Electric cable for laying in the ground in the country. Basic safety rules for laying cables in the ground Laying cables in the ground at a country house

Usually, a number of buildings are erected on a summer cottage: a country house, a bathhouse, a summer kitchen, a utility block, etc. etc.

Initially, electricity was supplied to one of them, and everything needs to be electrified. Yes, and outdoor lighting want to do. And there is a problem of choice - which of the methods of laying electrical communications, air or underground, is more suitable for your dacha.

Choose a method

The aerial method is simple and cheap if the distance between objects is small. If the distance is large, then you will have to put an additional pole, support. And hanging garlands overhead do not decorate the country landscape.

The underground method of laying cables in the country is more aesthetic and suitable for laying over long distances or for outdoor lighting equipment.

In order to lay the cable underground in the country, you must comply with all the necessary requirements of safety rules, and you should also study the features of your summer cottage.

Rules for laying cables underground

First you need to choose the best way to lay the cable underground at their summer cottage. It is important here that the cable runs at least a meter (and usually more!) From large trees and in places where digging will certainly not be carried out. The cable path should not run under places where there is an increased load on the ground, for example, a platform that is used to park your car in the country. Think over the laying route so that communications do not interfere with you during further construction. Let the communications be a little longer than holding them under arable land or a future building. It is best to lay the cable under the tracks, and best of all next to them. We strongly recommend drawing a plan for its location.

You should not use the same cable to connect buildings and external lighting - first make communications between buildings. They must be done once and for all. When everything is done, start experimenting with outdoor lighting: this is a creative job and does not always work the first time.

Cable laying underground in the country begins with marking and excavating a trench. Its optimal depth should be at least 70 centimeters, and given the pillow, it is better than 80 centimeters. This is for communication between buildings. For cable laying underground for external lighting, these figures are usually 40-50 cm.

After the trench has been dug, it must be cleared of objects such as stones, pieces of iron, or pieces of glass that can damage the cable insulation. Then you need to make a pillow out of sand. The thickness of the pillow should be at least 5, and best of all 10 centimeters, and the sand itself should be fairly evenly distributed along the entire length of the trench.

Material used

It's time to choose a cable. All modern types of cables and wires have the necessary water resistance for laying in the ground. Even conventional installation wires of the series (PBPP / PUNP, PVA, ShVVP) can be safely laid underground or in water.

Power cables VVG(especially VVGz), KG are even better suited for these purposes. All these wires do not require any additional waterproofing.

But still, it is better to lay these cables in HDPE pipes. If it became necessary to lay a cable protected by a case, then HDPE technical pipes are an ideal technical solution. The most popular use of these pipes is to protect electrical, television and telephone (internet) cables. The use of a GOST HDPE pipe in this case is possible, but impractical, because. the high cost of raw materials and compliance with all standards for the production of drinking pipes increases the cost of the project at times. In the manufacture of HDPE technical pipe, various polyethylene additives are used (the basis is secondary raw materials and defective "pipe" production), which significantly reduces its price.

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The base color of the pipes is black, but the presence of recycled materials can give different shades. According to technical requirements, the presence of recycled low and high pressure polyethylene of certain grades is allowed. Pipes must be round, smooth and even both outside and inside.

HDPE pipes they are connected by couplings (fittings), but this does not guarantee 100% tightness - it is better to put them in one piece from building to building.

There is also a special armored cable for underground installation - VBBSH. The steel sleeve is already built into this cable and it has a very good waterproofing. It can be placed without additional protection.

For laying a cable underground in a country house between buildings, it is highly recommended to use it.

Carefully inspect the cable from all sides in order to check the integrity of its sheath. It is necessary to lay the cable in a trench (or in a pipe) in such a way that it lies freely, and not stretched.

You can already start backfilling. The cable must be covered with sand 10 centimeters thick. The cable must not protrude anywhere from the sand layer. A 15-cm layer of soil is poured on top of the sand. Then you can (at an amateur) lay the signal tape in such a way that the middle of the tape is located just above the cable.

We fill the entire trench, while leaving a small mound, since the soil tends to settle. When using HDPE pipes, the outlet to the building should be provided with fittings.

A few additional tips. Firstly, when laying a cable underground in a country house between buildings, use a cable with a cross section of at least 4 mm. Secondly, lay only one-piece cable underground, do not make connections.

When planning the electrification of a summer cottage, house or production area, each master acts on the basis of the general rules of construction, as well as the norms of the PUE and other documents. According to the indicated data, there are many ways to lay a power line, the most common is the air line. But it often happens when, for reasons of architecture and aesthetics of the territory, installation by this method is not appropriate, in which case the most acceptable would be laying the cable in the ground. This article discusses the basic rules for such work, as well as the question of how to lay a cable in the ground, the stages of the project.

Scope of the method

Cable laying in the ground can be used for electrical supply of any objects. It can be conditionally classified into several categories, depending on the complexity of the work in terms of safety and the height of the voltage in the wire:

1. For supplying current to a private house, summer cottage or outbuildings. This is the simplest option when an underground cable is used, since subsequently no major earthworks are carried out on a frequent site by strangers, the owner always has the opportunity to accurately determine the location of the wire and prevent its mechanical damage. As a rule, protective and signaling grids and platforms are rarely used in such a system, since the current flowing through these wires has a low voltage of up to 10 kV;
2. Laying of an electric cable of medium power for supplying industrial facilities and industrial buildings. In this case, a prerequisite is the development of a project with the calculation of all parameters, from the depth of the trench to the calculated load on the main, for which it is necessary to comply with the provisions of the PES and other standards;
3. Construction of high voltage lines. Here, work on laying the cable underground should be carried out only by qualified personnel who have a safety certification and a permit to operate on objects with high voltage. Most often, these are special organizations that have technical supervision licenses and have all the necessary equipment.

To supply electricity to a private house or summer cottage, the voltage of which will not exceed 10 kV, you can not involve a specialized organization, but do all the work yourself, observing safety precautions at the facility. Most often, such a route is used to organize outdoor lighting, laying a cable into the ground around the entire perimeter of the site between poles or masts of lamps.

Which cable to use

The electrical installation rules list the types of electrical cable that are suitable for laying in the ground. These wires include:

1. VBBSHv is a wire that has sufficient protection of the outer winding in the form of a steel tape, the cores are made of copper, and the internal separation between the lines is made by a polyethylene layer;
2. AVBBSHv - this abbreviation means everything the same as in the first case, but the inner cores in the cable are aluminum.

Both types of wire have sufficient protection against moisture and mechanical damage, as well as overpressure during ground movement. There are no exact recommendations in the rules regarding the diameter of the cable section, here it is necessary to calculate the load on the conductors and select a product corresponding to the rated voltage in the network. Most often, for a copper cable, the thickness is 10 mm, and for aluminum, it is 16 mm, but with an increase in the power of the route and an increase in voltage, the cross-sectional diameter must be increased.

Basic rules for laying cables in the ground

Laying cables in the ground is a responsible job that is best left to professionals. In extreme cases, when carrying out actions on your own, it is necessary to carefully study all the rules and regulations for the installation of power plants, as well as the recommendations of specialists:

1. Use only specialized materials intended for this purpose, such as cable and protective conduit. It is forbidden to use wires for internal power distribution, as they do not have sufficient winding thickness and a metal shield;

Important! When laying a cable in a protective channel, a plastic or metal pipe, you should not use a corrugated hose, because when exposed to soil in a year, nothing will remain of the corrugation, its ribs will fall inward and damage the wire cores, which will lead to an emergency.

1. The laying of cable lines in the ground should be carried out below the freezing level of the soil, otherwise, when the water freezes, the soil will swell and the line will break. If it is not possible to fulfill this condition, then the pipe in which the conductor is located must be additionally secured with clamps with driven fittings or support pads should be installed pressing the line;
2. The laying of a power cable with a voltage of more than 10 kV must be carried out to a depth of at least 70 centimeters, with the installation of a signaling tape or grid. This material, in the case of work on the site and digging a trench, will report proximity to the wire, which will prevent its rupture or mechanical damage;
3. Parallel laying of cables is possible only if separation structures made of plastic or concrete are installed between the routes. It is not necessary to make such a partition solid; dotted placement through equal segments is allowed;

1. Often you have to lay wires under the road or the foundation of the building. In this case, the diameter of the sleeve should be 2-3 times larger than the size of the cable. Often these works are carried out without digging a trench and disturbing the roadway, using a puncture or horizontal drilling method. These methods allow you to conduct electricity in a short time and without additional costs for the restoration of the coating;
2. If the cable is laid in a trench during the cold season, then the wires must be preheated in a warm room or using a transformer. It is allowed to lay the cable in the channel without preparation if the ambient temperature is not lower than -5 degrees. In other cases, the outer sheath of the conductor must be made of soft polypropylene or rubber - these materials do not break in the cold and do not lose their flexibility;
3. The connection of cable segments, when they are located at a depth, is carried out by a special coupling, which compresses the two ends and forms a monolithic joint. This place needs additional protection with insulation or plastic heat shrink tubing;
4. In special conditions, when serious ground movements are observed, it is possible to additionally use an asbestos-cement pipe with a coupling joint, the laying rules do not prohibit this. You can also use ceramic bricks, building a channel with it, inside which the highway will be located, but only a solid block is suitable for this purpose;
5. The distance between the pipeline being laid and the water supply must be at least 1 meter, and from the gas pipeline - from 2 meters.

How to lay a cable underground: an algorithm of actions

For the correct installation of an electrical wire into the ground, it is necessary to act strictly sequentially, based on the following algorithm:

1. Preparation of a project or scheme for future communication. All buildings are marked on the drawing, the distance between them and the exact location of the channel;
2. Site marking. To do this, using a tape measure and metal pegs, you need to measure the distance from the buildings to the future trench, based on the diagram;

1. The next step is to dig a trench for laying the cable in the ground. It can be dug using special equipment or independently manually, while the cable laying depth must comply with the standard specified in the PUE. It is necessary to remove all large pieces of earth, stones or pieces of metal from the channel, which can subsequently damage the route, as well as eliminate the unevenness of the soil at the bottom;
2. Next, a base of fine sand is prepared by adding a layer of 5-10 centimeters with an intermediate rammer;
3. Then a special-purpose wire is laid on the bottom, which has metal reinforcement and protection. Wires laid in one trench should be at a distance of 10 centimeters from each other. If necessary, at the intersection with other communications, under the road or buildings, protection is put on the wires in the form of a pipe made of asbestos cement or plastic;
4. The cable is "ringed" by a special test device, which determines the integrity of the line by applying high voltage to the ends. Test measurements must be carried out in a special protective suit, with personal protective equipment;
5. The resulting route over the laid cable is covered with fine sand, the layer of which must be at least 15 centimeters. This layer must be compacted with a special apparatus or manually;
6. A re-check of the entire line is carried out to exclude damage to the cable during tamping. On top of the laid conductor and the sand layer along the entire length of the trench, a signal rent or grid is mounted, which, upon further maintenance of the line or the occurrence of an emergency, will report on the proximity to the electrical main. When re-digging the channel, the layers will be removed gradually to this tape, then the work is carried out manually so as not to damage the existing cable;

1. The final step will be backfilling the soil into the canal. Due to the layers of sand, excess soil is formed, it does not need to be removed or used for other purposes, since as moisture enters the surface of the earth, the soil will shrink, and additional backfilling will be required;
2. After the cable is finally laid underground in the country house, and the trench is backfilled, it is possible to restore the original coating in the form of a lawn or roadway.

This algorithm is established by the PUE and is universal, applicable to all types of cables, ranging from 10 kV and above. But the technology may not be partially observed when the wiring is local, low-current and not loaded with high voltage. For example, communication or access control cables do not have metal protection, but can be laid in the ground using plastic pipe as a conduit and cover protection. Such lines carry a current much lower than 10 kV, and a short circuit will not lead to a major emergency. In addition, if necessary, this wire can be replaced by pulling it out of the channel and laying a new one, without opening the main soil cover.

The main danger for the cable sheath is the underground "stray" current. This is a physical phenomenon that occurs from the operation of electrical appliances that have grounding, such as washing machines, household networks or electric trains. The electric current of these devices and units penetrates the soil along the laid conductor and randomly moves in the thickness of the soil, affecting the communications, while the plastic insulation can crack and harden. To avoid such consequences, if it is established that the land is saturated with stray currents, a cable can be laid inside a plastic pipe. This will give additional insulation of the wire from the ground and increase the life of the line.

Thus, for the proper organization of the power supply of a building or territory by laying a conductor underground, it is necessary to strictly observe the rules for the installation of electrical installations, as well as general building codes. Only under such conditions will the supervisory authority give permission to use the highway, and its operation will be safe and durable.

Video

Everyone who has ever thought of ennobling his suburban area was worried about the pressing question: how to make wiring in the garden so that it leads to a variety of sockets and light bulbs in gazebos, to lighting lamps? I also had to deal with this difficult task.

I immediately warn you that I am an electrician by profession, so I did everything myself, if someone does not have special knowledge, you can’t start “tricking” something with wiring and electricity on your own. In the best case, nothing may simply work, on average, all connected equipment will break, and in the extreme, you can harm yourself or some of the madmen who agreed to deal with the "self-made" electrification of the garden. The electrification of the site should only be carried out by a specialist, no matter how simple it may seem. But even in general terms, knowing how to do the wiring will not hurt anyone, if only to control the quality of the work of the same electrician - they are also different. So, the topic of this article is how to lay wiring in the garden.

How to make wiring: materials and tools

For the installation of garden wiring, you need a standard set of tools:

• drill with a set of drills
• Screwdriver Set
• good cutters
• pliers
• sharp knife
• a hammer
• voltage indicator
• protective gloves

This is the minimum required list, without which work can not be started. If the wiring is underground (more on that below), then you can’t do without a good shovel.

Selecting the type of wiring and installation methods

Garden wiring can be outdoor and hidden. The first is still temporary and stationary, the second is most often buried in the ground. Here the choice depends on the possibilities and needs. Temporary wiring is suitable for those who rarely need electricity in the garden - it is the cheapest, but also the least beautiful and safe. Such a system is simply unwound from home and rewound if necessary - no problems. Stationary external wiring is mounted for permanent use and is led to the places of electrification along posts, trees and external walls of buildings, stretched on cables.

It will cost a little more (you need a better wire), but it is not always possible to perform it aesthetically - it all depends on the layout of the garden, the number of connection points and all that.

I'll tell you how to lay the wiring underground. This electrification of the site is much more efficient and safer than the others, but you will need a special expensive cable with reinforced insulation. When connecting pieces of cable to each other, electrical tape is no longer suitable - special hermetic couplings are needed.

How to lay the wiring: the sequence of work

All work performed can be divided into several stages in sequence.

1. Development of a project in which all lamps, switches, sockets, etc. are clearly indicated. This is the most important stage, on the correct implementation of which the success of the entire event depends.

Even if you want to do all the work yourself, the project must be developed or at least approved by a good specialist. For example, you can order a detailed garden electrification project with precise specifications and detailed instructions and work on it as if it were a good instruction.

2. Next, trenches are dug into which, according to the previously developed project, the cable will be laid. Laying is simple, but time-consuming: the cable is laid in a trench at least sixty centimeters deep on a ten-centimeter sand cushion.

The ends of the wires are brought out of the ground to the places where the equipment is installed and connected to the main power grid.

3. Now you can mount all the fixtures, sockets, and more. All switching fittings should be placed in places absolutely inaccessible to atmospheric precipitation, even if the seller swore that it was waterproof - it would still leak and close. We know we passed.

4. And only after that you need to install protective automation and connect to a permanent power supply. Trenches, on the other hand, can be buried already firmly convinced that everything works. The cable is covered with sand and covered with bricks, tiles and other materials that protect against mechanical damage.

The work is done.

Selection and placement of sockets, lamps

Depending on the type of wiring, site lighting fixtures can be suspended and ground, they can give diffused and directional light that will illuminate a small area or the entire building.

To illuminate garden paths, ground lamps with soft, diffusing shades are most often used, this is how everything was done with me.

There will be no problems with the choice of lamps, sockets and switches - there are a lot of types, the main thing is to place them safely.

Wiring security

The two main criteria for safe wiring in the garden are a good cable and a qualified person working with it.

Many hope that in the event of a circuit failure, they will be protected by a central machine, usually located near the meter. I installed an additional AMS (automatic power breaker) at my place, which only works for the garden network. Why risk all the appliances in the house?

In order to temporarily conduct electricity to certain garden objects, it would be wise to use a ready-made kit that just needs to be plugged into the power grid. Such kits are also equipped with an AMS unit, and all junction boxes and switches in them are made watertight.

That's all. The science is simple, but it requires accuracy of execution and vigilance in work, because harnessed electricity is good, but when it “breaks off the leash”, it almost always ends badly.

The question often arises before the owners of private households, is it possible to lay a power cable underground? What is the best wire to use? What rules must be observed?
The main way of laying power lines to a private house, a summer residence is - air or underground. To transfer electricity to the point of consumption, a method such as laying a cable in the ground is used. This is an economical option for installing power lines. The advantage of this method is the secrecy of the wiring, which does not spoil the appearance of the building, the wires do not clash in the wind, and when moving oversized cargo, the wires will not interfere. Well, as a bonus, the cable is cooled in the ground, which prevents it from overheating and damage.

Laying wires and cables in the ground has many advantages. When installing this wiring, a special technological process must be observed. The following advantages can be distinguished:

• Profitability, the cost of work will not exceed the cost of the materials used. The most acceptable option, in comparison with the laying of an overhead line, which requires special approval, additional materials, equipment;
• In order to avoid damage to the cable, a shallow trench is not made and material and other means for maintaining the line will not be required;
• The ability to lay the cable with your own hands without the help of installers and without involving special equipment in the form of a tower;
• The wiring place is hidden from view, so it does not spoil the appearance of the area;
• This method allows the use of electrical high-voltage cable of various cross-sections, without the use of suspension reinforcements.

Rules that must be observed for laying wires underground

Installation is carried out in compliance with PTEEP as well as PUE, regardless of the purpose and type of wire used. The following points must be observed:

• The cable is laid at a depth of 70 cm or more. If the power line is short (less than 5 meters) and the cable is protected in the form of a pipe, then laying at a depth of 50 cm is allowed;
  
• It is not allowed to lay wiring under the foundation of the building. At least 60 centimeters should be measured from the foundation for the installation of the line. If a wire is pulled from one building to another through the foundation, then it must be protected with a steel pipe. Such protection is mandatory since any cable is subject to all sorts of harmful effects;
• The distance in the trench between the wires is usually at least 10 centimeters. Based on this, the size of the trench is calculated;
  
• When laying a cable, it is worth retreating at least 2 meters from the trees on the site, the distance from the bush is required -75 cm. These rules can be violated if there is additional protection, for example, in the form of a steel pipe;
• From communications such as sewerage, water supply, it is necessary to make a distance of -1 meter or more, from a gas pipeline -2 meters or more;
• If cables intersect in trenches, then they should be isolated from each other with an earthen layer, 50 cm or more in size;
• If an underground wiring method is used, then the wire should be chosen armored, specially designed for this purpose. This is necessary to create protection from the influence of physical influences and underground pests;
  
• When laying using a winch that unwinds the drum, it is necessary to equip the mechanism with a limiter. In this case, installation with a snake is possible, then the line will not have a stretch;
• If it is necessary to connect an electrical wire, metal couplings are used independently. This connection method gives good contact for a long time;
• For additional protection of the power line, an asbestos-cement pipe or a special brick construction is used;
  
  
• After laying the wiring, a signal tape is laid on top with a designation and a warning about the wiring.
  

The choice of electrical cable for wiring underground

In underground wiring, types of armored cables are used - VB 6ShV, as well as VB6ShVng, these products have steel protection. This option is resistant to mechanical damage and will not allow rodents to damage the wiring.
With such protection, the cable will last for many years. The armored cable is laid without a pipeline, but the use of a pipe is recommended in order to avoid damage to the wiring by government employees. organizations in the course of work.
The electric wire for laying in the ground should be selected, taking into account the required power of the consumers of the facility. For example:

• • Cable VBShvng 4x6 is designed for power 11kW;
  • Cable VBShvng 4x10 is designed for power 15kW;
  • The VBShvng 4x16 cable is designed for a power of 21 kW.

Work order

There is a certain sequence when laying leashes in the ground:

• Designation of the location of the power line;
• The choice of a cable suitable for this type of work;
• Arrangement of a trench for wiring;
• cable laying in the ground;
• Arrangement of wires sewn up with a pillow, then with soil and signaling tape;
• Carrying out verification work on the functioning of the line;
• The final stage is the digging of the trench.

Stages of work on laying electrical wiring

To create wiring underground, you need to have special knowledge:

• The first thing is the marking of the route on the ground for a power line in a summer cottage, suburban area, etc .;
• When marking, it is possible to use all kinds of stakes, ropes. It is necessary to carefully monitor that there is no intersection with communication networks;
• It is worth creating a cable layout plan. The drawing indicates the distance of the cable exit from the ground, as well as its turns. It is important to check whether the wiring is disconnected from the mains voltage before laying;
• Then a trench is dug according to the markup. As a rule, its depth is 80 cm, the width for laying one cable is 20 cm. The bottom of the dug trench should be rammed;
• There is an option - the bottom of the trench is laid out with red brick;
• If you plan to conduct electrical wiring across the road, then in this case the depth should be at least 120cm;
• When laying the cable into the ground, it is necessary to clear the trench from branches, stones and other objects;
• Next, a pillow of sand is poured -12 cm. It will protect against the possibility of a wire break;
• The de-energized wire must be laid so that it is not too tight. As a rule, a whole wire is laid without connecting sections;
• The final step is backfilling the trench with electrical wiring. After that, the cable is checked for a short circuit and its armor is grounded.

How to properly lay the cable in the ground, be sure to watch the video:

In winter, the underground laying of the electrical wiring line is permissible, the following must be taken into account:

• Before laying the cable warms up in the living room. The heated cable is laid, preventing freezing. If the frost is more than 20 degrees, the possibility of installation is excluded;
• If the air temperature is minus 5 and above, it is possible not to carry out the warm-up procedure if the high pressure wire;
• At a temperature of minus 7, it is permissible to lay a conductor protected by insulation;
• If the temperature is minus 15 and above and the conductor is protected by a PVC film or a rubber sheath;
• Laying at minus 20 degrees is possible, if the wire is protected by PVC or rubber insulation and if there is a lead sheath on top.

There are details that are worth considering, they will help to carry out the work more correctly:

These rules for laying underground wiring must be observed for safe work and subsequent operation. If the rules are violated, troubles may arise that will be difficult to correct.

Connecting a private house, dacha or any other low-rise facility to electrical networks can be done in three ways: by air, in the ground or combined. The owner himself chooses the option of electrification, depending on the cost of work, his own preferences and, of course, on the actual possibility of implementing one or another type of connection. Leading an electric wire through the air is the cheapest way, but it has a number of disadvantages: the possibility of damage to the cable is high in strong winds, icing and other natural factors. In addition, the theft of an expensive wire cannot be ruled out.

All these shortcomings are deprived of the option in which for the electrification of the object, a cable is laid in the ground. The cost of such work is much higher than the air connection, but the high financial costs are offset by the reliability of underground utilities and a longer service life. With proper installation of a power cable underground, it can last for several decades. Below we will consider all the advantages of underground laying of electrical communications, as well as provide complete instructions for independently performing such work.

Benefits of laying cables underground

As mentioned above, laying an electrical cable in a previously dug and prepared trench has only one advantage over an air supply and no disadvantages in terms of reliability. Of course, all this is valid if the installation is carried out in compliance with all the rules. Let's look at the main advantages of this method of electrification of a private house, cottage or other object.

1. The possibility of using an electric cable of a larger cross section, so to speak, with a margin, without the reinforcement of the supporting structure necessary for overhead lines.
2. Minimization of all external devices such as switches, isolators and so on. It is enough to install one machine at the input to completely de-energize the internal electrical network.
3. The aesthetics of the general appearance of the building is also an important advantage of this connection option. Hanging and swaying wires do not add to the attractiveness of the building as a whole.
4. With sufficient deepening of the trench and proper installation of communications, you can forget about the cable forever. The possibility of its failure with subsequent replacement is practically excluded.

How to lay a cable in the ground? The technology of such work is almost the same for any regions of the Russian Federation, with some nuances for different soils and climatic conditions. It is regulated by GOSTs and norms that have not changed since the 60s of the last century. Cable laying underground in a country house, in a private house or other low-rise facility begins with the development of the route.

Underground cable route project

The owner receives a plan of the route from the pole to the building along with the project for connecting to the power grid, but he does the wiring on the site to the bathhouse, garage and other objects on his own. The most economical option is to lay the cable in a straight line, but in reality this is rarely feasible, since you will have to bypass various obstacles. When developing an underground cable layout plan for the site, the following rules must be followed.

1. If possible, exclude intersection with other communications. If this can be done, then the cable without a protective sheath must be located at a distance of at least 0.5 m from gas, water and sewer pipes. When laying the conductor in the casing, this distance is reduced to 0.25 m. When crossing with another electric cable, this parameter is 15 cm.
2. It is necessary to bypass the places of parking of cars and the arrival of motor vehicles. If this condition cannot be met, then it is necessary to increase the depth of the trench or pass the cable through a protective case. Large trees and shrubs should be avoided. When passing the route along the foundation, the distance from it must be at least 60 cm.

As a result, the cable laying plan will follow a broken line, not a straight line. Trench marking is best done with a stream of sand or pegs. After the preparatory work, it is necessary to once again check the plan for compliance with the standards and transfer it to paper, with reference to all objects on the site and underground utilities.

This drawing will subsequently come in handy during the construction of new facilities, redevelopment of the site, as well as in case of a need to repair an underground power line, which can happen if the technology for laying an electric cable in the ground is not followed or in other force majeure circumstances. The plan has been developed, transferred to paper - it's time to start the main work!

Underground cable installation technology

The laying of an electric cable in the ground at a summer cottage, the territory of a private household or another object begins with earthworks. Before this, it is necessary to determine the depth and width of the trench. The depth must be at least 80 cm, and the width must be 30 cm for each cable, if there are several. In accordance with the developed plan and the marking of the route, soil sampling is carried out. The trench is cleared of foreign hard and sharp objects, and its walls should have a slight slope. After earthworks are completed, the cable is laid according to the following algorithm:

• the bottom of the trench is leveled, covered with sand with a layer of 15 cm and compacted;
• protective cases are placed on the prepared pillow, if necessary;
• a cable is pulled through the cases, subject to the necessary slack;
• the protection pipes are connected into one whole in one of several ways;
• a layer of sand 25 cm thick is poured on top of the laid cable in protection;
• the top backfill is lightly compacted, best with your own feet;
• a plastic signal tape is laid with the inscription up;
• the trench is covered with soil, in layers with obligatory tamping.

Attention! Do not rush to bury the cable! Be sure to invite a representative of the energy company that gives permission to connect to the public electricity grid. It is possible to carry out underground laying and installation of the necessary equipment on your own, but authorized power engineers do a check for compliance with GOSTs and PUE (rules for electrical installations) without fail!

It is advisable to lay the cable in one single piece, without any connections. If this option is not possible, then you need to connect the individual pieces in mounting boxes specially designed for outdoor use. The device is installed on a column above the soil surface, at the junction of the cable, where its ends are brought to the surface. Do not bury the box, as this will quickly damage the line.

At this, the laying of cable lines in the ground ends and the stage of connecting underground electrical communications to the general power supply networks and entering the buildings located on the site begins. At each stage of work, both when laying the cable and connecting it, there are some nuances that will be highlighted below. We will start this description with the choice of cable for underground routes.

Which cable is suitable for laying in the ground

The answer to this question is clear! It is best to use the highest protection class cable, preferably with a hard sheath. Such a product can be buried without protective cases, with the exception of parking areas and vehicle arrivals. These characteristics correspond to electric cables of the following brands: AVBShv, VVB (moisture-resistant armored), VVBbG (armored with waterproofing), VBBShv (armored in a polyethylene hose). It should be noted that this is an expensive product and it is advisable to use it to supply electricity from the pole of the general power grid to the main building on the site.

When selecting armor, one should take into account the acidity of the soil and the presence of foreign bodies in it. Depending on these indicators, cables with aluminum, lead or steel armor are selected. Underground wiring around the site can be done using cheaper products. For these purposes, NYM and wire brands enclosed in polyethylene pipes may also be suitable. It is undesirable to use VVG, since their service life underground is unlikely to exceed 2 years. In terms of long-term savings, it is best to use expensive cables. Large initial investment will be compensated by a long service life!

Important! Before laying the purchased cable in a trench, it is advisable to measure the resistance of the insulating layer. This operation is performed using a megohmmeter. If it was not possible to find such a device, then you need to at least check the product for a breakdown between the cores, which can be done using a conventional tester.

Protection of underground electrical lines

To protect the cable, you can use a special corrugated plastic protective sheath, asbestos-cement or PET water pipes. Sewer should not be used, as they have thin walls that cannot provide protection from heavy loads. It is also not recommended to lay the cable in steel pipes. To ensure reliability, when the ground moves, they must be welded along the entire length, otherwise the sharp edges may fray the wire. It should be said that armored products do not need such protection, but many consumers use protective cases for such products.

If pipe cases are used on an underground cable route, then the joints must be properly sealed to prevent water and soil from entering the internal cavity. For these purposes, you can use a masonry mortar, rags soaked in cement milk or special sealants. Who likes what! It is only necessary to remember that the cable in the case must have a certain slack, that is, it should not be pulled. That's pretty much all there is to say about cable sheaths.

In addition, underground electrical lines must be shielded from above. Such protection eliminates the possibility of damage to communications during various construction and land works. For lines with voltages up to 380 V, plastic signal tapes or a brick row are used. Lay protection to a depth of 25 cm from the soil surface. For high-voltage underground cable lines, concrete slabs are used, laid according to the appropriate technology on special supporting structures.

Important! The method of laying an electrical cable line underground in a protective sheath has one significant plus: in the event of a cable failure, there is no need to dig a trench, it is easiest to tighten it into a protective case. A new cable is tied to a failed one and pulled out, thereby replacing it with a serviceable product. But this is only possible if the integrity of the protective case is not broken!

Entering the cable into the house and connecting to the pole

Entering an underground electrical line into a building can be done in various ways, but the PUE prohibits laying it directly through the foundation, without the use of additional structural elements. The following methods exist for connecting indoor wiring to an underground cable.

Connecting underground cable lines to a power pole will not cause difficulties. Power engineers do not impose special requirements on this stage of laying the cable underground. The upper part of the connection area, from electrical wires to the equipment box, must be enclosed in a corrugated plastic pipe, and the lower part is at the discretion of the user. Of course, it is desirable to pass it through a curved metal pipe to avoid accidental damage, but according to the rules of the PUE, this is not a mandatory requirement.

Conclusion

The article addresses the question: how to lay a cable underground in a summer cottage or on the territory of a private household? The advantages of this method of connecting low-rise buildings are obvious! But this technology has one problem that needs to be taken seriously! A person cannot see what is happening underground. Washing the soil with groundwater, the invisible activity of moles, corrosion and seasonal movements of the earth cover - all these factors can create an emergency. Therefore, underground cable laying is carried out with accurate calculations and the exclusion of factors that can de-energize your household!

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