Knowledge modern technologies and methods of working with electrical fittings, is it really necessary? Yes, you need to know how to connect electrical wires correctly.
This can be useful during installation and installation of any power supply systems. Is the wiring burned out, does the lighting fixture need to be replaced, or new equipment needs to be installed. Such knowledge may not be needed, but it would be better to know all the common connection methods electrical wires
Application in terminal block circuits
Terminal blocks are electrical products made of non-conducting material, inside of which a conductive sleeve is inserted, having a pair of screws at opposite ends. They serve to secure the wire. An excellent choice for implementing a modern way of connecting wires.
When choosing a reliable connection of wires, it is important to remember: terminal blocks are produced with different holes for many cross-sections.
This method is almost always used for connections in junction boxes of any type, during installation, installation of wall and other lamps. It is suitable for. It is easy to mount a network using such fittings; you just need to insert the bare ends into the holes and, using moderate force, securely tighten the screws. The wire itself should not be crushed. Having figured out how to properly connect electrical wires using terminals, it is worth exploring other equally reliable methods.
Terminal method rating: Excellent fastening quality. Their prices are reasonable. Quite quick and easy installation. A good opportunity to connect different conductors, for example, aluminum and copper.
It is not recommended to connect aluminum and stranded circuits with blocks. This is due to the high fragility of aluminum wires and the great flexibility of the stranded wire conductors themselves. But overall a decent method.
Spring terminals
Quick installation of electrical networks is sometimes simply necessary. For example, install temporary lighting on a balcony, terrace, gazebo. Wago spring terminals are an excellent product for such work. A modern and of course reliable way to connect wires. Although they are new to the electrical accessories market, installation using spring terminals is quick and, importantly, convenient.
The main difference between the use of the Vago terminal blocks themselves: they are more convenient to connect any wires in electrical boxes than with twisting. Here, for high-quality installation, a unique clamping mechanism is used, rather than a simple screw. Manufacturers produce both disposable and reusable vagon systems.
- In the usual version, this product is used for one-time use; during repair work in the future it cannot be restored. It is removed and a new one is installed in its place.
- Wago reusable terminals are a little more expensive, but with their help you can disconnect the assembled contacts several times, rewiring the circuit to suit your needs. This speeds up the process of repairing or installing permanent and temporary networks. A simple lever-type mechanism provides the advantage that it is possible to carefully but efficiently fix any wire without damaging or squeezing it.
With the help of a vault, it’s easy to do the fastening yourself; you just need to strip the insulation and insert the required wires into the mounting hole. Press the lever. It's important to get it right.
Wago Clamp System Rating: A unique opportunity to combine any aluminum, copper and other conductors. There is an option for connecting multi-core cables simultaneously (two or more).
Wago universal clamps allow you to fix any thin stranded conductor without damaging it. Another plus is the compact size of the pads.
Wago self-clamping terminals Excellent quality and durability. The Vago type block has a technological hole that provides access for a screwdriver with a voltage indicator. The operation of any power line can be checked at any time. Perhaps one drawback is the considerable cost of the terminals themselves. But this type of wire connection is the most modern and fastest.
Isolation with PPE caps
Deciphering the product is not difficult, connecting insulating clips (PPE). They are ordinary nylon or plastic caps with an internal lock.
The simplest type of connection of wires, it is carried out after twisting the conductors themselves, the cores. Caps are often used to connect wires in junction boxes and to mark connections with the desired color.
Evaluation of the use of such products: Enough low cost PPE. The use of safe material prevents ignition of electrical wiring. Easy installation, put it on a twist of wires and you're done. These caps have a wide range of colors, which is convenient. Of course, if the wires are not color coded, colored PPE has the ability to determine or simply mark zero, phase and other necessary electrical routes.
There are also disadvantages: Insufficient level of fixation. Multicore wires can be installed only after soldering.
Installation of networks using sleeves
This option claims to be the most reliable connection method. Any load and quality of wires.
Crimping wires with sleeves The conductive wires are inserted into a special tube - a sleeve, and crimped with a certain force. There is one thing, but... The cross-section of the wires should not exceed the cross-section of the mounted sleeves. Having inserted and crimped the clip, the sleeve is carefully insulated with heat-shrinkable tubing or other insulating materials.
Overall rating. A great way to securely connect wires. The direction of the conductors can be on different sides of the tube or on one side. The sleeves are quite inexpensive. Good way how to reliably connect the wires to each other.
There are also disadvantages. Disposable use of sleeves, they are not dismountable. To carry out such work you will need a tool: pressing pliers, which are also used as a special tool. They remove the insulation. They have a crimping device in their arsenal, and electrical installation work takes a little longer.
Soldering or welding wires
This method is reliable. Typically, this method of connecting in a junction box first involves stripping and twisting the ends, after which they are dipped into heated solder. It is advisable to connect aluminum to aluminum wires by soldering. They are then insulated using a heat pipe or insulating tape.
Evaluation of the soldering method. It gives strong chain contacts and excellent quality, not expensive, it is the most reliable method of connecting electrical wires in a soldered box.
Technological disadvantage. You can't do this without a soldering iron. The speed of work is not high. The connection is naturally not detachable. It follows from this that soldering is done in extreme cases, using more modern connection methods. It has not been popular among masters for a long time because it takes more time.
There is also a less common method for connecting electrical wires, welding. The process is similar, but requires the use of a special welding machine, of course, and certain skills.
Contact twisting method
Not a new, one might say “old-fashioned” method, it consists of spiral twisting of the cores among themselves. The essence of all work is to twist the stripped conductors using pliers, and cover the twisted area with insulation. These are, perhaps, all the ways to twist wires.
Evaluation of this connection method. High speed of all installation work. The cost part is minimal.
Flaw. It is prohibited to connect together strands of different compositions, copper and aluminum wires., oxidation is inevitable. According to the regulatory framework, fastening wires with twists in a junction box is not recommended for use in rooms with flammable materials, high humidity, basements, or in any house built of wood. More details about the twisting method. I definitely recommend watching a video about which is better: twisting or Vago terminal blocks.
Wire clamp "walnut"
Such a device is simply a cable clamp that has two plates inside and several screws for tightening, usually in the corners. It is enough to screw the wires to the plate itself. Then put a carbolite shell on top.
Grade. An excellent option for connecting any electrical wires in a large and medium-sized junction box. Definitely, these types of products are quite convenient and have a high degree of protection. Makes it possible to quickly connect a wire to a thick gauge track without tearing it.
Flaws. Dimensions allow installation only in spacious distribution boxes and switchboards. Over time, the screws loosen.
Tip: When choosing fittings and method, remember the following:
- It is necessary to work only with an isolated tool and use protective equipment.
- Be sure to post a “do not turn on” warning sign on the shutdown panel or meter.
- Connect electrical appliances according to the attached instructions.
Having considered the main types of wire connections, you can easily select the right option. And having a simple tool and a diagram at hand, you can mount it yourself. More details
About 70% of installation errors are related to wires. The lack of electricity may be due to unreliable contact or its absence in the junction box or electrical appliance. Further in the article - all the options for connecting wires, their installation and types.
Methods for connecting wires and cables
Electricity is an area in which you need to carefully select materials and monitor reliability and performance.
For high-quality and uninterrupted power supply in the house, the electrical wires must be connected correctly.
In case of an error, not only the functionality of household appliances will be at risk, but also fire safety.
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:
- For the first group, no special equipment is required.
- The second group already requires certain skills and professional tools.
Work on connecting cables must be carried out in compliance with safety regulations.
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.
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.
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 number of wiring, 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
Solderless connections are made 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.
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 ones 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 twist 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.
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.
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. The exception is multi-core electrical wires, which are crimped with special lugs. Also, a screw clamp 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 to each other. 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.
Connection blocks for electrical wiring if it is damaged
If electrical wiring with stranded conductors is damaged, clamping blocks must not be used. They additionally put pressure on the conductors, causing the conductors to become deformed and damaged. As a result, the connection heats up, melts and there is a risk of fire.
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.
Useful video
The need to fasten wires together can arise for many reasons, and if you are interested in the question: “How to connect wires correctly?”, We advise you to read the materials in this article. To carry out this type of work, you need to understand what the order and features of connecting the wires are, and carefully study what methods can be used to connect them.
Let's try to tell you in as much detail as possible about the main ways to solve this problem, consider the process of fastening the cables step by step, and show a photo of how to properly connect the wires on your own.
Connection methods
Today, electrical wires can be connected in several ways. The choice of one method or another is made based on your preferences: having learned about all the methods, you can choose the option that is most suitable and convenient for each specific case.
There are six main types of wire connections:
- twist;
- crimping;
- welding;
- soldering;
- screw terminals;
- self-clamping connections.
Let's consider step by step instructions, how to connect cables in one way or another.
Twist
Today, connecting electrical wires to each other by twisting is prohibited, since it is considered the most unreliable and unsafe compared to other methods. By choosing the twist option, all responsibility for possible consequences will be assigned only to you.
The connection will be very simple: you need to remove about 10-15 mm of insulation from each cable and carefully screw them onto each other. When fastening wires with a cross-section of up to 1 mm, at least 5 turns must be made, with a larger cross-section - at least 3 turns.
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.
Welding
Using this method, at the end of the work you will receive an essentially solid cable. He will not be afraid of oxidation processes or any other negative impact characteristic of disconnected wires.
To complete the work you will need the following elements:
- welding machine;
- sandpaper;
- flux;
- personal protective equipment – gloves, goggles;
- carbon electrode.
At the first stage, you need to clean the cables from insulation and strip the wires until shiny using sandpaper. Then twist the wires together. The third step will be to fill the recess of the carbon electrode with flux.
Afterwards, you need to put it into working condition, press the electrode to the place where the cables are twisted and hold it there until a ball is formed, in other words - a contact point.
The resulting contact point must be cleaned of flux and coated with a special varnish. At the final stage, you need to insulate the connection.
Soldering
The sequence of actions will correspond to the previous method using a welding machine, the main difference is that the wires are connected to each other using solder, which is melted with a soldering iron.
The connection obtained by soldering is considered reliable and durable, but this method should not be used in places where the wires may become very hot. It is also not advisable to carry out soldering in places where there is a possibility of mechanical stress on the resulting connection.
Screw terminals
This method will allow you to quickly and easily connect wiring, for example, in a junction box. Such clamps allow you to connect both homogeneous and dissimilar conductors.
The algorithm of actions will be as follows:
- peel the insulating layer from the cables (about 5-7 mm of insulation);
- insert their ends into the clamp and tighten the screw tightly.
Self-clamping connections
This method is the most popular and modern. Self-clamping devices are easy to use.
Also, inside these compounds there is a paste that completely eliminates the possibility of metal oxidation. This function allows you to place both homogeneous and dissimilar conductors in the clips.
The actions will be as follows:
- remove 10 mm of insulating material from each cable;
- lift the lever of the self-clamping device;
- place the conductor in the clip;
- lower the clip lever.
Clamps that do not have levers simply need to be snapped into place.
Even a person who has no experience working with electrical wires can connect the wires with their own hands.
After studying all possible methods, you can choose the one that seems most understandable and easy to you. And having studied detailed instructions For each cable connection method, a favorable outcome can be guaranteed.
It would seem that what could be simpler than connecting wires? After all, there are several ways to connect wires. This includes twisting wires, soldering wires, welding wires, crimping and connecting wires using a terminal block. Even a schoolboy knows the easiest way to twist conductors. You need to put the ends of the metal wires, called strands, together and twist them into one “pigtail”, and then wrap them with electrical tape. There is no need for a soldering iron, terminal block, connecting caps and other “unnecessaries”.
Any “own electrician” has mastered this operation. And, when the need arises, he applies this method in his daily practice. For example, it splices the power cord wires of a household appliance, tablet or computer adapter after a break.
Russian “technicians” use this technology for fastening wires everywhere. It’s just that the rules for constructing electrical installations of PES do not provide for “twisting”, all kinds of “bends” and “rivets”. There are no such electrical installation methods in other regulatory documents. Why?
We often don’t think about the consequences of such a “simplification”. Meanwhile, an unreliable contact will fail at the most inopportune moment; the power supply to consumers/power receivers can always be cut off. Voltage “surges” cause a breakdown of the elements of the power cascades of complex SBT household appliances. Even special protection devices used in the most “sophisticated” models of foreign manufacturers cannot save you from breakdown.
The induction of short electromagnetic pulses with a voltage of several thousand volts onto the electronic filling causes “harmless” sparking at the joints. At the same time, the standard protection equipment that apartments are now equipped with (RCD, circuit breakers, fuses) such short low-current pulses are not “seen”, so they simply do not trigger, and we do not customarily install special devices for this. Uninterruptible power supplies for computers also did not become a panacea for transient impulses. The occurrence of “jabs” causes malfunctions in the operation of electronic equipment and computer equipment, leading to the failure of electrical components and expensive functional modules.
Overheating at the site of a poor connection leads to even more catastrophic consequences; when current passes, the weakened connecting node becomes red-hot. This often causes fires and fires, causing enormous damage to the owners of the premises. Statistics show that 90% of all electrical wiring faults occur due to twists and poor contact connections of conductors. In turn, the very malfunction of electrical wiring and equipment, according to the Ministry of Emergency Situations, is the cause of one third of the fires that occur in Russia.
However, historically, several decades ago, in conditions of a shortage of electrical accessories/copper conductors, twisting aluminum wires was considered the main method used in electrical installation work. Twisting as a connection can be used in electrical engineering when carrying out repair and restoration work.
How to connect wires correctly
How to connect the wires: we start by removing the insulation. Correct connection conductors must satisfy three basic requirements:
- Ensure reliable contact with a minimum transition resistance between each other, close to the resistance of a single piece of wire.
- Maintain tensile strength, fracture resistance and vibration resistance.
- Connect only homogeneous metals (copper to copper, aluminum to aluminum).
There are several connection methods that satisfy these requirements. Depending on the requirements for electrical wiring and the possibilities of practical application, the following types of wire connections are used:
All these methods require preliminary preparation of the wire or cable - removing the insulation to expose the connected cores. Traditionally, rubber, polystyrene, and fluoroplastic are used as insulating shell materials. Additionally, polyethylene, silk and varnish serve as insulation inside. Depending on the structure of the conductive part, the wire can be single-core or multi-core.
By single-core is meant a wire whose cross-section is formed by an insulating sheath with a metal core or wiring inside.
In a stranded wire, the metal core is formed by several thin wires. They are usually intertwined and represent a lay, surrounded on the outside by an insulator. Often, individual wires are coated with polyurethane varnish, and nylon threads are added to the structure between them to increase the strength of the wire. These materials, like the fabric braid on the outside, complicate the process of removing the insulation.
Depending on the type of connection, 0.2–5.0 cm of insulation is removed from each end of the wire. Several types of tools are used for this.
Using a 5-point system, you can evaluate the quality of insulation removal and the degree of protection against cutting - damage to cores by each device:
Damage to insulation/core
Monter (kitchen) knife – 3/3
Side cutters (nippers) - 4/3
Stripper - 5/4
Soldering iron or electric loop burner - 4/4
In low-current television/computer networks, coaxial cables are used. During the cutting process, it is important to carefully cut and remove the insulating jacket without damaging the shielding braid. To access the central vein, it is fluffed up and removed, exposing the trunk. After which the polyethylene insulation is cut with a knife or a special device, the trim is removed from the core.
The bifilar in the screen consists of a pair of wires in the screen, which, in order to access the conductors, is also pre-fluffed into wires, allowing access to each core.
Important! To remove the insulating material of an enameled wire with a cross-section of less than 0.2 mm², a soldering iron should be used. The enamel is carefully removed using sandpaper and moving the paper along the wires.
How to twist wires correctly
Most often, twisting is used in the repair of electrical wiring, cords and adapters (including low-current) household appliances and equipment. If we are talking about the home electrical network, then the standards provide for the use in homes of wires with a current-carrying core cross-section of 1.5–2.0 mm made of copper and 2.5–4.0 mm made of aluminum. Typically, wires of the VVG and PV brands in a polyvinyl chloride sheath are used for wiring. Power cords of the ShVL and ShTB brands with rubber or PVC insulation have a cross-section of 0.5 - 0.75 mm.
You can splice the wires together step by step as follows:
- Degrease the bare ends of the wires by wiping with acetone/alcohol.
- We remove the varnish layer or oxide film by sanding the conductors with sandpaper.
- Apply the ends so that they intersect. We wind clockwise at least 5 turns of one core onto another. To make the twist tight, use pliers.
- We insulate the open current-carrying parts of the wires using electrical tape, or screw on an insulating cap. They should extend beyond the insulation for 1.5–2.0 s to cover the exposed areas of the conductors.
To splice a stranded stripped wire with a single-core wire, another winding technique is used:
- A single wire is wrapped with a stranded wire, leaving the end free without winding.
- The end of the single-core wire is bent 180° so that it presses the twist, then pressed with pliers.
- The connection point must be firmly fixed with electrical tape. For best performance, an insulated heat pipe should be used. To do this, a piece of cambric of the required length is pulled over the connection. To make it grip the wiring more tightly, the tube should be heated, for example, with a hair dryer or lighter.
With a bandage connection, the free ends are placed next to each other and wrapped on top with an existing piece of wire (bandage) made of a homogeneous material.
Coupling with a groove provides that before mutual twisting, small hooks are configured from the ends of the wire, they are interconnected, then the edges are wrapped.
There are more complex varieties of parallel/serial connections. Connecting wires using the twisting method is used by professional electrical repairmen when carrying out restoration work.
Important! Copper and aluminum have different ohmic resistances; when they interact, they actively oxidize; due to different hardnesses, the connection turns out to be fragile, so the connection of these metals is undesirable. In case of emergency, the ends to be connected should be prepared - tinned with tin-lead solder (PLS) using a soldering iron.
Why is it better to crimp (crimp) wires?
Wire crimping is one of the most reliable and high-quality methods of mechanical connections currently used. With this technology, loops of wires and cables are crimped into a connecting sleeve using press pliers, ensuring tight contact along the entire length.
The sleeve is a hollow tube and can be made independently. For liner sizes up to 120 mm², mechanical pliers are used. For large sections, products with a hydraulic punch are used.
When compressed, the sleeve usually takes the shape of a hexagon; sometimes local indentation is made in certain parts of the tube. In crimping, sleeves made of electrical copper GM and aluminum tubes GA are used. This method allows for crimping conductors made of different metals. This is largely facilitated by the treatment of the constituent components with quartz-vaseline lubricant, which prevents subsequent oxidation. For joint use, there are combined aluminum-copper sleeves or tinned copper sleeves GAM and GML. Wire connections using the crimp method are used for conductor bundles with a total cross-sectional diameter between 10 mm² and 3 cm².
Soldering as a reliable alternative to twisting
The closest alternative to twisting, which is prohibited for electrical installation, is to connect wires using the soldering method. It requires special tools and consumables, but provides absolute electrical contact.
Advice! Overlapping wire soldering is considered the most unreliable in technology. During operation, the solder crumbles and the connection opens. Therefore, before soldering, apply a bandage, wrap a piece of wire of a smaller diameter around the parts being connected, or twist the conductors together.
You will need an electric soldering iron with a power of 60–100 W, a stand and tweezers (pliers). The soldering iron tip should be cleaned of scale, sharpened, having first selected the most suitable tip shape in the form of a spatula, and the device body should be connected to the ground wire. Among the “consumables” you will need POS-40, POS-60 solder from tin and lead, rosin as a flux. You can use solder wire with rosin placed inside the structure.
If you need to solder steel, brass or aluminum, you will need a special soldering acid.
Important! Do not overheat the junction points. To prevent the insulation from melting when soldering, be sure to use a heat sink. To do this, hold the bare wire between the heating point and the insulation with tweezers or needle-nose pliers.
- The wires stripped of insulation should be tinned, for which the tips heated with a soldering iron are placed in a piece of rosin; they should be covered with a brown-transparent layer of flux.
- We place the tip of the soldering iron tip into the solder, grab a drop of molten solder and evenly process the wires one by one, turning and moving along the tip blade.
- Attach or twist the wires together, securing them motionless. Warm up with the tip for 2–5 s. Treat the areas to be soldered with a layer of solder, allowing the drop to spread over the surfaces. Turn over the wires to be connected and repeat the operation on the reverse side.
- After cooling, the soldering joints are insulated in the same way as twisting. In some compounds, they are pre-treated with a brush dipped in alcohol and coated with varnish.
Advice! During and after soldering for 5–8 s. The wires cannot be pulled or moved, they must be in a stationary position. A signal that the structure has hardened is when the solder surface acquires a matte tint (it shines in the molten state).
But welding is still preferable
In terms of connection strength and contact quality, welding surpasses all other technologies. Recently, portable welding inverters, which can be transferred to the most inaccessible places. Such devices are easily held on the welder's shoulder using a belt. This allows you to work in hard-to-reach places, for example, welding from a stepladder in a distribution box. To weld metal cores, carbon pencils or copper-plated electrodes are inserted into the holder of the welding machine.
The main disadvantage of welding technology - overheating of the parts being welded and melting of the insulation - is eliminated using:
- Correct adjustment of the welding current 70–120 A without overheating (depending on the number of welded wires with a cross-section from 1.5 to 2.0 mm).
- The duration of the welding process is no more than 1–2 seconds.
- Tightly pre-twist the wires and install a copper heat sink clamp.
When connecting wires by welding, the twisted wires should be bent and the cut side must be turned upward. An electrode is brought to the end of the wires connected to ground and the electric arc is ignited. The molten copper flows down in a ball and covers the twisted wire with a sheath. During the cooling process, an insulating belt made from a piece of cambric or other insulating material is put on the warm structure. Lacquered fabric is also suitable as an insulating material.
Terminal blocks are the most ergonomic electrical installation products
The PUE rules, clause 2.1.21 provide for the type of connections using clamps (screws, bolts). There is a connection directly using hanging fasteners, when a screw and washer are threaded through the loops of each wire and secured with a nut on the reverse side.
This installation is wrapped with several turns of electrical tape and is considered quite practical and reliable.
Electrical installation products called screw terminal blocks are more ergonomic. They represent a contact group housed in a housing made of insulating material (plastic, porcelain). The most common way to connect wires using terminal blocks is in junction boxes and electrical panels. To connect the wire, you need to insert it into the socket and tighten the screw; the clamping bar will securely fasten the wire to seat. Another connecting wire is connected to the mating socket, short-circuited with the first one.
In self-clamping terminal blocks of the WAGO type, the wire is snapped into the socket; for better contact, a special paste or gel is used.
Branch clamps are a permanent version of a screw terminal block with several short-circuited taps; they are used mainly outdoors and in places with unfavorable environmental conditions.
The connecting clamps are an insulating cap with a thread inside; it is screwed onto the twist, simultaneously compressing and protecting from mechanical stress.
Any man strives to ensure that the electricity supply in his own home or apartment is of high quality, uninterrupted and reliable. Therefore, when carrying out electrical work during construction or repairs, it is necessary to correctly connect electrical wires. But in everyday life you still have to face problems when the lamp wire broke, the socket stopped working. Of course, if you have basic knowledge of electrical engineering and the ability to carry out electrical installation work, it is easy to fix all these faults yourself.
The connection of conductors made of different metals must be made taking into account all the properties of the material from which they are made. Currently, copper, aluminum and steel are used to transmit electrical energy. Each of these metals has different densities, conductivities, and resistances that are taken into account when making good electrical contact. It is also necessary to take into account the magnitude of the electrochemical potential that arises when current is applied to the metal.
Therefore, if aluminum and copper conductors are connected incorrectly, problems may occur. serious problems problems that many specialists who repair wiring in apartments encounter. Previously used in homes copper wires , which were much superior to aluminum ones in terms of electrical performance. And currently use of copper conductors faded into the background.
Aluminum, having a high level of oxidation, forms a specific film when combined, which has a fairly high electrical resistance. This property manifests itself especially in humid environments. The same film is formed on copper, only its resistance is much lower. Therefore, due to this difference in resistance, direct connection of these metals results in difficult electrical conductivity. A oxidation processes lead to sparking, heating and fire of wires.
Methods for safe contact
To create reliable contact between electrical wires, there are several methods, both using special equipment and using improvised means.
Types of wire connections:
- Twisting (twisting) is the most common method, the use of which is desirable for temporary connections.
- Welding is the most reliable method that ensures excellent contact of conductors. Requires welding equipment and certain skills to carry out the work.
- Soldering - has excellent connection performance, but requires compliance with the temperature regime (not higher than 65℃).
- Terminal blocks are a fairly simple and reliable connection.
- Connecting wires using clamps - subject to operating conditions - allows you to obtain excellent contact. Installs very quickly.
- Crimping with sleeves requires special pliers and knowledge of installation technology, but the method is very reliable.
- Bolted connection - used in difficult situations, easy to perform and does not require special devices.
When choosing the type of connection, it is necessary to take into account: the material of the conductive part; wire section; number of conductors; type of insulation; terms of Use. Most often, the selection of the type of connection is carried out at the work site.
This technological operation is common to all methods of connecting conductors. Before combining the wires into a common electrical unit, it is necessary to strip them of the insulation layer.
The easiest way to do this work is with a mechanic's knife, but in this case there is a possibility of damage to the conductive core. To avoid this, you need to:
- Place the wire on the table surface.
- Press it with the index finger of your left hand.
- Holding the knife in your right hand, cut the insulation. In this case, it is necessary to direct the blade at an angle to the cut so as not to damage the core. Otherwise, the conductor may break.
- Using the finger of your left hand, twist the conductor one turn to cut the insulation.
- Remove the cut piece of the insulating sheath.
Experienced electricians have in their arsenal a multifunctional tool - a stripper, which is designed for cutting cables and removing insulation. This device does not damage the core when removing insulation from a conductor of any cross-section, since it has a special calibrated recess for the required wire diameter.
The length of insulation stripping is selected in accordance with the method of connecting the conductors.
The simplest and known method connecting electrical wires is by twisting them (twisting). Experienced electricians often call it the old-fashioned method.
Previously, this type of connection was used everywhere, but with increasing load in the electrical network in a modern apartment, twisting has become prohibited. However, this connection method must be studied first, since it is the main step in soldering and welding wires.
The main advantage of twisting is the absence of any material costs, since you only need pliers and a knife to remove the insulation. And of course, the advantage of twisting is the ease of its execution. Anyone who has held pliers in their hands can do this job without any problems.
Over time, the twist weakens, which is its main disadvantage. This process is connected with the fact that in any veins there is residual elastic deformation. Therefore, at the point of twisting, the contact resistance increases, which leads to weakening of the contact and heating of the conductor. It’s good if this defect is discovered in time and the joining point can be redone, but a fire may occur.
But if for some reason you do not have the opportunity to use more reliable methods, then you definitely need to familiarize yourself with how to properly connect the wires to each other using the twisting method. To do this, you first need to strip the cores of 70-80 mm of insulation. Then, holding both conductors where the insulation ends, use pliers to grab the ends of the wires and rotate them clockwise. Main the condition for reliable twisting is the simultaneous rotation of the conductors, and not alternately winding them on each other.
If the diameter of the wires is small, then twisting can be done entirely by hand. With your left hand you need to hold the conductors along the cut of the insulation, and with your right hand you need to rotate the conductors by the bend (10-15 mm) clockwise. For tighter contact at the end of the rotation, you can use pliers.
The next step is to insulate the junction of the wires. For this, insulating tape is used. To ensure reliability and protect the contact from moisture, you need to wind the tape in several layers, while stepping 2-3 cm onto the wire insulation. Very good option Insulation is carried out using thermal tubes; the main thing is not to forget to put it on one of the cores.
Professional electricians advise not to stop at the stage of twisting the wires, but to strengthen the joint by soldering or welding.
How to connect wires by soldering
The type of connection in which electrical wires are joined using molten solder is called soldering. This method is best applicable to wires with copper conductors, but the use of special fluxes allows you to obtain high-quality joints of other metals.
Advantages of using soldering:
- In terms of reliability, this type of wire joining is second only to welding;
- allows you to connect both single-core and stranded wires, as well as wires with different cross-sections;
- no maintenance of the contact point is required for the entire period of operation;
- low cost of work (flux and solder are inexpensive).
The disadvantage of soldering is considered to be rather high labor intensity. The surfaces to be soldered must be previously cleaned of oxides and tinned before twisting the wires.
An electrician must have certain qualifications and be able to use a soldering iron, because during the work it is necessary to strictly observe the temperature regime. A weakly heated or overheated contact point loses its reliability and strength.
The technological process for performing soldering looks like this:
- The insulation is removed from the conductors by 40-50 mm.
- Areas of exposed veins are well cleaned with sandpaper.
- Tinning of wires is carried out. To do this, a heated soldering iron is dipped in rosin and the tip is passed over the cleaned surfaces several times.
- The wires are twisted.
- Place solder on the soldering iron tip and heat the twist. In this case, molten tin should fill all the gaps between the turns.
- After cooling, the soldering is wiped with alcohol and insulated.
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 wire welding:
- We strip the conductors from insulation by 60-70 mm.
- We clean the cores mechanically (sandpaper).
- We twist the wires, and its length must be at least 50 mm.
- We fix the welding grounding contact on top of the twist.
- Lightly touch the bottom of the twist with the electrode. Wire welding occurs very quickly.
- 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.
For such a connection of conductors, special copper or aluminum sleeves are required, which are selected in accordance with the size of the bundle diameter. It is advisable to use the same material for the sleeves as that of the conductor.
The wires are stripped to the length of the sleeve, rolled up and placed in a tube. Then, using special pliers, the connection is pressed and insulated.
There are tube sleeves for extending conductors, that is, for their longitudinal fastening. The wires are inserted into such sleeves from different sides of the tube, then crimped individually.
Bolt method
This connection is used in electrical circuits with increased voltage. Its use is suitable for switching almost any conductor.
- put the washer on the bolt;
- first conductor;
- next washer;
- second conductor;
- puck again;
- screw.
Then the assembled assembly is tightened by hand, and then pressed with a wrench or pliers.
Modern industry has mastered the production of special wire connectors, which have made work much easier and have sped up switching work:
- Caps with built-in crimp spring. The stripped wires are inserted into such a cap and turned clockwise. With this action, the wires are securely compressed inside.
- Terminal blocks, which have tubular brass sleeves inside. Bare wires are inserted into these sleeves and clamped with screws.
- Self-clamping terminals The stripped wire is automatically fixed with a special plate.
- Lever terminal blocks are considered reusable devices. Fixation of the conductor is ensured by raising and lowering the lever.
Remember that the connection of wires must always be made on de-energized electrical networks. Without knowledge of electrical engineering, it is better to entrust work involving dangerous voltage to specialists.
