The main task solved during electrical installation is to choose the right wire connector that is optimal for the current operation. Reliability and safety of operation of any electrical wiring depends on the quality of this element. This explains the desire of users to understand in detail what types of these products are most often used in practice and for what wiring they are suitable. In addition, it is important to familiarize yourself with how to properly connect conductors, as well as with the peculiarities of using various types of connectors for electrical wires.
GOST classifications and requirements
The classification of electrical connectors is given in GOST 10434-82, according to which they are divided into classes (1, 2, 3) and groups (A, B). In addition, in accordance with the current standards, they differ in the type of contact formed and the method of fixing the cores.
The requirements of GOST stipulate the conditions for the use of various samples of connecting products and also their technical characteristics that ensure the required quality of switching. Before dealing with all these issues, it is advisable to familiarize yourself with the existing methods of connecting conductors recommended by the PUE.
Ways to connect wires
- traditional twisting;
- connection by soldering and welding;
- articulation by means of special adapters.
Twisting is the simplest form of connection, used only as a last resort. When choosing it, it is imperative to use protective materials in the form of ordinary insulating tape or special plastic caps.
It is not allowed to equip the connection by twisting if the wires are made of dissimilar metals (aluminum and copper, for example).
Numerous disadvantages of twisting conductors make it necessary to further improve the quality of contact by soldering or welding methods. After their application, a sufficiently strong and reliable joint is formed in this place. When dissimilar conductors are to be spliced, special adapter terminals have to be used.
Types of terminals for connecting wires
Before connecting the wires during installation, you should stock up on special terminals, through which it is possible to establish contact without the use of auxiliary equipment. The following types of contact connectors for electrical wires allow you to do without a soldering iron and a welding machine:
- coupling clamps;
- shoe and self-clamping terminals;
- knife contactors;
- screw and spring connectors.
Each of these varieties needs special consideration.
Coupling clamps
This type of wire connectors is designed for the installation of electrical buses with a cross section of the order of 0.25-16.78 mm square. It is made in the form of a hollow metal sleeve that fixes the cores by force crimping them. Another version of the clutch retainer involves the articulation of the wires due to the organization of the bolted connection.Usually, this type of connectors is used for single-core crimp conductors: the quality and reliability of fastening a multicore cable in this case drops sharply, since individual wires diverge under strong pressure on them.
Terminals on plastic blocks
Another very convenient way to fix wired products is to use special terminals located on durable elongated plastic blocks. They differ from conventional terminal connectors in that they guarantee uniform clamping over the entire contact area. A feature of their design is the presence of a special recess on the clamping surface, which limits the pressure on the switched conductor core.
These terminals are suitable for any conductor. To form a reliable joint, you will need to strip the ends of the wires to be connected from insulation and place it in the gap formed by the contact and pressure plates. These products are equipped with a transparent plastic cover that can be easily removed if desired.
Self-clamping terminals
Connectors for conductors of this type are distinguished by the convenience and ease of making contact. To do this, it is enough to insert the end of the core into the hole and sink it until it stops, after which it is automatically fixed with the built-in clamp. Thanks to the high-quality material of the terminal, the clamping force does not weaken over time and guarantees long-term operation of the established contact.
Self-clamping terminals are ideal for connecting copper and aluminum wires and are in high demand among professional electricians. The disadvantage of this type of clamps is the ability to use them only once, since after removing the ends of the wire, the contact loses its previous reliability.
Screw pads
Clamps of this class are a kind of box connectors; they are also made in the form of a sleeve, but with a rounded oval bottom. In its upper part there is a hole for a screw clamp, and the body of the product itself is placed in a nylon insulator. Through channels are provided in the insulation body for screwing in and loosening the screws.
These products are divided into single and group contactors, designed for a different number of interfaces. The former are made in the form of a separate pin connector connecting single-core conductors, and the latter as multi-connectors. With their help, it is allowed to switch conductors with a conductor cross-section of up to 25 mm square.
Spring loaded terminal blocks
Typical representatives of this class of connectors are terminals or sockets from WAGO. Connectors for wires under this name are produced in the following two versions:
- PUSH WIRE - disposable one-piece samples;
- CAGE CLAMP - reusable connectors.
It is almost impossible to get the already inserted wire out of the WAGO disposable terminal without damaging it.
Reusable connectors are equipped with a special lever that allows you to easily release the ends of the cable conductors. The cases of such products are made on the basis of polyamide or polycarbonate, which are resistant to temperature fluctuations and corrosive environments. The metal connectors themselves are made of tinned copper, which improves contact quality, reduces junction resistance and improves corrosion protection.
Knife blocks
Pluggable connectors of this type are not used very often in wiring practice. They are usually used in the organization of grounding or grounding circuits of a three-core cable, as well as in the installation of continuous conductive lines. Sometimes they are used when decorating branches in linear routes using the tie-in method.
Knife connectors are often used for switching wire lines in audio equipment. There are two types of products of this class: disposable and reusable. The former include the well-known Scotchlok pads from 3M.
Products are equipped with a special device, when using which several cores are inserted into contact by simple pressure. A distinctive feature and advantage of these contactors is the ability to dispense with connection operations without stripping the ends from insulation.
Connector selection procedure
- the brand and material of which the product is made;
- the voltage for which its contacts are designed;
- the minimum diameter of the switched conductors allowed for a given sample.
In addition to the voltage, it also turns out for what current load it is designed, after which you can safely buy a connector that is suitable for all parameters. It is recommended that you ask your sales representative if it is suitable for connecting dissimilar metal conductors.
The need to connect wires of different cross-sections most often arises when distributing distribution circuits in separate boxes. After that, it is allowed to proceed with the selection of a connector of a suitable type, the terminals of which are designed to connect conductors of various thicknesses.
Before connecting conductors at home, it is important to understand the types of connectors most suitable for the stated purposes. In addition, you will need to prepare a special tool, which cannot be dispensed with when pressing clutch-type clamps, for example.
