Terminal blocks are a necessary attribute in the field of electrification. Due to their diversity, it is possible to flexibly configure electrical circuits, closing the windings, due to their uselessness, and disconnecting unnecessary circuits.
Terminal blocks are made of a dielectric case and several fastening screws. In some cases, small metal lamellas are used (they allow you to conveniently fix the wire in hard-to-reach places).
Terminals are an integral part of supplies for electrical installation and commissioning. On one side of the terminal block (in accordance with the rules of the PUE), it is allowed to "plant" no more than two wires of the same diameter. Otherwise, the contact will be poor, and the wires simply will not crimp.
Terminal blocks are often referred to as screw clamp, pin clamp, terminal clamp, junction block or terminal block. All these are the names of the same attribute, and the specific name is formed based on the location of the terminal block.
The product allows you to connect single-core wires with stranded ones. In this case, both wires must be attached from different sides.boxes, on different screws. As a rule, terminal blocks are carbolite, however, this dielectric is quite fragile, so carbolite has been replaced by more reliable plastic counterparts. The products are mainly used for the installation of lighting equipment, household sockets, for connecting circuits of the power line protection terminal.
Today there are several types of terminal blocks:
- mounted;
- designed for installation in a junction box;
- designed for circuit breaker mounting.
In addition, terminal blocks come with screw and spring clamps. Materials for creating the product are also different. The pads are made of polyethylene and are used quite widely. Their feature is considered to be low cost and separation of current-carrying parts with the help of physical impact (for example, with a knife). The body of the pad has a special hole for rigid mounting. Most often, in polyethylene pads, all current-carrying nodes are made of brass, as this is a fairly good and inexpensive conductor.
Mainly this product is used for connecting wires in the installation of lighting fixtures and installation of junction boxes. In addition, the PE terminal blocks are suitable for wiring sockets for household appliances.
Modern terminal blocks are often made of polyamide. This material is used in professional equipment, such as branded protection terminals or important control boxes.high voltage equipment.
Polyamide is used in such circuits deliberately, because these terminal blocks are quite expensive, but of high quality. They are resistant to external influences, as well as elastic and have a high electrical resistance. What, unfortunately, polyethylene analogues do not have.
Polyamide has a high breakdown voltage, a huge resistance to stray surface current, a noticeably extended temperature range at which the material can be used. In addition, self-extinguishing is characteristic of polyamide terminal blocks, since the material is practically non-flammable, and there are no halogen impurities in the composition.
Usually, polyamide pads are made with brass current-carrying nodes, which are covered with a galvanic film.
