From time to time we make repairs in our apartment or in a private house, and as a rule we are faced with the need to replace the electrical wiring. Experts offer to carry out electrical work before proceeding with the main repair and decoration of the premises. In new apartments or houses, this work is usually carried out immediately after the construction of walls and internal partitions and before the start of the floor screed process. If your wiring is also made of aluminum wires, we strongly recommend that you change it urgently. Moreover, the replacement must be carried out entirely. After all, connections in junction boxes of old aluminum wires with new copper wires are extremely dangerous and can lead to a fire. Of course, the features of electrical installation, the specifics of working with hidden wiring are thoroughly known by professionals. They are the ones who know how to correctly calculate the cross section of the required wire and determine the allowable load. But every literate, educated tenant must have a basic understanding of the electrical wiring elements and the work associated with its installation.

Wiring planning

At the first stage, the owner plans the places where he is going to locate and install electrical appliances, suggests what his requirements for lighting in the premises are. Determined by the installation height of sockets and switches. A specialist electrician calculates the number of electrical outlets, draws up a diagram and determines on the spot how to properly connect hidden electrical wiring to all these devices, where to place sockets and switches, how to correctly distribute the leads for chandeliers, light bulbs, sconces, etc. The specialist also determines the installation location of the main electrical panel, the number and current characteristics of the protective shutdown elements. The peculiarity of this wiring is that all electrical communications are hidden, invisible. Recall once again that electrical installation should be done before the start of construction work, because the wiring is mounted in the voids of partitions, behind a false ceiling, in the plaster covering of walls, ceilings, etc.

Installation of hidden electrical wiring

In concrete and brick walls, chasing is carried out before the start of electrical installation. Small strobes are laid in the wall with a depth of 20 mm and a width of 10-15 mm. For this work, there is a wall chaser that makes even grooves in any material. You can use for such grooves and a simple puncher with a special nozzle for crushing. As a last resort, you can use a grinder with a diamond wheel to cut the grooves yourself. For reliability, it is recommended to fix the wiring in the strobes with dowel-clamps or with a mixture of alabaster, which instantly hardens, thereby firmly fixing the wire. This is the first, rough stage of laying the electrical wire. After the wires are routed from the junction box to the right places and rough fixed in the strobe, the next “cosmetic” step should be taken - to plaster or putty the groove.

Installation of electrical wiring in suspended ceilings

The most common, fairly simple, very quick way to carry out hidden wiring is laying behind false ceilings. When a false ceiling is mounted, there will certainly be a gap in which telephone, antenna and electrical wires can be installed. In the same place it is possible to carry out the wiring of electrical wires to all kinds of lamps. Installation always starts from the junction box upwards, clamps are fastened (screwed) along the ceiling, which firmly hold the cable. When installing wiring in a false ceiling, it must be remembered that there is air in the gap between the base of the ceiling and its suspended part. This is fraught with the fact that a short circuit may cause a fire. In order to avoid this, in suspended structures with cavities, it is recommended to lay the wires in a corrugated PVC pipe (corrugated hose), in which each cable is placed separately from the other. The corrugated hose has such an excellent property: in case of strong heating of the cable and fire, the corrugated hose shrinks in this place, localizes and extinguishes the fire.

Installation of electrical wiring in drywall

Running electrical wiring in plasterboard walls is somewhat similar to wiring in false ceilings. In this case, there is also a place where one or another communication can be carried out. And in this case, fire safety rules should not be neglected, and therefore also wiring in the corrugation. Work on the installation of communications in plasterboard structures is carried out before sheathing the ceiling, walls, and floor with plasterboard. Having installed a metal "skeleton" - a special frame, all the wires are led to the junction box - a node that is fixed in the box. From this node, the wires diverge to switches, sockets, lamps. After installing the wires and other communications, you should proceed to sheathing the frame with drywall, pre-cutting holes for boxes, switches and sockets in the right places. And at the end of the work, a bunch of wires is pulled out, a socket is installed.

Installation of electrical wiring in floors

Installation of hidden wiring in the floors also has its own characteristics. It is carried out before the floor screed is made. The main advantage of such a gasket is that it saves money on strobes in the walls. And also wires are saved due to their more direct laying to the places of electrical outlets. A solid wire is laid from the switchboard to the outlet, it is easy to fix it over the floor area, and then fill it with a screed from above. There are no special complications in this work, just in the project for electrical equipment, the places where the cable will be located should be clearly indicated. This is necessary, first of all, so that when laying floor coverings, if it is necessary to drill holes in the floor, do not damage the electrical wires.

Installation of electrical sockets, switches

Modern technologies are designed to ensure that boxes, switches and sockets are installed with a minimum protrusion from the wall. As mentioned above, special recesses are made in the walls with drywall, in which socket boxes are installed specially designed for installation in drywall structures. In rooms with concrete walls, everything is different, but not so difficult with certain knowledge and skills. In the recent past, a hammer and a chisel were used to install a socket in a concrete wall. Currently, there is a wonderful puncher with special nozzles, templates that drill the necessary hole in the wall. Then the recess should be cleaned of dust, dilute the alabaster, coat the recess, and then put the socket box on the mixture. The frozen alabaster mixture firmly fixes the socket. In the same way, junction boxes, switches, telephone and TV sockets are installed. When the alabaster hardens firmly, the wiring is pulled out into the socket and the inside of the socket, switch is mounted.

Conclusions on wiring hidden wiring

In the event that you want to install hidden electrical wiring in a wooden house without a false or plasterboard ceiling, then you should remember the following: when wiring inside the walls, either metal cable channels or metal hoses are required. Sockets and lifts to switches must be done strictly vertically. Socket boxes and boxes should only be steel. Wires are bought with an additional plastic braid. Sockets and switches should be selected to withstand heat. If you decide to replace the wiring, we recommend that you contact a professional electrician. And you can save money by buying the necessary

Everyone who has been doing repairs in the house is familiar with the concept of hidden wiring. Someone decided where and how to lay it, and someone needed to find it. But they have one thing in common: you have to tinker with the wiring. This article will discuss the basic principles that should guide the work when installing and searching for hidden electrical wiring, as well as equipment that should make work easier.

Advantages of concealed wiring

To begin with, it is worth deciding what is hidden wiring? As the name implies, it is not visible to the eye and can be located inside structures: in walls, under the ceiling, under the floor, in the ceiling. As a rule, it is laid in pipes, in PVC corrugations, metal hoses or in strobes.

There are many advantages to this type of wiring:

• as the name implies, it is not visible, which means it does not interfere with the design and does not distract the eye - the room looks more attractive;
• this method is safer from the point of view of fire safety and electrical safety (being in an inaccessible place for air, sunlight and ordinary consumers, any short circuit will remain local);
• thanks to modern materials, once you have installed all the wiring, you can forget about it for several decades, and it will work properly.

Disadvantages of hidden wiring

With so many advantages, there are also disadvantages, but they are leveled by competent installation and further proper operation. Flaws:

• inaccessibility after commissioning (over time, there may be situations when it is necessary to replace, repair the wiring or simply not get into it when installing new furniture or equipment, but this task can be difficult due to inaccessibility);
• the work of installing the wiring itself is quite laborious (chasing walls, laying pipes in grooves).

Hidden electrical wiring in a wooden house is most prone to such shortcomings. Therefore, in such situations, most often all the electrics are pulled into cable channels.

Installation of hidden electrical wiring

When performing the installation of electrical wiring, it is worth remembering some requirements for it:

1. 1. fire safety requirements. For example, it is forbidden to lay wires without corrugations under the inner lining of a wooden house. It is worth laying metal pipes or PVC corrugation, and the corrugation must be fire-resistant. The same requirements can be attributed to brick, concrete houses, as well as when installing behind drywall;
   2. Wiring must be replaceable. This is a very handy property for future renovations. If the wiring is deep in the wall, but it can be freely extended and replaced, this will greatly facilitate the work. But as a rule, this requirement is not met, because it is very difficult to lay a pipe in a concrete wall, and PVC corrugation is often pinched with mortar or makes sharp turns, through which nothing can be pulled through. So that in the future you do not have to look for wiring in the walls for a long time, making unnecessary destruction, you should immediately do a competent installation. For example, be sure to wire at a right angle, not diagonally. This will allow you to easily trace the path of the wire in the future. It is also worth trying to lay pipes strictly vertically along the walls or horizontally under the ceiling;
   3. After installation, it is worth compiling an accurate and detailed wiring diagram indicating the location of junction boxes and wires. This scheme should be saved for future repairs, so as not to accidentally get into a live wire when you need to hang a new photo frame;

1. For laying wires in a hidden way, it is worth laying a lot of power. For example, for lighting it is worth using wires with a cross section of 1.5 square meters. mm, for sockets - 2.5 sq. mm. It is also recommended to use a three-wire cable, even if the ground wire has not yet been brought into the house. Perhaps in the future it will appear, and in the junction boxes everything will already be assembled properly;
2. Shtroblenie. This is the dirtiest job in home electrical work. It should be carried out at the initial stage of repair. Immediately with the strobes, you should prepare holes for the sockets. After laying all the wires, the strobes are sealed with plaster or plaster.

Search for hidden electrical wiring

Everyone who has ever made repairs in the house, faced the problem of finding hidden wiring. If you need to hammer a nail, and in doing so you get into a live wire, this can lead to serious consequences. In addition, after such an unwanted contact, you have to change the wiring. Therefore, experienced builders, before any action, search for hidden wiring. How to find electrical wiring in the wall? If there is no executive wiring diagram, you can use the device to detect hidden wiring.

The cheapest tool is a voltage gauge or indicator screwdriver. The price is about 150 rubles. It works on the principle of detecting the presence of an electromagnetic field. As a rule, it has three levels of sensitivity:

"O" - the definition of the phase in the supply network.

"L" - non-contact detection of the presence of electrical wiring with low sensitivity.

"H" - non-contact detection of the presence of electrical wiring with increased sensitivity.

This device can detect only those wires that are currently energized. At the same time, it will show the location of the field within a radius of 10-20 cm from the wire itself. Therefore, a screwdriver should be used only in cases where accuracy is not so important.

Those who have about 1500 rubles. can purchase the E-121 signaling device, popularly called the Woodpecker. It allows you to find wiring at a depth of up to 8 cm. The essence of its functioning is based on the principle of electrostatics of an alternating electric field. When the antenna approaches the current source, the electrodynamic force begins to work, and the equipment gives a signal. It can be seen that the "Woodpecker" finds only those wires that are energized. As you approach the voltage source, the intensity of the signals supplied by the devices increases. Thus, it is possible to determine quite accurately both the location of the wires and the break in the hidden wiring.

Metal detector Zircon TriScanner PRO SL. It costs a little more - about 2 thousand rubles. But the device allows you to detect metal structures, wooden structures, as well as hidden wiring, even if it is not energized. This is possible due to the fact that it works on the principle of a metal detector. Therefore, this device can quite accurately determine the path along which the wires are laid. But the disadvantage is that, perhaps, there are not wires, but self-tapping screws, nails or fittings.

Outcome

When installing electrical wiring, you should think about how to conduct it in a hidden way, because. it is safe and aesthetically pleasing. The main thing is to remember where it is!

Laying concealed wiring is a set of measures for laying cables inside walls. This option is used more often in houses and apartments, where the interior issue has a huge impact. Next, we will provide readers of "" with detailed step-by-step instructions for electrical work, so that you know how to properly lay hidden electrical wiring in a brick house and apartment.

What are the advantages of this method

Hidden wiring is used during the overhaul of housing or the replacement of wiring with a new, more powerful one.

The advantage of concealed cabling inside walls is as follows:

• The interior of the rooms does not deteriorate, because. electrical wiring will be hidden under a layer of plaster or in plasterboard partitions.
• Increased fire safety of housing if the walls are concrete, not wooden (or, for example, made of plaster or other non-combustible material). This is due to the fact that when the insulation ignites, the fire will not spread further, due to the lack of oxygen and flammable materials.
• Increased service life of the electrical network associated with reliable protection of the cable from ultraviolet and mechanical influences.

Among the shortcomings, one should highlight the complexity of installation, compared with the open method, as well as the complexity of repair and maintenance of hidden electrical wiring. The last two disadvantages are due to the fact that all the wiring elements are hidden under a layer of plaster and to access them, the destruction of the wall decoration will be required.

We figured out the advantages, let's move on to the main issue of the article!

Step-by-step instructions for electrical installation

So, now we will look at how to properly make hidden wiring in a brick house with our own hands using small instructions as an example.

Creating a schema

The first thing you must do is, on which the route of the cable along the walls, places, switches and junction boxes in each of the rooms will be marked. Based on this scheme, the calculation of materials will be carried out and, in fact, the installation of hidden electrical wiring.

1. The cable must run strictly vertically and horizontally over the surface. The only rule is that the distance from the floor and ceiling should be 15-20 cm (for ease of repair and installation of hidden wiring).
2. and switches is not standardized and is usually selected based on individual conditions. For example, in the kitchen, the outlet can be installed above the countertop, and in the hall - behind the TV. The junction box is installed at the entrance to the room.
3. When laying in parallel, the distance from the wires to the heating pipeline, hot water, cold water and others must be at least 100 mm (2.1.57). And the distance to pipelines with flammable gases or liquids (gas riser) must be at least 400 mm.
4. If the wiring crosses the pipeline - the distance must be at least 50 mm, and if it is a gas riser - at least 100 mm. Moreover, if the wire is laid at a distance of less than 250 mm, it must be (for example, a metal hose) at a distance of 250 mm in each direction from the intersection, according to PUE 2.1.56.
5. The distance from the gas pipeline to the outlet, according to PUE 7.1.50, must be at least 0.5 m.
6. If the pipeline is hot, then it is necessary to provide protection for the cable from high temperatures, even when crossing, even when laying in parallel.
7. According to the PUE, clause 2.1.67, wiring cannot be laid in ventilation shafts, and according to SNIP 41-01-2003, clause 7.11.16, the cable is laid at a distance of at least 100 mm from the walls of the duct.

We prepare tools and materials

At this stage, it is necessary to calculate, according to the project, the number of sockets, switches, as well as the length of the conductor in order to install hidden wiring in the walls. First you need to do to choose the most suitable core diameter. If this point is neglected, there may be a threat associated with the fact that the conductor will not be able to withstand current loads from powerful electrical appliances. After that, select the most suitable sockets for the rooms, for example, in the bathroom you need to use waterproof products (for safety reasons).

The minimum set of materials is as follows:

• sockets;
• switches;
• socket boxes;
• distribution boxes;
• cable;
• protective plastic corrugation (optional);
• connecting terminal blocks;
• insulating tape;
• plaster mortar.

The most necessary materials for electrical installation are discussed in the article:.

As for the tools, you will need the following for wiring:

• wall chaser, grinder or puncher (for chasing);
• chisel and hammer;
• multimeter;
• or a knife for an electrician;
• Screwdriver Set;
• building level;
• pencil;
• Master OK.

Also do not forget to make recesses for sockets and junction boxes. To do this, it is best to use a drill with a special crown. For concrete, cinder block and other hard materials, crowns with victorious soldering or diamond are used. There are also special crowns for wood and drywall, usually they are sold as a set with a replaceable cutting part of different diameters. The diameter of the crown is selected for the junction box and the socket that you will install, for your information, the standard one is 68mm.

Video instruction for wall chasing

We install socket boxes

At this stage, everything is simple - you need to make junction boxes for hidden wiring in the prepared holes.
In order for them to “sit” securely in their places, use a gypsum mortar (alabaster), which will securely grab the plastic to the concrete. The edges of the products must be placed flush so that there are no problems when decorating the walls.

Laying the cable

Now that the sockets and the junction box are installed, it is necessary to carry out hidden electrical wiring through the strobes. To begin with, we cut the cable into suitable segments (for example, from the box to the switch), leaving a small margin for connecting the cores. Next, we place the segments in the recesses under the ceiling and in the walls, after which we grab them with a plaster mortar.

The places for tacking (attaching) wires must be at a certain distance from each other, which are regulated by SNiP 3.05.06-85, and today its updated version is SP 76.13330.2016. In short, in horizontal and vertical sections with hidden cable laying, the distance should be 0.5 m for cable bundles and 0.9 for single laying. With open wiring, horizontal sections are fastened every half a meter, and vertical sections - every meter.

Also, the cable can be independently laid hidden in the floor, but this installation option is not very good because the repair and maintenance of internal electrical networks will be difficult.

Regarding the protective corrugation, the question is individual, you can not use it. The purpose of the corrugation is to provide additional protection against mechanical damage. If you choose a marking cable, you don't have to worry about additional protection, because. the insulation of this conductor is quite reliable.

When the line is stuck with plaster in some places (as shown in the picture), it is necessary to check the correctness of all connections, as well as the operability of the mains. If everything is fine, we putty the wall.

That's the whole technology of installing hidden wiring in a brick house and apartment with your own hands. As you can see, there is nothing complicated, the main thing is to observe when connecting the cores, and also to do everything carefully. Upon completion of the work, sockets and switches are mounted, and protective automation is installed on the switchboard, after which you can proceed to the installation of chandeliers and the arrangement of rooms.

The only thing I would like to talk about is plasterboard walls, because. above, we provided instructions for flush-mounted wiring in concrete and brick, which is much more complicated and is used less and less today.

If you decide (panel, frame or from a log house), we recommend that you read the article we referred to.

Features of work with drywall

When things are much easier, because. In this case, no strobes are needed. The line is drawn under the sheets of plasterboard partitions between the profile structure, as shown in the photo. So you fulfill the conditions prescribed in the PUE 2.1.37-2.1.40.

The problem is that if the insulation of the conductor is damaged, it can occur on the profile. The result of a leak is the likelihood of electric shock to a person. To prevent this from happening, it is recommended to lay the cable in the corrugation, or better, in a plastic pipe. At the installation sites of junction boxes, you will need to cut out special hatches in drywall yourself for quick access.

That's all I wanted to tell you about how to conduct wiring hidden in concrete and plasterboard walls with your own hands. As you can see, the installation of hidden electrical wiring in a brick house and apartment is not difficult. We hope that the information was useful and understandable for you! For you to clearly see the whole process, we provide a detailed video instruction:

Visual video lesson

Most of the modern living quarters, the owners try to create with perfectly aligned walls, floors and ceilings without excessive protrusions, and all electrical communications are hidden inside the building structures. This allows you to create a unique design, limits access to electrical wiring, but complicates its inspection and maintenance.

The technology of installation of hidden electrical wiring can be performed in various ways, which are constantly being improved with any method of building construction. For each specific case, choose the best option that meets two basic requirements:

reliability of work;

safe operation.

The cost of installation should also be taken into account, but it must be considered not at the time of laying the electrical wiring, but considered in conjunction with ensuring the possibility of long-term, safe operation, excluding the occurrence of malfunctions, emergencies, including the consequences of their elimination.

Hidden wiring diagram

Its presence is a mandatory attribute before starting electrical work. Design organizations create documentation at a professional level, take into account the rules for safe operation, the necessary protection, and the specific requests of the owner.

Drawing up a closed wiring diagram on your own without proper experience can complicate the work, lead to unnecessary waste of material resources, and create serious errors for which electricity punishes.

Experienced electricians can do the wiring diagram with their own hands. A separate one is devoted to this issue. We recommend that you read it carefully.

Requirements for wiring lines

In hidden wiring, the current-carrying cores of cables and wires must provide two functions:

1. current flow through the elements of the electrical circuit with minimal power loss and voltage drop;

2. reliable isolation of the formed chains between themselves and the ground loop, excluding the occurrence of short circuit currents and leakages.

The choice of wire for metal core

To solve the first task, trade provides the consumer with wires and cables with metal conductors from:

aluminum;

or copper.

The advantages of aluminum conductors include:

1. lighter weight;

2. reduced cost.

However, they have disadvantages:

underestimated mechanical strength, providing a break after several bends, twists and tensions;

increased plasticity of the wire in the clamped terminal. When it is heated from the current load, an additional deformation of the metal occurs due to the expansion of the contacting steel parts. After cooling, the steel returns to its original dimensions, while the aluminum remains in a reduced dimension. The contact weakens, and the resulting layer of an oxide film on aluminum further worsens the electrical resistance at the junction, which leads to overheating, sparking, ignition, and fire.

In a closed modern electrical wiring, even at rated loads, a high heating of the wires is created. The removal of heat from them to the external environment is limited. Ductile and weak aluminum in such conditions is prone to creating malfunctions, is prohibited.

We choose copper.

Dielectric properties of insulation

The outer sheath of current-carrying conductors may have one dielectric layer on the wires or several on the cables.

Trade provides cable products designed to transmit electrical energy of different voltages from low-current circuits of several tens of volts to high values ​​measured in kilovolts.

In a household network, it is sufficient to use conductors with insulation that can withstand 0.4 kV. They cope well with the loads arising from short-term emergencies associated with overvoltages in the supply circuit, which are eliminated by appropriate protections.

However, when choosing a cable, you should pay attention to its fire-fighting qualities. In a closed version, the wiring can be subjected to high temperature loads. It must have non-combustible properties.

This parameter is indicated in the marking with the symbols "ng", for example, cable VVGng 3x1.5. Simple insulation of conductors during overloads in the network can ignite, support combustion, and cause a fire.

About flat wires PUNP, APUNP

Cable products of this brand, deciphered as a flat wire with universal properties (the letter "A" denotes aluminum inside the conductive core, not copper). Wires PUNP have long been a household name.

They are produced not according to state standards, which are the law, but according to local technical specifications "TU" of the manufacturer. The wire cross section indicated on the factory label can be reduced by up to 30%. The insulation layer of low-quality materials is also underestimated.

Even with a double sheath of insulation, PUNP wires do not meet safety requirements and are the cause of numerous fires in household electrical wiring.

The use of wires of the PUNP and APUNP brands in household closed or open wiring creates increased risks for people's lives and the safety of property.

Directions of concealed wiring highways

Among electricians, it has long been a rule to uniformly orient wires inside building structures with maximum observance of horizontal and vertical lines located at right angles. They correspond to the main directions of architectural structures.

This technique facilitates troubleshooting in closed electrical wiring, allows owners to better navigate the drilling of walls when installing fasteners for furniture and accessories.

Features of the installation of electrical wiring in panel buildings

In older reinforced concrete panel houses, the method of arranging wires horizontally and vertically was often broken in the past in order to save materials. In the slabs for walls and ceilings, during their casting, special pipeless voids and recesses were created for laying electrical mains. These channels were located at arbitrary, but typical angles for the entire series of buildings.

It is not required to mark the places for installing electrical appliances and laying cables with this method. At the joints of building structures, recesses were created for connecting electrical wires. At one of the wall panels, niches were prepared for accommodating an apartment electrical panel and low-current circuits.

You can familiarize yourself with a similar arrangement of cable routes in the construction technical documentation or clarify the passage of routes from neighbors or maintenance electricians.

When pulling wires in such channels, check the cross section of their free space by pulling the caliber, as well as the absence of cutting edges that can damage the outer insulation when the cable is wound.

The force of tightening the wires into the prepared cavities is limited to 20 N per 1 sq. mm of the total cross section of the area of ​​the conductors used. When the free diameter of the channel is 20 mm, then it is permissible to place 5 wires with a cross section of 2.5 mm square, and for 25 - 8.

Features of the installation of electrical wiring in buildings made of building blocks and bricks

Concealed installation is associated with the implementation of a large amount of dirty, dusty work on the processing of wall material and building structures. It is best to carry out before finishing the premises.

Work begins with marking according to the design scheme and the execution of electrical points - places where cables are switched with wires and sockets, switches, lighting fixtures, junction boxes, shields and other electrical equipment are placed.

Then all electrical points, starting from the introductory or apartment shield, are marked with lines for laying cables between electrical points. According to the markup, recesses are created in building structures.

For indoor installation in a plastered wall, the cable can be placed inside the tie joints, under a layer of plaster or in.

When chasing, pay attention to the thickness of the wall and the required depth of its processing. It is impossible to go beyond the permissible limits. Otherwise, there is a weakening of building structures, which can cause the collapse of the supporting element.

It must be clearly understood that the gating of load-bearing structures and ceiling slabs is not allowed, it is prohibited.

The cable can be placed:

1. into a pipe or corrugated sleeve, which is puttied directly into the strobe;

2. or mount without it.

In the first case, it is possible to quickly extract the cable damaged in this section from the corrugation and replace it with a new piece. In the second variant, a non-separable connection is formed, which requires dirty work during repairs.

However, with the right choice of a cable with additional protection of the sheath against mechanical damage and the exclusion of its emergency operation modes, the second method is economically justified. It is most often used in practice.

But, in this case, first, local fixation of the cable inside the strobe is made, for example, with plaster or alabaster, and then the final electrical installation of the circuit is performed, and the quality of its work is checked. After eliminating the errors that have arisen, the plastering of the cut line is completed.

Hidden wiring on plasterboard partitions

Plasterboard sheets are used to level walls, divide rooms into zones, create suspended ceilings and multi-level structures. They install sockets, switches, light sources.

The technology of mounting wires and cables in this situation is less laborious. Strobes are not necessary. All communications are hidden behind the sheet. At the same time, attention is paid to the exclusion of damage to the outer layer of insulation during installation on reinforced metal structures for fixing drywall. Otherwise, leakage currents and a dangerous phase potential may occur on the mounting device.

The best protection option is to place the wires inside a corrugated pipe, mounted on metal profiles and protecting the outer insulation layer.

Hidden wiring in wooden buildings

Now construction companies mass-produce houses from logs, glued and rounded timber. They are in demand due to natural eco-friendly materials, and the owners want to have all the conveniences of modern civilization and want to operate the electrical wiring installed in a hidden way.

In carrying out such a plan, three important conditions must be observed:

1. wood, even impregnated with special fire-fighting compounds, is a combustible material. If the electrical wiring is damaged, sparks or an arc occur, causing a high temperature, which the impregnation layer cannot withstand - a building fire is inevitable;

2. Wood products contain moisture in their structure, which dries out or accumulates during operation. Houses in the first few years after construction reduce their dimensions - they shrink;

3. Condensation occurs in the internal wire ducts at low temperatures.

Let's analyze them in more detail.

1. How to protect wood from fire in hidden electrical wiring

On this issue, paragraph 7.1.38 of the current seventh edition of the EMP clearly defines three important points for our case:

1. carry out concealed electrical wiring exclusively inside metal pipes and ducts that have a localized ability to ignite;

2. use only flame retardant cables;

3. Realize the ability to replace damaged cables.

Features of cable protection from wood

The PUE rules unambiguously indicate the method of flush-mounted installation of electrical mains in environments capable of ignition, focusing on the fact that the protective cable fencing should prevent the development of a fire and localize it.

The fact is that the wiring can be operated with overload, when the protective devices do not have time to eliminate it. In this case, the insulation undergoes small but irreversible processes, gradually deteriorating its dielectric properties.

As a result of its premature aging, a short circuit occurs over time, an electric arc is formed with a temperature of about five thousand degrees. It instantly burns through the outer shell. If the cable is located near wood, then the latter ignites.

When the highway is hidden inside a wooden wall and a fire has started, it is very difficult to put it out because the fire is hidden, it is problematic to get to it with simple fire fighting equipment. The situation is aggravated by the accumulation of dry wood dust, which, in the event of a fire, ignites with an explosion along the entire length of the highway. When the fire flared up well and broke out, it immediately covers a large part of the building.

Therefore, the cable must be protected from wood reliably. Since the corrugated hose burns out from high temperature, like thin-sheet pipes, it makes no sense to use them.

On forums of electricians on this issue there are disputes. But, in the event of a short circuit, the cable fencing must withstand the temperature flash of the created electric arc, prevent the metal protection from burning out, and therefore ensure the tightness of the volume.

Then there will be no inflow of fresh air to the place of ignition, and the fire of the electrical wiring will self-destruct due to the lack of oxygen, as an oxidizing agent for the combustion process.

It is important to focus on the fact that the metal channel with the cable must be reliably sealed from the surrounding air. Otherwise, self-extinguishing of the fire is excluded. For this purpose, individual pipes are interconnected in advance in one of two ways:

1. welding;

2. sealed threaded connection.

In the second case, it is necessary to provide electrical connection between the individual pipes. After all, the entire metal pipeline will still need to be connected to a protective grounding device in the potential equalization system to eliminate sparks or breakdown.

The cable entry into switchgears, junction boxes, sockets and switches is also sealed, and they are installed in a metal socket.

Flame retardant insulation features

Since the short-circuit current of an electric arc is of the same nature as that of welding, it is proposed to conduct a simple experiment with two pieces of cable with ordinary insulation and non-combustible: subject them to high temperatures.

As a result, you will see that in both cases, the outer protective coating will become burned through. But in one case, the insulation will continue to burn, and in the other it will stop.

This will help to understand that the cable marked "ng" does not protect against burnout of the emergency short circuit current, but only does not aggravate the fire. Its insulation is destroyed and requires subsequent replacement.

Possibility to replace damaged cables

This requirement of the PUE also complicates the installation of hidden electrical wiring in a wooden house. In the design of a metal pipe, it is necessary to provide hermetically sealed windows through which the faulty cable is removed and a new one is mounted.

Without the technical implementation of this possibility, a clear violation of the rules for the installation of electrical installations is created.

2. Taking measures to protect hidden electrical wiring from shrinkage of the building

A building built of wood with natural moisture can dry out and settle up to 15 ÷ 20 cm per floor in 3 years at a height of about three meters.

A thick-walled metal pipe mounted inside the wall will not change its dimensions. It will be affected by external mechanical loads of contacting building materials.

To exclude pipe deformation, it will be necessary to introduce compensating devices into its design, which will eliminate vertical compression forces, prevent destruction of the sealing of internal cavities and violation of the integrity of the cable.

The technical implementation of this method in each specific case requires calculation and justification.

3. Taking measures to protect against the formation of condensate

Let's say that we have created a house from glued laminated timber, in which we want to preserve the natural color of natural wood and therefore emphasize its natural look from the inside with various design techniques. Inside the walls, according to all the rules of the PUE, hidden electrical wiring was placed, placing it in sealed metal pipes, and even devices were provided to compensate for the shrinkage of the building.

If the house is located in a warm area where low temperatures are excluded, then you can calm down on this. When in winter the temperature outside drops to minus 25 degrees or lower, condensation will begin to appear in the metal pipe with the cable, caused by the temperature difference between the outer and inner sides of the walls.

Moisture from it will flow from top to bottom where sockets and switches are located. With an increase in the thermal difference, its amount will increase. When the temperature inside the pipe reaches minus, the accumulated water will turn into ice.

To prevent the formation of condensate, it will be necessary to apply a layer of thermal insulation on the outside and inside of the wall. How efficiently it will work remains a question, but the design plan for decorating the walls with natural wood trim will have to be broken.

It remains to consider the option of installing hidden electrical wiring only in internal walls or to think over other technical solutions, for example, placing it in the floor and raising it to a small height to the sockets.

As a result, it turns out that for a wooden house it is possible to carry out safely hidden electrical wiring only in compliance with all the requirements of the PUE. However, for this it will be necessary to provide for the issues of shrinkage of the building and prevent the formation of condensate in winter.

Violation of any of the above safety requirements, of course, will not immediately lead to a building fire. But the owner must clearly understand that an accident in the electrical circuit can occur at any time. Automatic protections prevent it not instantly, but with the minimum possible time delay. The break in the load current is often associated with the formation of an arc, the flame of which is not immediately extinguished.

Dried wood ignites quite easily from damage to electrical wiring. To live in a house built in violation of existing rules is to put yourself at risk, to repeat the path of those who have already experienced the consequences of a fire.

Installation of concealed electrical wiring in everyday life after it is done inside the house from any materials must be inspected and checked by electrical measurements before connecting to voltage:

for compliance of the assembled circuit with the continuity of sections of the mounted circuits;

Between all phase and zero wires, as well as to the ground loop.

Without measurements, short circuits and leakage currents are possible, which will manifest themselves due to errors made immediately when the assembled circuit is turned on under load.

In most cases, when installing electrical wiring, it is hidden under a layer of plaster. This method is safer and more reliable: after all, the wires walled up in the wall are reliably protected from mechanical stress, moisture and corrosion. This method of laying also has disadvantages - it will be impossible to move it to another place, and it will be difficult to determine the location of the cable in the absence of a diagram.

What comes first, plaster or wires?

When to do electrical wiring - before or after plastering? is a dispute between an electrician and a plasterer. It is more convenient for everyone to do his part of the work first without any interference. But if you are doing the repair yourself, or it is done by one master, then the procedure will be as follows:

1. What do you think first?

   Electricianplastering

1. The walls are stripped of old finishes. Lines are drawn on them along which wires will pass, installation locations for socket boxes and junction boxes.
2. Under thick wires and corrugation, a strobe (groove) is laid along the entire length to the exit points: switches, sockets. The use of corrugated channels is mandatory when the walls are made of combustible materials. They are also used to be able to pull out and replace the wires. Laying cables in plaster is allowed without corrugations.
3. Thin wires can be laid directly on the surface without chasing if a layer of plaster will hide them.
4. Next, the wiring is laid and fixed to the wall.
5. The walls are plastered with beacons or without them. The ends of the wires protruding from the channels can be wound and covered with a film.
6. After the walls have dried, a puncher with a crown drills out places for sockets, junction boxes and switches. This is done after plastering, because otherwise it is not clear to what depth they will be mounted.
7. Then the final finishing is done - wallpaper or decorative plaster. After that, sockets and switches are inserted.

But there is one point in favor of the fact that all electrics must be carried out after the walls are plastered. If strobes are laid in the walls, then this is much easier to do on a layer of plaster, for example, on the second or third day, when it has not yet completely dried out. Chasing concrete or brick will take longer and there will be more dust.

Electrical Installation Rules

Compliance with generally accepted building codes and requirements is the key to the safety and durability of electrical wiring. Therefore, before preparing the shtob in the wall for the cable, it is necessary to familiarize yourself with the rules for the installation of electrical installations (PUE). The location of the wiring is determined by the following points:

• above the baseboards by 15-20 cm;
• below the ceiling and beams by 20-30 cm;
• from the corners at a distance of 10 cm;
• in the area of ​​\u200b\u200bheating pipes, gas pipes with an indent of 50 cm.

This also applies to TV cables.

It is better to buy wires in bays. In this case, the loops will be solid, and it will not be necessary to lay spliced ​​and insulated joints under plaster.

Electrical wires are laid hidden in walls, floors or corrugated pipes. When laying in a non-combustible surface, including plaster, the absence of corrugations is allowed.

According to the PUE, aluminum wires can only be used with a cross section of 16 mm2 or more. Smaller section - only copper. This is due to the fact that aluminum has a higher electrical resistance than copper. Under heavy load, it heats up and can melt.

Depending on the laying conditions, wires of the brand are used:

• VVGng: resistant to ignition, non-flammable, for laying under plaster;
• VVGng-LS: mainly under drywall, for protection against mechanical stress it is placed in a PVC box; its analogue can be a gray cable NYng-LS with a layer of rubber, more expensive, easy to install, not very convenient for strobes, since it has a round cross-section, not a flat one;
• PVA: stranded, white, may only be used as an extension cord or when connecting electrical appliances directly to a socket.

In old electrical wiring, a 2-wire cable is used, and in new 3-wire cable. Chandeliers with a two-gang switch require 4 cores.