Do-it-yourself hidden wiring in a wooden house, step-by-step instructions, installation rules, under drywall, in a metal hose and cable channel

Wooden houses are in demand due to the speed and ease of construction, the low cost of construction work and the environmental safety of the material.

Many people are stopped by the fire hazard of objects, because the tree is exposed to fire and burns quickly when ignited. That is why, when buying a wooden house, it is important to carefully consider the choice of equipment and the installation of electrical wiring. This is especially true if the work is done by hand.

Advantages of concealed wiring

When installing electrical wiring, many choose a hidden installation option that does not spoil the interior design of the room.

The advantages of the method are obvious:

1. The absence of cable channels on the walls, conspicuous and interfering with wallpapering the surface.
2. Low risk of fire with strict observance of the rules of the PUE in the process of flush mounting.
3. Ease of cable replacement if it is laid in a corrugated pipe.
4. Low risk of mechanical damage due to installation of the product in concrete, metal products or plaster layer.
5. Safety for residents of the house, because the wires are hidden from view, and access to them is limited.
6. No difficulties in finishing work, because the cable is inside the finish.
7. There are no negative environmental influences.

These reasons are enough to give preference to hidden wiring when arranging an electrical network in a wooden house.

How not to do it, installation rules according to PUE

Some “specialists” are taken for the installation of hidden wiring, without having sufficient knowledge, and, accordingly, without taking into account the requirements of the PUE.

A common mistake that is made during work is mounting the wire on a wooden surface, followed by closing it with wood trim.

The calculation is done on the strength of the wire and its insulation. Such connivance can lead to a fire, because processes occur in wooden recesses that cannot be predicted.

Over the years, cable products have been adversely affected by temperature changes, dust, sudden changes in humidity, or damage to insulating materials.

At increased loads, when electrical equipment is turned on in all rooms (heaters, TV, multicooker and other equipment), a large current flows through the wires. As a result, the risk of a short circuit between two adjacent wires is increased.

If there is no reflective non-combustible surface near the cable, a wooden building can catch fire even though it is impregnated with a special fire-fighting compound. Stopping the fire is almost impossible.

When choosing a hidden wiring option in a wooden house, you need to take into account the complexity of the process and the importance of meeting the requirements of GOST R (50571.1-2009) and PUE-7.

In the absence of experience, it is better not to take on the installation. Invite qualified specialists who know the norms of the mentioned documents and follow the rules. But you don’t have to stay away either. Knowledge of the requirements of the PUE and GOST R helps to control the hired electricians.

Project preparation

When creating a project for hidden wiring, attention is paid to the fire safety of a wooden house. This is true even to the detriment of the deterioration of appearance.

There should be a minimum of turns in the flush wiring diagram. In this case, contact with wood must be avoided. The cable must be laid in copper and steel pipes. In a PVC corrugation or a metal hose, installation under asbestos or plaster is allowed, but according to PES 7, this is prohibited.

Before starting work, it is necessary to develop a project and coordinate it with the local power supply company (District Electric Networks).

Employees of the TCP service develop technical conditions that apply when performing work. First, the total power of electrical appliances is calculated, and then a wiring diagram is developed.

Algorithm of actions when creating a project:

1. Development of a technical plan for a wooden house. The diagram indicates the location of electrical sockets, lamps, switches and electrical appliances with a separate supply.
2. A type of cable is selected for each electrical point. If switches with two buttons and “triple” sockets (with a ground outlet) are used, a cable with three cores is connected to them.
3. The hidden wiring diagram of a wooden house shows places for mounting junction boxes. To reduce their number, one junction box is used for two rooms.
4. The power consumption of each receiver is indicated. If the device is equipped with an electric motor, the parameter is indicated taking into account the starting current of the motor.
5. Bulbs, sconces and other lighting equipment are reduced to one group, and consumers of higher power to the second. For reliability, both branches are connected to their machine with an individual rated current.
6. The distance from the place of installation of hidden wiring to window and door frames, as well as electrical outlets to the ceiling or floor is indicated. Such information is useful and helps to protect the wiring from damage during repairs. The electrical cable turns are carried out only at a right angle.

After preparing the circuit, the power that is consumed by electrical appliances is calculated, provided that they are turned on simultaneously.

It also calculates the rated load current for the input circuit breaker (the one at the entrance to the room).

Wire (cable) for electrical wiring in a wooden house: rules for choosing and using

After preparing the hidden wiring diagram and indicating the branching points, you need to decide on the wire used during the installation process.

In wooden houses, special wires are used, denoted by the letters VVGng (A) or VVGng-P (A).

The conductors are made of copper, single-core with up to five wires. Cable feature – double insulation:

1. The inner part of the manufacture using PVC, which isolates the current-carrying parts from each other. For ease of installation, each wire has its own shade.
2. The outer insulation is covered with a protective layer of composite material providing fire resistance. Its feature is strength and flexibility, which eliminates the difficulty in pulling the cable through the pipe using a cable.

The optimum temperature regime is from -50 to +50 degrees Celsius. The advantages of the insulating layer are corrosion protection, no reaction with chemical components, resistance to deformation due to temperature changes. Fire resistance is confirmed by the requirement of GOST R IEC 60332-3-22.

You can choose other types of cables:

• VVGng LS or VVGng-P LS – additional resistance to certain substances (for example, hydrogen chloride);
• NYM is a copper cable that meets the requirements of GOST 22483 and is distinguished by reinforced insulation in three layers. The cores are insulated with multi-colored PVC, and then wrapped in a special protection with refractory qualities. The number of lived in such a product is up to five. In the manufacture, modern German technology is used, which guarantees high quality products.

When choosing a cable for hidden wiring, you need to take into account the features of the room and not save money on the purchase of a quality product.

Main and introductory cables, circuit breaker

When choosing a cable for hidden wiring in a wooden house, you need to consider that it can be of two types – general (goes through the building) and introductory (to the machine). Consider the features for each option.

Main wiring

The common cable is selected taking into account the loads in the room. When choosing, you need to know the maximum power (current) of electrical equipment.

So, when using cable products with copper conductors for a cross section of 1,5 mm. sq. rated current is 19 A (for voltage 220 V and 4,1 kV). With a cross section of 2,5 sq. mm. copper wiring withstands 27 A (5,9 kW).

In rare cases, it may be necessary to install a wire on 4 “squares”. In this case, the rated current is 38 A, and the power is 8,3 kW. When choosing a section, the nameplate power of each electrical appliance is taken into account.

The most popular type of cable for flush wiring is NYM (its features are described above). The advantages are density, ease of installation and the presence of additional insulation, which is important for wooden houses.

Minus – the fear of strong bends, which can lead to damage. When leading to sockets, cable products with three cores are used, which protects against electric shock. Grounding is also necessary when using powerful spotlights on the site.

Entering

When choosing an input cable, the power of the electrical receivers is also taken into account. These parameters are summed up and the final indicator is determined, which is used when selecting a section.

When replacing hidden wiring in a wooden house, one should not forget about updating the input cable. If the section is not enough, the risk of ignition of the house increases.

If it is impossible to replace the input cable with your own hands, you need to involve specialists in the work. As a rule, work is performed during the installation of the meter and its sealing.

Circuit breaker

An error in the choice of automatic switches (AB) is also fraught with consequences. When buying a product, you need to go through two stages:

1. Determination of the sum of the powers of electrical equipment and calculation of the limiting current parameter. To obtain the desired indicator (I), the total power is divided by voltage and cosine “phi” (0,8). A correction factor of 1,1 will be applied to the calculated figure. After performing the calculation on hand, the maximum tripping parameter of the circuit breaker. As a rule, an AB with a rated current of 25A is enough for a small wooden house.
2. Select the type of circuit breaker. Here, a lower short-circuit current threshold is required. To determine the current in a 1-phase 220V circuit, it is necessary to multiply 3260 by the wire cross-section (sq. mm), and divide the resulting number by the length of the cable product. The formula is used to calculate the longest section with the minimum conductor cross section.

The ratio of short-circuit current and rated I indicates the AB characteristic. The optimal solution for hidden wiring and a wooden house is to buy an automatic machine with characteristic C.

The device copes well with work in circuits with different electrical consumers.

An important point is the number of poles. If a three-phase wiring is used in the house, a three-pole AB is used, and for a single-phase wiring, respectively, a 1-pole switch.

The place of installation of the introductory AB is after the electricity meter. All circuit breakers, including those supplying power and lighting groups, are installed in a shield on a DIN rail (a special mount is provided for circuit breakers). After installing the AB, wiring is done around the room.

When choosing an introductory machine, you need to focus on the maximum current so that the cut-off or thermal element does not work from the working I load.

Installation of hidden wiring in a wooden house

Installation of hidden wiring can begin after purchasing the equipment. The work will require cable products, AB, switches, sockets and light bulbs (chandeliers).

Junction boxes are also bought, which are installed in strict accordance with the specified scheme. When using a finishing material, the wires are laid in an armored sleeve.

Subtleties and installation rules

Unlike external wiring, where it is routed using ceramic rollers or staples, in the hidden version, the cable is hidden in the walls, cable channel or baseboard.

Installation is carried out carefully, because any damage to the insulation is fraught with short circuit and possible fire. When an arc occurs, the surrounding air warms up to a temperature of 5000 degrees Celsius (this is enough to ignite the tree).

The use of plastic corrugations or pipes for laying is unacceptable, because the products do not withstand prolonged use and burn out when exposed to high temperatures.

Special wood impregnation does not protect against ignition. By the way, corrugation made of steel does not protect from 5000 degrees, because its walls have a small thickness and are not intended for such heating.

That is why, when flush mounting, it is necessary to select equipment that can withstand the high temperatures that occur during short circuits. If the arc encounters an obstacle in its path, it quickly decays.

A better solution is to make hidden wiring in a wooden house using steel (copper) pipes or ducts. Their peculiarity lies in the convenience of cutting pieces and the possibility of combining using different adapters, soldering or welding equipment.

To increase the resistance to rust, the surface of the pipes must be coated with a special paint.

Copper pipes can be used, which are resistant to corrosion and easy to bend, but they come at a high price.

Rules for installing hidden wiring in a wooden house:

1. Touching the cable to a wooden surface is excluded. It is necessary to make sure that every centimeter of wiring is in special protection (metal pipe or box).
2. To mount the tube into the wall, it is necessary to make a strobe, holes for fastening or cut out a recess for wiring. It takes skill and perseverance to do this job.
3. Vertical channels are drilled during the installation of log crowns. Laying horizontally is carried out after the installation of the walls.
4. To pull the cable inside the pipe, a conductor (thin wire) is laid.
5. Places of installation and transitions between rooms are isolated with the help of additional elements (asbestos, alabaster, sleeves, metal boxes, etc.)
6. When attaching hidden wiring, you need to take into account the number of highways. If several cables run in one armored sleeve, this requires a greater thickness. To hide such a product in a wooden house is a difficult task.

When creating hidden wiring, you need to remember the importance of RCDs. The device provides instantaneous shutdown in the event of leakage currents. For reliability, there should be several devices (for each group).

Selecting a wiring route

When choosing a place for laying a route in a wooden house, the requirements of the PUE must be taken into account. Think over everything in such a way that the number of turns and bends is minimal.

If there are difficulties with pulling the cable due to the characteristics of the building or communications in the walls, junction boxes made of steel or copper are installed at problem points.

The maximum number of these devices is not specified, but their installation cannot be abused. Connection points, even when meeting the requirements of the PUE, reduce the reliability of the entire electrical network.

When installing junction boxes, you must follow these rules:

• you can not close the boxes with decorative elements;
• the use of overlaps that complicate access for control, replacement or measurement of the voltage level is prohibited.

The depth of pipe installation is chosen so as not to disturb the strength and load-bearing parameters of a wooden house.

The number of bends, junction boxes and other nodes is calculated in such a way as to, if possible, change the wire in the problem area without dismantling the building elements.

Switchboard installation

The casing of the electrical panel is attached taking into account the hidden wiring diagram. After installing it, the following work is done:

• counter mounting;
• installation on a DIN rail of a special introductory AB;
• connection of wires (phase and zero);
• wiring to the input of the main machine;
• cable entry into the house and connection to the input terminals of the meter;
• mounting on a DIN rail voltage relay and AB, feeding different groups of electrical wiring;
• connecting electrical appliances with a wire.

Grounding and RCD installation

In a wooden house (as in other residential premises) it is difficult to do without high-power equipment (washing machine, boiler, refrigerator, and others).

The use of equipment with a metal case requires grounding. Its arrangement occurs according to the following algorithm:

1. Prepare three metal rods that are three centimeters in diameter and 3 meters long.
2. Dig a hole in the ground in the form of a triangle. Each of the faces should be 100 cm long.
3. Drive metal rods into the corners of the triangular figure.
4. Combine the rods with each other using welding and a metal corner.
5. Weld a loop to one of the corners, and then fix a steel centimeter rod with a screw or welding.
6. Lay it in a trench for connection to earth in the electrical panel.

For ease of identification, the grounding cable core is made in yellow-green insulation.

More information can be obtained from the article about grounding in a private house.

Additional protection is the installation of an RCD. The device is mounted in the shield after the counter. When choosing a residual current device, knowledge of the rated current is necessary (it is calculated when choosing a machine).

The task of the RCD is to respond to any leakage, which is especially important for wooden houses and rooms with high humidity.

Power cable entry

Before installing hidden wiring, preliminary measures must be taken – bring a power cable to a wooden house (electric panel).

The work is carried out in strict accordance with SNiP and PUE, with the involvement of specialists who understand these issues. The cable product is supplied by air or in the ground.

The first method is more attractive due to the ease of implementation and lower costs. Aerial mounting uses a self-supporting insulated conductor. It is also necessary to install a sleeve that is resistant to heat (a cable passes through it).

The second method (hidden laying in the ground) requires the use of a metal pipe that protects the cable from damage. When choosing this method, you need to coordinate the work with the employees of the distribution zone.

Wall mounting in cable duct

If there is no desire to “hide” the wiring in the walls of a wooden house, you can simplify the task and use special cable channels. The work is performed according to the following algorithm:

• marking the line along which the hidden wires will go (the work is carried out taking into account the existing scheme);
• selection of the cable channel section, which depends on the number of wires passing inside;
• removing the cover and fixing the box to the wall or ceiling surface using self-tapping screws (mounting range – 50 cm), and additional fasteners are provided at the turning points using self-tapping screws;
• laying wires in cable channels with the subsequent installation of a cover (a supply of wire is left near the switches and sockets for connection);
• combining wires in distribution boxes, connecting with machines, sockets and switches.

Before installing hidden wiring, you need to prepare tools and equipment, and then get to work.

in metal pipes

A reliable method of hidden installation is the use of metal pipes that protect a wooden house from fire in the event of a short circuit. The diameter of the tube is selected taking into account the properties of the cable used.

The product should occupy no more than 40 percent of the internal area and easily pass along the entire length.

It is allowed to lay several cables in one pipe at once (the above rule must be observed). When determining the cross section, the full diameter is taken into account (including taking into account insulation).

When choosing a thickness, you must follow the requirements of VSN 370-93 or SP 31.110-2003. Recommended parameters for the section of aluminum / copper wires:

• 4/2,5 sq. mm. – not standardized;
• 6/- – 2,5 mm;
• 10/4 — 2,8 mm;
• 16-25/6-10 — 3,2 mm;
• 35-50/16 – 3,5 mm.

Before pulling the cable into the pipes, it is necessary to measure the insulation resistance to check the integrity of the product.

Work helps to ensure that there is no damage during storage, transport or preparation.

When pulling, a special wire is used from end sleeves that protect the cable from damage. After the work is completed, the cable is once again checked for damage.

Grounding metal pipes

It’s no secret that metal is an excellent conductor of electricity, so pipes for hidden wiring in a wooden house must be grounded. In this case, the products should not be torn in mounting or junction boxes.

If such a fact exists, it is necessary to connect metal structures using a grounding conductor.

In a metal hose or a plastic pipe: what are the risks

Hidden wiring in a wooden house excludes laying cable products on a wooden surface. It is also prohibited to lay a conductor using metal corrugations, plastic pipes or metal hoses. This requirement is spelled out in the PUE (7.18).

The above products are subject to the negative effects of rodents, which easily damage their surface and get to the wires.

In addition, wood dust, which is prone to ignition, accumulates in the boxes. If the flame flares up, it will not be possible to stop it.

Laying in a corrugated metal sleeve or PVC corrugation is possible (this does not mean that it is allowed) provided that the plaster is applied on top with a layer of 10 mm or protected with an asbestos layer.

Which metal hose is recommended for use

There are several types of metal sleeves for hidden wiring on the market:

• RZ-CH;
• RZ-SL;
• With PVC insulation (high temperature resistant).

The first type of product (RZ-CH) is a leaky corrugated sleeve made of galvanized steel. Cotton material is used to seal the joints.

RZ-SL is a corrugated sleeve made of white tin. Before twisting, the product withstands electrolytic tinning, which means applying tin sputtering to the surface.

The task of the layer is to protect the product from corrosion and extend its service life. For insulation between joints, a polypropylene film is used. Its feature is resistance to stress and the ability to withstand high humidity.

The metal hose in PVC insulation is a hermetic structure that can withstand high humidity, chemical and mechanical stress.

In addition, the product protects the cable from exposure to sunlight. Can be used for all types of wiring in a wooden house (inside and outside).

An alternative option is a metal hose made of stainless steel, but its disadvantage is a high price. Plus, it guarantees high performance and a long service life.

When choosing a suitable solution, you need to consider the following features:

1. For rooms with high humidity, a sealed armored sleeve is used that does not allow moisture to enter the product.
2. In ordinary rooms of a wooden house (residential or non-residential), it is allowed to use a simple product of the RZ-CH type.
3. Under harsh operating conditions, it is necessary to buy a metal hose with polymer insulation.

Metal corrugation goes on sale in bays 30 and 50 m long. If cutting is necessary, a special tool is used – a grinder, scissors, a metal saw or others.

A good solution is to use plaster around the metal sleeve. For hidden wiring, such a step is required (you cannot use a “bare” metal hose). The thickness of the plaster should be from 1 cm or more. The solution seems simple, but it’s not.

Disadvantages:

1. Difficulty repairing or replacing wiring. Tightening the wire without dismantling is a very difficult task.
2. The plaster does not adhere well to the wooden surface. Over time, cracks may appear, and it will begin to crumble.
3. The use of plaster on a tree does not make sense, because the very essence of a wooden house is its naturalness.

Despite a number of shortcomings, the laying of an armored sleeve in plaster does not violate the requirements of the PUE, therefore it has the right to life.

Placement of switches, boxes, sockets

When installing hidden wiring, you can not do without mounting switches and sockets on the walls. At the points of fixation of the elements, it is necessary to make recesses and fix the products.

The work is carried out according to a special technology provided for buildings made of wood.

Highlights:

• grounding is mandatory for the entire structure;
• if the metal elements do not break over the entire length, grounding on the electrical panel is enough;
• the presence of gaps requires the installation of additional grounding by soldering or in another way.

The boxes are fixed to the pipes in several ways – welding or soldering, which guarantee high quality contacts, protection against rust and resistance to damage.

If copper pipes are used for hidden wiring, they are flared when approaching the box.

In the case of steel structures, a thread is made for fastening with a nut. When choosing boxes (technological, distributive), it is necessary to pay attention to the protection class. It must be from IP-54 and above, which guarantees protection against dust and moisture.

Wiring Order

The PUE clearly spells out the rules regarding the connection of wires inside the box (installed together with the taps of the main cable).

Combining wires involves the use of the following methods:

1. SELF-CLAMPING TERMINALS WAGO. To apply this method, 1 cm of insulation is removed from the wire. When choosing terminals, the cross section with insulation must be taken into account).
2. CAPS FOR TWISTING. The insulation is removed taking into account the length of the cap, in which a conical spring is provided. When putting the product on a twist, the spring clamps the wire, and the plastic sheath provides reliable insulation.
3. TWIST. When choosing this method, the wires are stripped of insulation to a length of 4 cm, and then twisted together. The twisting points need to be soldered, and then wrapped with electrical tape. More about twisting wires.

It must be remembered that the number of joints affects the ability of hidden wiring to withstand loads. The greater the number of connections, the lower the load capacity.

In addition, in order to avoid confusion, you need to consider the purpose of colors. Yellow-green is ground, red or brown is phase, and blue or white is zero.

Wiring test

After installation of hidden wiring, it must be tested. This is especially important for wooden houses, which have a low level of fire resistance.

When checking, special devices are used, and trained employees of electrical laboratories are invited to work.

The set of activities includes:

• visual inspection;
• ground resistance measurement;
• AB check;
• phase-zero circuit test;
• check of protective devices;
• control of the circuit between the ground electrode and the devices.

After completion of the work, a test report is drawn up and transmitted. Such measures are mandatory, because they help to avoid accidents and prevent equipment breakdowns.

Useful Tips

In conclusion, we give tips and results regarding the implementation of hidden wiring in wooden houses.

Base points:

1. For electrical wiring in a wooden house, it is better to use NYM – a cable with triple electrical insulation.
2. The best circuit protection is provided by differential circuit breakers that protect the network from short circuits and leakage (RCD).
3. Grounding junction boxes and metal pipes is a mandatory safety feature.
4. During installation, it is necessary to take into account the shrinkage of a wooden house in order to avoid distortion and damage to the wires.
5. The pipe connection must be as reliable as possible. For joining, welding and soldering are used.
6. The best pipes are copper. Their advantages are corrosion resistance and ease of bending.
7. Plastic inserts are used at the ends of the pipes to protect the cable from damage.
8. If lining or wooden wallpaper is used during installation, pipes can be run through the existing recesses.
9. In a wooden house, it is allowed to combine hidden and open wiring.
10. Installation is done exclusively according to the scheme agreed with the experts.
11. The main attention is paid to protection against fire, and only after the aesthetic component.
12. The optimal solution is to lay channels in existing recesses, window and door openings, under skirting boards or ceiling cladding.
13. When using corrugated pipes, it is necessary to cover the surface with plaster or asbestos gaskets.
14. Pipes are combined by threading or welding.
15. Junction boxes must be freely accessible.

Results

Hidden wiring in a wooden house is mounted only if you know the regulatory documents and follow the current requirements.

Violation of the rules is fraught with negative consequences, up to the fire of the building. In the absence of experience, it is better to refuse to work with your own hands, and entrust the work to the masters.