What cable to do wiring in a wooden house: types of non-combustible cable and its safe installation

Vasily Borutsky
Checked by a specialist: Vasily Borutsky
Author: Lydia Korzheva
Last update: October 2019

Comfort in the house is inextricably linked to electricity. Therefore, uninterrupted and safe operation of the power grid is very important. Since buildings made of timber or logs are the most complex objects in this regard, you must definitely figure out which cable to make wiring in a wooden house to ensure the safety of your home.

We will talk about how to choose a cable to fully protect an easily flammable building. We will show you how to eliminate the occurrence of risky situations associated with illiterate wiring. In our proposed article, brands of products acceptable in the arrangement are described, recommendations are given for choosing a cable section.

Design features of non-combustible cable

First of all, the electrical wiring in a wooden building must meet the requirements of the PUE. For this purpose, non-combustible cable brands are used and laid in special systems. Non-combustible cables, if you focus on GOST 31565-2012have several types of execution.

Consider all types of structures of a non-combustible cable structure:

  1. Products that do not spread combustion in the case of single wiring.
  2. Cables ng - in which combustion does not apply to group wiring.
  3. Type NG-LS - the same, but also with low gas and smoke emission.
  4. Ng-hf cables - the same, and not emitting gaseous corrosive substances during combustion and decay during group wiring.
  5. Type NG-FRLS - flame retardant, incapable of spreading combustion with a group gasket method with low gas and smoke emission.
  6. Ng-frhf cables - not emitting gaseous corrosive substances during group wiring during combustion and smoldering.
  7. Type NG-LSLTx - not supporting combustion during group wiring with low gas and smoke emission, with products of combustion of low toxicity.
  8. Ng-hfltx cables - not supporting combustion with the group method of wiring, not emitting gaseous corrosive substances during combustion and decay, with products of low toxicity combustion.
  9. Type ng-FRLSLTx - not supporting combustion during group wiring with low gas and smoke emission, with products of combustion of low toxicity.
  10. Cables ng-FRHFLTx - not supporting combustion with the beam method of wiring, not emitting gaseous corrosive substances during combustion and decay, with products of low toxicity combustion.

It should be noted that the frequently occurring expression “non-combustible cables” does not sound correctly. It often means products that are fireproof, flame retardant, cables with sheaths that are difficult to burn.

Cable structure
Cable cores are equipped with individual vinyl insulation. They are in a PVC hose. The base for the production of non-combustible cable products

Cables that do not spread combustion with any type of installation, immediately stop working under the influence of fire, as the insulation and the shell burn or melt. If a fire starts, for any type of cables and wires fire should not spread.

Fire-resistant products for wiring for a certain time retains the ability to function in case of fire. This is the main difference between these two types of cable products.

Cable Labeling

All types of non-combustible cables, which were released by domestic manufacturers, have in their designation the letter combination "ng". It indicates that the product is a non-combustible cable product.

The following symbols are also found in the marking, characterizing their behavior during combustion:

  • LS - low gas smoke.
  • LSLTx - low gas emission, low toxicity of emissions.
  • Hf - both during combustion and during smoldering there are no corrosive gas emissions. As part of such products there are no halogen additives - bromine, fluorine, chlorine and other non-metals.

To execute wooden surface wiring in a private house, according to its parameters, a cable marked only with the letter “ng” is suitable. If it is necessary to ensure the safety of people in the event of evacuation to the maximum, it is better to take more expensive products - “LS”, “LSLTx”, “HF”.

VVGng cable
When the voltage in the network does not exceed 660/1000 V, they use a VVGng or NYM cable - an import analog of the first, and products with a shell and insulation made of polymers are also suitable

The VVGng cable is resistant to high temperature, as in its production, polyvinyl chloride plastic without halogen additives is used. This type is characterized by an ideal ratio of price and quality. Lay in places where there is a fairly high explosion hazard. The systems where these cables are used are in operation for over 180 minutes.

Details about VVGNG cable and its type LS

With the help of this external cable they provide power for stationary and mobile electrical appliances. Both VVGNG and LS can carry out the tasks assigned to them in a variety of conditions.

The main properties of the latter are:

  1. Moisture resistance. The ability to function in rooms with high humidity.
  2. Possibility of high-rise laying. With it, you can mount the wiring underground, in the mine.
  3. Fire resistance. He not only does not promote combustion, but also does not smoke under the influence of fire.
  4. High technical specificationsgiving the opportunity to use VVGNG LS in the oil and chemical industries.

The technical parameters of the products in this series are different. In accordance with the norms, the voltage value of the permissible current is 0.6 V. In practice, cables are also found with higher values ​​of this parameter. The frequency of the current is a maximum of 50 Hz.

These products are flexible, have such a strong insulation that it is almost impossible to spoil it. The service life of cables belonging to this series is up to 30 years.

Using a non-combustible cable
It is advisable to use such an electric cable for the project of wiring a wooden house, since here fire can occur with a high probability

All cables VVGNG, and LS including, belong to power. They are made from copper. The maximum number of cores is five. Two-core products are most often used for a home. The minimum core section of all products of the VVG series is 1.5 mm².

The most popular color of the outer insulating shell is black, but quite often can be found in white insulation.

Cable options
With the parameters of the main current-carrying conductors of the cable, the size of the core is zero. If the size of the current-carrying core is in the range of 1.5 - 2.5, the zero cross section will be 1.5

The symbols in the designation VVGng indicate:

  • AT - vinyl shell material;
  • G - the cable has a “bare” core with protection in the form of double insulation made of PVC;
  • ng - non-combustible.

Since the “A” symbol is missing in the marking, a copper cable is made. LS, but completely low smoke indicates the inability of the product to burn. The price of one meter of cable is related to the number of cores and their cross section. In the case of a three-phase voltage, a multicore conductor is used.

The design of VVGNG LS includes single-wire or multi-wire cores. The geometry of the cores can be either in the form of a circle or a sector. Do not recommend its underground installation without special protection. So that the cable does not spread combustion, it is used for packet wiring in special bundles.

Multi-wire power cable
This power wire does not have armor, so during installation and operation it is necessary to exclude the possibility of mechanical stress on it

VVGNG LS is used at temperature indicators of 30 - 50 ° C, and its characteristics remain unchanged even when the cores are heated to +400 ° C.

If the integrity of the cable is not broken, and it contains single-wire cores, it can be bent under the mounting radius identical to a dozen external diameters. In the presence of multi-wire cores, the maximum radius is 7.5 outer diameters.

With the rules and formulas used in the calculation of the cable section, will introduce next article, which we strongly recommend reading.

Safe styling tips

Both the choice of materials, the method of wiring, and the method of installing installation products in a wooden house has its own specifics. The priority is security.

What regulations should the wiring comply with?

If the base is combustible, the installation must be carried out by the open method or the conductor must be localized by enclosing it in a protective sheath.

Cable passage through partitions
In the case when the internal partitions in the house are frame, equipped with a non-combustible filler, usually the cable is placed in a metal hose or corrugation. A more correct solution would be to fit the racks through which the cable passes

An important point is providing good access to the cable when placing it in a protective casing.

Even if the wiring in a wooden house is performed by experienced electricians, in order to evaluate their work, you need to know the three basic rules that apply to it:

  1. Prevent even the possibility of ignition of electrical cables, or at least minimize it. In any case, they should not transmit open fire to wooden elements in the event of short-circuit. (short circuit) in the electrical circuit. Consequently, the wires should not come in contact with a wooden surface.
  2. The cable parameters must be 100% consistent with the PUE, have a power reserve in order to calmly transfer maximum loads. Any degree of heating of the terminal connections and input cable is not permitted.
  3. Electric wires must be in perfect technical condition to exclude the slightest chance of electric shock to the inhabitants of the house.

Safety rules cannot be pushed into the background for the sake of the aesthetic component. The consequences may be irreversible. All branches of the wiring in the house of wood should be equipped circuit breakers and other residual current circuit breakers.

Subtleties of cable entry into a wooden house

There are two key ways of introducing a non-combustible cable for its further wiring in a wooden house in compliance with safety. The first - laying underground. The method is reliable, since the cable is protected from external influences.

The underground way to enter the cable into the house
A significant minus is excavation work associated with the construction of a trench at least 0.8 m in depth. This entails additional financial costs.

The second method is air wiring. An access is required here, and without it it is impossible to work on electric poles. Therefore, only qualified electricians can carry out the work.

The diameter of the cable on the pole-house section cannot be less than 16 mm. It is better to use self-supporting aluminum wires with good insulation and a service life of 25 years. It is impossible to continue the line with such a wire further - a copper conductor is needed for the room.

Cable entry into the house
If there is no project, then before putting electricity into a wooden house, it is necessary to calculate the load in case all electrical appliances are functioning

Actually, the input is performed in a metal sleeve. To do this, make a hole in the wall, fix the pipe in it, and lay a cable inside it. The space that remains is filled with cement mortar. You can soak the tow in the solution and use it as a pipe filler.

The cable is attached to a wooden wall using special clamps. They provide good non-oxidizing contact. In the case of using a cable to suspend the cable, an eye bolt is installed to fix it to the enclosing structure.

It is not permissible to mount a cable with a pull. It should hang freely over its entire length, and before entering the wall, it is necessary to ensure a position below the hole. Otherwise, atmospheric moisture will penetrate the cable into the house. Do not pull the cable itself.

The rules regulate the thickness of the pipe walls. For a powerful cable, protection up to 1 cm thick is needed. When the cable cross-section does not exceed 4 mm, a sleeve with 2.8 mm walls is enough. This rule is followed for all wiring in the house.

The nuances of laying on the site to the switchboard

This is also one of the important areas of electrical wiring. Its specificity lies in the fact that from overloads at short circuit it is not insured by automatic protection. The problem is solved by the following option: in a section up to 3 m long, the cable is placed completely in a metal pipe.

External arrangement of the machine
The machine can be placed outside the log house in a protected casing. This option is reliable, although not very convenient for residents of the house.

RCD and a set of machines are dustproof and waterproof street boxing just before entering a wooden house. The operation occurs at a load level exceeding the corresponding parameter of the main automaton located in the switchgear.

When installing the meter, the basic condition must be observed - to prevent breaks in the supply line. Twisting is categorically unacceptable, so only a solid cable should be used for this.

Features of networking inside the house

Safe wiring of electricians inside the house can be done in two ways: open and hidden. The first is simpler, but may not always correspond to the style of the premises. But the hidden installation option, made in accordance with the requirements of electrical safety, will cost more.

Installation methods for open wiring

There are several ways to install open wiring. All of them are safe, they are often chosen according to the style of design. There are many on sale overhead wiring accessories for laying open wiring, there are installation techniques, thanks to which a certain color can be brought into the interior.

Open wiring
In open wiring, everything is in sight. All faults can be fixed very quickly by replacing the problem area. This method was once very popular, but now for a wooden house it is the only reasonable solution.

The cable is routed inside the building along the walls and ceiling. Wherein cable ducts made of plastic can be replaced corrugated polymer pipe or wire PV-1. A twisted cord is wound around ceramic insulators, which can become a highlight of the design. Such wiring can be upgraded, new lines laid.

The market has a large assortment of self-extinguishing channels. You can always choose them according to the color and style of the room.

Concealed wiring in a wooden house

Installation of hidden electrical wiring in such a fire hazardous building is a laborious process. Choosing this option can create a lot of problems if you need cable repairs or network upgrades. Nevertheless, due to the reluctance to see open wires and distribution boxes, many prefer hidden installation.

Such wiring should be provided at the design stage. To ensure maximum safety, the wiring is insulated with a metal or galvanized pipe, which is always coated with paint. The cable is led to the outlet, as well as to the switch, through openings that previously protect against fire.

Hidden installation method electricians in a wooden house implement exclusively in accordance with the regulations. Materials are used special, serving as fire protection. The cable laid in the ceilings should be in a plastic non-combustible pipe or in a metal sleeve.

Hidden wiring
When making hidden wiring, it should be borne in mind that the log house will be seated. Therefore, the interaction of wood with wires, metal or plastic channels must not be allowed.

As practice shows, most often the methods of open and closed wiring are combined.

What you need to know about cable cross-section?

This parameter is determined based on the magnitude of the current. If the cross section and the loads do not correspond to each other, short circuits will occur, and as a result, a fire. So, if the plans are closed wiring, and the rated current is 16 A, a cable with a cross section of 2 mm² minimum is required. With a rated current of 25 A - 4 mm².

Choose a cable according to distribution groups and depending on the expected load. In order to connect the sockets, you need a cable with copper conductors with a cross section of 2.5 mm². The maximum total power is 4.6 kW.

Lamps in the room
Lighting devices are fed with a cable with a cross section of 1.5 mm². The power of this group is up to 3.3 kW. Therefore, the number and location of light sources must be planned before installation begins - when drawing up the electrical circuit

High-power home equipment is connected with a cable having a cross section of 4 mm². You must connect such devices to an individual outlet and you cannot connect it to another group.

Conclusions and useful video on the topic

The main thing about the wiring in a fire-hazardous house:

The correct selection of cable for wiring in a wooden house is the key to the safety of its inhabitants. In connection with the increased fire hazard of such a structure, it is necessary to use cable brands with a high degree of reliability.

Do not miss the moment that the cables and devices should not come into contact with the tree. With the right choice and implementation of wiring, taking into account the recommendations, the effectiveness, durability and safety of the wiring can be guaranteed.

Tell us about how you selected a cable to provide electricity to a suburban wooden house. Share interesting technological nuances that will be useful to site visitors. Please leave comments in the block below, ask questions, post a photo on the topic of the article.

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Visitors Comments
  1. Alexei

    In a wooden house it is worth paying increased attention to fire safety. And the cable for wiring is also worth choosing based on these considerations. Although it is not so easy to understand them, there are a lot of types of cables, each with its own marking. But do not forget that safety depends not only on the cable, but also on the correctness of its installation. All kinds of “snot” should be avoided.

  2. Sergei

    Running a cable to the house itself through the ground is not worth it. Typically, this technique is used only in large courtyards to draw electricity between household units. In addition to digging, you will have to buy an HDPE pipe for cable insulation. In this case, you will have to immediately calculate, even before the purchase, its length, since if you make a mistake, even after securing individual pieces with a sleeve, it will not be possible to completely isolate the cable inside. It is better to take VVGz.

    • Expert
      Vasily Borutsky

      Good day, Sergey.

      The impression is created that the article you have not learned. Against trench laying, you have shaky arguments: you can make a mistake buying a pipe (measure carefully); used in large farmsteads (where are the statistics?); you have to dig the earth (you have to climb the attic, mount the external input). In parentheses, of course, counterarguments.

      Here are some more arguments based on the article - the author of the trench laying wrote one proposal, noting the reliability of the solution. The author’s air input took almost twenty lines. I’ll add to the advantages of the trench: a backup cable can be laid in the pipe.

      By the way, the fire safety class of VVGz is O1. What does this mean, look at the screenshot.

      Attached photos:
  3. Stepan

    I would prefer to use NYM cable in my house, which, in addition to electrical insulation, also has a filling (between the core insulation and the sheath) with a non-combustible filler. Something like chalk rubber. Fire safety is higher, in addition, and mechanical protection is better, due to the filler. And a small plus - it is not black, but gray. With an open installation of aesthetics, attention must be paid.

    • Expert
      Vasily Borutsky

      Good afternoon, Stepan.

      Without diminishing the merits of NYM, I want to note that the wiring and cable products mentioned by the author of the article are no worse. By the way, the finely packed rubber acting as a filler improves cable flexibility - mechanical protection is not provided. About fire safety: during the operation of NYM, heating of conductors up to + 40º is allowed, with VVGng - up to + 50º. In order not to describe the advantages of VVGng - I attached a screenshot of the comparison table.

      Attached photos: