Electrical wiring in the apartment and house

Have you ever thought about what path electric energy takes before you find yourself, for example, in a power outlet, into which your computer is now plugged in? Synchronous generators, transformers, power lines, distribution and step-down substations, cable or overhead lines of 0.4 kV ... In short, the path is not easy and not close.

But here the coveted 220 or 380 volts through the input cable came to your apartment or private house. It would seem that all ordeals are over. But it was not there. It turns out that in an apartment, electricity also needs to be divided, distributed across various networks. And this completely responsible task is often necessary for the owners of residential premises to solve independently or with the help of hired specialists.

Wiring harness. How was it before?

It was only at the dawn of the use of household electricity that it was customary to bring two wires into the house, and then twist them in one input box with wires from sockets, switches and bulbs. Systematic fires caused by short circuits or overcurrents have clearly shown people what they need electrical wiring in the apartment and house.

The classic wiring in the apartments of the era of socialist construction was simple. The input was carried out with an aluminum wire in single insulation, which "sat" on the opening bag. If an electric stove was provided for in the apartment, then the input wires had a cross section of 4 square meters. mm If the stove was gas, then often 2.5 square meters were content. mm By today's standards, this is, of course, quite a bit.

After the opening bag, the phase wire went to the input terminals of the circuit breakers, and the neutral wire went to the working zero bus. The inputs of the automata were connected by jumpers, and from their outputs were phase group wires, which, together with the corresponding zero wires, diverged in their individual groups. Groups could be, for example, “corridor-bathroom-kitchen”, “rooms” and “electric stove”. The section of group wires is 2.5 square meters. mm for aluminum, and the rating of the machines is 16 amperes. For a two-room standard apartment, such wiring is still not uncommon. It is called "room-by-room" and is not approved by modern electrical installation rules.

And the point here is not that the use of aluminum wires with a cross section of less than 16 square meters. mm prohibited today. And not that the cross section of these wires is too small, but their insulation is single. The problem is that the chains in the apartment and the house are divided not by rooms, but by consumers. Consumers include: networks of sockets, lighting networks and networks of stationary power consumers.

Modern wiring

According to the PUE, the minimum cross-section of the input cable for the apartment is 2.5 square meters. mm on copper. In practice, I usually use a cable with a cross section of 4 or 6 square meters. mm In private homes, where energy consumption is greater, the input cross-section can reach 10 square meters. mm

Most power outlets in homes are designed to connect portable power consumers. Many of these outlets are provided literally “in reserve”, so that there is where to connect if necessary. Therefore, it is customary to combine plug-in single-phase sockets into groups of three to five pieces, and they are powered using a VVGng 3 * 2.5 copper cable. In this case, the sockets are connected to the network not from each other, but through junction boxes. The rating of the circuit breaker protecting such a group is usually 25 amperes.

As a rule, sockets that are part of the same group are located in one room or in the same room at home, but this is not necessary.The number of groups and, accordingly, group machines in the shield depends on the total area and the total number of outlets. IN three phase household network the number of groups and the load on them, it is desirable to distribute evenly between the phases in order to maintain the symmetry of phase stresses.

The rating of the circuit breaker per lighting group, unlike socket groups, never reaches 25 amperes. Indeed, even the largest lamps with incandescent or halogen lamps consume relatively small current from the network. Therefore, in order for each lamp to have at least some kind of protection against overcurrent, the lighting automats should be at a maximum of 10 amperes. If the total power of all the lamps in the house does not fit into these 10 amperes, then it makes sense to create two lighting groups.

Often, the lighting circuit of an apartment is so modest that there are too many 10-amp automatic machines. This is quite possible, for example, for a one-room apartment, the lighting of which is designed without unnecessary claims to chic, and the lamps are LED or compact fluorescent. In this case, the rating of the automatic machine of the group can be limited to six or even three amperes.

VVGng 3 * 1.5 is most often chosen as a cable for powering the lighting group. Cable conductors from luminaires, switches and circuit breakers are connected in junction boxes using terminal, PPE or welding - as in rosette chains.

Stationary power consumers in a household network require special treatment. Their stationarity, of course, is somewhat relative. After all, no one bothers us to rearrange the same electric stove to a completely different place. But still, most of the time, the stove stands in one specific place, at which either a large current socket (for a single-phase network) or a three-phase socket (for the corresponding network) is mounted. The socket for the stove is usually powered from a separate circuit breaker with a copper cable with a cross-section of 4 sq. mm VVGng is also preferred, and the number of cores depends on the network - for a three-phase - four, and for a single-phase - three.

Stationary power consumers can be considered both a washing machine and air conditioning, despite the fact that these devices are connected to an ordinary 220 volt outlet. Since this is a serious and relatively expensive equipment, it is better to include it in a separate line with a circuit breaker carefully selected for the rated current of the device.

A separate circuit breaker and, accordingly, a separate cable line VVGNG 3 * 1.5 or VVGNG 3 * 2.5 will also be required to provide power to the underfloor heating controller. The exhaust fan can also be powered from a separate circuit breaker for several amperes.

Which wiring is best?

Despite current requirements and recommendations for wiring, many electricians still prefer room wiring. It allows them to save time and effort, and also allows you to simply reduce the cost of cable products. After all, with room wiring, it is enough to simply bring the line into the room, and then from it already power the lamps, and sockets and stationary power consumers, if any.

However, we should not forget that with room wiring of electrical wiring, it is simply impossible to provide overcurrent protection for each power receiver. In addition, when the protection is triggered, the room will be completely de-energized, which will be inappropriate at night: there will be no light or voltage in the sockets to power the portable lamp. Modern wiring with the division of circuits into the categories of such shortcomings is devoid of.

Alexander Molokov

See also: Top Site Articles about wiring in the house and Wiring diagrams in the apartment