Modern methods of connecting wires. Part 2

2. Professionals use terminal blocks for connection of conductors more often, cutting off or cutting off with a knife the required number of cells. Rigid single-wire veins during connection fix with caps, soldering, screw clamps, welding, spring terminals. For example, it is convenient to clamp one clip. Two wires are simply inserted into the hole and fixed with a screw.

Another type of terminal block is capable of pressing two wires simultaneously with one screw, placed in parallel, - twisting in most cases is not required at all. The terminal blocks are basically arranged so that no additional isolation is required. The degree of protection they have is IP20, and it is impossible to touch the current-carrying parts with a finger. Another protection line is the plastic case of the shield or the junction box.

3. Spring terminals are a good alternative for domestic use. The wire must be cleaned from the insulation and inserted into the hole - there it is fixed by a spring. And there are models for both rigid single-wire, and for soft multi-wire veins. One of the advantages of these compact devices is the problem-free connection of wires of different diameters, both copper and aluminum. They do not contact, which excludes electrocorrosion. Moreover, the gel that fills the internal volume, destroys the oxide film on aluminum and protects it from corrosion.

Using spring terminals, it should be borne in mind that they only connect the number of wires to which they are designed. Preparing for electrical work, you need to think carefully about how many and what terminals you need.

Spring terminals are also a good means of connecting together not two, but several wires, and besides different cross-sections. But for similar purposes suitable and conventional terminal blocks. They have many isolated nests from each other. Usually there are two screws in each socket. Under one screw in the nest we start the wire, and the second presses the comb, which electrically connects all the sockets of the terminal block.

4. The terminal block is easier to use to connect several conductors (there can be as many as you like). This is a single copper strip with holes and screw clamps. All current-carrying parts are well insulated. It is fixed in a junction box or switch cabinet - two or three pieces, depending on the type of wiring. This design is good for rigid conductors, but not entirely convenient for flexible ones: they need to be handled or pressed with a tip.

5. "Nuts" . In order to make a branch from the whole wire, you need to make a twist and propate it. And you can, for this, use tap- off clamps , known among electricians as "nuts." They are so called because of the similarity of the shell with the walnut. Inside, two steel plates with grooves under the conductors, compressed by four screws. Between them there is one more - flat. It serves as a barrier when connecting copper and aluminum wires.

There are models for both "street" and "home" works. Most often they are used when connecting to aluminum wires, for example, overhead lines. In multi-storey apartment houses with their help make bends to apartments from an aluminum "riser" (since 2001 they are supposed to be performed only with copper wires).

Despite the fact that there is a general transition to copper conductors, many aluminum wires are on sale. Once they are produced, it is necessary and consume somewhere. The material is cheap, and its use is justifiable when it does not pose a danger. That is why the new rules for them left a loophole.

Aluminum wires are allowed to supply stationary consumers with known in advance, guaranteed capacity, for example, pumps, air conditioners, fans. To household sockets, where today the load is 1 kW, and tomorrow - 6 kW (they wanted to, say, get warmed by the radiator), only copper wires and cables are fed.