Connecting electrical wires - 8 best ways
Today, there are many ways to connect wires in a junction box.
These factors determine the choice of connector:
- Core material (copper or aluminum).
- Working conditions (on the street, in an apartment, in water, in the ground, in the floor, normal conditions).
- The number of conductors (two, three, four, etc.).
- Cross section (identical, different).
- Core structure (single-wire or multi-wire).
Based on these factors, the most suitable and correct method is selected. To begin, consider the materials with which you can connect the electrical wires in the junction box.
- Existing methods
- Using terminal blocks
- Spring terminals
- Installing PPE caps
- Crimping with special sleeves
- Soldering or welding
- Twist and isolation
- Nut Clamp
- Bolt use
- What to do if there are several wires?
- What if veins of different sections?
- Combining stranded and solid wires
- How to carry out work in water and land
The following connection options are considered the most popular and effective:
- use of terminal blocks;
- installation of spring terminals (wago);
- fixation with PPE (plastic caps);
- crimping with sleeves;
- installation of "nuts";
- the use of bolts.
Consider the nature, advantages and disadvantages of each of the methods!
Important! Immediately, we note that direct contact of aluminum with copper is not permissible, regardless of the type of connection. For this, adapter plates, washers, etc. are used. This issue is considered in more detail in the article: https://my.electricianexp.com/en/kak-soedinit-alyuminievyj-provod-s-mednym.html.
Using terminal blocks
Terminal blocks They are plastic products, inside of which there is a brass sleeve, which has twisted screws on both sides.
In order to connect two wires to each other using a terminal block, it is necessary to insert on each side at the end of the product and tighten them thoroughly with screws (with force). This connection method is most often used in junction boxes, as well as in installing chandelier, switches and sockets.
We draw your attention to the fact that terminal blocks come with a different inlet suitable for a particular section of the core.
- low price of terminal blocks;
- quick and convenient installation of products;
- good quality bonding;
- can connect aluminum with copper.
- Very often, terminal blocks are of poor quality, which can lead to breakage of the connector during installation.
- The ability to combine only two conductors with each other.
- It is not recommended that terminal blocks be used to tighten aluminum and copper stranded conductors. This is due to the high fragility of aluminum and the thinness of the conductors of the stranded wire: when tightening the screws, the contacts can be damaged.
- When using soldering, reliability will be much higher.
- Flexible multi-wire cores for connection in screw terminal blocks of any design (including circuit breakers, sockets, etc.) are crimped with lugs of the type NSHVI and the like.
Spring loaded wago terminals appeared on the market relatively recently and undoubtedly became the most effective and safe connectors.
The difference between the wagon terminal blocks and conventional terminal blocks is that a special mechanism is used to connect the electrical wires, not a screw. This lever-type mechanism allows you to gently fix the product without damaging it. In order to independently fasten the wagons, it is necessary to strip the insulation and insert the cores into the hole.
We draw your attention to the fact that there are disposable and reusable terminal blocks wagon. The first option involves a one-time connection, and it will not be possible to restore it during the repair of electrical wiring: it will be necessary to cut off the wagon, repair the problem and install a new terminal block. Reusable wago terminals are more expensive, but they can be used to easily disconnect a contact if necessary. ”
- depending on the terminal block model, the connection of copper and aluminum conductors is allowed, as well as the protection of aluminum from oxides using quartz-vaselin paste .;
- the ability to connect several cores at the same time (more than two);
- wago clamps allow you to fix a thin stranded wire without damage;
- terminal blocks are very compact;
- work does not take much time;
- good quality bonding;
- the car terminal block has a special hole that allows you to control the operation of the mains using an indicator screwdriver.
Only flaw - Higher cost of terminals, but this is not critical even for household wiring. It is also important to note that WAGOs are not suitable for connecting wires from powerful consumers, such as an oven or electric stove. These terminal blocks are more suitable for switching circuits in the outlet line, as well as lighting groups.
You can learn more information about using vag from our article: https://my.electricianexp.com/en/kak-soedinit-provoda-klemmami-wago.html.
Installing PPE caps
PPE stands for connecting insulating clamps. Products are ordinary plastic caps that have a special spring inside, which holds the wires.
Most often, such caps are used to connect the cores in junction boxes.
Benefits of using these products:
- low cost of PPE;
- caps are made of non-combustible material, therefore spontaneous combustion of electrical wiring in the place of twisting will not happen;
- quick installation;
- caps have a wide range of color shades. For example, if the wires do not have color marking, using PPE can be noted phase, zero and ground (using white, blue and green cap).
- relatively poor quality of insulation and fixation;
- it is impossible to connect aluminum with copper.
About how to use PPE for connecting wires, read our article: https://my.electricianexp.com/en/soedinenie-provodov-kolpachkami-siz.html.
Crimping with special sleeves
Crimping with sleeves is one of the most reliable options. Its essence lies in the fact that the bare veins are placed in a special tube - a sleeve, and crimped with effort. After crimping, the sleeve is carefully insulated with a heat shrink tube (cambric) or electrical tape.
Conductors can be routed from different sides of the tube or from one side. In the first embodiment, their joint should be approximately in the middle of the sleeve, in the second case, the cross-section of all cores (total) should not exceed the cross-section of the sleeve.
- high-quality connection and isolation;
- sleeves have a low cost.
- The sleeve is disposable (one-piece). If repair is necessary, the sleeve must be cut off and discarded, after which a new one must be installed.
- A special tool is needed for the connection: a press pliers and a pipe cutter (in order to shorten the sleeve if necessary). You can also use special stripping toolwhich has a compact crimp device.
- It is possible to compress aluminum and copper wire only with a special sleeve, which is not often seen on sale.
- Electrical work will require more time.
Soldering or welding
This method is the highest quality of all. In order to connect the two wires together in a junction box, it is necessary to carefully strip their ends, twist them and dip them into the molten solder. Further, the cores must be immersed in a soldering bath. After that, they should cool down and, in the end, be insulated with cambric or electrical tape.
If you do not have a portable crucible for soldering wires, you can do it yourself as shown in the video:
Or solder with a soldering iron, but in this case a 3-4x spike lived with a cross section of 2.5 square meters. mm is difficult. Therefore, for soldering thick wires, it is necessary that the soldering iron has a thick copper tip with good heat capacity and a power of 40, and preferably 60 watts or more.
We draw your attention to the fact that it is strictly forbidden to cool the solder in cold water, as in this case, the quality of bonding will noticeably deteriorate (due to the appearance of microcracks).
Advantage soldering method - excellent connection quality and reliability.
- the need for a special tool - a soldering iron and, accordingly, the ability to work with it;
- the complexity of the work;
- one-piece soldering;
- restriction in conditions of use according to PUE;
- soldering resistance increases over time, which affects voltage losses and electrical conductivity.
Based on this, soldering is recommended to be avoided using more modern bonding methods.
It should be noted that there is also a connection of electric wires by welding. The process is similar, but requires the use of a welding machine instead of a soldering iron, and, consequently, skills in welding.
These two methods of connecting wires in a junction box are discussed in detail in separate publications:
Twist and isolation
The old "grandfather" method consists in twisting the veins among themselves. The essence of the work lies in the fact that the conductors are stripped and carefully twisted with pliers, after which the place of twisting is isolated.
- simplicity of electrical work;
- lack of material costs.
- poor quality of vein bonding;
- connection of aluminum and copper products is unacceptable.
Most often twisting wires used in the installation of temporary wiring. For insulation, it is recommended to use cambric. According to the PUE, this method of connecting wires in a junction box cannot be used in rooms with high humidity and in a wooden house.
"Walnut" is a cable clamp that has two special plates and four screws in the corners, as can be seen in the photo below. For wire connections walnut it is necessary to strip the two ends of the wire and fix it in the plate, then put on the carbolite sheath.
- low cost of clamping;
- the installation process of the "nut" does not cause any difficulties;
- can connect copper and aluminum conductors;
- good enough insulation.
- it is necessary to periodically tighten all the screws;
- the dimensions of the "nut" are not suitable for installation in a junction box or other compact places.
A simple, but nonetheless effective option for connecting electrical wires to each other is with a bolt. All you need is to have a short bolt, 3 washers and a nut on hand.
A washer is put on the thread of the bolt, then a stripped core is wound, after which another washer - a core - washer is placed (as shown in the diagram above). In the end, the bolt is carefully tightened with a nut and insulated.
- simplicity and minimum cash costs;
- can connect aluminum and copper conductors.
As for the disadvantages, they are as follows:
- low quality of fixation;
- need to spend a lot of insulation;
- the bolt dimensions will not fit in the junction box.
In more detail about how to connect the wires with a bolt, we described in the article: https://my.electricianexp.com/en/kak-soedinit-provoda-boltom.html.
We figured out the existing methods of connecting the wires in the box, now we will consider the remaining, important issues of this topic.
What to do if there are several wires?
When bonding two contacts, problems usually do not arise. But what to do if at the same time it is necessary to combine three, four or more?
In this case, it is recommended to opt for the following connection options (from best to worst):
- using wago terminal blocks;
- crimping with sleeves;
- twisting using sizy;
- twisting and wrapping with electrical tape.
The order of connecting the wires for each of the methods we examined in detail above. We strongly recommend that you use the first option, as It is one of the most modern and efficient. At the same time, the cost of vag is not too high, and the wiring lasts more than 30 years.
What if veins of different sections?
To connect the wires of different sections in the junction box, it is recommended to use all the same terminal blocks of the car, or a cheaper option - ordinary terminal blocks. In this case, it is necessary to carefully tighten the cores with a screw or fix them with a flag, and that’s all, the work is finished.
We draw your attention to the fact that if the wires are made of various materials, it is necessary to use special pads with paste inside, which will prevent oxidation of the wires. These pads include wago products.
Also, veins of different sections can be fixed by soldering.
Combining stranded and solid wires
The connection of single and multicore wires individually does not have any features, so you can use any of the above methods.
In order to carry out the bonding, you must choose one of two options: the terminals of the car or soldering. Here it all depends on your preference, the advantages and disadvantages of each method we have provided.
How to carry out work in water and land
During electrical work, a situation often occurs when it is necessary to fasten the wiring under water or in the ground. Now we will briefly consider the features of each of the cases!
In water (for example, when installing a submersible pump), it is recommended to use the following technology. To begin with, the ends are soldered, after which the soldering place is carefully insulated with hot-melt adhesive, over which it is worn shrink. If everything is done efficiently and honestly, the joint will be airtight and safe. Otherwise may happen short circuit and power failure.
To connect the electric wire in the ground (for example, after mechanical damage), it is recommended to use the method provided above (hot melt and heat shrink), but it is better to protect yourself and use the following method. Clamp the ends of the cable with the terminal block, install a sealed junction box, and then carefully fill the box with special silicone sealant. We draw your attention to the fact that the track underground must be additionally placed in a pipe or duct to ensure reliable rodent protection!
It is also recommended to combine the damaged ends of the wiring in the ground using a special cable sleeve, as in the photo below!
That's all I wanted to tell you about this issue! If any nuance has been missed, we advise you to watch visual video tutorials. We hope that now you know what kind of connectors are best used for certain application conditions, as well as how the wires can be connected in the junction box.