Types of terminal blocks for electrical wiring
In this spelling this word is used quite often, although it was born from the familiar term "terminal".By designation, any terminal block is an ordinary connector of wires, including different electrochemical properties( for example, copper and aluminum).Any design of the terminal block should provide a reliable and safe contact of electrical wires in the power grid assembly, and primarily in junction boxes.
Let's consider the basic variants of convenient and fast contact installation of electric wires with the help of terminals.
- Self-clamping terminal blocks .The easiest to install mechanical devices for fixing stranded conductors. Various sources mention both snap-on terminal blocks, spring clips, quick-release clips, etc. The bottom line is that not even a very qualified electrician( and most of us among them) will be able to insert wires into the nests and finish them. The main thing is to choose the correct hole calibration. For 24A networks, terminals for a range of 0.75-2 sq.mm have been developed, with two to eight outputs, which fully cover the needs of household electricity networks. They are made in accordance with the safety requirements of non-flammable plastic. Clamping in the terminal is carried out by simply inserting a bare wire under the plate. Screw connection terminals .The design is not the most successful, especially if the play in the fastening unit is designed for a whole set of sections, but quite popular. We note two drawbacks of such models. First, working with a screwdriver with screw terminals in a confined space is not always convenient. Secondly, the soft aluminum electrical wiring, with a working force in the terminal, can deform and eventually break down. The pluses include cheapness, small size and the ability to connect wires from different materials, for example, copper and aluminum. The quality of the housing makes it possible to mount these terminals in the junction boxes of the modular modifications without fear.
- PPE( connecting insulating clips) .Compare these caps with a clean terminal block, probably would be wrong. But for connecting single-phase conductors they are quite suitable. The spin inside the PPE somewhat spoils the picture, but the other has not yet been invented.
What to choose for the wiring: twisting or terminal
Here we have a contradiction between practical experience and normative documents. PUE( rules for the installation of electrical equipment) unambiguously prescribe the wiring of electrical networks in residential and industrial buildings exclusively using terminal blocks. Experienced electricians assure that the sealed( tinned) twist provides not only better contact, but also lasts longer.
The truth, as always, is within these extreme points of view. When carrying out electrical wiring by citizens, citizens often face the impossibility to lay their grandiose circuits in the terminal boxes with the help of terminals and forcibly connect the wires with isolated twisting. If this operation is performed carefully, identical electrical conductors go into the pigtail, the contact point is treated with rosin and a soldering iron, then what is better. Especially the soldering option is convenient when the wiring is open in a country house, when there are many places for branching, and all of them are newly installed.
When the terminal strip for wiring is indispensable
There are a number of cases in which the terminal block seems to be the best or even the only output and situation.
- Connection of incompatible chemical conductors. In an old house with aluminum wiring you need to make a branch with a copper cable. Most of the modern terminal blocks carry current through an independent bus, equally tuned to the oxide films of metals. Coefficients of electrical. The resistance is leveled, and the system works reliably.
- You decided to hang a new chandelier, connect the lamp. Simply simple: the main thing is not to forget which vein where to connect, take a self-clamp terminal strip and quickly repeat the connection.
- The distribution of electrical equipment and, as a consequence, the scheme of electricity supply of the country house are made correctly. You can expect that in this case, the terminal blocks perfectly fit in the switch boxes and relieve you of the need to use a soldering iron and electrical tape.
There are infinitely many such examples, but one conclusion: if someone has invented the wiring terminals, and they are widely used in electrical engineering, it means that this is a useful and necessary thing.
