How to properly connect solid and stranded wires

How to connect a stranded wire to a single-core wire: description of methods, installation features

In any case, electrical installation work involves connecting wires and cables. At the same time, the same types of flexible conductors do not always come across. Any master can handle this kind of work, provided there is the desire, time and necessity. At the same time, not everyone knows how to connect a stranded wire with a single-core one.

Methods for connecting dissimilar wires

In order to ensure the correct connection of wires, and dissimilar ones (with one or two cores), there are dozens of techniques.

These methods can be divided into two main categories:

• The first includes those techniques, the implementation of which requires specific equipment or skills.
• Secondly, those where almost any home craftsman can prove himself, since no special skills are needed here.

Each method has its own advantages and disadvantages. Let's start with ways to connect stranded and single-core copper wire (or aluminum), where additional elements in the form of terminals are not needed, which significantly reduces the cost of the process.

Twist

Although this method is highly discouraged by the requirements of the PUE, many home craftsmen continue to use it. And if everything is done correctly and with a responsible approach to work, the result will be reliable and durable for electrical networks with an average current load.

Using parallel twist, a single-core wire can be easily connected to a multi-core cable. In this case, the monolithic core is additionally bent, which gives more rigidity than twisting two identical wires with several cores. Moreover, this method is relevant for wiring not only from copper, but also from aluminum.

Those craftsmen who want to know how to properly connect a stranded wire to a single-core wire should understand that this method is not suitable for dissimilar metals! This is due to the fact that the connection can last only a short time, because metals of different natures form a galvanic couple. And under the influence of current it begins to collapse, and quite quickly.

Connecting wires by soldering

This type of connection is an improved version of twisting wires. And at the same time, the quality is much higher than in the absence of solder. In addition, by coating copper wire (which is now much more commonly used than aluminum) with molten lead-tin mass (tinning procedure), reliable protection against oxidation due to high humidity can be provided.

The solder itself, based on its composition and melting point, can be of several types:

• POS 15 (280o);
• POS 25 (206o);
• POS 33 (247o);
• POS 40 (235o);
• POS 60 (191o);
• POS 61 (183o);
• POS 90 (220o).

With this method of installing a multi-core wire with a single-core wire, for a high-quality connection, all the wires must be tinned with rosin (flux) and the solder itself.

Tinning and soldering techniques

The procedure is carried out as follows:

1. Conductors must be stripped of insulation (a small area) and traces of oxidation (if present).
2. After the soldering iron has warmed up to operating temperature, they should heat the rosin. And after it melts, dip the wire.
3. Next, put a little solder on the end of the soldering iron tip.
4. Now, making smooth movements along the core line, the solder is transferred to it.

After the tinning procedure, the wires can be connected by twisting, which was described above. Just before pulling them off, it is necessary to remove evaporated flux residues from the surface. And since the wires are now more rigid, you should use pliers to ensure secure twisting.

What is the best way to connect solid and stranded wires? Now all that remains is to heat the joint until the solder melts. If necessary, you can add a little more. Copper is a good conductor of heat, so due to the strong heating of the conductive wires, the insulation may melt. For this reason, you should opt for solder with an optimal melting point. It is also worth reducing the duration of exposure to the soldering iron.

Crimping method

With this method of connecting wires, additional equipment will be required, since it is carried out by crimping with sleeves. They can be made of copper or aluminum, depending on the material of the conductors themselves. The main thing when installing a stranded wire with a single-core wire in this way is to choose the right size. In each specific case, this is done taking into account the diameter and number of cores.

Almost the entire space of the sleeve should be filled with conductive ends, but at the same time there should be some free space left. For this reason, it is necessary to select the correct dimensions of the sleeve, since the quality of the crimp depends on this factor.

Actually, this is the main difficulty of this method of connecting wires - the sleeve should not be too large or small. The procedure itself looks like this:

1. First, you should strip the ends of the wires from insulation (the length of the section should slightly exceed the dimensions of the sleeve).
2. Each core should be stripped to bare metal. Oxides can be removed with fine-grain sandpaper.
3. Next, the wires are twisted in a way that is already familiar to us.
4. Upon completion of the process, the sleeve is compressed with special pliers.

Connecting a stranded wire to a single-core wire does not cause any difficulties. Difficulties arise only at the stage of selecting cartridges and the presence of pliers. Of course, you can use pliers or pliers for this purpose. However, no one can give any guarantees regarding the reliability of such a connection.

Using Terminal Blocks

The wire connections listed above in any case have certain disadvantages. And twisting is generally prohibited by the rules of electrical installations (PUE), although this method is still in use today. They are unreliable, short-lived, and some methods require special electrical tools or appropriate professional skills.

Not every home craftsman has the soldering skills to connect stranded wires to single-core ones. Although the procedure does not seem so complicated. Moreover, how can it be done when the object is de-energized? Even bigger problems arise when it is necessary to deal with wires made of different metals. They cannot be connected by twisting.

However, despite these difficulties, there is a sure way out, which is to use different terminal blocks. There are a great variety of them today, and they are designed for almost any situation. What can the stores offer?

Types of pads

By and large, it is the terminal elements that ensure high quality wire connections. Moreover, this is not only a guarantee of their reliable fixation, the electrical contact itself is quite strong. The conductive surface of terminal blocks is usually made using brass or any other material that is not able to interact with either copper or aluminum.

You can easily connect a stranded wire to a single-core wire using such elements. Moreover, they can even be heterogeneous in nature.

Of the variety of terminal blocks, two main groups can be distinguished:

• Clamping elements. The core is fixed with a built-in spring.
• Screw structures. The wire is clamped directly with a screw.

Regarding the use of screw terminal blocks, it is worth keeping in mind that both aluminum and copper are quite soft materials.

Therefore, excessive tightening can result not only in thread breakage, but also in squeezing of conductive wires. The possibility of their breakage cannot be ruled out either.

Knife and pin connection

Essentially, this is a plug-in type of connection, which is very easy to implement. A kind of socket or socket is attached to the end of one of the wires (by crimping or soldering), and a pin or plug is attached to the other. The connection is made as simple as pie: the plug is inserted into the socket.

At the same time, this method of connecting a stranded wire to a single-core wire has more disadvantages than advantages:

• neither the pins nor the sockets are designed for high current;
• the structure is often bare;
• The process takes quite a bit of time (crimping or soldering), and is also quite labor-intensive.

As for the advantages, there is, perhaps, only one thing - the ease of connecting and disconnecting the circuit. In this regard, this technique is relevant only in cases of equipment installation, rather than for electrical wiring.

Features of insulation of electrical connections

It is important not only to ensure a strong and reliable connection of the wires, it is also necessary to take care of high-quality insulation of their exposed parts. This will prevent accidental contact of conductive elements with the human body or with each other. Neither one nor the other ends well.

When thinking about how to connect a stranded wire to a single-core wire, you should take time to choose the insulation material. It will largely depend on the operating conditions of the electrical contact. In most cases, it will be sufficient to stick with heat shrink or vinyl tubing, including the use of special insulating tape.

When exposed to high temperatures, use varnished cloth and fabric insulating tape to seal the joint. This insulation can withstand temperatures up to 100°C for long periods of time.

Source: https://FB.ru/article/452650/kak-soedinit-mnogojilnyiy-provod-s-odnojilnyim-opisanie-sposobov-osobennosti-montaja

How to connect stranded and solid wires - and do it correctly

We connect single-core and stranded wires

How to connect a single-core and stranded wire so that this does not lead to problems in the future, and the contact connection serves us for many years? And in general, how to properly connect different types of wires?

We will try to answer all these questions in our article, and we will also analyze what such rules are associated with and what dangers are hidden behind an incorrect connection.

Why contact connections must be made correctly

First of all, let's look at what the requirements for high-quality contact connections are related to. It is not without reason that clause 2.1.21 of the PUE separately stipulates methods for connecting wires, and allows only screw or bolt clamps, crimping, welding or soldering.

Poor contact is the main cause of fires

• This is primarily due to the fact that these types of connections can provide the required level of durability and reliability of the connection. After all, any electrician will tell you that more than 90% of all damage occurs at contact connections, and that is why so much attention is paid to them.
• After all, what is a poor-quality contact connection is a connection that has a high contact resistance. And since we have resistance, this means heating.

Dependence of resistance on conductor temperature

• As we remember from the physics course, any conductor in a heated state has greater resistance than a conductor with a lower temperature. Therefore, an avalanche-like process results. A poor-quality contact connection causes the conductor to heat up and its resistance increases even more. As a result, it heats up even more until it reaches the point where it simply melts.
• As a result, our main task is to ensure minimum resistance between the two conductors being connected. This is achieved by ensuring the proper area of ​​contact between the two conductors, as well as by ensuring the maximum possible contact between them.
• Let's immediately look at why we will not consider the question of how to twist single-core wires or their multi-core counterparts. Indeed, with the right approach, and through twisting, it is possible to ensure a sufficient area of ​​contact and compression of the conductors with each other.

Twisting is prohibited

• The fact is that in any case, the contact connection will be subject to temperature influences. That is, it will heat up and cool down. And as we know, heating leads to expansion of materials, and cooling, accordingly, to contraction. As a result, our contact connection, which is not fixed by any third element, can quickly become of insufficient quality.

Note! Surely each of you can give dozens and hundreds of examples where twisting has lasted for decades, and even now looks better than screw or bolt connections.

But, as they say, exceptions to the rule only confirm the rule itself. According to statistics, twisted joints are damaged much more often than other types of joints.

Correct connection of conductors

Now we can talk about how to correctly connect a single-core and stranded wire, two single-core or two stranded wires. And also, which type of connection for each of these types will be optimal, and which should be used only with certain restrictions.

Connection using the compression method

By compression method, PUE means screw or bolt connection of conductors. The same type of connection includes the now popular Wago terminals, which use the compression method through the use of springs or special mechanisms.

Different types of terminals and lugs for connecting wires

• At the moment, the compression method is one of the most popular joining methods. After all, the price of terminals based on this method is one of the lowest. The installation process is simple and does not require additional equipment, and the method itself is quite reliable.

Note! Here and below we give examples of connecting conductors of small cross-sections, up to 16 - 25 mm2.

For larger cross-section wires, these rules are not always suitable - or they have their own nuances.

• For wires of small cross-section, the screw connection method is predominantly used - or the compression method using a special mechanism. The essence of the screw method is that two conductors are installed in a brass tube, which are then each clamped with its own screw.
• This method is well suited for connecting two single-core copper conductors. If aluminum is used, then this material is softer, and when clamping it with a screw, you can either critically reduce its cross-section or completely crush it. Therefore, for aluminum wires, the use of this method is undesirable, or it should be used with extreme caution.

In the photo - a tip for a stranded wire

• Using a screw clamp to connect multi-core wires is also associated with the possibility of breaking individual wires that make up the conductor in whole or in part during the process of tightening the screw. To protect the wires from mechanical influences, special tips should be used.
• Using special lugs, stranded wires can be connected both to each other and between single-core wires using screw terminals.

Screw terminals with clamping pad

• There are screw terminals with a special clamping pad, which provides clamping over the entire cross-section of the brass tube. In this case, the use of special lugs for stranded wires is not necessary.

• As for Wago terminals and the like. There is still debate among electricians about their reliability and durability. Some argue that using springs in terminals is not the best option, others that it is very convenient and the springs are quite reliable.

Note: Experience carried out personally by the author of these lines confirms the reliability of such terminals under conditions of increasing current. But I cannot say how such terminals will behave over time. But be that as it may, such terminals make it possible to ensure contact of wires of any type quite reliably, quickly and efficiently.

Connection by pressing method

The instructions also provide for connection using the pressing method. This method requires the presence of a special tool - pliers. This tool comes in manual and hydraulic types. For small cross-section wires, hand-type pliers are sufficient.

Sleeves for pressing wires

• Special sleeves are used for pressing. These sleeves can be aluminum, copper or brass. The first, respectively, are used for aluminum wires, the second for copper, and the third for connecting both copper and aluminum wires.

Wire crimping pliers

• For connections, the same lugs can be used as for connecting stranded wires to screw terminal blocks. They are usually used if it is necessary to connect several wires in front of the terminal block.

Pressing of stranded wires

• The pressing method can be used to connect any wires: single-core, multi-core, or a combination of both. The main thing here is to correctly determine the type of sleeve and the pressure force.

Welding connection

Connecting wires using the welding method is one of the most reliable. At the same time, it is quite difficult to implement it with your own hands due to the need for a special welding machine.

Connecting wires by welding

• The essence of this method is that the ends of the conductor strands are melted using a welding machine. When they harden, they form a single whole and provide reliable contact.

Wire welding machine

• You can connect an almost unlimited number of conductors at one point in this way, which is an undoubted advantage. At the same time, connecting single-core and multi-core conductors to each other is fraught with certain difficulties.
• If no special work is required to connect single-core and stranded wires to each other, then to connect these two types of conductors to each other you will have to perform several additional operations.

Welding stranded wires

• In this case, you need, as shown in the video, to first melt the end of the stranded conductor so that it becomes a single whole. And after this, the termination is connected to a single-core conductor. Otherwise, you may experience burnout of individual conductors of a stranded wire, and only partial connection of the conductors with each other.

Solder connection

The last option in our article, but far from the least popular, is connecting conductors by soldering. To use this method we need rosin, soldering oil, solder and, of course, a soldering iron.

To connect two single-core conductors, it is enough to strip them, treat them with rosin and solder them. Moreover, if a single-core tinned wire is soldered, then it does not even need to be treated with rosin.
Soldering connection of stranded wires	Soldering multi-core wires is difficult because we have to work hard to clean all the conductor wires. However, it may not be possible to completely clean them. Therefore, solder fat is often used for their processing. Although for conductors with a small cross-section, consisting of only a few wires, rosin can also be used. Subsequently, the stranded conductors are connected to each other with a pigtail or twist, and processed with solder.
Non-separable option for soldering single-core and stranded wires	If we need to connect single- and multi-core wires together, then everything is a little more complicated. After treating the surface of both conductors, the stranded wire is wound onto the single-core wire. After this, the single-core wire is bent and crimped with pliers in such a way as to clamp the twisted area. Then this place is treated with solder fat, and then solder.
Separable soldering of single- and multi-core wires	The second option involves treating the conductors separately with solder fat and rosin. They are then connected in parallel and the entire joint is treated with solder. Such a connection is more advantageous from the point of view of its further dismemberment.

Conclusion

Single-core tinned wire, stranded wire, or any other types of wires can always be reliably connected to each other. There are usually several options available.

But at the same time, you should choose not only the simplest and most accessible, but also the more reliable method. Indeed, to a greater extent, the reliability of your entire electrical network depends on the quality of your contact connections.

Source: https://Elektrik-a.su/energii/soedineniya/kak-soedinit-mnogozhilnyj-i-odnozhilnyj-provod-253

How to correctly connect a stranded wire to a solid one

Wires and cables are structures represented by one or more conductors isolated from each other and enclosed in an insulating sheath. Before connecting a stranded wire to a single-core cable, it is very important to determine the physical and mechanical properties of the contact used, as well as all the installation features and operating rules of such electrical products.

In what cases is it necessary to connect a stranded wire to a single-core cable?

In accordance with the current PUE clause 2.1.21, several acceptable methods of wire connection are separately specified, represented by screw or bolt clamps, as well as crimping, connection by welding or soldering.

Main Application:

• overhead power transmission lines;
• connections in high-power electrical networks;
• fixed connection;
• temporary connections;
• outdoor installation;
• assembly of groups of connections in electrical panels for various purposes;
• standard living conditions.

Correctly performed connection of a stranded wire with a single-core cable helps ensure proper reliability and durability. If the connection requirements are met, it is possible to obtain the highest quality connection that can be used in almost any area of ​​modern electrification.

How to connect a stranded wire to a solid wire

The main installation task when connecting a multi-core wire to a cable with a single core is to obtain the most reliable and durable contact at the connection sites while minimizing the risk of overheating at the point of the electrical circuit. Although connecting wires involves the use of several methods, to determine the optimal method, you need to evaluate all their advantages and disadvantages.

Terminal block method

Modern devices based on high-strength plastic with an installed brass bushing and easy-to-tighten double-sided screws are the best option for self-connection.

The connection method involves only a few steps

Execution technology:

1. Stripping the cores at the ends of the wires.
2. Placing a pair of stripped ends inside the block.
3. Tightening the assembly screws with little physical effort.

The advantages of this method are its low cost, reliable connection and the possibility of using wires made of various materials.

Spring terminal method

Modern terminal devices are distinguished by the presence of a special convenient mechanism that allows you to carefully fix the wires without damage.

Unlike conventional terminals, spring terminals are equipped with a special locking mechanism

The execution technology involves:

1. Stripping the cores at the ends of the wires.
2. Lifting the lever or pressing the terminal spring.
3. Placing the ends stripped of insulation into the openings of the junction box.
4. Release of the spring or lowering of the terminal lever.

Disposable and reusable devices today are available in a wide variety of price categories, which allows you to choose the optimal model depending on the operating conditions. The advantages of this option also include the ability to connect multi-core thin wires, compact dimensions and the presence of a convenient built-in indicator for monitoring the operation of the electrical network.

Source: https://aqua-rmnt.com/ehlektrosnabzhenie/kak-soedinit-mnogozhilnyiy-provod-s-odnozhilnyim.html

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:

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

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 cross section is selected depending on the load:

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

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

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:

Simple connection methods that do not require tools or knowledge:

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

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

With soldering

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

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

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

No soldering

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

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.

Is it possible to connect cables by twisting?

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

Stranded and single-core

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

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

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

Twisting methods

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

Correct twisting of electrical wiring in a junction box

When twisting, you need to follow the following procedure:

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

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

Twisting of different sections

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

Twist caps

The caps help to reliably insulate the contact point. The cap is made of fire-resistant material, inside it there is a metal part with threads.

Making twists using caps is quite simple - you need to remove 2 cm of insulation and lightly twist the wires. A cap is put on them and turned several times until the metal wires are inside.

With terminal clamps

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

How to brew twist

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

Methods for connecting wires or cables to each other

The junction of two conductors must meet the following requirements:

• reliability;
• mechanical strength.

Source: http://gidpotolok.ru/info/kak-pravilno-soedinit-mnogozhilnyj-provod-s/

Connection of stranded wires: with single-core wires, with each other, soft and hard

A high-quality electrical connection is the most important requirement for home safety. Unreliable contact can lead to a short circuit and fire, so it is important to be able to efficiently and reliably connect two conductors in a junction box. There are different methods of creating a contact, and they all have their own characteristics.

The need for a reliable connection

Poor connections become the main cause of fires

First of all, you need to understand why it is so important to pay attention to the reliability of the conductor connections. Even the PUE give recommendations on the choice of connection method and strictly prohibit twisting of wires.

Consequences of incorrectly connected conductors:

• Fire. A poor-quality contact has a high contact resistance. This leads to heating, which can later lead to a fire.
• Damage to wiring. Due to high resistance, the conductor heats up faster. As a result, the insulation may melt and the contact itself may collapse. Damage to the insulating layer may result in electric shock.
• Short circuit. It also depends on the value of the contact resistance.

High contact resistance leads to negative consequences. Therefore, it is important to reduce it, for which permitted methods of connecting multi-core conductors are used.

Connection methods

Various types of wire connections

Of the permitted methods, the PUE allows you to create a contact in the following ways:

• clamps;
• terminals;
• crimping;
• soldering, welding.

Twisted connections are prohibited. This is due to the fact that the contact will be exposed to temperature. As the temperature rises, the material expands; when cooled, it contracts. Since the contact is not secured by anything, it will quickly fail and collapse. Twisting can only be used in conjunction with another joining method, such as welding or soldering.

Squeeze method

WAGO connection terminals

This method includes screw and bolt connections, as well as contact using Wago clamps. Such mechanisms allow you to connect single-core and stranded copper wires. At the moment, this method is the most common and convenient. The advantages include low cost, reliability, simplicity of the process and no need to purchase additional equipment.

It is better to connect wires with a cross-section of up to 25 sq. mm in this way. Conductors with a large cross-section require a different connection or it will be necessary to take into account the nuances of contact using the compression method.

Screw connection is used for cables of small cross-section. Its essence is to install two conductors into a brass tube and clamp each section with its own screw. When connecting solid and multi-core cables, there is a risk of damaging the thin wire.

For this reason, it is recommended to protect them with a special tip. There are special terminals with clamping pads that do not require the use of lugs.

They provide high-quality clamping without damaging the wire over the entire cross-section of the brass tube.

Wago terminals are a variation of the squeeze method. They are reliable, but experts debate the durability of such products. Advantages: speed of work, quality of contact, simplicity.

Pressing method

Wire crimping options

Crimping of wires is carried out using a special tool - pliers. It can be manual or hydraulic. For conductors with a small cross-section, hand pliers are suitable.

You will also need special sleeves made of copper, aluminum or brass. Selected for the appropriate material of the cable cores. If you need to connect several stranded wires in front of the terminal block, lugs are used.

Pressing is used for all types of cables - multi-core, single-core, or combinations thereof. It is only important to choose the right type of sleeve and pressure force.

Welding method

When welding wires, tin solder is used

Welding wires is the most reliable and durable connection method. Its only drawback is that it is difficult to implement with your own hands, since the work will require a professional welding machine. There are also requirements for the experience of the master - if you do not have the necessary skills, you should choose another connection method or entrust the work to a professional.

Using a welding machine, the ends of the wires are melted. When they harden, a single whole is formed between the two segments and high-quality contact is ensured. Using this method, you can connect an unlimited number of conductors at one point. But you need to understand that difficulties will arise when contacting a single-core and multi-core cable. The technician will need to perform a few additional steps before welding. Connecting a four-core wire to a single-core wire:

• Melting the end of a stranded wire.
• Connection of a molten conductor with a single-core segment.

If the welding technique is violated, individual wires may burn out and contact will not be ensured for all wires.

Soldering

To solder two sections of cable, you will also need additional tools - a soldering iron, rosin, solder, solder fat. The master must be able to solder, otherwise reliable contact will not be possible.

How to twist a stranded wire together with a solid one:

1. Stripping of insulation.
2. Treatment of the surface of both conductors with rosin.
3. Winding a multi-core cable onto a single-core cable.
4. Bending a single-core cable, crimping with pliers.
5. Treating the area with solder grease and solder.

There is also a connection option when the treatment with fat and rosin is carried out separately for each part of the wire. Then the conductors are connected in parallel and the contact area is treated with solder.

Single-core conductors are easier to connect. To do this, it is enough to strip them of insulation and treat them with rosin. Then the cables need to be soldered. If a tinned single-core conductor is used for connection, rosin treatment is not required.

Stranded wires are also stripped of insulation. This can be more difficult since each core has its own insulating layer. Next, the conductors are connected with a pigtail or twist and processed with solder.

Connection of flexible and rigid wires

Connection of flexible and rigid wires

Typically, conductors of the same type are connected. But sometimes a connection between a flexible and a rigid wire is required, which is carried out in compliance with some nuances.

First, cut the cable so that its end is tapered. The rigid wire needs to be melted and a loop made at its end. A thin wire is passed through the loop made and wrapped around the rigid cable. The resulting connection must be treated with solder and reliably insulated. A similar method is suitable for aluminum conductors.

Source: https://StrojDvor.ru/elektrosnabzhenie/kak-soedinit-odnozhilnyj-i-mnogozhilnyj-mednyj-provod/

Connection of stranded and solid wire

Wires and cables are structures represented by one or more conductors isolated from each other and enclosed in an insulating sheath. Before connecting a stranded wire to a single-core cable, it is very important to determine the physical and mechanical properties of the contact used, as well as all the installation features and operating rules of such electrical products.

Engineering systems

When installing electrical wiring in buildings, one of the key points is wire switching. Very often it is necessary to connect stranded and solid wires. The differences in their structure determine certain switching features. If you do not take them into account, you will not be able to ensure a high-quality connection, which can cause serious problems. Therefore, you need to know how to connect a stranded wire to a solid wire correctly

Contents:

Why is it important to connect wires correctly?

The most vulnerable point of any wiring is the wire connections. If they are performed poorly, reliable contact is not ensured, which leads to a significant increase in the transient electrical resistance. As a result, the junction of the wires begins to heat up.

As is known, the resistance of an electrical conductor is directly dependent on its temperature. Therefore, heating the connection zone leads to an additional increase in resistance, which further increases the temperature increase.

Thus, if there is poor contact in the area where the wires are connected, a temperature limit can very quickly be reached at which the insulation begins to melt and a fire occurs.

In this regard, a poorly executed connection of single-core and stranded copper wires can cause a fire. In the most harmless case, the wiring may fail. However, repairs can be very problematic, since finding the location of damage in the wall is often very difficult. In such cases, it is often necessary to completely change the wiring or its problematic part.

Very often, in domestic conditions, contact connections are made by twisting. This is the simplest method that does not require the use of a special tool. A well-made twist provides a fairly low degree of transition connection. However, the problem is that such a connection is fixed only due to the elastic force of the twisted wires.

During operation of the electrical network, the connection will experience alternating temperature effects: under load it will heat up, after removing the load it will cool down. As a result, the twist, which does not have additional fixation, gradually weakens under the influence of temperature expansion. Over time, the contact becomes too poor and intense heating of the switching zone begins.

An additional problem is that twisting solid and stranded wires is very difficult. This is due to the difference in their hardness. Therefore, the contact may initially be of poor quality.

To avoid such problems, you need to know how to connect solid and stranded copper wire so that the transition resistance is minimal. This is achieved by pressing the conductors as tightly as possible and ensuring maximum contact area. In addition, the connection must be securely fixed.

Such switching is provided by the following methods:

• compression method;
• commutation by pressing;
• switching by soldering;
• connection by welding.

Let's take a closer look at each of these methods of connecting a stranded wire to a solid wire.

Wire connection by compression method

For this method, special terminals are used, with which switching is performed. This is the simplest of the correct connection methods, which provides much higher reliability than simple twisting of single-core and stranded wires. In this case, the method does not require large expenses, since the terminals used are inexpensive.

The most common switching device is the screw terminal. This is a brass tube sealed with polyethylene insulation. The wires to be connected are inserted into the tube from both sides, each of which is clamped with a separate screw. These terminals are best suited for switching solid copper conductors. When connecting aluminum wire, you need to tighten the screw carefully.

This metal is softer, so if the clamping force is exceeded, the wire can be crushed by the screw. In the case of connecting a stranded copper wire with a simple screw terminal, the screw can pinch and destroy part of the wires, which leads to a decrease in the cross-section and contact surface, and therefore to an increase in resistance.

To avoid this, it is recommended to use special lugs for copper wires.

Special screw terminals with a clamping pad are also used, which have a more complex design. The wire in them is pressed not by a screw, but by a metal plate. Due to its large area, destruction by squeezing individual wires or an aluminum core is eliminated.

Welding connection

The connection of single-core and stranded wires by welding, provided they are performed correctly, ensures maximum reliability and efficiency in electrical terms.

The essence of the method is that, using a special welding machine, the current-carrying cores of the connected conductors are melted. When the metal cools, a monolithic compound is formed.

In terms of its conductivity, it is not inferior to a solid conductor, since with this switching method there is no transition resistance. The connection made by welding can withstand mechanical loads well.

In this way, you can connect wires of almost any type with each other. The number of connected conductors can be any. However, it is important to know how to connect solid and stranded wire correctly. Installation by welding is performed after twisting the wires. Before twisting a stranded wire with a solid wire, it must be thoroughly cleaned.

After this, the end of the stranded wire should be processed with a welding machine. At the same time, it must fuse into a single whole. After this, the conductors are twisted together and their ends are melted with a welding machine to form a reliable and high-quality connection.

If installation is carried out without first melting a stranded wire, then its individual wires may burn out during welding, which will lead to a decrease in cross-section, and therefore an increase in resistance at the junction.

If you need to connect a single-core wire with a stranded one

Rigid wire is convenient when laying stationary networks in a hidden or open way. Its monolithic rod fits well under the screw and terminal. But the low mechanical resistance to repeated bending limits when it is necessary to connect equipment whose position changes. Then, if all the wiring is not laid with a soft cable, you need to connect conductors of different designs.

This article will tell you how to properly connect stranded copper wires with single-core ones.

The need to make correct contact

The reliability of a section of a circuit or an entire power supply network depends on the quality of workmanship and the tightness of the joint.

Electrical engineering operates with the concept of transient resistance to electric current that arises along the boundary of the inhomogeneity of two media. The surface of the metal, under the influence of atmospheric oxygen, becomes covered with an oxide film, which increases the value of contact resistance. The contact area of ​​the conductor cores is of great importance; it must be larger than the nominal cross-sectional area of ​​the core.

When connecting wires, the following requirements apply:

1. Thorough cleaning of the connected cores from oxide;
2. Obtaining the normal contact area of ​​the wire surfaces:
3. Guarantee of maintaining contact density throughout the operation of the electrical network.

To illustrate, let’s take a job not permitted by the PUE, simple twisting of wires. The ends of the cores, pre-cleaned from oxide, twisted 8-10 times, fulfill the first two points of the requirement. But any metal, even relatively ductile copper, has residual elasticity, which over time weakens the twists.

A microscopic gap is formed between them, which is filled with air, causing the formation of oxide. The increased contact resistance begins to heat up when current passes, although the load has not changed. Linear thermal expansion of the metal leads to an increase in the gap and a decrease in the contact area. This increases the current density, increasing the heating of the metal.

The contact deteriorates like an avalanche, and the temperature of the joint rises.

Strong heating of the joint will destroy it, but more often the high temperature of the joint will ignite nearby flammable materials before the current is interrupted. A fire breaks out, and no one can predict the severity of the consequences. Compared to this, the activation of protective automatics and disconnection of a section of the circuit shorted by melted insulation will seem like a blessing that only requires repair of the wiring.

Design difference

Let's figure out what determines the flexibility class of cables.

https://www.youtube.com/watch?v=a2J-6t4Rfb0

A single-core wire has a monolithic core of one wire of the required nominal cross-section. The limit of resistance to bending before breaking is different for different materials. Copper can withstand about 80 bending cycles; for aluminum this figure rarely exceeds 10. This is the first class of flexibility.

The core of a multicore cable is made up of a large number of thin wires twisted together, the sum of the cross-sections of which forms the nominal value. The cross section of the core resembles the design of a metal cable. The number and thickness of the wires determine the degree of flexibility. The maximum number of bending cycles reaches more than 30,000 for grade 5 copper conductors.

A soft cable is convenient for connecting the terminals of sockets and lamp sockets, where the monolith often breaks off. It is convenient to turn on the cooking surface of the electric stove, which has to be moved when cleaning. Permanently connect a washing machine that vibrates during operation to the network.

Preparing a Stranded Conductor

The basis of any connection is the removal of insulation on the desired length of the conductor.

When stripping the end of a stranded copper conductor, it turns out that the thin wire cable begins to change shape. Before this, the twist was held in place by a layer of insulation, but now the hold is gone, residual elasticity causes the wires to straighten, and the rod fluffs up into individual elements. Each unconnected wire:

• Reduces the overall nominal cross-section of the joint, the permissible current density through the contact drops, the temperature rises;
• If left outside the insulation, it may cause electrical injury and short circuit.

Pre-treatment of the stripped ends of the stranded wire is required to prevent fraying and obtain a homogeneous, monolithic section.

Service

Until recently, one of the more accessible, popular methods of preparation was tinning. For this:

• The insulation is stripped to the required length, the wires are carefully twisted tightly together;
• Using a heated soldering iron, melted rosin is transferred to the surface of the core. The metal warms up, the rosin impregnates the wire rope;
• The tip of the soldering iron tip picks up solder and transfers it to the tinning site. The solder spreads over the surface of the hot wires, filling all the gaps, forming a molecular bond with the metal;
• After cooling, the remaining rosin is removed with gasoline or alcohol, and the surface is treated with sandpaper to remove possible “strings” of solder in the form of thin long needles.

Has the meaning:

1. Rosin is a flux that is used during soldering to remove oxides from the metal surface, improves heat transfer and heat distribution at the soldering site. For tinning the conductors, it is prohibited to use fluxes containing acid or other active components for removing oxide, which will lead to destruction of the conductor;
2. Lead-tin solder is used. The retail chain offers a huge number of solder pastes, consisting of a mixture of solder and flux. They are very comfortable. It is allowed to use only those that have a mark on the trade label indicating that the flux is not active.

The prepared tinned end is used for any type of connection - bolted, terminal, clamped, welded.

But, if the soldering iron is still hot, the easiest way is to tin the same hard conductor and connect them by soldering. The result is a strong, reliable joint with minimal contact resistance.

The method requires a soldering iron, consumables, the presence of electricity at the installation site, work skills, careful careful execution, and takes a lot of time.

Crimping

This method of preparing the stripped end of a flexible core requires the presence of press jaws and consumables - sleeves, the internal diameter of which corresponds to the diameter of the core. The process takes incomparably less time and labor than tinning:

• The stripped end of the strand is twisted tightly and placed in a sleeve;
• Press pliers compress the outer surface of the sleeve, tightly clamping the wire with the body. The resulting dents hold the cores more securely.

The finished pressed end is used in any type of joint. If you need to connect it to a single-core one, it makes sense to immediately take a sleeve, the diameter of which will allow you to place two conductors inside it. Simultaneous crimping will give a good joint. In this case, preliminary tinning of the stranded wire is not required.

Types of connection

Joining by soldering and pressing has already been considered. Other methods:

• Bolted, with washer:
  • Tinned stranded and monolithic ends are bent into a loop, the internal diameter of which is equal to the diameter of the bolt;
  • On the bolt, alternating, put on: a steel washer - a loop - another washer - a second loop - the last washer;
  • This cake is held in place by a nut through a washer - a groover, which prevents the twist from loosening.
• Terminal, screw. The prepared ends are inserted into the terminal block sleeve and clamped with two screws. If the size of the terminal tube allows, pre-twist the cores. This is used in a terminal distribution box, where the nut is pressed into the box body and there is a screw and washer.
• Self-clamping spring. Fashionable quick way. The prepared end is inserted into the socket, where it is clamped tightly with a special spring. The sockets are connected to each other by a plate that ensures contact. To create a quick-release joint, WAGO terminals with a locking lever are used, by folding which you can remove the wire;
• Welded, with a welding machine or inverter. Tinning or pressing the end will prevent the wires of the multi-core conductor from fluffing up and will ensure that they all participate in creating the contact.

In conclusion, it must be said that connecting wires by simple twisting is not permitted by the PUE. It is recommended to use it as rarely as possible, to temporarily turn on not very critical places in the network.

If you need to connect a single-core wire with a stranded one Link to the main publication

Source: https://VseOToke.ru/montazh/esli-nuzhno-sostykovat-odnozhilnyj-provod-s-mnogozhilnym

How to connect a stranded wire or connect it to a solid wire

You are here: Stranded wire strands consist of thin copper strands twisted together, which is why they are commonly referred to as “stranded.” They are used for extension cords and connecting household appliances; it is not recommended to use them for wiring. Despite this, they are often used specifically for house wiring. In production, they are used to assemble electrical panels, both power and operational circuits.

However, connecting a conductor causes a lot of inconvenience, and all of them are related to its design. The main task of the installer connecting a stranded wire or cable is to achieve the most reliable contact at the connection point, and thus reduce the likelihood of heating at this point in the circuit.

In this article we will try to explain in detail how to correctly connect stranded wires with solid wires and how in general you can connect a stranded wire to any device.

Rules for connecting a stranded conductor

Very often, when laying a multi-core cable or wire, it becomes necessary to connect it to such common elements of the electrical circuit as a circuit breaker, socket, meter, plug, lamp socket, and so on.

Most often, copper wires are used, especially in everyday life. The task is to ensure reliable contact with the clamping bolted connection of these devices and devices, and therefore to make the stranded wire as monolithic and homogeneous as possible.

You can perform this procedure in several ways:

• Twist all the thin strands into a tight bundle and, if the cross-section allows, bend it in the opposite direction. This can be done with pliers or by hand, it all depends on the cross-section of the conductor. This method is the simplest and is used in modern wiring only in emergency cases, but it also has a right to exist. It will not be possible to perform this procedure with a large cross-section cable in this way, so it is more suitable for supplying voltage to a plug, socket, or socket of a low-power lighting fixture.
• By tinning the conductor. This method is more effective than the previous one and will ensure reliable contact. Its main disadvantage is that you do not always have a soldering iron at hand, and even electricity for its operation. Tinning can be done either with a straight conductor or with a terminal block bent into a ring along the diameter of the bolt, but before doing this, again, it is necessary to tightly twist all the thin wires. This method can be applied in all cases of connection to electrical appliances, to a machine, socket, etc., if the cross-section allows it.
• Tip crimping. The tips allow you to achieve reliable and durable contact without soldering. There are two types of tips: bolt-on and simply sleeved. Depending on the element to be connected, you need to select the appropriate type and appropriate cross-section. With a tip and sleeves you can connect any type of cable, of any cross-section, both stranded and single-core, but for this you will need a special tool that will need to be purchased before carrying out installation work, especially at a professional level. Connecting a stranded wire in this way in the panel, to the terminal block, to the meter not only looks aesthetically pleasing and correct, but also reduces the likelihood of heating at the connection points. The photo below shows NShVI type lugs on stranded wires.

Although tinning is a good method, in practice the cores are often terminated with lugs; this is faster, easier and often more reliable than other methods. However, do not crimp the tips with pliers - the core will simply jump out of them and you will not get a good connection. To do this, it is better to buy crimping pliers with square dies; you can find them for about 1000 rubles.

Connection of solid and stranded wires

There are times when it becomes necessary to connect single-core and stranded wires together.

In this case, you immediately need to pay attention to the materials from which they are made, since copper and aluminum will inevitably enter into a chemical reaction over time, oxidation and disruption of electrical contact will occur, which will lead to heating and an emergency situation.

The connection of an aluminum wire with a copper wire should be done through a bolted or terminal connection, using any of the methods of fixing a stranded wire described above and used to form a monolithic structure.

If you need to connect a single-core and stranded copper wire, this can be done in several ways:

1. Twist as shown in the photo below.
2. Twisting followed by soldering.
3. Using a terminal block.
4. Putting the ends under the bolt and pressing them.

After any connection is made, it is necessary to carefully insulate this place with insulating tape or heat shrink.

But since twisting is prohibited according to Chapter 2.1 of the PUE, clause 2.1.21, this method is suitable for a temporary connection. It is better to make rings, tin them and connect them with a bolt, or use lugs with ring terminals. You can also use WAGO type terminal blocks.

Methods for connecting stranded wires

Let us now proceed directly to connecting two or more stranded wires. It should be noted that with a cross-section larger than 16 mm2 and with corresponding large loads, the connection of two or more cables by twisting is not performed, as it is considered unreliable and incorrect. This can only be done through the terminal block and using lugs.

However, when organizing lighting systems and connecting household appliances, a wire with a diameter of 1.5 is used; 2.5; 4 mm2, so let’s look at how to install them. In fact, twisting copper and aluminum wires is prohibited!

• Twisting two copper stranded wires. This connection is very simple and common in the form of parallel twisting, resulting in a reliable contact for such a cross-section and the current flowing through it, but does not withstand rupture well due to force and vibration.
• Twisting three or more wires. Similar to the previous one, but requires more effort and tighter twisting of the bundle.
• The serial connection of two stranded wires is the “winding” method. This technique will be needed if connected to the main line.
• Bandage. It is performed by twisting with a separate wire; it can be an additional element of the serial or parallel method. Provides additional tensile strength.

It is recommended that each of these methods, after twisting, be additionally pressed into a tip (sleeve) or soldered, which will improve its contact characteristics several times and increase reliability during operation.

Finally, we recommend watching video lessons that clearly show how to connect stranded wires:

It will be useful to read:

• Is it possible to change the wiring in parts and how to do it correctly

How to seal grooves for wiring - step-by-step instructions

How to replace wiring in a panel house - step-by-step instructions

Source: https://samelectrik.ru/kak-podklyuchit-mnogozhilnyj-provod.html