?> How to connect stranded and solid wire correctly

How to connect stranded and solid wire correctly

  1. Why contact connections should be made correctly
  2. Proper conductor connection
  3. Squeeze joint
  4. Compression by pressing
  5. Connection by welding
  6. Solder connection
  7. Conclusion

We connect single-core and stranded wire

How to connect single-core and stranded wire so that in the future it does not lead to problems, and the contact connection served us more than one year? Anyway, how to properly perform the connection of various types of wires?

We will try to answer all these questions in our article, as well as analyze what these rules are connected with, and what dangers lie behind the wrong connection.

Why contact connections should be made correctly

First of all, let's look at what are the requirements for the quality performance of contact connections. After all, it is not for nothing that clause 2.1.21 of the Electrical Installation Code separately specifies the methods of connecting the wires, and allows only screw or bolt clamps, crimping, welding or soldering.

21 of the Electrical Installation Code separately specifies the methods of connecting the wires, and allows only screw or bolt clamps, crimping, welding or soldering

Bad contact is the main cause of fires.

  • This is due primarily to the fact that such types of connections can provide an adequate level of durability and reliability of the connection. After all, any electrician will tell you that more than 90% of all damage occurs on the contact connections, and therefore they pay so much attention.
  • After all, what is a poor-quality contact connection is a connection that has a large contact resistance. And since we have resistance, it means heating.

Dependence of resistance on conductor temperature

  • As we remember from the course of physics, any conductor in a heated state has greater resistance than a conductor with a lower temperature. Therefore, an avalanche-like process is obtained. From a poor-quality contact connection, the conductor heats up, and its resistance increases even more. As a result, it heats even more - until the point at which it simply melts comes.
  • As a result, our main task is to provide minimal resistance between the two connected conductors. This is achieved by ensuring the proper area of ​​contact between the two conductors, as well as due to the maximum possible contact between them.
  • Let us see at once why we will not consider the question of how to twist the single-core wires or their stranded counterparts. After all, with the right approach, and by twisting, you can provide a sufficient area of ​​contact and compression of conductors with each other.

Twist Connection Prohibited

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

Note! Surely each of you will be able to cite dozens and hundreds of examples when twisting has stood for decades, and even now it looks better than screw or bolted connections. But, as they say, exceptions to the rule only confirm the rule itself. According to statistics, twist-type joints are damaged much more often than other types of joints.

Proper conductor connection

Now you can talk about how to properly connect single-core and stranded wire, two single-core or two multi-strand wires. And also, what type of connection for each of these species will be optimal, and which should be used only with certain restrictions.

Squeeze joint

By the method of compression, PUE implies a screw or bolt connection of conductors. The same type of connection can be attributed to the now popular terminals Wago, which use the method of compression by using springs or special mechanisms.

The same type of connection can be attributed to the now popular terminals Wago, which use the method of compression by using springs or special mechanisms

Different types of terminals and lugs for connecting wires

  • At the moment, the method of compression is one of the most popular methods of connection. 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! Hereinafter, we give examples of the connection of conductors of small cross section, up to 16 - 25 mm2. For wires of a larger section, these rules are not always suitable - or have their own nuances.

For wires of a larger section, these rules are not always suitable - or have their own nuances

Screw terminals

  • For wires of small cross section, the method of screw connection is mainly used - or the method of compression using a special mechanism. The essence of the screw method is that two conductors are installed in the brass tube, which are then clamped each with its own screw.
  • This method is well suited for connecting two single-conductor 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 even transfer it altogether. Therefore, for aluminum wires using this method is undesirable, or it should be used very carefully.

On a photo - a tip for a multicore wire

  • The use of screw clamp to connect stranded wires is also associated with the possibility of breaking the single wires that make up the conductor in whole or in part in the process of twisting the screw. To protect the wires from mechanical stress, special tips should be used.
  • With the use of special lugs, stranded wires can be connected both between themselves and between single-core wires - using screw clips.

Screw terminals with clamping plate

  • There are screw terminals with a special clamping pad, which provides a clamp across the entire cross section of the brass tube. In this case, the use of special tips for stranded wires is optional.

Wago terminals

  • As for the terminals Wago and the like. Until now, electricians have debated their reliability and durability. Some argue that the use of springs in the terminals is not the best option, others that it is very convenient and the springs are quite reliable.

Note: The experience personally conducted by the author of these lines confirms the reliability of such terminals in terms of increasing current. But here's how such terminals will behave over time, I can not say. But be that as it may, such terminals allow you to reliably, quickly and efficiently ensure the contact of wires of any type.

Compression by pressing

The instruction also provides for the connection by pressing. This method assumes the presence of a special tool - ticks. This tool is manual and hydraulic type. For wires with a small cross-section, hand-held mites are sufficient.

For wires with a small cross-section, hand-held mites are sufficient

Sleeves for pressing wires

  • For pressing used special sleeves. These sleeves can be aluminum, copper or brass. The first, respectively, are used for aluminum wires, the second for copper, and the third - for the connection and copper, and aluminum wires.

Wire crimping pliers

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

Pressing stranded wires

  • By pressing it is possible to connect any wires: single-core, multicore, and their combination with each other. Here the main thing - to correctly determine the type of liner and pressure force.

Connection by welding

Connection of wires by welding, is one of the most reliable. At the same time, it is rather difficult to realize it with your own hands, in view of the need for a special welding machine.

At the same time, it is rather difficult to realize it with your own hands, in view of the need for a special welding machine

Welding wire

  • The essence of this method is that the ends of the conductors of the conductors melt with the help of a welding machine. When frozen, they form a single whole, and provide reliable contact.

Welding machine for welding wires

  • It is possible to connect in this way a practically unlimited number of conductors at one point, which is an undoubted advantage. At the same time, the connection between single-core and stranded conductors presents certain difficulties.
  • If the connection of single-core and stranded wires between themselves does not require any frills, then to connect these two types of conductors between themselves will have to perform several additional operations.

Welding stranded wires

  • In this case, you need, as shown in the video, to first melt the termination of the multicore conductor, so that it is a single whole. And after that, the termination is connected to a single conductor. Otherwise, you may have blown individual conductors of stranded wire, and only a partial connection of conductors between themselves.

Solder connection

The last option in our article, but not the last in popularity, is the connection of conductors by soldering. To use this method, we need rosin, solder grease, solder and, of course, a soldering iron.

To use this method, we need rosin, solder grease, solder and, of course, a soldering iron

Solder wire

To connect two single-core conductors, it is enough to clean them, process them with rosin and solder. Moreover, if soldered single-core wire is soldered, then it can even not be treated with rosin. To connect two single-core conductors, it is enough to clean them, process them with rosin and solder

Solder connection stranded wire

  • Soldering stranded wires is difficult because in order to clean all the wires of the conductor, we have to sweat.
  • At the same time completely clean them may not work. Therefore, soldering fat is more often used for their treatment.
  • Although for small cross-section conductors consisting of only a few wires, you can use rosin.
  • In the future, stranded conductors are interconnected with a pigtail or twist, and are processed by solder.

Not folding option of soldering of a single-conductor and multicore wire

  • If we need to interconnect the single and stranded wire, then everything is a little more complicated.
  • After processing the surface of both conductors, the stranded wire is wound on a solid wire.
  • After that, the single-conductor wire is bent and crimped with pliers in such a way as to clamp the place of the twist.
  • Then this place is processed with soldering grease and then with solder.

Detachable soldering of single and stranded wires

  • The second option involves the processing of soldering grease and rosin conductors separately.
  • Then they are connected in parallel, and the entire junction is processed by solder.
  • Such a connection is more beneficial in terms of its further dismemberment.

Conclusion

Single-core tinned wire, stranded wire, or any other type of wire can always be reliably connected to each other. Several options are usually available at once.

But at the same time it is necessary to choose not only the most simple and affordable, but also a more reliable method. Indeed, to a greater extent, the reliability of your entire electrical network depends on the quality of your contact connections.