, the resistance increases, and with it the heating.
Yes, both of these factors can be compensated: the first with tight clamps, the second with the use of special lubricants. But let's be honest: who and when does this when equipping the simplest twists?
- Electroplating. Copper and aluminum are a galvanic pair. This means that when these metals are combined, the resulting oxides will decompose into charged ions, moreover, the higher the humidity in the room, the more actively the process will go. As a result of electrolysis, the reliability of the connection will fall - primarily due to the appearance of voids, and then due to the emerging heating.
Taking into account these arguments, I strongly advise against connecting copper wire to aluminum without the use of "intermediaries" - terminals, adapters, clamps and other devices.
Algorithms for mounting basic connections
Method 1. Twisting with soldering and heat shrink tubing
Different ways of connecting electrical wires require a different approach. In this section, I will provide step by step instructions on the design of the most commonly used circuits.
Let's start with the simplest - twisting. Yes, it is not very reliable, but it can be successfully used in low-current circuits. And if you solder the contact point, then you can use the conductors almost everywhere.
| Illustration | Execution technique |
 |
Cleaning conductors.
Using a special tool or a sharp knife, remove the insulation from the ends of the conductor. We need to expose about 25mm of wire. |
 |
Insulation preparation.
We cut off a fragment from a heat-shrinkable tube of the required diameter, the length of which will be approximately twice the length of the section to be joined. We put the tube on one of the conductors and move it to the side so that it does not interfere with us. |
 |
Twisting.
The sections of the conductor, cleared of insulation, are twisted together. When installing single-core conductors, we make sure that they are connected in a spiral, and not one wraps around the other. We first “fluff” stranded wires, then weave the wires together and twist them in a spiral. |
 |
Soldering.
Using a soldering iron on medium heat, carefully solder the joint. When soldering, we make sure that the solder evenly fills the voids between the individual cores in the twist. |
 |
Insulation.
We shift the heat-insulating tube to the soldered or twisted section, so that it completely overlaps it and enters the insulated sections on both sides. |
 |
Insulation seal.
Using a building hair dryer (better) or a regular lighter (worse, but also possible), heat the heat shrink tube until its diameter decreases and it compresses the connection along its entire length. |
Method 2. Installation with pressure testing
The connection of conductors in the junction box can be made by crimping. To do this, we will need special crimp sleeves and a tool that allows you to fix them on the wires.
Mounting instructions using crimp sleeves:
| Illustration | Execution technique |
 |
Removal of general insulation.
With a sharp knife, we cut the insulating casing on the wires brought out into the junction box. We remove the insulation and disassemble the wires by color, collecting them into groups. So it will be much more convenient to work. |
 |
Cleaning conductors.
With a special tool or a knife, we remove the insulating layer of conductors. It is advisable to remove a little less than can enter the crimp sleeve - this will make it easier to insulate. |
 |
Putting on a sleeve.
Conductors that require connection in one group are assembled together without twisting. We put a sleeve on the conductors, pushing its edge onto the isolated area. |
 |
Crimping.
Using a special tool, we crimp the wires. We crimp the sleeve in at least two places, after which we check the strength of the fixation. |
 |
Connection of other conductors.
We repeat the operations for the remaining groups of conductors. |
 |
Insulation.
We put on a heat shrink tube for each group of wires with an installed crimp sleeve. We heat the insulation to seal it along the entire length. |
 |
Installation of the second isolation circuit.
We bend the free ends of the heat shrink tubing. From above we put on pipes of a larger diameter. |
 |
Insulation seal.
As in the first case, we warm up the heat shrink tubes with a hair dryer. By contracting, they will fix the bent ends of the insulation, ensuring maximum tightness. |
Method 3. Twisting with welding
The most reliable type of connection without additional parts is welded. It can be used where the contact point is subjected to severe stress.
You can mount wires in junction boxes by welding as follows:
| Illustration | Execution technique |
 |
Wire preparation.
We bring the wires to the junction box, after which we remove the outer insulation and disassemble them into cores. We clean the ends of the veins, forming sections 50–70 mm long that are free from insulation. We collect the wires by color to facilitate the formation of twists. |
 |
Formation of twists.
We bring all the wires of the same color together, fold them in parallel and bend the edge by about 1 cm. Holding the bent part, we twist the wires in a spiral. To increase reliability and seal the twist, we make the last few turns with the help of pliers. |
 |
Preparation of the welding machine.
You can weld wires with almost any household appliance - there is enough power. For welding, it is desirable to use graphite (special insert, motor brush, battery rod). |
 |
Wire welding.
We install one clamp on the twist in the upper part, with the second clamp with a graphite insert, we weld, starting from the bottom of the twist. At the same time, we make sure that the connection is not overheated and does not begin to collapse. Thoroughly weld all connections. |
After that, it is enough for us to insulate all the stripped sections of the wire. This is done using insulating tape, heat shrink tubing or special caps.
Method 4. Connecting copper and aluminum using a screw
Above, I noted that it is impossible to directly connect copper and aluminum. And yet, sometimes it is necessary to equip a reliable contact of such conductors - for example, when "splicing" old and new wiring.
If we have two solid wires, then the easiest way is to connect them using a clamping screw:
| Illustration | Execution technique |
 |
Formation of end rings.
We clean the ends of both wires by about 30–40 mm. Using round-nose pliers, we make “ears” on both wires. The diameter of the ring should advise the diameter of the screw to be used for the connection. |
 |
Bolt installation.
We use an M4 bolt as a connecting element. We put a washer of such a diameter on the rod under the hat so that it completely covers the end ring of the wire. We put the wire with the ring on the bolt in such a way that when the fastening is tightened, the bent part does not open, but, on the contrary, bends even more. |
 |
Connection formation.
We cover the first wire with a second washer of a suitable diameter. Then we put a second wire on the rod - also with a ring. We cover it with a third washer, and install a grover (spring washer) on top, which will prevent the mount from unwinding. |
 |
Fastening tightening.
We install the nut on top and tighten the fasteners, holding the screw head with a screwdriver. When fixing, you need to tighten the mount tightly, but without undue effort, otherwise there is a risk of damaging the soft conductor. This is especially true for copper stranded wires. |
 |
Insulation.
We isolate the junction using either tape or large diameter heat shrink tubing. When using a heat shrink tube, it is advisable to additionally fix its edges to the left and right of the contact point. |
Method 5. Using terminal blocks
The use of terminal blocks of different types allows not only joining wires made of copper and aluminum, but also makes it possible to create collapsible connections.
The details apply as follows:
| Illustration | Execution technique |
| Conventional terminal block | |
 |
Wire stripping.
We clean the ends of the connected wires. At the same time, approximately 5–7 mm must be released from the insulation - this is quite enough for reliable contact inside the terminal block. |
 |
Preparing the terminal block.
We cut off a fragment from the product with the required number of contacts. We loosen the fixing screws of the terminal block, opening the holes for installing the wires. |
 |
Installation of the first wire.
On the one hand, we insert the stripped ends of the wire into the holes, advancing them so that they do not reach the middle. Tighten the mounting screws with a screwdriver, clamping the wire inside the block. |
 |
Installation of the second wire.
Repeat the steps for the second wire. We make sure that the wires inside the block do not touch each other. |
 |
Completion of work.
We check the reliability of the connection, after which we isolate the contact point, protecting it from moisture and dust. |
| Spring terminal block WAGO 222 | |
 |
Preparation for installation.
We clean the wires intended for installation in the same way as for installation using a terminal block. Raise the clamping lever on the terminal block, opening the hole for installing the conductor. |
 |
Wire installation.
We insert the conductor into the hole, advancing it until it stops. We make sure that the wire does not bend inside the device. |
 |
Conductor fixation.
Lower the clamping lever. In this case, the contact plate inside the terminal block rises, clamping the conductor and securely fixing it inside the device due to spring action. |
Conclusion
A reliable and secure wire connection can be achieved in many ways. The options listed above are quite enough to perform the most common types of work. If you need more information, watch the video in this article or ask a question in the comments!
In the process of installing electrical wiring, especially in residential premises, it is necessary to use technologies for connecting wires and cables. This process requires some skills and knowledge. After all, an incorrect connection can lead to irreversible processes. A disruption may occur general power supply as well as fires. The fact is that a carelessly made connection of stranded wires can lead to a fire, which in turn leads to a threat to life and health of people. Wiring requirements for residential buildings are spelled out in the Rules for Electrical Installations, abbreviated as PUE. The PUE allows the use of electrical wiring in residential premises made only with copper wires. The connection of stranded and solid wires is allowed only by crimping, welding, soldering or using crimps. In clamps, the connection is made mechanically, using screws or bolts and clamps.
Various twist options
non-professional connection. This is a twisting of a stranded wire with a single-core. This type of connection is not provided for by the rules, and if such a connection of wires is discovered by the selection committee, then the facility will simply not be accepted for operation.
The twisting of a stranded copper wire in a steamed box is used as an intermediate operation before soldering or welding the joint, and soldering or crimping is required.
However, twisting is still used, and here you need to know how the correct twisting of stranded wires is performed. It is often used in emergency cases when it is not possible to professionally make a connection, and the service life of such a connection will be short. And yet, twisting can temporarily be used only for open postings so that you can always inspect the junction.
Bad wire connection
There are several types of twists. When twisting, it is necessary to achieve good electrical contact, as well as the creation of mechanical tensile strength. Before proceeding with the connection of wires, they should be prepared. Wire preparation is carried out in the following sequence:
- from the wire, the insulation is removed at the junction. The insulation is removed in such a way as not to damage the wire core. If a notch appears on the wire core, then it may break in this place;
- the exposed area of the wire is degreased. To do this, it is wiped with a cloth dipped in acetone;
- to create a good contact, the fat-free section of the wire is cleaned with sandpaper to a metallic sheen;
- after connection, the insulation of the wire must be restored. To do this, an insulating tape or a heat-shrinkable tube can be used.
In practice, several types of twists are used:
Connecting the wire to the main 
Connection of stranded and solid copper wire - other various connection options.
In detail, about the methods of connecting single-core wires
Professional Connection
Consider various options for a reliable connection according to technology: soldering, crimping, welding and terminal connection of wires. You will refuse unreliable twisting when installing unsoldered boxes and other connections.
Soldering wires
The connection of copper stranded and solid wires by soldering is one of the reliable methods. With this connection, a good electrical contact is created, and the junction is mechanically resistant to tensile loads. This method can be used for: Splicing two broken wires, extending wires, relocating sockets or switches. The wires connected in this way can be used in hidden wiring. If the junction is well insulated, then such a wire is not inferior to a solid section. 
The technology of such a connection is as follows:
- preparation of wires is carried out in the same sequence as before the start of twisting;
- cleaning to a metallic sheen of wire sections;
- solder coating of joints (tinning);
- wires are connected by one of the types of twisting;
- twisted wires are soldered with solder;
- the place of soldering is processed with an emery cloth. There should be no burrs at the soldering point that could damage the insulation;
- the junction is carefully isolated.
The wires connected in this way can be placed under the plaster. For reliability, the junction should be placed in a PVC tube.
welding method
Welding belongs to the category of permanent connections. This type is the most reliable. It is with this method that the connection site acquires solidity. The contact resistance and mechanical strength of the connection section is no different from that of a solid wire. Welding is carried out both on direct and alternating current. 
For professional wire welding Various types welding machines, but the most widely used devices are inverter current. These devices are mobile, they are easily carried on the shoulder of an electrician, they are small in size.
Inverter devices are distinguished by a wide range of operating current regulation. The welding arc easily ignites even at low operating currents, and is stable during the entire welding period.
In addition to a welding machine for welding copper wires, it is also necessary to have copper-coated carbon electrodes.
Welding technology consists of several simple operations. First, the insulation is removed from the wire. Then, according to the technology described above, the wires are twisted. Twisted wires are aligned by trimming their ends. In order not to overheat the wires and their insulation, it is necessary to remove heat during the soldering process. For this, a special clamp is used, which is connected to one of the poles of the welding machine. Welding is carried out by touching the ends of the wires of the working electrode, which is held in a welding holder connected to the other pole of the welding machine.
Crimping
When crimping, the wires are placed in special mounting sleeves, which are made of the same material as the wires. In this case, copper. Then the sleeves are compressed with a special tool. When the sleeve is compressed, the wires are deformed. Deforming, the wires are tightly compressed with each other. With local indentation, the wires are deformed in such a way that their individual points penetrate each other's body. Thus, a reliable electrical contact is created, and the junction becomes mechanically strong. Crimping connects wires that are placed in junction boxes and electrical cabinets.
To perform crimping, special mounting pliers are used. Crimping pliers model PK-16 have gained wide popularity for connecting wires during installation of wiring in residential premises. To connect copper wires, connecting copper sleeves of the GM type are used. They are made of copper and have a red color. 
In order for the junction to not come into contact with oxygen, it is preserved with special technical vaseline. Thus, the junction is isolated from the harmful effects of the environment. The wires will not oxidize and the connection will last long time. The connection point can also be sealed with a heat shrink tube.
Threaded connection
Stranding of stranded wires using the method of braiding and clamping with a bolt This type of connection, the connection of single-core and stranded wires, belongs to the category of detachable connections. For this, special terminal blocks are used, consisting of housings and devices built into them, designed for screw clamping of the wire. It is imperative for a reliable connection to communicate or tin the wire. The most widely used are when connecting end consumers. (lamps and chandeliers) 
Self-clamping terminal block Vago It is used to connect wires with a cross section of not more than 2.5 mm 2. With this type of terminal block, up to 8 wires can be connected simultaneously. They are used to connect wires in electrical cabinets. Mainly used for lighting. In the outlet group for heavy loads, use more reliable connection options.
The electrical network of a single house is a complex system of wires, electrical installations and a protective automatic group. The most vulnerable points are the switching points of two or more conductors.
The task of the electrician is to select and correctly install wire connectors that will be as suitable as possible in terms of characteristics, perform their function perfectly and, most importantly, ensure reliability and safety.
Let's figure out what types of connectors are most often used in everyday life, for what work certain switching devices are suitable, what are the features of their installation. In addition, we provide practical advice on choosing the right type of connector.
Wire connectors are any devices that serve to close / open electrical circuit. These can be electrical installation products - sockets, switches, as well as metal tires and plates, lugs, terminals and terminal blocks - blocks with several sockets.
We will focus on connectors in a narrower sense - on elements that create collapsible and non-separable connections and ensure their reliability and functionality - that is, on all kinds of terminals, terminal blocks and sleeves.
The simplest example of a ferrule for stranded wire. The terminal is a metal sleeve-tube fixed at the end of the conductor using crimping pliers
Terminals are called both metal elements for decorating the ends of single- and stranded wires, as well as small plates inside connecting devices - sockets, terminal blocks, patch panels.
We will send the material to you by e-mail
Old-fashioned methods of primitive twisting of wires with mandatory insulation with the notorious blue tape are long gone. requires a professional approach, which means it is necessary to use materials and devices that meet not only the highest safety requirements, but also simplicity, reliability and attractiveness appearance. One of these devices is the terminals for connecting wires. Today we will talk about how to choose and use them correctly.
Small terminal - the solution to many problems in wiring
How two wires are connected depends on many factors. The metal of the conductor, the thickness of the wire, the number of strands and the type of insulating material should be taken into account. An important factor is the conditions under which the connection will be operated.
There are several main types of connections:
Let us consider in detail the main characteristics of all these compounds.
Features of professional twisting
Twisting is the simplest method of connecting wiring. No special tools are required for work, a knife and pliers are enough. To make the connection strong, experts recommend stripping the cores by at least 5 cm. To make the contact tight, the wires are clamped with pliers and twisted in a rotational motion. After the resulting connection is wrapped in one direction and tightly wrapped with electrical tape. This is the simplest version of such a connection.
Professional electricians have other ways to connect wires with a twist:
Important! If you are using electrical tape, do not skimp on the winding. The insulation should cover not only the twist itself, but also go to the wires for at least a couple of centimeters.
Can be used instead of tape modern material- heat shrink tubing. Before connecting the conductors, heat shrink of the required length is put on one of the wires and then pulled onto the twist. It remains only for a moment to bring a match or a lighter to the tube, it will shrink and tightly fix and isolate the cores.
With reliable insulation, such a connection will last a long time. Its advantage is good vibration resistance, which is good for moving machinery. Electricians do not recommend using this method when connecting wires of different sizes. During operation, excessive resistance heats up the contact point so that the insulating layer can melt. Professionals do not recommend twisting wires with strands of different metals and cables with a large number of strands.
Soldering for perfect conductivity
Not only the flawless operation of the mechanism, but also the safety of its user depends on the reliability and strength of the connection of the conductors. Soldering is one of the most reliable types of connection.
There is a soldering iron in almost every home, and the procedure itself does not take much time.
Rosin is used for tinning, and tin or other fluxes are used as solder. Copper wires are recommended to be soldered with tin or lead, aluminum wires with zinc compounds with tin, aluminum or copper. Before soldering, the wires are stripped and twisted using one of the above methods. After that, rosin and flux are applied to the place of twisting with a soldering iron.
Important! The heated solder should fill in all the bumps and holes in the twist.
After soldering, the connection is insulated with tape or heat shrink. The hardest thing to solder is aluminum wiring. It oxidizes rapidly at high temperatures and does not form a strong bond with the solder material. For a strong connection, you need to use tinning.
If the soldering is done correctly, the contact should be good. The only drawback is the fragility of the connection; with vibration and mechanical loads, it will not last long.
For professionals: welding
Welding allows the metal of the conductors to merge and provide optimal resistance. This contact is strong and durable.
You can use arc, spot, torsion, plasma, ultrasonic and beam welding.
Such work requires experience and skill, so the welding method is a tool for professional electricians. They use graphite and carbon electrodes, operate stationary, and use high-precision, voltage-regulated inverters. This technique is not suitable for domestic conditions, only experienced welders know how to properly connect the wires to each other in such a complicated way.
Important! All welding work must be carried out in a protective helmet. It will be very difficult for a beginner to achieve a high-quality connection of conductors.
After welding, the contact point is also insulated with tape or heat shrink.
Crimping with sleeves
Returning to more accessible methods for connecting wiring for domestic use, it should be noted that crimping is a simple and affordable method that can be used without special skills.
The technique is very simple - wire strands are inserted into a metal sleeve and then the soft metal is crimped with pliers or a vice. It is best to use special pliers for this purpose. They can manually crimp sleeves with a cross section of up to 120 mm². If you need a larger sleeve, use hydraulics. The disadvantage of the sleeve connection is that it is final, and, if necessary, it will not be possible to fix the contact without cutting the wire.
For your information! For crimping, sleeves of the appropriate material should be selected to ensure optimal contact. There are sleeves made of aluminum, copper and alloys. The diameter of the conductor section is also taken into account, the cores must fit tightly into the sleeve.
The use of terminal blocks for connecting wires
The easiest to use and at the same time reliable is the installation using terminal blocks.
Terminal clamps for wires can be used when mounting conductors made of different metals. At the same time, the design of the terminals makes it possible to avoid direct contact between aluminum and copper and the formation of corrosion, which is inevitable for such a connection.
Terminal blocks are divided into three main types: knife, screw and spring. As a rule, a brass alloy is used as the main material. Some models are filled with a gel that protects the contacts from corrosion.
Standard requirements for terminal blocks
Like any electrical component, the terminal block has developed standards of reliability and quality:
| Requirement | Description |
|---|---|
| Thermal stability | The material of the terminal body must withstand high temperatures and do not give any possibility for ignition. The body must not be deformed when heated, and the protective cover is not made of combustible material. |
| Strong fixation | Terminal blocks should be fixed without undue force and at the same time securely hold the wire strands. In this case, the conductors do not need to be somehow additionally processed or twisted. |
| Corrosion resistance | The contact plates in the terminals are of such length that direct contact between the conductors is excluded. In this case, even if the wires are made of different metals, there will be no electrochemical corrosion. |
| informative | Each connector for electrical wires contains information about the diameter of the cores and the allowable voltage in the mains. |
Pros and cons of terminal switching
Like any device, terminal connections have their advantages and disadvantages. First about the benefits:
- Ease of connection. The terminals can connect two or more wires with different cross-sections and metal, while each core is placed in a separate socket and can be easily separated if necessary. If welding, jacket or soldering were used for switching, it would be necessary to remove the insulation, break or unwind the contacts and then repeat the switching procedure again.
- Safety. The terminals are made of insulating material. Even if you accidentally touch the switching point, you will not receive an electric shock.
- There is no need to use a special tool. For screw connection, you only need a suitable screwdriver.
- Fastening reliability. The junction of the wires is resistant to mechanical and thermal stress, vibration and stretching.
- Aesthetics. Connecting wires with clamps looks much neater than winding electrical tape.
Disadvantages of clamp connections:
- Price. The price of a quality terminal is 10 ÷ 12 rubles apiece. If you just need to connect a couple of wires in a chandelier, this is not essential. But with a set of terminal contacts can cost a round sum. But this shortcoming is a matter of time. A lot of competition in this market and the development of new technologies will soon make these devices cheap.
- Some difficulties in installation in hard-to-reach places. If you need to install a terminal block in a place where it is difficult to reach your hand or fingers, the task may seem too complicated. On the other hand, it is not easy to perform any other switching in such a place.
How to choose terminals for connecting wires
To choose the right terminal, first of all, you should study the cable that you plan to connect. You need to find out, it is usually indicated in the wire marking.
The second selection criterion is the quality of the terminal material. It must be sufficiently rigid and have reliable insulation. It is better if the screw and bracket of the device are made of steel. Terminals must be compact. It is possible that you will have to place the contact group in a limited space, so the size of the connections will matter.
Another criterion for the right choice is ease of installation and maintenance. Particularly convenient in operation are terminals with a guide cone and a flag marking the conductor entry point.
Important! Terminals with a small cross section up to 16 mm² have insulation installed on one side, so you need to carefully monitor their installation, otherwise a short circuit may occur.
It is convenient if the terminal surface is suitable for marking. Sometimes it is necessary for the further operation of the connection.
Types of terminal contacts
Modern manufacturers offer a wide range of switches to perform connections of various purposes. Each model meets certain tasks and requirements, we will consider them in more detail.
Screw switches
These simple and reliable devices are great for installation in outlets and similar outlets. The cores are fixed in the terminal with screws.
For your information! Lead and copper switches can be used to connect a car battery. Auto mechanics recommend giving preference to lead fasteners. They do not oxidize as much as copper, under the influence of acid.
Screw terminals are not used for aluminum wiring. This is due to the fact that the aluminum core is destroyed under the pressure of the screw fastener. If the switch is provided, the screw head is marked with green paint.
Terminal clamps for wires
The design of such switches provides for the use of a small spring that fixes the core in the desired position.
Such terminal blocks are installed in an instant: just insert the stripped wiring and fix it in one click.
Junction Box Switches
Such terminals are used to connect wires in junction boxes. The body of the switch is made of polycarbonate, and the contact point is made of copper. Springs are used to fix the cores.
For reliability, the terminals are treated with a special paste that protects the contacts from overheating.
Video on how to properly connect the wires in the junction box using terminals
Fuse terminals
A separate type of switches - with a built-in fuse. Such contact groups additionally protect the wiring from a short circuit.
Such wads for connecting wires take up more space than conventional terminal blocks and are used in cases where electrical appliances do not have built-in fuses in their design.
Connection blocks
Pads are a handy gadget for connecting multiple wires. In the case of such a device, brass tubes with threaded holes are placed. With the help of such small devices, it is possible to connect copper and aluminum wires to each other, as well as conductors of different sections.
Switching in the block occurs in such a way that the cores do not contact directly. The only thing you should pay attention to is the rated current indicator on the block itself.
Blade terminals
Such switches are also called crimp terminals for wires. They are used for power conductors with a small cross section up to 2.5 mm. The maximum voltage for such a connection is 5 kV. Such a connection will not withstand a more powerful current, so knife terminal blocks are not used in large power plants.
Which terminal blocks are better
In fact, the choice of a suitable terminal should be approached very seriously. Especially if there is a need to connect wires with conductors made of different metals. During operation, such contacts are very hot and deformed. This can lead to a complete loss of circuit integrity and even short circuit. It is worth remembering that spring and screw terminals are not suitable for fastening aluminum and copper wiring.
A few words about switch manufacturers
On the shelves of electrical goods stores, products of European, Chinese and domestic manufacturers are presented. As a rule, few ordinary buyers are puzzled by the origin of switches. And in vain. The safety of your property can directly depend on these tiny devices the size of a fingertip. Do not blindly trust Chinese consumer goods. In most cases, the products of the Middle Kingdom do not meet the requirements of domestic standards.
Domestic products are more reliable, but less aesthetic and technologically advanced. European goods are more expensive, but I bought such a terminal and forgot about it. Manufacturers guarantee long-term and reliable operation of their products. Here are some of them:
LEGRAND
Screw switches from this manufacturer are the most popular product in this category. Brass products are nickel-plated and can reliably withstand powerful temperature changes. Such terminals are characterized by high strength and a wide range of sizes.
WAGO
The products of the French company guarantee a strong connection of wiring of various types and sections. The devices perfectly resist possible vibration and stretching and are installed without special tools. The main material of the French terminal blocks is tinned copper, which gives good contact with low resistance. Some models are filled with anti-corrosion gel.
PHOENIX CONTACT
The German manufacturer is distinguished by excellent product quality. It offers more than 200 kinds of different switches for different types of connections. Among the presented models there are resistant to high humidity and explosion hazard.
WIEDMULLER
Another European brand offers one and a half hundred terminal models. The range is based on screw connections made according to DIN technology.
Common problem: how to connect aluminum and copper wire
This problem is often faced by residents of Soviet-built houses. At that time, almost all wiring was carried out using aluminum conductors. Modern electricians mostly use copper wire. How to connect aluminum wire to copper? There are skeptics who argue that such a connection is impossible. You shouldn't believe them. If you correctly use the techniques that we will give below, switching will be reliable and durable.
As already mentioned, the usual twist for such a connection is not suitable. The contact of copper and aluminum is very hot and can damage the insulating layer.
Option 1 - Bolted
This is a simple and affordable method that uses a steel nut, bolt and washers. Due to the impressive dimensions of such fasteners, it is unlikely to be placed in a modern small junction box. But on the other hand, such switching allows you to combine wiring not only from different metals, but also with different cross sections. Such connections are easy to disassemble and assemble if necessary.
Option 2 - "nut" connection
The name of such a connection was invented by electricians because of the external similarity. For fasteners, a special crimp is used, which is sold in electrical stores. The device consists of two dies with grooves for conductors. After fixing the cores, the dies are wrapped with electrical tape.
In stranded wires, the cross section is formed by several, sometimes intertwined with each other, cores. Knowing how to connect stranded wires to each other, you can quite easily do this work yourself and get a strong, absolutely safe contact during operation.
Where are stranded wires used?
Any stranded conductor contains at its base a large number of thin wires. The use of a multi-core cable is relevant in areas requiring a large number bends or, if necessary, pull the conductor through holes that are too narrow and long enough.
The scope of application of stranded conductors is presented:
- extended tees;
- mobile lighting devices;
- automotive wiring;
- connecting lighting fixtures to the electrical network;
- connecting switches or other types of leverage to the electrical network.
Flexible stranded conductors can be repeatedly and easily twisted, which does not negatively affect the functionality of the system. Among other things, it is this type of electrical wiring that is distinguished by its plasticity, and greater flexibility and elasticity is given to the wire by weaving a special thread, which is a bit like nylon in strength and composition.
Methods for connecting stranded wires to each other
The methods of electrical installation connections of stranded conductors used today are distinguished by the ability to obtain not only strong, reliable and durable, but also completely safe contact of the cores.
Stranding stranded conductors
This option is the simplest and most intuitive, not requiring the use of special equipment or professional tools.
Twisting is the easiest way to connect stranded wires
The second method consists of the following steps:
Twisting wires by the third method:
There is also a fourth method, which is as follows:
Soldering method
Soldering conductors with a household soldering iron provides high-strength contact and good electrical conductivity. Tinning of stranded conductors is carried out using rosin (flux) and standard solder according to standard technology.
Terminal Type Connections
The use of terminals of various types is the most affordable way to connect stranded wires in everyday terms. In most cases, the terminal blocks used are divided into a couple of basic types.
The principle of operation of the clamping terminals involves fixing the wire using a built-in spring mechanism.
Terminals are often used to connect wires.
The screw-type terminal block assumes reliable fixation of all connected stranded wires with a screw. To increase the area of wired contact with a conductive surface, it is required to perform an additional bend of the core.
In the terminal block, the wires are fixed by tightening the screws.
Phased work:
Crimping method
The crimping method involves connecting wires or cables using a copper or aluminum sleeve using special hydraulic or manual crimping pliers.
In this case, the connection is made using a special sleeve
The pressing technology consists in stripping the insulation according to the length of the sleeve, and too thin wires should be connected by twisting. Then all the cables are folded together and placed inside the sleeve, after which a double crimping is performed along the entire length. The method allows you to perform a reliable and safe connection of stranded wires made of different types materials.
Bolted connection
The simplest, but not sufficiently reliable way to connect stranded wires is twisting followed by bolting. This type of plug-in connection is most often used in open wiring conditions.
Bolted connection is the simplest, but not very reliable
To increase the level of reliability of the connection of stranded wires, it is recommended to strip the ends of the insulation, then tin the cleaned sections and fasten them with a bolt.
Application of connecting insulating clamps
PPE elements are used when it is necessary to connect stranded wires with a small cross section (within 25 mm 2). The design feature of this clamp is a plastic housing with a built-in conical spring.
This method is suitable for connecting wires with a small cross section.
Stranded wires are first connected into one bundle using a twist, on which the clamping part is then wound. Among other things, the wire connection does not need additional insulation.
welding method
Permanent connection is the most reliable way when working with stranded wires. With properly performed welding, the general indicators of mechanical strength and contact resistance in terms of reliability do not differ from those of a solid conductor.
Welding wire connection is considered the most reliable
Welding can be performed on alternating and direct current. On preparatory stage the wires are stripped of insulation, after which they are twisted and aligned by trimming the ends. To ensure that the conductors do not overheat during the welding process, it is necessary to ensure high-quality heat removal.
Security measures
In order to ensure the safe operation of the connected stranded wires, it is important to isolate all parts of the electrical wiring without fail. Proper insulation helps to prevent dangerous contact of conductive parts with each other or with the human body. When choosing an insulating material, it is necessary to take into account the operating conditions of the electrical circuit, but in most cases, insulating tape is used for this purpose, as well as a special vinyl or heat shrink tube.
If the connection area is exposed to negative impact high-temperature conditions, it is recommended to use varnished fabric or fabric insulating tape as an insulating material. Of no small importance is the correct execution of all stages of electrical installation. Only with a reliable connection and proper connection of all elements of the electrical network can it be possible to minimize the risk of areas with poor contact, as well as prevent local overheating and breaks in electrical wiring.
Multi-core cables are a popular and common option, widely used for arranging electrical wiring for various purposes. General rules separate connection of stranded and solid conductors do not have any differences or features, therefore it is allowed to use twisting, screw clamp, PPE elements, welding and soldering for this purpose.
