Environmental deterioration 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, a relatively low specific gravity and is easy to process.
In private housing construction today, wood is not a way out of a situation with a limited budget, but a full-fledged building material, but due to its flammability, it requires the use of special technologies, including when installing residential power supply systems.
Let's consider the installation of electrical wiring 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 installed in two ways:
- hidden – less in demand;
- open – more common.
Both technologies do not eliminate the factor of electric current, but they minimize the risks associated with it, since all wood is flammable, and even impregnation with special compounds only reduces the degree of flammability 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 impenetrable suspended ceilings and in partitions are considered as hidden electrical wiring and should be installed: behind ceilings and in the voids of partitions made of flammable materials in metal pipes with localization capabilities and in closed boxes; behind ceilings and in partitions made of non-combustible materials* - in pipes and ducts made of non-flammable materials, as well as flame retardant cables. In this case, it must be possible to replace wires and cables.
*Suspended ceilings made of non-combustible materials mean those 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 installing electrical wiring in a wooden house that are common to both installation methods:
- use of cables with copper conductors;
- the insulation of the conductive cores must be made of non-flammable material (the best choice is NYM cables or its analogues VVGng);
- calculation of cable cross-section for current load with a margin of 30%;
Table of dependence of cable cross-section on 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 grounding loop;
- The distribution panel must be isolated from the base - placed in a mini-box.
Power supply to a wooden house
The internal power supply system of the house is connected to the electrical network by the local energy supply organization - at the request of the consumer, with the installation of an electric meter and only subject to the availability of a project.
Power supply to a wooden house is carried out in one of two ways:
- By air line.
- Underground cable laying.
Overhead connection
The rules for connecting a private house to power supply from an overhead line are determined by clause 3.18 of SNiP 3.05.06-85.
According to these standards, the following must be used at the power supply input to the building:
- insulated cables in an NG class sheath (non-flammable) with a conductor cross-section from 4 mm² for copper and from 2.5 mm² for aluminum;
- insulated wires of the same cross-sectional dimensions.
In the designed places for the passage of cables through combustible structures, sections of steel pipe (sleeves) are installed so that their cuts 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 passage sleeves in the external walls are mounted with a slope of 5 degrees.
In the section 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, maintaining alignment, special input fittings are put on: on the outside there is a funnel, and on the inside there is a bushing. These products are made solid from porcelain or split with tightening clamps - 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 bitumen waterproofing compound upon completion of installation.
Conventional section of the power supply input from an overhead line into the wall of a wooden house
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 power into the house (hook with an insulator) is located at a height of at least 2.75 m from the surface of the blind area.
In addition to porcelain and metal lugs, when installing a cable entry into a house from an overhead line, various UCPs (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 installation of wiring inside the house at the cable exit from the porcelain bushing depends on the design method of its installation (hidden, open).
Input of electricity through a pipe stand
If the height of the building is insufficient to meet the requirements of the PUE for the vertical parameters of the overhead line connection, the power supply to the wooden house is carried out through a pipe stand - a hollow mast, vertically mounted outside on the wall or roof and serving as a channel for the cable.
Pipe stands are made of steel pipes with an internal diameter:
- from 20 mm – when power is supplied by two wires;
- from 32 mm - for four conductors.
On the upper section of the pipe stand, to prevent rainwater and snow from getting into it, a semicircle is formed using a pipe bender.
Approximately in the middle of the height, a horizontal crossbar made of a 40x40 mm steel angle, 45-50 cm long, with two vertical steel rods for mounting ceramic insulators, is welded to the pipe stand.
At the transition of the arc to the straight section, a ring (washer, nut) is mounted to the pipe, to which two guy wires made of steel wire will be attached to counteract the tension created by the overhead line.
Some hardware (bolt, nut, stud) is also welded to the pipe stand - to “zero” it by connecting it to the neutral core.
In the lower part of the pipe stand, 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°. At the bottom of this bend, a Ø 5 mm hole is drilled in the pipe for the condensate outlet.
The cut edges of the pipe stand are processed with a file, after which the structure is coated 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 for the supply of power to the home through the roof. Particular attention in this situation is paid to the rigidity of the installation of the rack on the roofing and the sealing of the passage in it.
Before installation at the design location, a “conductor” (cable or thin wire) is pulled through the pipe stand for subsequent pulling of the cable through it. The structure is installed in place and attached to anchors mounted on the base, after which it is equipped with guy wires and the gaps in the passage are sealed. Threaded connections “bolt-nut” are made using screw washers and are covered with a protective layer of technical petroleum jelly.
Connection with underground cable
Inputting power into a wooden house using an underground cable is more reliable and safe, since the impact of external factors on the conductor when installed correctly is minimal.
The supply of electricity to a house via an underground cable line is regulated by clause 12.1 of VSN 59-88 (Departmental Construction Standards).
Underground power supply to the house should only be carried out
armored cables that are laid in a trench without protection by pipes. The practical use of unprotected cables placed in electrical polymer pipes is a violation of current standards.
From the trench, the power cable is inserted into the building in one of two ways:
- through the foundation or wall of the basement - with the installation of a thick-walled passage sleeve made of steel;
- through an external wall - with an entrance to the building at a height of at least 2.75 m and pipe protection up to a height of 1.8 m.
The power supply to the house via an underground cable is arranged during the construction of the building - at the stage of constructing the foundation, which makes it possible to provide everything necessary for the input of communications.
Electric meter installation
According to the requirements of energy regulatory authorities, electricity meters in private homes must be installed in places with constant access for supervisors. Consequently, the shield has to be mounted outside, where the components placed in it are exposed to weather conditions. Taking this into account, two distribution panels are installed in a private house:
- external – for placing an 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 switchboard, equipped with the equipment necessary for 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 when choosing a mini-box they give preference to built-in models, in wooden houses they install wall-mounted distribution boards that are dust- and moisture-proof.
The electrical wiring diagram with the method of its installation is an integral part of the house design. If a hidden installation of the internal power supply system is designed, then the possibility of implementing such a solution begins to be ensured during the process of assembling the log house.
In beams or rounded logs through which vertical sections of wiring must pass, technological passages for cables are made before laying them at the design site - strictly in accordance with the power supply diagram. To form a vertical channel in a wall from logs stacked on top of each other, the holes made in them after assembling the structure must be strictly coaxial.
Horizontal passages are arranged after the walls are erected:
- for cables - along and across the logs;
- for mounting and distribution boxes - across.
Horizontal transverse and vertical channels are made with a powerful drill with a core drill or Forstner drill.
Longitudinal hidden passages are, as a rule, grooves along the beams, made using hand or power tools (chisel, milling cutter). The least labor-intensive way to perform this type of gating is with a grinder and 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. Installation and distribution boxes must also be made of steel or copper. The sections of steel protective channels are connected to each other and to the boxes by welding or threading; copper tubes are connected by soldering and crimping. Protective channels and boxes must be grounded.
In a wooden house, it is prohibited to conduct hidden wiring cables in metal hoses. Corrugated metal covers are a strip 0.2 mm thick, twisted in a spiral. Protection made of metal of such thickness is not capable of localizing a short circuit, since its walls cannot withstand the temperature of the arc and instantly burn out. The metal hose in the polymer shell is also not capable of localizing the arc.
Corrugations made of a homogeneous polymer are also not suitable for placement 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 susceptible 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 internal diameter.
| Maximum 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.
One of the ways to place hidden electrical wiring is along the beams of interfloor floors. The pipes, according to the wiring diagram, are cut into pieces of the required length, after which threads are cut at their ends, and a “conductor” is pulled through each element to tighten the cable after installing the channel in place.
Fragments of pipes are attached to the beams using clamps, connected to distribution boxes and bent down at design locations to supply power to the chandeliers. At the same time, the electrical wiring lines are tightened in them.
After installation, distribution boxes must remain accessible for maintenance, so on the floor between the attic and the second floor they are placed with the covers up for access on the floor, and on the beams between the first and second floors with the covers down, with access from the ceiling.
Upon completion of the assembly of the power supply system, it is tested, threaded pipe connections are pulled, grounding resistance is measured, and the outside of the channels is coated with two layers of anti-corrosion paint. Then the 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 plasterboard. To do this, grooves of the required cross-section are made in logs or beams, into which the profile is sunk and secured with self-tapping screws. A strip of plasterboard 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 plaster over the strip, after which the entire volume of the profile is filled with gypsum. The completed groove is sealed to its full depth with a special putty, after which the channel dries and is painted to match the main background. 
The requirements for ensuring the fire safety of houses made of SIP panels are especially high, since these structures are flammable.
A SIP panel is a “pie” of two oriented strand boards with a layer of insulation between them, in which manufacturers install internal channels for the installation of hidden wiring. 
According to SP 31-105-2002, hidden wiring in this case can be installed using standard channels - without additional protection with pipes, but using NYM cable. However, the PUE requires that electrical wiring in a wooden house be installed only through metal pipes.
There are two ways to resolve this contradiction, but both of them are costly financially and time-consuming:
- according to the PUE, install hidden wiring in metal pipes along the walls and ceiling, then lath them and cover them with plasterboard (the method also “steals” the dimensions of the premises);
- sequentially install 3 layers of gypsum board on the walls - the first as a gypsum protective base, in the second, after installation, make grooves for wiring, cover the second with a third continuous sheet.
A reasonable alternative to these expensive solutions in houses made of SIP panels is the installation of open wiring.
Advantages of hidden electrical wiring
- There is no need for masking or decorative design of electrical wiring elements.
- Minimum chance of cable damage.
- Easy to replace lines by pulling a new cable through the old pipe.
- High electrical and fire safety when installed correctly.
- The hidden power supply system does not interfere with finishing work.
Disadvantages of hidden wiring
- The complexity of the implementation of both the main power supply system and additional hidden branches.
- High prices for installation.
- Additional costs for pipes.
- Impossibility of visual inspection of the technical condition of the wiring.
Installation of wiring in steel pipes does not eliminate the need to correctly calculate the cross-section of conductors, grounding devices and the use of RCDs, but is only a mandatory requirement for hidden cable wiring.
Open electrical wiring in a wooden house
Open wiring in wooden houses is used more often - due to its 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. Open wiring- laid along the surface of walls, ceilings, along trusses and other construction elements of buildings and structures, along supports, etc.
For open electrical 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 construction, since it is carried out after the construction of the log house. In addition, with open wiring, switches, sockets and external boxes are used, which eliminates the need to install mounting sockets in logs.
For external sockets and switches, when installing them on wooden walls, additional special overhead sockets are required.
Laying cables and wires of open electrical wiring is carried out in the following ways:
- conventional installation (cable with double or triple insulation) directly on the surfaces of building structures - using various types of staples;
- laying in protective corrugated pipes;
- placement in cable channels;
- on ceramic rollers or insulators.
The listed methods for installing open electrical wiring are applicable not only to houses made of logs and beams. Wooden frame buildings and cottages made of SIP panels, despite the design 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
Electrical mounting brackets are cheap and easy to install, but the wiring made with their help is not aesthetically pleasing.
When laying on a wooden surface, a steel strip, galvanized or painted, must be installed under the cable along its 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 fastened to the wall with self-tapping screws in increments of 0.8-1.0 m.
To fix the cable on the strip, holes are pre-drilled in it for staple nails - in increments of 30-50 cm.
If the cable does not have a grounding conductor, the strip must be grounded. Using asbestos tape instead of steel is tempting, but this material is carcinogenic.
Installation of open wiring in protective corrugated pipes
Pipes used to protect exposed electrical wiring are made of polymers (PVC, PE, PP), steel (tinned, galvanized or stainless) and metal in a PVC sheath.
Protective polymer tubes intended for use in wooden houses must have a fire safety certificate and the marking “ng” - non-flammable.
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 external wiring exposed to ultraviolet radiation.
A corrugated steel tube is a twisted strip that is not inferior in flexibility to a polymer cover, but is more resistant to mechanical loads (compression, tension). Accordingly, the durability of steel corrugations is stated 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 select protection for a cable of any cross-section, including for placing several wires in one channel.
The diameter of the corrugated channel must be twice the sum of the diameters of the cables placed in it.
To tighten the cable, a “conductor” is first pulled through the corrugation, 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 cover and easily push the conductor through the entire length of the protection.
Metal corrugated tubes are fixed to the base using steel brackets with one or two legs; polymer covers are secured with nylon ties and clamps. The fastening pitch is maintained within 30 cm. The layout of the channels on the base is carried out so that the tubes do not cross each other and do not have twists.
The passage of external wiring through the internal wall is made using a sleeve - a piece of steel pipe protruding from both sides by 1 cm. To prevent damage to the cable by sharp cutting edges, protective tips are put on the ends of the sleeve.
It should be taken into account that a newly erected wooden house with a wall height of 3 m will shrink during the first year, depending on the material of the frame:
- log (regular/rounded) - up to 10 cm/8-10 cm;
- timber (natural humidity/chamber drying) - up to 6 cm/2.5 cm;
- glued beams – up to 2 cm.
Therefore, 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 ducts:
- the difficulty of cleaning corrugated walls from dust accumulating in the folds;
- the inevitability of sagging of channels along the spans;
- the difficulty of replacing a section of wiring without dismantling the protective channel.
Open electrical wiring through cable channels
Cable channel is a protective structure made of aluminum, galvanized steel or flame retardant plastic, consisting of a U-shaped profile for placing wires in it, an easily removable cover for it and connecting (transition) elements. At the installation site, cable channels are:
- wall (parapet) - produced in strict and decorative design;
- floor - differ from parapet ones in greater strength and streamlined cross-section;
- plinth - available in various sections, including those simulating a plinth, with a groove for cable placement.
According to the markings, the box is attached to the wall, the cables are laid in it, after which the channel (groove in the baseboard) is closed with a lid.
In boxes, wires and cables can be laid in multilayers with an ordered and random (scattered) mutual arrangement. The sum of the cross-sections of wires and cables, calculated by their outer diameters, including insulation and outer sheaths, should not exceed: for blind boxes, 35% of the clear cross-section of the box; for boxes with openable lids 40%.
Advantages of cable channels:
- ease of installation;
- availability of cables for periodic inspection;
- ease of replacing a wiring section;
- aesthetics;
- affordable price.
Flaws:
- a certain volume of the structure;
- low strength of wall-mounted products.
Open wiring on ceramic rollers or insulators
In wooden houses, this method of installing electrical wiring is popular, since, if it complies with the PUE standards, it also visually harmonizes with the base material - wood.
The technical execution of installation on insulators is not difficult and is possible with your own hands, since with correct calculations of the parameters of the power supply system it only requires compliance with the wiring diagram. However, the price of modern components made as antiques is quite high. At the same time, it is also necessary to purchase fireproof socket boxes for sockets, switches and boxes.
Basic installation rules:
- horizontal line insulators are placed in increments of no more than 45 cm, vertical lines - up to 50 cm;
- when turning the cable at right angles, 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 tied with a nylon clamp - to prevent further unraveling of the thread weave;
- Wire passages through walls are made using porcelain bushings.
The aesthetics of electrical wiring through insulators is high, but only under the condition of a simple internal power supply system. And numerous twisted lines of wires on the walls are far from attractive, not to mention the difficulty of repairing such foundations.
Approximate prices for electrical installation work in Moscow and the Moscow region
| Type of work | Cost, rub.) |
|---|---|
| Installation of a socket box in a wooden base | 300 |
| Installation of one electrical point (for hidden wiring) | 250 |
| Installation of one electrical point from external wiring | 200 |
| Replacing an old electrical point | 250 |
| Installation of distribution box | 250 |
| Preparing the space for the junction box | 250 |
| Installing a telephone socket | 250 |
| Installing an outlet for a TV cable | 250 |
| Installing a computer network outlet | 300 |
But even taking into account the high cost of services, in the absence of experience in electrical installation work, it is better to entrust the installation of electrical wiring to professionals, since the cost 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 execution of each of them. The cost of installing wiring by third-party contractors also takes into account the factor of the contractor’s responsibility for the result.
Calculate the cost of installing electrical wiring in a wooden house!
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A wooden house is a beautiful, cozy structure, but easily flammable, requiring increased attention to the process of power supply. Making electrical wiring with your own hands is not an easy task, but it can be done. You just need to approach the issue responsibly, in compliance with the norms and rules.
Electrical wiring in a wooden house must meet the main requirement - to be safe. More than half of the fires in buildings of this type occur due to a short circuit in the electrical network due to mechanical damage to the insulation or increased load on the cable.
You can eliminate the risk of fire if you follow the basic requirements:
- Correct selection of materials.
- Reliable insulation.
- Possibility of automatic power interruption.
- Regular network diagnostics.
Compliance with these requirements will reduce the likelihood of fire in wooden structures and ensure the safety of property in both city and country houses.
Regulations
The provisions governing the installation of electrical power in wooden buildings are contained in "Rules for electrical installations" (PUE) and in the Code of Practice “Design and installation of electrical installations of residential and public buildings”.
They provide criteria for selecting switchgear, conductors, automation, lighting, and indicate the terms used and their meaning.
Electrical wiring is also regulated by Building Codes ( SNiP).
SNiP 3.05-06-85 describe methods for introducing a power cable into a living space, and SNiP 31-02-- requirements for the installation of power supply systems in residential buildings.
Preparation of a power supply project
The first stage of electrification of the facility is project preparation. In a private house, drawing up an electrical wiring diagram can be done on your own. To do this, you need a house plan with the placement of furniture, equipment, electrical appliances, and the designation of sockets and switches. The installation location of the distribution panel and the passage of cable lines are marked.
The location of the distribution boxes is indicated, the maximum power consumption of all devices, the total number of machines and the rated load on the input machine are calculated.
Cable selection
After drawing up the electrical diagram, you need to decide which wire to use for wiring in a wooden house: aluminum or copper. The first one is cheaper, the second one is more reliable. Having settled on aluminum, you need to remember that its cross-section should be larger than copper, and it is brittle when bent. A more suitable material is copper, wires from which can withstand temperatures from -50 to +50 °C.
Having decided on the house, you can move on to choosing its brand. For wooden structures, VVG non-flammable copper wire with solid cores and reduced smoke emission is more suitable. It has high anti-corrosion properties and does not deform due to temperature changes.
When planning how to conduct wiring in the house, you need to remember the requirements of the PUE for insulation coloring: the cable cores must be of different colors. This will simplify the process of installation, maintenance and repair.
Selection of devices and automation for the distribution panel
The purpose of selecting automatic protection devices is the safety of the network and equipment in emergency situations. Each device has its own purpose. All devices are located in the distribution panel.
Circuit breakers protect against voltage overload and short circuit.
(RCD) - from fire and electric shock.
Voltage relay - against load drops affecting the operation of devices.
They combine the functions of a circuit breaker and an RCD and save space when installed in a panel.
The integrated use of these devices guarantees reliable operation of the devices and the safety of people in the room.
Installation of electrical wiring - step-by-step instructions
Installation of electrical wiring in a private house requires preliminary preparation and adherence to step-by-step instructions consisting of the following steps:
- project development and determination of the total equipment capacity;
- selection of cables, automation devices and electrical appliances;
- power supply, connection of circuit breakers, electricity meter;
- installation of an electrical panel;
- internal cable routing;
- installation of sockets, switches, lighting devices;
- system testing.
This sequence will show how to properly install electrical wiring in the house and ensure its reliable operation. It is important to remember that each step must be carried out in compliance with safety rules: turn off the power to the room in which work is being done, do not use bare wires, place all connections and branches in boxes, lay the cable either vertically or horizontally, avoiding its intersection.
Following the step-by-step instructions will allow you to complete the installation efficiently.
Installation of distribution panel
The distribution board is designed to receive and distribute electricity indoors. All electrical work begins with its installation. It doesn’t matter whether the wiring is in a country house, a city cottage or a country log house.
The shield must be made of fireproof material, placed in a dry place and locked with a key. Rooms with high humidity cannot be located above it ( shower, bath, toilet), and within a radius of half a meter - heating equipment, water and gas supply systems.
An electric meter, an input circuit breaker, an RCD, grounding bars, voltage relays and circuit breakers for different power groups are mounted in the panel.
Grounding device
Any modern home is equipped with household appliances in a metal case, and possible contact of metal with electricity requires grounding - protecting people from electric shock through electrical appliances.
You can do it yourself.
A trench 30 cm deep is dug in the shape of an equilateral triangle with a side of 1 m. Pins 3 m long and 3 cm in diameter are driven into the corners, which are connected together with an angle using welding.
A hole is cut in one of the corners, a grounding wire is attached using a bolt and nut, which is connected to the busbar in the distribution panel. The grounding conductors of cables in yellow-green insulation are attached to this bus.
Inserting the power cable into the room
Electricity enters the building through a power cable that enters the distribution panel. It can be supplied in two ways: aerial and underground.
In the first case, the cable is supplied through the air from the electric pole to the house, where it is attached to porcelain fittings. This method is simple and cheap, but has a number of disadvantages: it is less durable, there is a high probability of damage to the wire by wind, snow, and branches.
The underground method is more reliable, but more labor-intensive and expensive. A trench is dug into which the armored cable or metal pipes are laid. A layer of sand 20 cm thick is poured on top, a warning tape is laid, and the trench is buried.
The main element of the wiring, because it bears the load from all the electrical appliances in the house.
Laying cables and connecting them
Installation of electrical wiring in a private house is carried out along the routes indicated in the project diagram. Distribution boxes are mounted along it, switches and lighting fixtures are fixed. In wooden buildings, wires are used only with special markings, the insulation of which does not ignite even at high temperatures.
“Twisting” and “temporary work” are not allowed. It is better to minimize the number of turns and bends. Where possible, run the entire wire from the machine to the end point.
When installing electrical wiring in a wooden house with your own hands, you must remember that the boxes cannot be covered with decorative panels or ceilings that impede access for maintenance.
Installation of switches and sockets
Surface-mounted sockets and switches are selected based on the calculated current value and the possibility of connection under one frame. Before installation, turn off the power and make sure there is no voltage in the cable.
The safest way to mount switches and sockets in a wooden structure is to mount them on metal substrates. This will protect against possible sparks when closing or an arc when removing the plug. For a wooden house, it is preferable to use carbolite rather than plastic devices that have greater heat resistance and can withstand strong heat.
Methods for open wiring
Open electrical wiring in a wooden house is laid along the inside of the room. The main requirement is that the wire does not directly touch the walls, ceiling or floor and is protected: it is located in the middle of a channel, pipe or has several layers of insulation. Pipes and channels must be made of materials that do not support combustion.
Installation of wiring in a wooden house can be done in several ways:
- In a corrugated pipe made of PVC;
- In a metal sleeve;
- In PVC pipes or boxes;
- On staples;
- On ceramic insulators.
The most common options are the use of corrugated pipes and cable ducts.
The use of ceramic insulators or “” is becoming popular when there is an air space between the twisted electrical wire and the wall. This option also decorates the home.
Open wiring in a wooden house can combine several options. On walls and ceilings that have a flat surface, you can use plastic boxes, and in other areas - corrugated pipes.
Hidden wiring in a wooden house
Internal electrical wiring in a wooden house has its advantages and disadvantages. The advantage is the absence of corrugated pipes and cable ducts that spoil the appearance of the room. There is no risk of mechanical damage to the cable. On the other hand, installation complexity, increased fire safety requirements, and additional financial costs.
Unlike external wiring, it is more difficult to conduct internal wiring in a wooden house. To do this, you need to know more requirements and nuances related to this type of power supply arrangement.
Hidden wiring should not have many turns, because... The cable must be laid in steel or copper pipes. The use of metal hoses and PVC corrugations is allowed only if they are protected with plaster or asbestos padding.
If installing external wiring does not require a special tool, then for hidden wiring it is necessary. It is necessary to drill in horizontal and vertical directions and cut out seats for insulating boxes. You will have to pull not only wires and cables, but also a large number of steel or copper pipes. The latter are better suited because they bend well, taking the desired shape.
You can conduct wiring in the house with your own hands in an open or closed way. This is done in places where the wires are connected to switches or sockets.
Installation errors
Typical mistakes when laying electrical networks indoors:
- the power cable is bent or weakened;
- fastening the wire to a wooden structure, which is prohibited by the rules;
- installation of hidden wiring using corrugated pipes, metal hoses and plastic boxes;
- installing the distribution panel too close to the power cable entry point;
- the number of machines is calculated incorrectly: either more or less than necessary.
Wiring test
After installation, the wiring must be tested: conduct a visual inspection, measure the insulation resistance and ground wire, check the operation of circuit breakers, RCDs or automatic circuit breakers. The reliability of the electrical network must be maximum, because Electrical wiring requires increased attention and regular monitoring.
Electrical wiring in a wooden house is an important aspect in construction. Despite the fact that the wood that is used to build houses and cottages is treated with a variety of impregnations to increase fire resistance, this material still remains vulnerable. If you do not install the electrical network in your home according to the rules, you can put your family in danger.
If you want to install an electrical network in a wooden house yourself, you need to adhere to a certain set of rules - PUE and SNiP. They provide a short general list of requirements, subject to which you can protect yourself as much as possible and prevent fires in a wooden room. Do-it-yourself wiring in the house must be laid according to clear instructions and each step must be provided for.
PUE (electrical installation rules) – determines the requirements for the installation of an electrical network in premises. Compliance with the requirements of the PUE is considered expensive to implement, but a very advisable method. It is tough and labor-intensive to execute. For this reason, these rules are not often followed.
SNiP and PUE were prescribed in order to calculate absolute safety under the condition of any load flowing through the cable, to protect oneself from a short circuit or ignition of the line. If homemade wiring in a wooden house is not exposed to relatively high voltage, then this does not pose any particular danger.
Therefore, when laying electrical wiring in such a building, you should take into account all risk factors and make the right decision. Either the line is made in accordance with all the rules of the PUE and SNiP - expensive, but reliable, or it will be carried out faster and cheaper, but under high loads your home will become unsafe.
The regulation PUE-6 has special requirements for laying electrical wiring in wooden premises. To prevent moisture and steam condensation from accumulating on the cables, they are placed in pipes and metal sleeves or boxes are bent. This also gives the wires additional protection from mechanical damage.
It is allowed to connect such pipes, ducts or metal hoses if the room is dry, there is no accumulation of gas, vapor, condensation and the humidity level is normal. Connecting metal hoses, ducts and pipes is necessary under negative conditions in the house. They should be fastened together when the room contains vapors and gases that negatively affect the insulation of the cables, their protective sheath, as well as when installing the wiring externally, if moisture, oil and other liquids may enter the power line. After bonding, they are compacted and sealed.
In dusty houses, sealing joints and branches of pipes, hoses, and boxes are made to protect against dust and small debris. Connecting pipes, sleeves and boxes are used as a grounding or neutral protective conductor, performing the function of “ground” or “zero” in electrical wiring. It is prohibited to route cables through ventilation ducts and shafts. Only crossing with a single wire, which is located in a protective metal sleeve or pipe, is allowed.
Also, the laying of wires behind the suspended ceiling must be carried out in accordance with the standards of Chapter 7 of the PUE. When installing an electrical network in a private wooden house, the use of exclusively copper wires is required. You also need to carefully select the type of cable that can withstand the required load with a reserve. It is imperative to follow safety precautions when laying an electrical line in the house.
How not to do it
In order to install an electrical network into a wooden building, you cannot use all installation methods for stone houses or apartments. Do not install the wire on a wooden beam or other structures without protection. The main power line should not be covered with flammable materials or finishes. Do not allow the wiring insulation to be exposed to temperature changes, humidity, accumulation of dust and dirt on the wires, frequent deformation and bending of the wires. It is necessary to avoid increasing the load on the entire home network.
All these factors can cause damage to the wiring, resulting in a short circuit. If the exposed part of the electrical wiring ignites in a wooden house, then a fire is inevitable. Wires should also not be left unprotected. Pets or rodents may chew through the wire, which must be avoided. When processing wood near laid wires, a large amount of shavings and debris accumulates. In the event of a short circuit, the presence of flammable material will help ignite.
Entering cables into the house
Laying electrical cables into a private wooden house is a very important area of work. You should not focus entirely on the internal wiring in the building. The entry of the power cable into the house must meet modern requirements. It must be taken into account that energy consumption has increased, which increases the load on the line, as well as the impact on the external insulation of solar radiation, temperature changes, and moisture, which subsequently exposes the metal conductors of the wires. There are two possible ways to install a power line into a private house - underground and overhead.
The underground method of laying an electrical line is more reliable, but complex and expensive. The power transmission cable is completely hidden from external factors, which reduces the risk of mechanical damage to the wire, moisture ingress, etc. For this purpose, excavation work is carried out. The cable is placed at a depth of more than 80 centimeters, and the security zone must be marked with special signs. The passage of the power line under the foundation of the house is done with a special metal sleeve through which the wire passes. The sleeve is made of thick-walled pipes and durable metal.
Today, this method is used in the construction of new houses, since it is possible to think through the passage of all communications into the building using new construction technologies. Air method. This method has been used for a long time. Only qualified workers with appropriate clearance are allowed on power line poles. Therefore, you cannot enter the cable yourself.
A SIP type cable is used from the pole to the house. The self-supporting insulated wire has a very durable sheath of polyethylene structure and is resistant to solar radiation and temperature changes. Service life is about 25-30 years. This line does not go inside the building, only to the switchboard. For a separate section that connects the line connection point and the distribution device, a VVGng cable is used. Can be used for fixed wiring, as well as for outdoor wiring. For reliability, it is placed in an electrical corrugated pipe.
The connection usually takes place outside the building. Where the VVGng wire crosses through the wooden beams of the house, attic walls, or ceilings, a metal sleeve is built in for additional protection of the wire.
Video “Wiring in a log house”
Shield installation
When installing the shield, you need to follow the step-by-step instructions for installing it. All wiring goes directly to the distribution panel. It contains an electric meter, additional protective devices, automatic plugs (a modern way to de-energize an overvoltage network), a DIN rail, as well as ground loop and “zero” busbars. What dimensions the box should have is not regulated, but it is better not to skimp on this, so that it is possible to increase the equipment when the need for electricity increases.
The installation of the meter is carried out by specialists from a government agency, who seal it. The power of operating machines is calculated for each zone separately. When a sector is overloaded, the direct supply of electricity is turned off in order to avoid negative consequences. The RCD can be connected to the entire intra-house network. This may result in the machine triggering more frequently, but this is not critical. Installation of the shield is carried out on a strong, stable vertical surface in an accessible place. In private sectors it is located outside the building.
When connecting wires to the distribution panel, ordinary twisting is not used. For this purpose, soldering or terminal connections are used. The terminals are reliable and can be easily replaced if necessary. When choosing which method can best protect the electrical distribution panel, you can choose a protective sealed box, which will prevent moisture from entering and physical damage.
Open wiring
According to PUE-6 standards, open electrical wiring in a wooden house is laid on the surface of the walls of the building, along the ceilings, as well as along trusses and other building elements of the structure (supports, beams, etc.). Open wiring is laid along a tension string, cable, or on special wheels. Insulators are used for electrical cables and cords, metal pipes, more flexible with hands for line mobility, in trays. There are also special electrical skirting boards in which the wire is placed, platbands with this purpose, and free suspension.
Open wiring in a private wooden house involves the use of a special electrical corrugated pipe to create an electrical line. For its production, a special stable and non-flammable type of plastic is used. It is much more expensive than conventional insulating elements, but is justified by its reliability. This corrugated tube is very convenient for installation, as it is quite flexible. Despite its unesthetic appearance, this insulating material is one of the best for open wiring in a wooden house.
The electrical tube collects a large amount of dust due to some characteristics of the material, which requires constant care and wiping of dust from its surface. Electrical boxes can be used for installation of open wiring. After the construction of a private wooden house, channels are installed in special boxes, which are usually made of fire-resistant plastic. Cables are pulled into them and then sealed with lids.
The main problem with using such installation is the shrinkage of the building after construction. The higher quality the wooden beam used for construction, the lower the level of shrinkage of the house. If the building is made of laminated veneer lumber, then the shrinkage is usually 1 centimeter per 1 meter of house height. Then, over time, on average, for a two-story wooden house, the shrinkage will be about 3 centimeters. If the wiring was made with tension on the cord, then it may burst from excess tension and pressure. Otherwise, the lids of the boxes will fly off and they will crack. Then the wiring will need to be re-strung. Therefore, it is necessary to take into account shrinkage, make a small supply of wire at the joints, near the distribution panel, and also at the electric pole.
Hidden wiring
The PUE-6 standards stipulate that hidden wiring in a wooden house can be laid directly inside the structural elements of the building (wall, floor, ceilings, foundation), in the wooden floors, as well as under removable beams. Hidden electrical wiring in a house can be done in several ways - placing the cable in flexible protective sleeves, pipes, boxes, in hollow building structures or closed channels. Also, laying the wiring can be done in a grooved furrow, which is covered with special plaster, or creating a “monolith” in various building structures when they are manufactured at the factory.
It is recommended to begin installing hidden wiring in a wooden building using metal hoses or pipes to protect the room. By adhering to such rules, you can avoid the consequences of sparking wiring and overheating of cables from excessive load in the network.
Typically, hidden wiring is laid behind the wooden beams of the walls or floor. It is necessary that the protective elements are minimally vulnerable to corrosion. To do this, you need to pre-paint the structures with durable paint to reduce the likelihood of rusting and increase service life, or use pipes made of a special material - stainless steel (expensive and reliable), galvanized.
After the pipes and hoses have been cut to the required length, sharp iron burrs and edges remain at their ends, which should not be allowed when laying the cable. Since these edges can damage the braiding of the cord, they must be cleaned with a sharpening stone or file. Specially designed plastic plugs can be used.
If the electrical wiring in the house will be done under a wooden floor, then you need to raise several bars for more convenient laying of the hose or pipe. In the places where the wiring exits, to connect the fittings you need to drill in the timber. The wires coming from the main line can be placed in a copper tube and recessed into the wall. Copper is quite flexible, resistant to corrosion and is well suited for further installation work, but this material is quite expensive. If the electrical cables will be recessed into the wall, then you need to use a drill and a hammer drill. In this case, the beam is not removed, but a longitudinal hollow is drilled into it, where the wire will be laid in the future.
According to GOST and PUE, there is a standard for installing power lines in rooms with temperature changes. If a stable temperature corresponding to the season will not be maintained in a wooden house, then the pipes with cables should be placed at a slight slope. This is due to the fact that condensation can accumulate in such houses, which cannot be allowed. A slight slope will allow the accumulated condensate to gradually flow into the lower part of the pipe and gradually evaporate.
Since there is no point in using plaster in wooden houses, the wiring is usually placed on a wooden floor beam or between wall partitions where there are recesses.
The 21st century is the century of synthetic materials. Most of the things around us, buildings, household items, and even our food are artificially created substances that have many useful qualities, except one. All of them are alien to the human body. We can’t talk about direct harm to humans, but we can’t talk about significant benefits either.
In the process of evolution, the human body, as one of the most complex systems, was formed surrounded by natural materials. Therefore, he must live in the natural environment. Naturally, no one calls for being like Robinson. But creating your own environmentally friendly corner in the form of a wooden house or cottage is the best way to organize your life in accordance with the requirements of soul and body.
In this article we will look at how it should be installed according to all the rules and regulations.
But the structures of wooden houses have one unpleasant property - they burn. A fire can start from an improperly constructed stove or chimney, but more often it occurs as a result of problems with electrical wiring. No matter how much a person wants to get closer to nature, it is impossible to do without electricity in the modern world.
The days when it looked like a thick black wire wound around ceramic insulators driven into the wall are long gone. Modern wiring must comply with certain technical parameters, at the same time be invisible and accessible for carrying out preventive, repair and measuring work.
Most often, in reports about fires in wooden houses, where property is destroyed, people are injured and killed, it is written about the cause of the fire that it occurred as a result of a short circuit. But it is very rarely mentioned that the cause of this notorious “short circuit” is other factors, among which the most common are illiterate installation of electrical wiring in a wooden house, the desire to save on important components and parts, elementary negligence and sloppiness. It's much easier to blame everything on a short circuit. The term is technical and does not imply anyone’s direct guilt.
What causes a short circuit? First of all, this is an insulation breakdown. It may appear due to mechanical damage to the outer layer of the wire when fixing the line in the wall, overheating of the network when the permissible loads are exceeded, or other reasons caused by the human factor. A short circuit is accompanied by a very rapid, almost instantaneous release of a huge amount of thermal energy. In which the wires themselves and part of the insulation ignite.
The only threat this process poses is the tripping of automatic fuses and the interruption of electricity supply to the home network. It is much worse if there are wooden or plastic structural elements of the house in the high temperature zone. A fire in this case is inevitable.
How to correctly calculate and install internal hidden wiring in a wooden house, without the risk of unforeseen situations? There is a special document for this - “Rules for the construction of electrical installations”. It should not be treated with disdain as just another bureaucratic invention. Like military regulations, most safety regulations are written in blood. Each limitation arose not only as a result of engineers' calculations, but also as a result of specific accidents.
One of the requirements for such work is that hidden electrical wiring in a wooden house must be carried out using wires coated with non-flammable insulation. Some of these are wires of the brands VVGng (A), VVGng LS, RKGM or NYM.
The wires are laid inside metal tubular channels, securely connected to each other by welding or bolting with electrical conductivity. The tubular circuit must be grounded to avoid sparking or breakdown.
The use of corrugated pipes made of plastic or metal in wooden buildings is not allowed unless they are reliably insulated from contact with flammable materials by a layer of non-flammable substances of low thermal conductivity. Treating wood with non-flammable impregnation is not such a protection, since at high temperatures of an electric arc it does not have a deterrent effect.
How not to do wiring in a wooden house
When installing power lines in wooden houses, many electricians, especially non-professional ones, make the most common, and therefore most dangerous, mistake - they mount the wire directly on a wooden structure, and even cover the line with wooden finishing materials.
Excessive reliance on the strength of the wire insulation turns into a fire after several years of operation. Many processes occur inside wooden channels that cannot be foreseen.
Temperature changes, changes in humidity, dust accumulation, and deformation cause microdamage to even the highest quality insulating materials. At sufficiently high loads, for example, when the lights are on in all rooms, the TV, refrigerator, and even a bread machine or multicooker are running, a breakdown between parallel conductors is possible. If they are not fenced off from the wooden base, electrical wiring in a wooden house catches fire- a fire is inevitable.
I would like to draw your attention to: When installing hidden electrical wiring in a wooden house, it is prohibited to lay the cable directly on wooden bases, as well as to carry out installation using corrugated pipes (corrugation), metal hoses and plastic boxes. This is a violation of the “Rules for Electrical Installations” 7.1.38.
The use of plastic smooth or corrugated pipes is dangerous due to the possibility of damage by rodents. As practice shows, modern mice and rats love to feast on the insulation of wires, and even the pipes themselves. The accumulation of wood dust in boxes and channels leads to a very rapid ignition and spread of fire throughout the house.
The danger is that the flames spread inside the walls. It is almost impossible to extinguish it with conventional fire fighting equipment, even if it is detected at the initial stage.
Installation of electrical wiring in a wooden house, especially if performed carelessly, is often accompanied by microscopic damage to the insulation, which, when heated, can cause a short circuit. The temperature of the arc that occurs when the conductors are short-circuited reaches 5000 °C.
Plastic boxes and corrugated sleeves cannot withstand this temperature and burn out, allowing flames to reach wooden structures. Even wood impregnated with special substances ignites when heated to such an extent.
Corrugated steel hoses do not protect against such high temperatures. Their walls are very thin and are not designed for such a high level of heating. One of the characteristics of protective channels for laying electrical wiring is localization ability - the ability to withstand the short circuit process without burning out for the time required for the arc to self-extinguish.
Only steel boxes and pipes have a sufficient level of this parameter. They are the only possible elements for laying hidden electrical networks in wooden buildings.
Metal pipes are very technologically advanced for installing electrical cable channels. In addition to the possibility of cutting them into pieces of the required length, they can be connected in various ways: welding, soldering, threaded couplings, tees, etc. The resistance of pipes to corrosion can be increased by painting it with protective paint.
The cost of steel pipes is comparable to the cost of a good quality corrugated hose. Copper pipes are somewhat more expensive, but they are easier to install and are practically not susceptible to weathering.
How to properly install hidden electrical wiring in a wooden house
There are many ways to install hidden electrical wiring in wooden houses, but only a few of them are correct. The first rule that must be followed during design and installation is maximum compliance with fire safety requirements.
Hidden electrical wiring in a wooden house should be laid in non-combustible materials with localization ability.
Aesthetic and design considerations should take a back seat. The same applies to the cost of work. In the event of a possible fire, the losses will be significantly greater than the costs of high-quality electrical wiring.
As mentioned above, the highest quality material for laying cables and wires in hidden cavities and voids behind the cladding of walls or ceilings are metal pipes and steel boxes. If PVC-NG (non-flammable) materials are used in the form of corrugated pipes or mounting boxes, then they must be protected on all sides by gaskets made of non-combustible materials that poorly conduct heat.
Alabaster, cement plaster, and concrete can be used as such insulating gaskets. The thickness of the layer is determined by the design power of the wiring.
But the most reliable way to protect your home from fire due to faulty electrical wiring is installation using steel or copper pipes and boxes. Copper pipes are much more technologically advanced - they can be bent in any direction without the use of complex special tools, which is especially important when laying wiring of a complex branched circuit.
The use of steel pipes is somewhat more complicated and requires certain qualifications of installers. This is especially true for work on replacing individual sections of electrical wiring. Sharp edges of metal boxes when pulled can damage the insulation. Therefore, these operations are performed using special tools. The thread cutting procedure also requires the use of additional tools when it is necessary to connect sections or secure boxes.
Electrician in a wooden house - choosing the wiring route
The selection and marking of the route for laying electrical cable lines must be made in strict accordance with the requirements of the PUE. The number of turns and bends should be minimal. If cable pulling is difficult due to the architecture of the building or the presence of communications in the walls, then special metal junction boxes (steel or copper) are installed in difficult places. Their number is not regulated, but should not be excessive. Each connection, even if made according to all the rules, is an extra link that introduces uncertainty into the system and weakens the overall strength of the chain.
Their installation must also comply with certain rules, for example, boxes are strictly prohibited from being covered with decorative panels, ceilings or other elements that impede access during maintenance, control or measurement.
The installation depth of pipelines for electrical wiring should be selected so that the load-bearing characteristics and strength of wooden walls and ceilings are not compromised. The number and location of bends, junction boxes and other elements are calculated so that, if necessary, it is possible to replace the wire in a section of the electrical network without the need to damage or dismantle wooden structures.
The diameter of the metal pipe and the thickness of its walls are selected based on the properties of the cable. The cable laid in the pipe should occupy no more than 40% of its internal cross-section and can easily be extended over the entire length of the section. In addition, it is allowed to lay not one cable in each pipe, but several. Moreover, their total cross-section should also not exceed 40% of the pipe diameter. The cable cross-section is determined by the outer diameter, including insulation.
When installing hidden electrical wiring in wooden houses using metal pipes, the thickness of the pipe wall should be selected based on the cross-section of the cable (wire) cores that runs in this pipe.
| Wire core cross-section, mm2 | Pipe with a wall thickness of at least, mm | |
| Aluminum wires | Copper wires | |
| 4 | 2,5 | not standardized |
| 6 | - | 2,5 |
| 10 | 4 | 2,8 |
| from 16 to 25 | from 6 to 10 | 3,2 |
| from 35 to 50 | 16 | 3,5 |
| 70 | from 25 to 35 | 4 |
Before pulling the cable, the insulation resistance must be measured. This is done to determine whether the wire meets the specifications of the design documentation and to check the condition of the cable. The check shows whether the insulation has been damaged during transportation, storage or preparation for use.
The process of pulling the cable itself occurs with the use of special end bushings made of plastic, which protect the insulation from damage from the sharp edges of pipes or boxes. After pulling, the insulation is measured again to exclude the possibility of connecting a conductor damaged during operation.
In wooden houses, only wires with special markings are used. Their insulation does not ignite even at very high temperatures.
Wiring in a wooden house - which wire to choose for laying in pipes
After drawing up a wiring diagram and marking all wiring nodes, it is necessary to determine which wire to use in the installation. Special wires have been created for wooden structures under the markings VVGng (A) and VVGng-P (A). These are copper wires with solid cores, of which there can be up to five.
The wire is double insulated. The inner layer is made of polyvinyl chloride and insulates each core separately, and each wire is painted a different color, which facilitates the installation of switches, lighting and other devices. The outer part of the cable is covered with special non-flammable protective insulation made of composite plastic. It is very durable and flexible, allowing you to easily pull a cable of considerable length through a pipe using a special steel cable.
Such wires are operated in a temperature range from -50 to +50 °C. The insulation has very high anti-corrosion properties, does not react with chemicals and does not deform under temperature changes. Flame retardation properties comply with GOST R IEC 60332-3-22.
Wires of type VVGng LS, VVGng-P LS are not inferior in quality to previous modifications of cables, but, in addition to them, when heated, they do not emit harmful opaque substances and poisonous hydrogen chloride. This is indicated by the LS index.
The NYM cable corresponding to GOST 22483 is also based on copper conductors, but has triple insulation. The cores are insulated separately with multi-colored polyvinyl chloride, then all together with polyolefin composite material and enclosed in a sheath of non-flammable polyvinyl chloride. Such a cable can have up to five cores. It is produced using modern German technology known as VDE.
Placement of sockets and switches
Hidden electrical wiring in a wooden house cannot do without installing sockets and switches. In places where sockets and switches are installed, it is necessary, using special tools, to drill sockets for the installation of metal boxes, where the devices are fixed. These boxes, as well as mounting, broaching and junction boxes, are installed using special technology.
It involves performing several mandatory operations that must ensure a reliable connection of the pipe and box into a single whole in order to establish reliable contact between all elements.
The contact is necessary to ground the entire structure. If ensured continuity of the circuit of the entire metal structure, then it is sufficient to perform grounding only at the distribution board. In case of possible breaks, it is necessary to install an additional grounding wire, which is connected by soldering to each box and pipe. Grounding the electrical network in a wooden house is a very important element in ensuring fire and electrical safety, protecting against possible sparking and overheating of circuit elements.
There are several options for attaching boxes to pipes. The most reliable and high-quality method is soldering or welding. They provide the most reliable contact, are protected from corrosion and are resistant to mechanical stress.
In the case of using copper pipes, their ends, located in the box, are flared. If the pipes are steel, then the connection to the box occurs by screwing in the nuts. In this case, a special thread must be cut at the ends of the pipe, and the nuts themselves, after being tightened as tightly as possible, must be fixed and protected from corrosion.
Distribution and technological boxes must comply with a protection class of at least IP -54, which corresponds to protection against the penetration of industrial and household dust into the volume and protection against splashes of water entering the box.
Test work after installing wiring in a wooden house
After completing the installation of metal pipes and boxes of the future electrical network, a grounding measurement is made, which should determine the reliability of the connection of all parts of the circuit. All structural elements must be connected into one continuous circuit that provides protection in any area when connected to a bus marked “PE”.
After completing the verification work and eliminating all possible deficiencies, work on laying the cable is carried out. It would not be superfluous to remind you that the insulation resistance of each section of the cable is carried out before and after installation. The cable length should be selected so that each junction box provides a certain amount of extra length that may be required when changing connections.
If the cable length exactly matches the distance between the installation boxes, if you need to connect another device, switch or perform other work, you need to change the cable along the entire length of the section. The process is quite labor-intensive, and the cost of a high-quality cable is quite high.
Used in laying networks of a wooden house only three-core or five-core cables with mandatory grounding. Electric current, although a familiar thing, is very dangerous. Operating a network without grounding is contrary not only to safety regulations, but also to basic common sense.
In terms of electrical installation, wooden buildings are the most complex objects. We have prepared for you a set of rules for installing wiring in a wooden house, which discusses in detail issues regarding the choice of materials and cable laying systems, as well as the installation of installation products.
1. Wiring in strict accordance with regulations
The organization of an electrical network in a wooden house is second in complexity only to buildings on permanent polystyrene foam formwork. Laying on combustible substrates is allowed only in an open manner or with 100% localization of the conductor inside the protective shell.
This requirement is not so strict for framed internal partitions with non-combustible filler. In the most correct version, the passage of the cable through the frame posts is accompanied by the latter being sleeved; in practice, most often the conductor is completely encased in corrugation or a metal hose, ensuring replacement.
Open laying is also a good solution. A number of fittings and installation techniques are provided that make open wiring aesthetically acceptable and even add some color to the interior. In addition to plastic cable channels, it is possible to lay PV-1 wire wound on ceramic insulators and use non-recessed housing installation fittings. In cases of hidden installation, non-flammable cable grades are used: VVGng or KGng.
Due to the complexity of installation, cable routing along the walls should be kept to a minimum. But for this you will need to thoroughly think through the layout of cable lines.
2. Wiring diagram for walls and ceiling
In the most acceptable version of the electrical network around the house, each electrical point is connected along one straight line to the frame floor, ceiling or sub-ceiling, covered by a suspended or tensioned covering. All the main wiring is carried out along the technological cavity, hidden from view, although more often the lines simply stretch one at a time to the panel panel. Naturally, the bulk of sockets and switches should be placed on internal walls, and on enclosing walls only if necessary.
A reasonable solution would be to run the lighting wiring from the switches to the ceiling, and lead the wires for connecting the sockets down to the floor. Due to their low load, lighting network lines can be organized using junction boxes that are inaccessible for maintenance. It is enough to connect the power line from the circuit breaker to such a box, and from it run a switching wire to the key and a power line to each lighting group.
Lines of sockets and general purpose groups can be combined into so-called garlands. It is important that no more than two wires are fixed on each terminal clamp of the sockets. Otherwise, each outlet and group is connected in hidden distribution boxes, and lines with particularly high loads from household appliances and heaters follow to the group panel without breaking.
It is recommended to cover the cables that are collected on the wall near the panel panel with a decorative casing. When laying cables in groups, it is also recommended to separate the base with a non-flammable substrate, for example, a piece of drywall.
3. Localization of conductors and branches
For some reasons, installing exposed wiring may not be acceptable. In this case, the task becomes much more complicated, despite the fact that the part of the wiring laid along the walls is only 15-20% of the total length of the lines.
The possibility of hidden installation should be included at the stage of preliminary assembly of the log house. According to the internal power supply plan, technological channels for the cable are made in the walls as they are laid. For this purpose, use either electric chisels or core drills. The approximate channel width is 30-50 mm.
Exit holes are drilled in the cross section of the floor or ceiling frame system. Installation of electrical fittings is possible using the recessed method; for this, the channel is found with a feeler gauge and a 60-80 mm hole is drilled in the solid timber using a core drill. Installation boxes for sockets and switches should be made of steel, preferably with a fiberglass liner.
Pipe sections laid inside walls must be localized from the environment. A smooth pipe is used for this: metal with a wall thickness of 2.5 mm or steel - from 1.2 mm. These values are approximate; a more accurate calculation requires taking into account the load and voltage on the line, as well as the type and number of conductors inside the shell.
For branching power lines hidden in the cavities of frame structures, it is recommended to use metal boxes. For indoor installation, protection from wood dust of at least degree 3 is desirable; moisture protection is not taken into account. The entry of cable line sheaths should be flared or equipped with a restrictive ring or nut that does not allow uncoupling.
4. Protective devices
Electrical installation in a wooden house can be complicated by the design features of group and distribution boards. The difference is observed both in the method of mounting the housings and in the selection of protective equipment.
The electrical panel housing must be installed on a non-combustible base. Therefore, under the central panels with ASU, it is recommended to cover the surface with tin, and when installing group panels, use linings made of textolite or fiberglass.
It is convenient to connect group panels with the ceiling and floor using a cable channel, in which usually 3-4 lines are laid for each room. It is not recommended to place shields close to the ceiling or floor.
Circuit breakers are selected according to the permissible continuous current for the cable on the outgoing line; the choice is always made towards a lower rating. Equipment that does not have internal short circuit protection, as well as lines with a fixed maximum load (ovens, air conditioners), are connected through a circuit breaker with a rating for power consumption and a low response delay in case of overload (characteristics B and A).
In wooden houses, it is customary to lay wiring according to a three-wire circuit, where the protective conductor is not connected to the neutral conductor. For this reason, the installation of differential protection against electric shock may be accompanied by false alarms. But a fire-diffautomatic device that monitors leaks in insulation will be very useful.
5. Installation of installation products and fittings
At the final stage, the finishing electrical installation is carried out. This is most easily done using non-recessed fittings. It is quite easy to screw it to a wooden wall with a pair of screws, after inserting it into the housing and connecting the wires.
Much more time and effort is spent on installing hidden (recessed) fittings. To tightly fit the frames, a flat surface is required, so the logs are pre-ground with a plane. Next, a hole is made connecting the surface with the hidden channel. It is used as a centering tool when drilling an installation niche with a core cutter.
It is characteristic that installation boxes can be embedded in the same way as in stone walls - by planting them on alabaster. Otherwise, the area must be contained and connected to the cable duct with a non-flammable rigid sleeve.