Exposed wiring is wires and cables on insulators attached to the surface of a wall or ceiling. This technique was popular at the beginning of the last century, but even today many people prefer it to closed electrical wiring. There are several reasons for this: the wires are always in sight, which allows you to quickly fix the problem, replace the damaged area, and in the case of wooden houses, open wiring is generally the only reasonable option. In this article we will talk about how to make open wiring in a wooden house with your own hands.
The problem of electrification of wooden houses lies in the combustibility of wood. If hidden electrical wiring is installed in such a building, then the slightest malfunction, a “stray” spark or short circuit can provoke a fire, and it will be almost impossible to find the source of ignition in time. To avoid such troubles in the log cabins, the wires are laid in the open. The rules for the installation of electrical installations state that the installation of open wiring in a wooden house must be carried out along walls or a stream. Laying wires inside the walls in this case is not only dangerous, but also technically difficult, since the channels for them must be made at the stage of building a house, which means that each crown will need to be carefully drilled. Despite the prohibitions of domestic SNiP, many do just that, creating potentially unsafe living conditions. Some consider open wiring a relic of the last century, disfiguring the interior of the house, but this is only one side of the coin. In this article, we'll show you how to make wiring not only safe and easy to use, but also aesthetically pleasing. It can easily become an interesting design element and emphasize the stylistic features of the interior.
Wiring RequirementsThe requirements for open wiring in a wooden house are different from a similar system, say, in a brick or concrete building. Since wood is prone to fire, all possible protective measures must be taken. Wood can catch fire as a result of a short circuit or overvoltage in the network, which often happens in electrical cables. Based on this, all wires must be mounted so that they do not touch wooden surfaces. This is the first and most important rule for installing open wiring.
In addition to keeping the distance between the wires and the wooden wall, care must also be taken to ensure that these wires are as insulated as possible. Choose products with a protective sheath or lay them in special channels (casings, pipes, etc.). Despite the fact that the rules for installing electrical equipment allow installation without additional protective elements, it is still better to play it safe. Mounting methodsSo, how can you attach a wire to a wooden wall so that it does not touch it? There are several methods for installing exposed wiring, all of which provide safe operation. The main criterion for choosing a method is, perhaps, its aesthetic appeal and compliance with the style of the interior. Of course, there is also a financial aspect, but while ensuring the safety of the house and the safety of residents, savings are relegated to the background. There are as many as five ways to arrange open wiring, so you can easily choose the best option for your home. Porcelain insulatorsInstallation of wiring on ceramic insulating rollers is a traditional, if not historical, way of electrifying wooden houses. Wires twisted together (twisted wire) are attached to porcelain ingots driven into the wall, resulting in a small gap between the wall and the wiring. This method is considered the most accurate and beautiful, so such wiring can often be found in country or retro interiors. At the beginning of the 20th century, such a picture could be observed in every house and apartment, but then people discovered the charms of hidden wiring. Today, fashion is back again, and designers use porcelain rollers to create original interiors.
Porcelain insulators are attached to the wall with a distance of 4 cm from the socket, junction box or switch in increments of 30-50 cm when mounted vertically. If the wire is planned to be placed horizontally, then the rollers are attached in increments of up to 45 cm, otherwise it will hang. On turns, two insulators are used, fixed at an angle of 45 °.
A twisted wire passing next to a switch or socket and tied up in the corners with a textile braid removed from excess cable lengths. Such a measure will prevent the wire from being pulled and extend its life. But such laying of open wiring has its drawbacks. So, stranded copper wire is quite expensive, especially considering that it must have double insulation. For this method, it is better to use a GPVOp or PVOP wire with an appropriate cross section. The usual VVGng is also suitable, which costs an order of magnitude cheaper, but has lower protective characteristics.
In addition, you will need to purchase special components for open wiring in a wooden house, which are also expensive: porcelain rollers, switches, junction box, sockets, etc.
Staples for open wiringThe brackets used for mounting are small plastic "hooks" that are nailed to the ceiling or walls. For this method, VVng single-core copper cables are usually used. You can also purchase NYM cable, a higher quality triple insulated product. The technology for mounting open wiring is determined by the type of electrical cable.
The use of brackets for mounting exposed wiring is very popular because it is the fastest and most inexpensive way. However, it has one serious drawback - the appearance of such wiring will be rather simple and unaesthetic, especially if several wires are laid in parallel. Corrugated pipe for open wiringCorrugated pipes are often used to install wiring not only in log cabins, but also in houses made of brick or reinforced concrete. Thanks to a wide selection of pipe models with different diameters, several wires and cables can be hidden in them at once. To fix the pipe to the wall or ceiling, screeds or clips are used. The main advantage of corrugations for wiring is its incombustibility and inability to spread combustion. This allows you to use it as additional insulation for any brand of electrical cable. Plus, it can be easily attached to any surface.
However, this was not without drawbacks. It is very difficult to lay such a pipe in a straight line - it strives to bend and twist. As a result, all the bends and sags spoil the appearance of the wiring. Also, dust constantly accumulates in the folds of the pipe, so it must be wiped regularly. For installation in a residential building, this option is not very suitable due to its aesthetic unattractiveness, but due to the low cost of corrugations and its good protective abilities, many people prefer to sacrifice beauty for the benefit of practicality. Metal sleeves, pipes and PVC pipes can also be equated with the use of corrugations, but unlike it, such products will be difficult to mount at corners and bends. Cable channels for open wiringCable channels are perhaps the most optimal way to mask open wiring in a house. They allow you to safely lay cables, provide quick access to them if necessary, and at the same time do not violate the integrity of the interior design, or even emphasize it.
An analogue of cable channels are special skirting boards, on the back of which there are grooves where the wires are laid. A wide selection of textures, sizes and colors allows you to choose a model for the interior, divert attention from its shortcomings and possible defects in the finish. Liquid nails, self-tapping screws and dowels are suitable for attaching cable channels and skirting boards. Since we are talking about installing wiring in a wooden house, in this case, fixing on self-tapping screws or nails without hats would be the best solution. Before installing the cable channel, it is necessary to determine its cross section. It should be such as to fit all the wires freely and with small gaps. It is not recommended to “stuff” it closely; it is best to purchase a model with separating edges so that each wire is in a personal groove. To compile a list of the necessary materials, and in addition to the cable channel, you will also need connecting fittings, corners, fasteners, sockets, etc., you need to draw the most detailed diagram of open wiring in a wooden house.
So, we have described the main ways of installing open wiring, and now you can choose the best option for your home. Of course, no one forbids combining them, on the contrary, this will achieve greater practicality and beauty. For example, under the ceiling, you can hide the wires in a plastic box, and use corrugated tubes on uneven areas. Open wiring installationIn this chapter, we will describe the general principles of installing open wiring in a wooden house. Depending on the selected installation method, the specifics may vary slightly. The first step is to draw up a detailed plan on which to mark the entire route of the wires, all sockets, switches and the power that the appliances in each room will consume. Based on this, the cross section of cables and wires should be selected. In each room, different cables must be installed to supply power to lighting fixtures and sockets.
To work, you will need the following tools and materials:
Progress:
If you do not have enough qualifications, it is better to entrust such work to specialists, otherwise you risk not only burning the wiring, but also endangering your life. Electrification is a serious business that requires caution and a lot of experience, so if you decide to do it yourself, follow all personal safety measures. |
A wooden house pleases its inhabitants with lightness and indescribable comfort. But wood, for all its merits, is a combustible material that requires increased attention from the point of view of fire safety. But since the need to equip a house with electricity is not discussed today, before starting work, you need to carefully read the rules for installing electrical equipment (PUE) and the provisions of GOSTs. There are no particular difficulties in observing these rules, but you need to know about them.
Basic requirements for electrical wiring in a wooden house
Codes of rules for PUE and SNiP are developed by security experts. This is not a whim of an armchair official, but a list of necessary norms, the observance of which brings the level of "carelessness" as close as possible to the desired one. It can be said that life itself writes these dry chapters, behind which human tragedies are sometimes hidden.
The main cause of fires in wooden buildings is a short circuit in the electrical wiring.
Fire statistics unfortunately leave no doubt that timber construction is always at the forefront of fire risk. However, if you remember that for hundreds (or maybe thousands) of years our ancestors lived in wooden log cabins, there is hope that everything is possible, you just need to correctly deal with the wiring. After all, it is in the vast majority of cases that it causes a fire.
The main requirements contained in the PUE and GOSTs are as follows:
- The calculation of the wiring should be made with a margin of up to 30%. This applies primarily to the selection of the cross-sectional area of the wires, since the degree of heating of the insulation and the likelihood of a short circuit during operation depend on this. In order to cover the whole picture of electrification as a whole, it is necessary to prepare a working draft with a detailed diagram and specification of electrical wiring, and upon completion of work, get certified and receive a wiring passport.
- The quality of the connections should not allow the slightest possibility of electric shock to the inhabitants of the house.
- Heating and ignition of cables is unacceptable, as this will most likely lead to arson of the entire house. The possibility of short circuits must be completely excluded.
The PUE welcomes the installation of lighting in wooden houses using 12-volt lamps and LED equipment, which is considered the safest today. For example, in mines and mines, especially those where methane gas accumulates and an explosion can occur from a single spark, all equipment is powered by a current of 12 volts. The same is done in cars.
A significant obstacle that makes it difficult to independently carry out work on installing wiring in a wooden house is the lack of a single document regulating the installation. The main regulations are dispersed in the regulatory documents of GOST and SNiP and are not systematized. Therefore, when drafting a project, it is better to contact a specialized organization that has a license for this kind of activity.
Preparation of a power supply project
Project documentation should include all the details of future wiring. It displays the location of lighting fixtures, sockets, mounting boxes, switchboard. The specification describes in detail the brands of conductors used for wiring, their total number and ratings. All electrical devices involved in the power supply scheme, such as an electric meter, RAM, automatic machines and others, are calculated in advance for compliance with the loads that are expected during operation.
A power supply project usually includes a wiring diagram indicating the markings of the cables used, the type of devices installed and the estimated load on each of them The presence of a project is a sign of a civilized and responsible approach to business.
You can, of course, separate the cables without it, but:
- practice shows that wiring without a preliminary project, as a rule, costs 10-15% more. At the same time, errors are possible, the correction of which also costs money;
- in the event of a fire, the insurance company will require a certified home electrification plan. In its absence, the coverage of damages will be postponed for an indefinite period (until the circumstances are clarified). Well, if only one house burns down. In densely populated areas, a fire can spread to neighboring areas. The culprit will be the owner of the wooden structure from where the fire began to spread. The only way to prove your innocence is to present a certified plan for the electrification of the premises;
- the presence of a plan significantly reduces the cost of preventive and repair work on electrical wiring during further operation, and also helps to quickly find and eliminate the source of damage to the power supply.
A full-fledged project consists not only of drawings, but also of a detailed description of all elements and equipment. It usually includes:
- A graphic representation of all levels of the living space, on which, using the accepted symbols, the locations of the cable routes, consumers and electrical equipment are reflected.
- Single-line electrical supply schemes.
- Detailed calculations of ground loops.
- Cross-sectional area of conductors.
- List of switching devices.
- The maximum current and voltage of the meter.
- Calculations of the power of electrical receiving devices.
In addition, the project must provide for outdoor lighting of the site and the connection of courtyard buildings - a bathhouse, a garage, utility rooms.
The electrical wiring project of a private house must contain a calculation and diagram of the outdoor lighting device for the adjacent territory Project documentation is developed in several stages:
- Formulation of the problem. Power supply is planned in accordance with the terms of reference and conditions. The customer expresses his vision to the contractor orally or with the help of a schematic image. As one of the options, a design project can serve as an order form.
- Development and approval of the project. If necessary, the project is defended and coordinated with representatives of inspection organizations. The parameters of electrification and their compliance with regulatory documentation are being specified.
- Project implementation support. Sometimes it is also called supervised installation, during which the designer exercises direct control over the execution of work.
Calculation of the cable section
The calculation of conductors consists in determining two parameters:
In conditions of increased requirements for fire safety, the rules require the use of three-core wires without fail. This measure is dictated by the need for protective grounding of the entire power supply system.
In private houses, wiring should be carried out with a three-core cable: one core is a phase wire, the second is zero, the third is grounding Table: selection of cable section depending on the current strength
| Section of cable laid openly | Single-phase switching, 220 V | Three-phase switching, 380 V | Cross section of the cable laid in the pipe | ||
| continuous current when heating the cable up to 60 o C | power, kWt | continuous current when heating the cable up to 60 o C | power, kWt | ||
| 0,5 | 10 | 2,2 | |||
| 0,75 | 13 | 2,8 | |||
| 1 | 15 | 3,3 | 12 | 8 | 1,5 |
| 1,5 | 20 | 4,4 | 18 | 12 | 2,5 |
| 2,5 | 30 | 6,6 | 27 | 18 | 4 |
| 4 | 40 | 8,8 | 35 | 23 | 6 |
| 6 | 50 | 11 | 45 | 30 | 10 |
| 10 | 75 | 16,5 | 65 | 43 | 16 |
Calculation of electrical installation devices
Electrical installation devices - sockets, switches and junction boxes are selected based on the technological conditions of their operation.
Selection of input cable and circuit breaker at the input
Of great importance in ensuring the safety of electrical wiring is the correct input of electricians inside the house. When choosing a cable and a circuit breaker, it should be borne in mind that in the future the load on it will only increase - the number of household appliances and units that are used at home increases over time.
The cross section of the input cable must be calculated for the future: over time, the number of electrical appliances used and their total power consumption will only increase The task of an electrician is to choose a cable that will allow the use of electrical appliances without the risk of overvoltage of the lead-in conductor. The optimal placement of the introductory circuit breaker (AB) is considered to be its location in front of the meter. Its task is to turn off the internal network in case of excessive current consumption, for example, in case of a short circuit. But at the same time, it should not turn off at the maximum allowable load. In order to calculate the rating of the input AB independently, use the formula I nom \u003d P / U x cos (f), where I nom is the rated current, P is the total power of all devices, cos (f) is the power factor, which for most electrical appliances can be consider equal to one. 10% is added to the obtained value of the rated current and a circuit breaker is selected relative to it. Most often, in a private house, AB with a rating of 25 A is enough.
The introductory circuit breaker must withstand the maximum load from all switched on electrical appliances, but open the network when too high currents appear, for example, from a short circuit Three-phase power supply of a private house
The vast majority of wooden houses use single-phase power. But if it is planned to use high-powered units - for example, powerful electric welding or woodworking machines - a three-phase current supply is necessary. In this case, to calculate the installation devices, you must contact a specialist. Calculations are made according to more complex formulas and in relation to a specific situation.
Do-it-yourself wiring installation in a wooden house
If there is an agreed project, executed in accordance with all legislative norms, you can carry out the installation of electrical wiring yourself. To do this, stock up on the necessary tools and materials, as well as familiarize yourself with the safety rules. Consider the main stages of electrification of the house.
Switchboard installation
The switchboard is the main point of power management. It is a cabinet, inside of which there are devices for monitoring and recording the consumed current. It can be metal or made of dielectric plastic.
The switchboard contains control and monitoring devices for the electrical network: meters, circuit breakers, residual current devices, etc. The shield is mounted in a convenient place for use, at a height of 1.5 to 1.7 m from the floor surface. Most often, it is located near the front door in such a way that when leaving you can turn off the electricity, and when you return, turn it on. An introductory cable is connected from the power lines to the shield, then the electricity is distributed throughout the house. Inside the shield is installed:
- electricity consumption meter;
- circuit breakers on a DIN rail;
- RCD (residual current device);
- tires for grounding and zero circuit output.
An introductory circuit breaker can also be located here, but it is also practiced to locate it outside the house at the point where the overhead line is connected to the home network. This option is not without meaning, since the risk of excessive load on the input cable is significantly reduced.
The switchboard is installed first. Particular attention should be paid to the selection of automation, using proven and reliable brands of devices from well-known manufacturers.
Video: switchboard overview for a private house
Entering the cable into the room
There are two options for entering the cable from the power line into the house.
- Air method, which uses a self-supporting insulated conductor.
- Underground method, when the cable is brought into the room from underground.
The first option is more common due to speed and economy. The second is more expensive, but has a number of advantages, such as a long service life and independence from atmospheric disasters.
The underground cable entry method is more laborious, but more reliable and durable. In any case, the rules prescribe to lead the cable into a wooden house through a metal thick-walled (from 2.5 to 3.3 mm) pipe. Its inside must be painted or galvanized, and the installation is carried out at an angle of 3–5 ° to the horizontal plane so that the resulting condensate can freely flow out (GOST R 50571.15–97 (IEC 364 5 52 93): clause 522.3.2).
The cable is led into a wooden house through a metal sleeve, which is placed at an angle to organize the drainage of condensate The installation of a metal sleeve and cable entry is always carried out from the outside of the wall. The installer must be suitably qualified and authorized. Most often, this work is performed by employees of the energy supply organization.
Video: cable entry into the house and connection to the shield
Installation of switches and sockets
In wooden buildings there are certain nuances in the installation of switches and sockets.
- If hidden wiring is installed, the sockets, in accordance with the PUE, should only be metal. Despite the fact that the contact pair of modern switches is securely hidden inside a plastic (or ceramic) base, a microspark occurs with each use of the device. The same thing happens in the outlet when the plug is plugged into it. In ordinary stone walls, this is not dangerous. But in dry wood, in which wood dust can also accumulate, such a spark can lead to the most unforeseen consequences.
In wooden houses, hidden wiring can be done, but all electrical appliances must be installed in metal sockets - For outdoor wiring, when the cables approach the sockets and switches along the wall surface, dielectric plates are used to separate the device from the wood. You should not neglect this, it is better to think in advance about how to make such a lining aesthetic. Retail chains offer a wide variety of protective pads for every taste and color from plastic to metal. According to the rules, the size of the site should cover the wall by 10 cm on each side (counted from the basement).
For safety reasons, when wiring outdoors, electrical appliances are placed on dielectric plates.
Otherwise, the installation of sockets and switches is no different from installation in a stone building.
- First, the wall is marked. It is best to use a building level or a laser level.
- Next, socket boxes or protective pads are installed.
- The base of the device is mounted on them.
- After connecting to the wires, the outer casing is attached.
All of the above applies to junction boxes as well. It is recommended to design wiring in such a way as to minimize their number.
Wire connection
Based on the same prerequisites for increased fire hazard, it is recommended to connect conductors in wooden buildings using factory terminal blocks. Twisting is allowed only in the case of additional soldering of current-carrying wires and using plastic caps.
Wire connections must be made using special terminal blocks, twists can only be used as a last resort Grounding and installation of RCD
Residual current device (RCD) is designed to protect people (and pets) from electric shock in case of possible leakage on damaged insulation or the metal case of household appliances.
In the electrical wiring diagram in a private house, it is necessary to provide for the presence of an RCD device that protects against electric shock in case of accidental leaks The device is able to detect minimal leakage and react to it by opening the circuit. The level of sensitivity depends on the brand of the device. The choice is made according to the main parameter - the leakage current, which is expressed in milliamps. If the RCD is included in the whole house protection circuit, a leakage current value of 30 mA is sufficient. If the device is intended to protect individual premises, for example, a bathroom or a bathroom, a higher sensitivity of 10 mA is selected. The RCD is installed in the switchboard. The connection diagram provides for the location of the RCD in front of the circuit breakers.
The residual current device for the common circuit of the house is selected for a leakage current of 30 mA Video: connecting a circuit breaker and RCD
The same tasks are assigned to the grounding of all electrical installations inside the house. Separately, we can say about the grounding device. In order for the stray current removal system to work properly, you need to follow the recommendations for self-arrangement of the ground strip.
The ground loop consists of three metal plates fixed on reinforcing pins. To do this, you will need metal fittings of three meters in length and three meter pieces of corners.
Do not forget about the seasonal expansion and contraction of the metal under the influence of changing air temperature.
To prevent the ground bus from breaking, a “compensation hump” is made in it, which is designed to absorb thermal changes.
Methods for open wiring
In practice, three types of external wiring are used in wooden houses:
- Corrugated wiring. Cables run inside a plastic or metal corrugated sleeve. The advantage of this wiring is the low cost of materials and the speed of installation. The corrugation is attached to the ceilings and walls with the help of special clips. The disadvantage is the ability of corrugated sleeves to accumulate dust, which is difficult to remove from them. In addition, over time, the wiring can sag, and it needs to be tightened.
Laying cables in corrugated hoses is very simple and convenient - Wiring in cable channels. One of the most popular types of wiring today. This is due to the fact that recently manufacturers have begun to produce a large assortment of connecting fittings, with which you can wire wires in any configuration without compromising the appearance. The main advantage of this type of wiring is affordability, speed of installation and a high level of maintainability. In this way, cable channels compare favorably with corrugations, which, in the event of repair of wiring, will have to be completely replaced. A big plus of wiring in cable channels is the availability of cables and the possibility of updating them if necessary. The only thing to keep in mind when installing cable channels is house shrinkage. Newly built wooden houses shrink significantly (up to 5% per year). And this means that the wiring lines can be deformed.
Wiring in the cable channel allows you to have access to cables at any time - Retro wiring. Quite a popular trend in interior design. It consists in the fact that the wires are fixed on the walls with the help of ceramic insulators in an open way. The cable is twisted in the manner of a twisted pair and in this form is pulled to lamps or sockets. The solution is not new, this is how wires were laid in residential premises 60-70 years ago, but at the same time it perfectly complies with safety standards - the cable does not touch the wall, remaining at a distance of 10 mm from the surface.
Retro wiring looks very aesthetically pleasing and meets electrical safety standards as much as possible
The choice entirely depends on the aesthetic inclinations of the inhabitants of the house. On sale there are all the necessary materials to realize your preferences in terms of design solutions.
Video: outdoor wiring in a cable channel in a wooden house
Hidden electrical wiring in a wooden house
If, for some reason, the customer is not satisfied with the external location of the wiring in the house, the cables are bred in a hidden way. In a wooden structure, this is a rather time-consuming and painstaking procedure. Each wire, regardless of its thickness, must be packed in a metal tube. Sockets and junction boxes must also be made of metal. Pipes are supposed to be protected from corrosion. To do this, they must be painted from the inside with moisture-resistant enamels, and to drain condensate, drill small holes at certain intervals. For the same purpose, it is necessary to place the pipe at an angle so that drops of moisture can flow out. To avoid damage to the insulation, the ends of the pipes are cleaned from sharp burrs and are additionally equipped with plastic tips.
For a hidden wiring device in a wooden house, cables inside the walls are laid in metal pipes and led out into niches covered with metal sockets - The best material for such wiring is copper pipe. Its cost is quite high, but due to the plasticity of the metal, bends can be made without special equipment. A steel pipe is much cheaper, and threaded adapters and spurs are provided to give it the necessary shape.
Steel pipes are cheaper than copper pipes, and there are special fittings for bending them. - If the wiring is installed at the construction stage, hiding it in the walls is simplified. Especially if it is a frame structure. In houses made of logs or timber, all wiring channels are cut out in the walls after they are erected.
For laying cables in wooden walls, strobes can be cut - Another way, allowed by the PUE standards for wooden buildings, is to locate the wiring inside the plaster applied over the wood. This method was practiced in old buildings - shingles (plywood reinforcement) were stuffed onto the logs and a layer of cement plaster was thrown. According to the rules, the plaster layer in this case should be from 10 mm on all sides. The modern analogue of this technology is the sheathing of a wooden wall with drywall, which in essence is dry plaster. With a standard drywall sheet thickness of 12.5 mm, the wall must be covered in two layers.
If you put a drywall sheet on top of a wooden wall or ceiling, hidden wiring can be done under it.
A big disadvantage of hidden wiring in a wooden structure is the inaccessibility of cables. If any problems occur, it will be very difficult to replace the old cable with a new one. However, this type of wiring has its fans. Especially among designers who are primarily concerned with the aesthetic solution of the home.
Video: hidden wiring in a wooden frame
Wiring test
After completing the installation, the customer needs to invite employees of the electrical laboratory. The purpose of the test is to measure the resistance of the system as a whole, ground resistance and check all automation: RCDs, circuit breakers, current consumption meter. If all parameters correspond to the norm, the customer receives a protocol signed by a responsible person. This document is presented to the service company when concluding an agreement for the supply of an object with electricity.
After the work is completed, it is necessary to invite a specialist to check the system and obtain a test report for the electrical wiring When carrying out the wiring installation activities yourself, it is important to observe personal safety measures. Electric shock can cause irreparable harm to health, cause death. Installation is carried out only when the power supply is switched off. Putting the equipment into operation is carried out in the presence of an authorized representative of the design organization.
The deterioration of the environment has led to an increase in demand for natural building materials, including wood. In Russia, wood is consistently in demand due to the availability of this environmentally friendly material, which has good thermal insulation properties, relatively low specific gravity and is easy to process.
In private housing construction, wood today is not a way out of the situation with a limited budget, but a full-fledged building material, but due to combustibility, it requires the use of special technologies, including when installing residential power supply systems.
Consider an electrical wiring device in a wooden house, regulated by the requirements of PUE-7, SNiP 3.05-06-85 and SNiP 31-02-2001.
Requirements for electrical wiring in a wooden house
In wooden houses, as in stone buildings, the power supply system is mounted in two ways:
- hidden - less in demand;
- open - more common.
Both technologies do not eliminate the electric current factor, but minimize the risks associated with it, since all wood is combustible, and even impregnation with special compounds only reduces the degree of combustibility of wood. The basic requirements for the installation of electrical wiring in wooden houses are defined in the Electrical Installation Rules:
Electrical networks laid behind impassable suspended ceilings and in partitions are considered as hidden electrical wiring and they should be carried out: behind ceilings and in the voids of partitions made of combustible materials in metal pipes with localization ability and in closed boxes; behind ceilings and in partitions made of non-combustible materials* - in pipes and ducts made of non-combustible materials, as well as flame-retardant cables. At the same time, it should be possible to replace wires and cables.
*Suspended ceilings made of non-combustible materials are understood to mean such ceilings that are made of non-combustible materials, while other building structures located above suspended ceilings, including interfloor ceilings, are also made of non-combustible materials.
In addition to those specified in the PUE, there are rules for wiring in a wooden house that are common to both installation methods:
- use of cables with copper conductors;
- insulation of conductive cores must be made of non-combustible material (the best choice is NYM cables or its analogues VVGng);
- calculation of the cable section for current load with a margin of 30%;
Table of dependence of the cable cross-section on the load power
| P(W) | I(A) | Copper | |||
|---|---|---|---|---|---|
| open wiring | Hidden wiring | ||||
| S (mm2) | d (mm2) | S (mm2) | d (mm2) | ||
| 500 | 2,17 | 0,43 | 0,74 | 0,54 | 0,83 |
| 1000 | 4,35 | 0,87 | 1,05 | 1,09 | 1,18 |
| 1500 | 6,52 | 1,30 | 1,29 | 1,63 | 1,44 |
| 2000 | 8,70 | 1,74 | 1,49 | 2,17 | 1,66 |
| 3000 | 13,04 | 2,61 | 1,82 | 3,26 | 2,04 |
| 4000 | 17,39 | 3,48 | 2,10 | 4,35 | 2,35 |
| 5000 | 21,74 | 4,35 | 2,35 | 5,43 | 2,63 |
| 10000 | 43,48 | 8,7 | 3,33 | 10,87 | 3,72 |
- mandatory installation of a ground loop;
- the switchboard must be isolated from the base - placed in a mini-box.
Power input to a wooden house
The internal power supply system of the house is connected to the electrical network by the local power supply organization - at the request of the consumer, with the installation of an electric meter and only if there is a project.
Input of power supply to the wooden house is carried out in one of two ways:
- Air line.
- Underground cable laying.
Overhead connection
The rules for connecting a private house to power from an overhead line are determined by clause 3.18 of SNiP 3.05.06-85.
According to these standards, at the input of power to the building, the following should be applied:
- insulated cables in an NG class sheath (non-combustible) with a conductor cross section of 4 mm² for copper and 2.5 mm² for aluminum;
- insulated wires of the same cross-sectional dimensions.
In the design places for the passage of cables through combustible structures, segments of a steel pipe (sleeve) are installed so that their sections protrude outward by 1 cm. The gaps between the sleeves and the walls of the holes made are sealed with cement mortar.
To prevent the ingress of rainwater and the accumulation of condensate, the bushings in the outer walls are mounted with a slope of 5 degrees.
At the point of passage through the steel sleeve, a piece of rubber tube is put on each wire - an additional rubber sleeve.
At the ends of each of the rubber sleeves, observing alignment, a special introductory fitting is put on: on the outside - a funnel, and on the inside - a sleeve. These products are made in one piece from porcelain or split with tightening collars - from stainless or galvanized steel.
For a wooden house, the distance between adjacent funnels (outside) must be at least 10 cm. The bushings and funnels of both pipes are filled with a bituminous waterproofing compound after installation.
Conditional section of the power supply input from the overhead line into the wall of a wooden house
The wires outside should be located at a distance of at least 0.2 m from each other and from the protruding structures of the house, and the point of entry of the power supply into the house (hook with an insulator) is arranged at a height of at least 2.75 m from the surface of the blind area.
In addition to porcelain and metal lugs, when entering a cable into a house from an overhead line, various UKPs (cable passage seals), including heat-shrinkable ones, are also used. As a rule, such devices are designed for a certain range of cable and sleeve diameters, so choosing the right size is not difficult.
Further wiring inside the house at the exit of the cable from the porcelain sleeve depends on the design method of its installation (hidden, open).
Entering electricity through a pipe rack
If the height of the building is insufficient to meet the requirements of the PUE for the vertical parameters of connection by an overhead line, the power supply to the wooden house is carried out through a pipe stand - a hollow mast, vertically mounted outside on a wall or roof and serving as a channel for the cable.
Pipe racks are made of steel pipes with an inner diameter of:
- from 20 mm - when power is supplied by two wires;
- from 32 mm - for four conductors.
On the upper section of the pipe rack, in order to prevent rainwater and snow from entering it, a semicircle is formed using a pipe bender.
Approximately in the middle of the height, a horizontal crossbar from a steel angle 40x40 mm 45-50 cm long with two vertical steel rods for mounting ceramic insulators is welded to the pipe rack.
At the transition of the arc to a straight section, a ring (washer, nut) is mounted to the pipe, to which two steel wire extensions will be attached - to counteract the tension created by the overhead line.
Some kind of hardware (bolt, nut, stud) is also welded to the pipe rack - for its “zeroing” by connecting to the zero core.
In the lower part of the pipe rack, using the same pipe bender, an angle of 85 ° is formed so that the bent section of the pipe (10 cm longer than the wall thickness) after installing the structure is located in the wall with an inward rise of 5 °. In the lower part of this bend, a hole Ø 5 mm is drilled in the pipe - for the condensate outlet.
The cut edges of the pipe rack are processed with a file, after which the structure is covered on the outside with two layers of anti-corrosion paint.
If, when installing a pipe stand on a wall, the distance from its lowest point to the ground is less than 2 m, then it is mounted on the roof, arranging the power supply to the dwelling through the roof. Particular attention in this situation is paid to the rigidity of mounting the rack on the roofing and sealing the passage in it.
Before installation at the design site, a “conductor” (cable or thin wire) is pulled through the pipe rack for the subsequent pulling of the cable in it. The structure is installed in place and attached to the anchors mounted on the base, after which it is equipped with stretch marks and the gaps in the passage are sealed. Threaded connections "bolt-nut" are made using grover washers and covered with a protective layer of technical vaseline.
Underground cable connection
Entering power into a wooden house with an underground cable is more reliable and safe, since the impact of external factors on the conductor when it is properly laid is minimal.
The input of electricity into the house by an underground cable line is regulated by clause 12.1 of VSN 59-88 (Departmental Building Regulations).
Underground power supply to the house should be carried out only
armored cables that are laid in a trench without pipe protection. The practice of using unprotected cables placed in electrical polymer pipes is a violation of current regulations.
From the trench, the power cable is brought into the building in one of two ways:
- through the foundation or the wall of the basement floor - with the installation of a thick-walled steel bushing;
- through the outer wall - with an entrance to the building at a height of at least 2.75 m and protection from a pipe up to a height of 1.8 m.
The power supply of the house through an underground cable is arranged during the construction of the building - at the stage of foundation construction, which makes it possible to provide everything necessary for the input of communications.
Electric meter installation
According to the requirements of the energy supervision authorities, electricity meters in private homes should be installed in places with the possibility of constant access by controlling persons. Consequently, the shield has to be mounted outside, where the components placed in it are exposed to weather conditions. With this in mind, two switchboards are installed in a private house:
- outdoor - to accommodate the electric meter and the required minimum of additional devices (at the expense of the energy supply company);
- internal - located in the house, connected to an external shield, equipped with the equipment necessary for the safe and convenient management of the housing power supply system (at the expense of the owner of the building).
Unlike stone houses and city apartments, where built-in models are preferred when choosing a mini-box, suspended switchboards are mounted in wooden houses - dust- and moisture-proof.
The wiring diagram with the method of its installation is an integral part of the house project. If a hidden laying of the internal power supply system is designed, then the possibility of implementing such a solution begins to be provided in the process of assembling the log house.
In beams or rounded logs, along which vertical sections of wiring must pass, technological passages for cables are made before laying at the design site - strictly according to the power supply scheme. To form a vertical channel in the wall of logs stacked on top of each other, the holes made in them after the assembly of the structure must be strictly aligned.
Horizontal passages are arranged after the walls are erected:
- for cables - along and across logs;
- for mounting and junction boxes - across.
Horizontal transverse and vertical channels are made with a powerful drill with a core drill or a Forstner drill.
Longitudinal hidden passages are, as a rule, strobes along the bars, arranged using a hand or power tool (chisel, milling cutter). The least time-consuming implementation of such chasing is with a “grinder” with a disk cutter for wood.
According to the PUE standards, when installing electrical wiring in a hidden way, all cables must pass through steel (copper) pipes or be insulated from wooden bases with a layer of cement mortar or alabaster of at least 1 cm. Mounting and junction boxes must also be made of steel or copper. The sections of steel protective channels are connected to each other and to boxes by welding or threading, copper tubes - by soldering and crimping. Protective channels and boxes must be grounded.
In a wooden house, it is forbidden to conduct hidden wiring cables in metal hoses. Corrugated metal covers are a strip 0.2 mm thick, spirally twisted. Protection made of metal of such thickness is not able to localize a short circuit, since its walls cannot withstand the temperature of the arc and instantly burn out. Not capable of localizing the arc and a metal hose in a polymer shell.
Corrugations made of a homogeneous polymer are also not suitable for placing them in channels for hidden wiring - it is almost impossible to fill them with cement mortar while maintaining a layer thickness of 1 cm around the cable. In addition, polymer corrugations are prone to damage by rodents.
The choice of steel pipes for hidden wiring channels is made taking into account the wall thickness, which is regulated by SP 31-110-2003, and the inner diameter.
| Max wire cross section (mm²) | Pipe wall thickness (mm) | |
|---|---|---|
| Aluminum | Copper | |
| up to 4 | up to 2.5 | not standardized |
| 6 | — | 2,5 |
| 10 | 4 | 2,8 |
| 16: 25 | 6; 10 | 3,2 |
| 35; 50 | 16 | 3,5 |
| 70 | 25; 35 | 4,0 |
The cable placed in the channel should cover no more than 40% of the lumen in it.
One of the ways to place hidden electrical wiring is along the beams of interfloor ceilings. The pipes, according to the wiring diagram, are cut into pieces of the required length, after which a thread is cut at their ends, and a “conductor” is pulled through each element - to tighten the cable after the channel is installed in place.
Fragments of pipes are attached to the beams with the help of clamps, connected to junction boxes and bent down in the design areas to supply power to the chandeliers. At the same time, electrical wiring lines are tightened in them.
Junction boxes after installation must remain accessible for maintenance, therefore, on the floor between the attic and the second floor, they are placed with lids up - for access on the floor, and on the beams between the first and second floors - with lids down, with access from the ceiling.
Upon completion of the assembly of the power supply system, its “ringing”, drawing threaded pipe connections, measuring ground resistance and coating the channels on the outside with two layers of anti-corrosion paint are carried out. Then a rough flooring is mounted on top of the beams. 
When installing longitudinal horizontal lines of hidden wiring along the walls, you can use a thin-walled steel profile for drywall. To do this, strobes of the required section are made in logs or beams, into which the profile is recessed and fixed with self-tapping screws. A strip of drywall is placed at the bottom of the profile along the entire length, fixing it pointwise with alabaster solution. A cable is also attached to the gypsum over the strip, after which the entire volume of the profile is filled with gypsum. The completed strobe is sealed to the full depth with a special putty, after which the channel dries to be painted under the main background. 
The requirements for ensuring the fire safety of houses made of SIP panels are especially high, since these structures are highly flammable.
A SIP panel is a “pie” of two oriented strand boards with a layer of insulation between them, in which internal channels are arranged by manufacturers for the installation of hidden wiring. 
According to SP 31-105-2002, hidden wiring in this case can be mounted through standard channels - without additional pipe protection, but using an NYM cable. However, the PUE prescribe to arrange electrical wiring in a wooden house only through metal pipes.
There are two ways to resolve this contradiction, but both of them are financially and time-consuming:
- according to the PUE, mount hidden wiring in metal pipes along the walls and ceiling, then carry out a crate on them and sheathe them with drywall (the method also “steals” the dimensions of the premises);
- sequentially mount 3 layers of plasterboard on the walls - the first as a gypsum protective base, in the second after installation, make strobes for wiring, cover the second with a third solid sheet.
A reasonable alternative to these expensive solutions in SIP-panel houses is the installation of open wiring.
Advantages of concealed wiring
- No need for masking or decorative design of electrical wiring elements.
- Minimal chance of cable damage.
- Ease of replacing lines - pulling a new cable through the old pipe.
- High electrical and fire safety with proper installation.
- The hidden power supply system does not interfere with finishing work.
Disadvantages of concealed wiring
- The complexity of the execution of both the main power supply system and additional hidden branches.
- High installation costs.
- Additional pipe costs.
- The impossibility of visual control of the technical condition of the wiring.
Installation of wiring in steel pipes does not eliminate the need for the correct calculation of the cross-section of conductors, grounding devices and the use of RCDs, but is only a mandatory requirement for hidden cable wiring.
Open wiring in a wooden house
Open-type wiring in wooden houses is used more often - because of the ease of execution and lower cost.
The essence of the method is explained in clause 2.1.4 of PUE-6 and consists in the open placement of all electrical wiring elements on the surfaces of walls, ceilings, trusses and other building structures.
PUE-6 2.1.4 Electrical wiring is divided into the following types:
1. exposed wiring- laid along the surface of walls, ceilings, trusses and other building elements of buildings and structures, along supports, etc.
With open wiring, the following methods of laying wires and cables are used: directly on the surface of walls, ceilings, etc., on strings, cables, rollers, insulators, in pipes, boxes, flexible metal sleeves, on trays, in electrical skirting boards and platbands, free suspension, etc.
With this technology, the installation of cables does not slow down the construction, as it is carried out after the construction of the log house. In addition, outdoor wiring uses switches, sockets and outdoor boxes, which eliminates the need for mounting nests in logs.
For outdoor sockets and switches, when installing them on wooden walls, additional special overhead socket boxes are required.
The laying of cables and wires of open electrical wiring is carried out in the following ways:
- conventional installation (cables with double or triple insulation) directly on the surfaces of building structures - using brackets of various types;
- laying in protective corrugated pipes;
- placement in cable channels;
- on ceramic rollers or insulators.
The listed methods for arranging open electrical wiring are applicable not only to houses made of logs and beams. Wooden frame buildings and cottages made of SIP panels, despite their structural differences, can also be equipped with open wiring according to the same rules, since the main material for the manufacture of their structures is wood.
Open wiring with staples
Wiring brackets are cheap and easy to install, but the wiring made with them is not aesthetically pleasing.
When laying on a wooden surface, a steel strip, galvanized or painted, must be installed under the cable along the entire length, protruding from under it on both sides by at least 10 mm. The thickness of the strip should not be less than 0.8 mm, it is fixed to the wall with self-tapping screws in increments of 0.8-1.0 m.
To fix the cable on the strip, holes for the nails of the brackets are pre-drilled in it - in increments of 30-50 cm.
If the cable does not have a ground conductor, the strip must be grounded. Using asbestos tape instead of steel is tempting, but the material is carcinogenic.
Open wiring device in protective corrugated pipes
Pipes used to protect open electrical wiring are made of polymers (PVC, PE, PP), steel (tin-plated, galvanized or stainless) and PVC-sheathed metal.
Protective polymer tubes intended for use in wooden houses must necessarily have a fire safety certificate and the “ng” marking - non-combustible.
When choosing plastic corrugated channels, you can first be guided by their color: the white tube burns only when supported by a flame and goes out when it stops, the gray sleeve burns independently after arson. 
Black corrugations should also not support combustion, but they are used for outdoor wiring exposed to ultraviolet radiation.
A corrugated steel tube is a twisted strip that is not inferior in flexibility to a polymer sheath, but is more resistant to mechanical stress (compression, tension). Accordingly, the durability of steel corrugations is declared by manufacturers to be several decades, and their price is several times higher than polymer ones. 
A wide range of pipe diameters (from 6 to 100 mm) allows you to choose protection for a cable of any section, including for placing several wires in one channel.
The diameter of the corrugated channel should be twice the sum of the diameters of the cables placed in it.
A “conductor” is first pulled through the corrugation to tighten the cable, to the end of which a conductor is attached. Instead, you can put a pen cap on the end of the cable, insert it into the case and easily push the conductor through the entire length of the protection.
Fixation of metal corrugated tubes to the base is carried out using steel brackets with one or two legs, polymer covers are fastened with nylon ties and clamps. The fastening step is maintained within 30 cm. The arrangement of the channels on the base is carried out so that the tubes do not cross with each other and do not have twists.
The device for the passage of external wiring through the inner wall is carried out using a sleeve - a piece of steel pipe protruding 1 cm on both sides. To prevent damage to the cable by sharp cut edges, protective tips are put on the ends of the sleeve.
It should be borne in mind that a newly erected wooden house with a wall height of 3 m during the first year will shrink, depending on the material of the log house:
- log (regular / rounded) - up to 10 cm / 8-10 cm;
- timber (natural humidity / chamber drying) - up to 6 cm / 2.5 cm;
- glued timber - up to 2 cm.
Therefore, the installation of open wiring must be carried out taking into account the amount of shrinkage, evenly distributing the technological slack of cables and channels between spans.
Disadvantages of open wiring in corrugated channels:
- the difficulty of cleaning the corrugated walls from dust accumulating in the folds;
- the inevitability of sagging channels on spans;
- the difficulty of replacing the wiring section without dismantling the protective channel.
Open wiring through cable channels
Cable channel - a protective structure made of aluminum, galvanized steel or non-flammable plastic, consisting of a U-shaped profile for placing wires in it, an easily removable cover to it and connecting (transitional) elements. At the place of installation, cable channels are:
- wall (parapet) - are made of strict and decorative execution;
- floor - differ from parapet in greater strength and streamlined section;
- plinth - are produced in various sections, including those imitating a plinth, with an existing groove for cable placement.
According to the markup, the box is attached to the wall, cables are laid in it, after which the channel (groove in the plinth) is closed with a lid.
In ducts, wires and cables are allowed to be laid in layers with an ordered and arbitrary (loose) mutual arrangement. The sum of cross sections of wires and cables, calculated according to their outer diameters, including insulation and outer sheaths, should not exceed: for deaf ducts 35% of the duct cross section in the light; for boxes with opening lids 40%.
Advantages of cable channels:
- ease of installation;
- availability of cables for periodic control;
- ease of replacement of the wiring section;
- aesthetics;
- affordable price.
Flaws:
- a certain volume of the structure;
- low strength of wall-mounted products.
Exposed wiring on ceramic rollers or insulators
In wooden houses, this method of installing electrical wiring is popular, since, in accordance with the PUE standards, it also visually harmonizes with the base material - wood.
The technical execution of mounting on insulators is not difficult and is possible with your own hands, since with the correct calculations of the parameters of the power supply system, it only requires compliance with the wiring diagram. However, the price of modern components, manufactured semi-antique, is quite high. At the same time, fireproof socket boxes must also be purchased for sockets, switches and boxes.
Basic installation rules:
- insulators of horizontal lines are located in increments of no more than 45 cm, vertical - up to 50 cm;
- when the device turns the cable at a right angle, two insulators are installed - to form a smooth bend of the conductors;
- the distance from the edge of the socket, switch or junction box to the wall of the nearest insulator should be 4 cm;
- after removing the fabric braid from the wire, it is tightened with a nylon clamp - to prevent further unraveling of the thread weaving;
- the passages of wires through the walls are carried out on porcelain bushings.
The aesthetics of electrical wiring along insulators is high, but - subject to a simple system of internal power supply. And the numerous twisted lines of wires on the walls are far from attractive, not to mention the difficulty of repairing such bases.
Approximate prices for electrical work in Moscow and Moscow region
| Type of work | Cost, rub.) |
|---|---|
| Installation of a socket in a wooden base | 300 |
| Installation of one electric point (for hidden wiring) | 250 |
| Installation of one electric point from external wiring | 200 |
| Replacing an old electrical outlet | 250 |
| Junction box installation | 250 |
| Preparing a site for a junction box | 250 |
| Installing a socket for a telephone | 250 |
| Installing a socket for a TV cable | 250 |
| Installing a computer network socket | 300 |
But even taking into account the high cost of services, in the absence of experience in performing electrical work, it is better to entrust the wiring device to professionals, since the price of even a minor mistake can be very high.
Conclusion
Installation of an internal power supply system in a wooden house is a complex of works, the safety of many people depends on the correct implementation of each of which. The cost of wiring installation by third-party contractors also takes into account the factor of the contractor's responsibility for the result.
Calculate the cost of electrical wiring installation in a wooden house!
Make a list of works and get a cost estimate in 10 minutes from teams and craftsmen!
Convenience and communication have become the main component of human life. Such comfort is hard to imagine without electricity. Supplying a house with electrical communications is not complete without taking into account certain rules. In this article, we will examine in detail the question of how electrical wiring is laid in a wooden house according to the scheme and requirements.
Today, wood has become very often used for the construction of private houses. This is done not only for aesthetic reasons, but also because of the naturalness of the raw materials. A very time-consuming process in construction is the wiring of communications, namely the electrification of a home.
Be sure to exercise caution - this is required for any work on electrical installations.
Rules for installing electrical wiring in a wooden house
Important! At the time of installation of electricians in the house, be guided by three rules: safety, fire safety and safety precautions.
It is known that open wiring is a good option for wiring cables in a wooden type of structure. Be sure to lay conductors in such houses with good insulating properties. Cables should not create friction between bare cores. If you are planning to enter electrical wiring in a room with high humidity, use options suitable for outdoor communications, as they have more stringent properties.
When laying conductors from the main meter to consumers, there should not be many connections. As a rule, it is not so easy to achieve the integrity of the network, so junction boxes come to the rescue, which provide reliable switching of electrical wires to each other.
In wooden houses, the device ground loop is more important than ever. Do not forget to check its functional features before finishing the wiring. When the network is connected to voltage, all sources must work. Plus - the absence of sparkles, sparks and hiss of conductors.
Stages of installation of electrical wiring in a wooden house
It is important to prepare everything before performing installation work; it is imperative to have a cable layout, both throughout the room and in separate junction boxes.
Wooden houses are a very ancient tradition of Russian architecture. Even in our time, when there is no shortage of modern building materials, many owners of suburban areas prefer to build housing from wood - no one can even compare closely with it in terms of natural warmth and the special comfort created.
Yes, and ordinary citizens - owners of small cottages, most often opt for wood, as the main material for construction. But both permanent and temporary housing in modern conditions cannot do without power supply. In both cases, it is extremely necessary to know how to make the wiring in a wooden house correctly so as not to endanger your health and even life, to ensure the safety of housing and property.
Basic requirements for electrical wiring in a wooden house
First of all, it is necessary to warn home craftsmen who believe that if they can fix a socket or a switch in an apartment, they know how to distinguish zero from a phase using a conventional indicator, then they can safely take on independent wiring in a country wooden house. Not everything is so simple - a wooden structure is characterized by an increased fire hazard, and the requirements for laying power here are completely different.
Poor electrical wiring is the most common cause of fires The bleak statistics show that the overwhelming number of fires that occur in wooden buildings are directly related to violations of the installation and operation of electrical appliances or wiring. By and large, you should not take on the independent laying of electrical lines at all - this is the lot of qualified specialists. However, any owner of wooden housing needs to know the basic rules, although would in order to evaluate the existing cabling or to control the work of the called electricians, since it is quite possible to run into "hacks" who perform work on the principle " it's okay, it will do".
So, what are the basic requirements for electrical wiring in a wooden structure:
- The probability of cable ignition with the transmission of open fire to the wooden structure of the building in the event of a short circuit should be completely excluded or minimized to the limit.
- The physical, technical and operational characteristics of the wires and electrical fittings used must correspond with a sufficient margin to the total power consumption at each specific section of the wiring, taking into account peak loads. Any manifestations of heating of cables or terminal connections are unacceptable.
- The condition of the wiring must completely eliminate the risk of electric shock to people or pets.
The problem of aesthetics in a wooden structure should go by the wayside. There are many acceptable ways to solve this issue as well (this will be discussed below). But you should never seek to improve the interior design of premises at the expense of even a slight decrease in the level of security - this is fraught with disastrous consequences.
The complexity of independent work on laying in a wooden house is also in the fact that there is no single regulatory document. Experienced craftsmen with extensive experience know the basic requirements for it and the technological methods for their implementation. It’s not so easy to pick up the necessary information, scattered but SNiPam, GOSTs and PUE (electrical installation rules), and it is often too specialized in nature, understandable only to a person with a specialized education.
The main objective of this publication is to give the owners of wooden houses a basic understanding of how to install electrical wiring. As an instruction on how to make wiring in a wooden house, addressed to an unprepared person, for completely independent electrical work, it should not be considered.
The entrance of the electric line to the house
it — very responsible area, which for some reason the owners often forget about, focusing on the internal wiring. The principle probably works - it has been standing for a long time and fully justifies itself. Meanwhile, the introduction of a power cable into the house could have been carried out for a very long time, using old technologies that no longer meet modern requirements. The equipment of houses with electrical appliances has grown literally at times, respectively, and energy consumption has also increased. Yes, and the cable part itself can become hopelessly outdated - the insulation bursts under long-term exposure to the sun and temperature changes, exposing metal cores and reducing the safety of the wiring.
Such a cable entry through a wooden wall is a “time bomb” A particularly vulnerable area is the passage of the cable through the wooden wall of the attic. At one time, it was believed that cutting a rubber hose was enough for safety. However, such a knot is fraught with a considerable threat - the composition of rubber contains a considerable percentage of soot, which in itself is carbon, i.e. conductive material. As such an “insulator” ages, electrical conductivity bridges with a sufficiently high resistivity appear. There may be areas of local heating, sparking, and for dry roof gable boards this may be quite enough.
In a word, if the goal is to completely update the wiring and bring it to a truly safe state, then you need to start from here.
There are two ways to bring a power line into a house - overhead and underground.
- The underground method is considered more reliable, since the cable is completely hidden and not subject to external influences. However, this is a rather costly method that will require significant excavation. The cable must be located at a depth of at least 0.8 m, the security zone must be marked with signs. The passage through the foundation and entry into the house is carried out with the obligatory installation of metal sleeves from thick-walled pipes.
As a rule, it makes sense to organize such a connection only when, thinking over the passage of communications in advance. If the power line is laid in an already built house, then it is easier and cheaper to use overhead wiring.
- It is strictly forbidden to carry out any independent electrical work on the poles of power lines - only a highly qualified electrician with the appropriate approval has the right to do this.
An approximate diagram of the required placement of overhead wiring from power lines to the house is shown in the figure.
The section of the line from the pole to the house is usually made of wire with a cross section of at least 16 mm. Basically, a SIP cable (self-supporting insulated wire) is used, which has a high-strength sheath made of cross-linked polyethylene, resistant to infrared radiation and thermal shock. The service life of such a wire should be at least 25 years.
However, this line never starts inside the house. According to existing rules, it is strictly forbidden to lay cables with an aluminum current-carrying part along combustible structural elements. And since we are talking about a wooden house, then starting from the entrance and up to The last socket or light bulb uses only copper conductors.
For the section from the line connection to the inlet switchgear, it is recommended to use the VVGng cable. The additional index "ng" indicates the incombustibility of its insulating coating. This cable fully meets the requirements for fixed wiring both indoors and outdoors. However, for greater reliability, it is also recommended to enclose it in a corrugated polymer pipe, which has the appropriate certification in accordance with the current fire safety rules NPB 246-97. The plastic from which the “corrugation” is made belongs to self-extinguishing, non-combustible materials.
Always carried out outside the building. Currently, for this, special hermetic compresses are most often used, providing reliable contact without the possibility of oxidation and sparking.
The sections of VVGng passage through the walls of the house and attic or interfloor floors must be enclosed in a metal sleeve made of a thick-walled pipe. This precaution has several purposes:
- The cable part will be protected from damage that may be caused by displacements of building structures, for example, due to shrinkage of the house or ground vibrations.
- The metal sheath will prevent the spread of fire to wooden structures to the maximum extent in case of an emergency - overheating or ignition of the cable.
- The cable in vulnerable places hidden from view receives protection from domestic rodents.
The pipe wall thickness is a regulated value. So, if a wire with a cross section of up to 4 mm² is used, it should be 2.8 mm, and when using more powerful cables - from 6 to 10 mm² - even 3.2 mm. This will eliminate the possibility of burning the pipe wall if a short circuit occurs inside it.
The same rule applies to all sections of the house wiring in a wooden building, without any exception.
The next important section is from the entrance to the house to the switchboard (according to the accepted terminology, the introductory switchgear - VUR). What is the special specificity of this section - it remains unprotected by automation from overloads or short circuits and, as a rule, is not in sight, often passing through attic or utility rooms. You should not rely on the automation of an electrical substation - there are completely different levels of operation.
There are several ways to radically solve this problem:
- The entire section of the cable to the ASU can be enclosed in a metal pipe with the same parameters as mentioned above. However, this becomes possible only with its small length - up to 2.5 - 3 meters and the absence of a large number of turns. Push a sufficiently rigid cable for considerable distances in the gap t t ruby will be simply impossible.
- It seems optimal to install a circuit breaker in a sealed box immediately before the line enters the building. At the same time, the threshold for its operation selects a step higher than that of the main AZ, which is installed on the ASU. So, if a 25 A machine is installed on the shield, then 32 A should be set on the outside.
This will protect the vulnerable area from overload, but at the same time, if such a situation occurs in the internal house wiring, the automatic switch on the ASP will work, and there will be no need to get to the external AZ.
- There is another option, when both the machine and the energy metering devices are carried out by the power supply organizations in general on the outer wall of the building or even on the power line poles. This, of course, is reliable, but not always convenient for the owners of the house.
Switchboard installation
The line from entering the house directly, without any branches, leads to the switchboard - ASU. What are its main components:
- A metal or plastic box with places for placing an electric meter and additional protection devices, a DIN rail for AZ, tires - zero and ground loop. The dimensions of the box are not regulated, so it’s better not to save money in this case, and install it with the expectation of a further possible “upgrade” - retrofitting, the need for which may arise as it expands electrical equipment at home.
- Sealed electricity meter.
- The main introductory circuit breaker, two-pole or three-pole, which is usually also sealed by the power supply organization.
- DIN-rail mounted single-pole AZ. Their number may vary. Typically, the power grid at home is divided into zones - each them they will correspond to your machine of a certain power. So, a kitchen, one or more rooms are separated into separate zones, which can also be divided into lighting and a socket group. Often a separate zone is the lighting of the yard, the power supply of the garage and outbuildings, external sockets that are used for chores on the territory.
The power of the machines is calculated for each zone individually. They are guided by the rule that it should provide overload operation on the weakest section of the local wiring. The lower the rating, the higher the safety of the operation of electrical appliances. So, if ordinary sockets have a permissible limit of 16 A, then the AZ should not exceed this value.
- RCD - a device for protective shutdown of power supply when a leakage current is detected. Due to the considerable cost of such a device, many simply neglect it. However, although it is not mandatory, it is still better not to be stingy, purchase and include it in the overall power supply system. The RCD will reliably protect residents from electric shock when using electrical appliances, and will not allow emergency situations in the network. It acquires special significance in areas with high humidity - kitchens, bathrooms, baths, boiler rooms, external fittings in yards, garages, etc. The selection of the RCD rating and its installation should be carried out by a qualified electrician, since several parameters are taken into account here - the total load of the site (maximum current) and leakage current.
The RCD can be installed on the entire intra-house network, but in this case there is a high probability of frequent false alarms, and besides, it will be very difficult to identify the source of a potential security threat. More convenient, but, true, and more expensive way becomes setting RCD also with zoning, similar to AZ.
Video: RCD installation example
All hardware of the switchboard must be exclusively from trusted manufacturers, have the appropriate certificates of conformity. It is important to remember that in many respects these are responsible for the safety of the owners and the safety of the building.
Prices for residual current devices (RCD)
Residual current devices (RCD)
How to make wiring in a wooden house - from the shield to the points of consumption
Now about one of the main points of the wiring device in a wooden house - the sections from the switchboard to the connection points for electrical appliances.
First of all, a few words about . Twisting must be avoided, even when using thick copper conductors of the same section. Soldering wires is allowed, followed by closing the bare part with plastic caps. The best solution would be to use special spring or screw terminal connections (for example, WAGO terminals). This is not so expensive, but it will provide both reliable contact and the required protection against short circuits. In addition, such connections are easy to check and, if necessary, replace.
The best solution for a wooden house is the open wiring on the walls. There are opportunities to place it hidden, but this will require large-scale and expensive work.
Methods for open wiring
- For a long time, it has been used to place internal wiring cables on wooden structural elements on insulating rollers, providing a safe gap of 10 mm from the wall.
In the houses of the old building, in some places such wiring has been preserved to this day.
There are numerous fans of this retro style ... By the way, this method of fastening has become fashionable again - many owners prefer such retro wiring. For this, special twisted cables of various colors are even produced.
… and you can even purchase special wiring Video: retro wiring on wooden walls
However, to take such approaches seriously d for the organization of all internal wiring is hardly appropriate. The number of electrical appliances and, accordingly, points of consumption in the average house has increased significantly, and laying many highways from the switchboard on rollers over the wall will look simply ridiculous.
- Single cables with a cross section of less than 6 mm² can be placed directly on the wall surface, fixing them with electrotechnical clips appropriate size. The main condition for this is the presence of double (or even triple) cable insulation. For such purposes, the already mentioned wires of the brand VVGng or NIM are suitable. If wires are used in ordinary insulation, then a fireproof gasket (asbestos or metal) will be required, protruding at least 10 mm on both sides of the cable, and this is unlikely to decorate the interior of the room.
- Wiring can be placed in a polymer electrical pipe. The advantage of this approach is that several wires can be placed in one pipe. It will already look a little better than single cables, but still the aesthetics in this case are “lame” - the corrugation is not easy to place perfectly evenly, even using clips. But on the other hand, the wires receive additional protection from external damage and the required clearance from the wall is created.
For inconspicuous wiring areas, for example, for utility or technical rooms, this method is probably optimal. However, it also has a drawback - if it is necessary to replace a single cable, you will have to remove the corrugated lining from the entire bundle of wires.
Find out some of the available ways in our new article.
A sleeve made of a metal pipe at the place where the wires pass through the ceiling - The growing popularity of polymer cable channels, closed with a removable cover . They are produced in various sizes, which means that it is possible to choose them both for a single wire and for several parallel lines. They are made of non-flammable plastic, which increases the safety of the wiring.
Such boxes can be selected according to the most suitable color - they are not only white, but also toned or having a decorative "wood-like" coating that will go well with the material of the walls.
A special advantage of such channels is the simplicity of preventive or installation work with the cable part - you can always remove the cover to replace a problem cable or add a new connection.
Considering that there are a lot of additional accessories for such cable channels- turns, external and internal corner elements, tees, plugs, etc., the owners can use them to solve the problem of the required decorativeness of the electrical wiring.
Video: open wiring in a wooden house using cable channels
- Another kind of similar cable channels are electrical skirting systems. They are also equipped with all the necessary elements for straight sections, turns, corners, rises to sockets and switches, junction boxes. This allows you to maintain the overall style of the room, despite the fact that, in fact, the wiring will be considered open.
Important note - installation cable channels should be carried out only after the initial shrinkage of the house and on condition that the wood of the walls is well dried. Otherwise, even minor changes in the “geometry” of the room can cause deformation and even destruction of the boxes.
- They also resort to placing open wiring in pipes, metal or polymer. You cannot call such a technology convenient - each straight section is threaded separately, then a transitional or rotary coupling is installed, and so on. Of course, the need to replace the cable part will also cause a lot of difficulties. This approach is rather a tribute to fashion, but by no means the optimal solution for outdoor wiring.
Sockets and switches installed with open wiring must necessarily have a non-flammable gasket at the bottom. Well, if it is provided by their very design. If not, then you will have to cut out sites from asbestos or metal.
You should immediately calculate the required number of outlets in a particular place in the room. The use of tees or extension cords during the operation of electrical appliances should be reduced to a minimum, and even better, completely eliminated.
Electric cable prices
Electrical cable
Hidden wiring in a wooden house
If the owners of the housing nevertheless prevail, the desire to completely hide the wiring, then they will face very large-scale work.
- To ensure complete fire safety, all wires must be replaced with a fireproof sheath, which can only be a steel or copper pipe. The inner cavity of the steel pipe must be either painted or galvanized to prevent corrosion of the walls.
- All transitions and turns are performed using threaded elements or by welding (soldering).
- The horizontal sections of the pipes must have a slight slope so that the condensate formed in the cavity has an outlet to the outside. Special holes are also provided in those places where moisture accumulation is most likely.
- Only metal sockets are installed in the holes cut out for hidden placement of sockets and switches, which must be connected to the ground loop.
- All branchings are carried out only in junction boxes, which must also be hermetically connected to the pipes.
- The entire pipe loop must be grounded. to remove possible static voltage from it and prevent electric shock in the event of a possible violation of the cable insulation.
- To prevent contact of the wire insulation with the sharp edges of the pipe, a centering plastic plug must be installed at the outlet.
Video: placing hidden wiring in metal pipes
Hidden wiring is allowed in another way - according to the outline of the plaster layer with a thickness of at least 10 mm. However, this is rarely used, at least for the reasons that covering natural wood with plaster is probably not the best option.
If you look at photos or videos posted on the Internet, you can see a lot of examples when hidden wiring is placed in metal or plastic, or simply bundles of wires are laid in strobes made in wood. What no matter what “authoritative” masters write, who convince that such a method is completely safe, this is a gross violation of existing requirements. It is hardly worth laying such a "time bomb" in your wooden house - the stakes are too high!
The article mentioned the ground loop more than once. However, this question is so peculiar and important that it deserves a completely separate detailed publication, which will definitely find its place on the pages of our portal.
