Dear Sirs! I believe that the main criterion when choosing a material for protecting an underground cable line should be the resistance of the material to mechanical overloads. NPTO "Belstroynauka" of the State Construction Committee of the BSSR in the late 80s developed recommendations for the pilot-industrial implementation of protective polymer coatings when laying electrical cables with a voltage of 0.4-10 kV ", where, in particular, to the physical and mechanical properties used for protection underground cables polymeric materials there was a requirement for tensile strength over 10 MPa. If such criteria were put at the forefront, at the present time, gentlemen, the designers would not have such questions and throws as polyethylene pipe choose with a thick wall or a thin one. You would simply simply ask the manufacturer for a test report on the mechanical strength of the pipe.
If you like, I will quote from European standards ("Rules for the installation of electrical equipment" chapter "VII. Cable lines in the land "currently operating in the Republic of Lithuania")
p. 169. The protection of cables laid in trenches from mechanical damage depends on the significance of the cable, its voltage, depth and location. Mechanical strength protective equipment cables (protective tapes) should be at least 6 MPa.
Cables with a voltage of 110 kV and above must be covered with reinforced concrete slabs not less than 50 mm thick.
Cables with a voltage of 6-35 kV in the city must be protected from mechanical damage by covering them with special caps, slabs, solid clay brick or protective tapes 1.5-5 mm thick at a distance of 0.10-0.15 m above the cable or cables must be laid in ceramic, plastic, asbestos-cement or cast iron pipes... The width of the protective tape for one cable must be at least 100 mm, for two cables - 200 mm. When using protective tapes, at a distance of 0.3 m from the ground surface for each parallel laid cable, a signal tape with a thickness of at least 0.5 mm with the inscription “Attention! Cable!".
Cables with a voltage of 6-10 kV, laid in uncultivated ground, at a depth of at least 0.7 m, and with a voltage of 35 kV, at a depth of at least 1 m, must be protected from mechanical damage by covering them with protective tapes and laying signal tapes at a depth of 0.3 m from the surface of the earth.
If the cables are laid in pipes or they are covered with special caps, slabs, solid clay bricks, then it is not necessary to lay signal tapes.
It is not necessary to protect cables with a voltage of 6-35 kV in arable lands from mechanical damage, however, a signal tape must be laid at a depth of at least 0.5 m from the surface of the earth.
Cables with voltages up to 1000 V, laid at a depth of 0.35-0.7 m and on those sections of the routes where there is a possibility of damage (for example, in places of frequent excavations), must be protected with slabs, caps, solid clay bricks or laid in pipes ... In other cases, in the city, also under the pavement and in uncultivated land at a depth of 0.3 m from the surface of the earth, and in arable land at a depth of 0.5 m from the surface of the earth, it is enough to lay only a signal tape ... "

There are pipes made of PVC, HDPE and LDPE. for cable is made of low pressure polyethylene. LDPE branch pipe is a polyethylene construction high pressure, which is vulnerable to the effects of gases and is sensitive to oxidation. Corrugated HDPE cable pipe is characterized by high chemical resistance, but at the same time it has a low resistance to mechanical damage, and also has a high water resistance. Used for installation of electrical wiring and laying cables in the ground. Laying corrugated pipes in HDPE soil is possible only when using smooth single-walled black pipes. The pipeline is placed in brickwork or in concrete mortar... Additionally used.

PVC sleeves for electrical wiring and cable routing are made of non-combustible polyvinyl chloride. They are characterized by high mechanical resistance, rigidity, and also a small coefficient of linear expansion. Mainly stretched in concrete walls... They protect the cable from mechanical damage, providing it with additional insulation. They do not condense moisture and do not emit toxic substances.



There is also a corrugated metal pipe for cable. Since it is made of metal, which is characterized by increased rigidity, its length in small-diameter areas is not very large. It does not stretch, unlike HDPE, LDPE and PVC structures. But at the same time it has the highest flexibility.

There are single-walled and double-walled structures, double-walled ones are more durable.

To protect communication and communication lines when laying wires, it is most often used for cables in the ground. Its use as a protective shell eliminates the risk of damage to products during the arrangement of highways and during their operation.

Low pressure wires are able to protect (incl. power cable) from the effects of soil, mechanical shock, as well as stray currents. Which ones are used to protect engineering networks and how to choose the right ones, read on.

Reasons for the high popularity of products

The most popular method for arranging electrical, communication, signaling and other networks is to lay cables underground. And most often it is in the HDPE pipe. Therefore, manufacturers strive to make the most diverse range of manufactured polyethylene products. special purpose... Despite the fact that this method of laying cables and wires is quite expensive, it is considered very popular.

For laying cables in the ground, they can prevent a variety of problems that are possible during the operation of utility networks.

The reasons for the growing popularity of these collectors in the arrangement of underground highways are:

1. Reducing the risk of damage to lines by external factors (for example, in adverse weather conditions).
2. Vandal and frost protection.
3. Avoid fire due to short circuit.

What kinds of products can be used to protect wires?

On the building materials market, you can find all kinds of products that are suitable for laying utility lines in the ground. It can be not only HDPE collectors, but also PVC pipes, asbestos or asbestos-cement, steel. However, most often it is polyethylene materials that are used to protect wires and power lines underground.

HDPE pipes (pipe for cable in the ground) are of several types:

1. or heavy
2. Hard with a smooth shell
3. (with 2 walls)
4. Halogen-free.

The main types of pipes that can be applied in the ground.

Collectors of one type or another are designed for specific purposes. For example, products with double walls can be used for underground wiring, one of which is corrugation, and the second is a LDPE sheath. Corrugated pipe is not suitable for laying cables in the ground. Even in spite of the fact that it is distinguished by increased elasticity and strength.

You can understand what certain materials are for by the markings on the product. It indicates (GOST, diameter and thickness of the shell, strength, nominal pressure indicator, product class and sometimes its purpose).

If you need a HDPE pipe for a cable underground, consider the purpose of its further use and specifications... So, the material in the corrugation is suitable for hidden electrical wires in rooms. Usually these are highways that are created during home improvement and are inserted into the walls or ceiling. The most durable corrugated DSK collectors can even be used in construction engineering network in the floor (for pouring with concrete or cement).

Depending on the number of cables in the proposed network, the pipe may be different diameters... For example, if 2-3 wires with a cross-section of 95 mm² are being laid, a product with an internal DN 63 mm can be used. They are sold in bays of 15 m or in separate cuts.

If it is necessary to lay a line of 2-5 cables with a cross-section of 25 mm² each, collectors with an internal opening of 32, 40 or 50 mm, etc. can be used. Some manufacturers offer for sale HDPE collectors with large diameter within 160mm-250mm. Such materials are sold in 12 m sections or 100 m (200 m) coils.

Styling methods and features

Laying of cables in pipes can be carried out by surface or underground method. It is also practiced to lay cables in a sheath indoors. If you need to equip an electrical or communication system in a residential building, before carrying out work, you should familiarize yourself with the features of the process. First of all, it is recommended to lay the networks at temperatures down to -30⁰С.

It is necessary to ensure the tightness of all joints and nodes on the line in order to exclude the risk of moisture and other contamination entering the collector. If the operating conditions of the network presuppose the formation of condensation in the pipe, additionally insert a broaching tube to collect excess liquid.

After making sure that such points are taken into account, you can proceed to the next stage of work. Laying a cable in the ground in a HDPE pipe is not a very laborious process, the main part of which is digging trenches. After preparing the deepening of the required size, the collector is first laid, and then the cable is inserted into it. After inspecting the lines for damage and depressurization of the units, the developers fill the structure with sand and earth. Finally, a signal tape can be laid around the entire perimeter.

Valuable product qualities

HDPE pipe, designed for cable and its protection in the ground (their price is relatively low, if we take into account the long service life), has a huge number of valuable qualities:

• lightweight and as well as simple cable routing with a probe;
• the possibility of underground wiring with large radius corners;
• resistance to different conditions operation (from mechanical stress to temperature changes);
• the ability to operate for 50 years or more;
• light weight;
• use without additional grounding, etc.

As you can see, the use of HDPE pipes when laying engineering underground lines is the key to their successful and reliable operation. Therefore, it is important to choose the right collector and take into account all the nuances of its use.

The video demonstrates fire testing of corrugations for PVC and HDPE electrical wiring:

Today plastic pipes are used both by professional installers and in everyday life at the most different stages construction or renovation works... In sewage systems, hot and cold water supply, heating, there is a steady trend to use plastic pipes instead of cast iron or metal.

Corrugated PVC pipes produced by the Russian company "Promrukav" are intended for widespread use in a single gasket: in household electrical installations inside or outside the premises. For computer, telephone, television, electrical networks in the case of their construction with insulated wires and non-combustible cables. The maximum allowable voltage is 1000V. Made from high-class PVC composition. Thanks to the use of corrugated pipes, the time for installing the power grid is significantly reduced.

Corrugations are stiffening ribs and therefore provide protection to the wires, excluding any mechanical impact. If you install cables along the walls, you will provide yourself with easy access to cables, repair, replacement at any convenient time. This is much easier than wiring deep into the wall.

Corrugated HDPE (low pressure polyethylene, material) pipes also designed for single laying of non-combustible materials. They are uniform along all lengths, do not form cracks. In terms of wear resistance, it surpasses PVC pipes.

Orange corrugated pipes HDPE halogen-free their HDPE is made with the use of special additives to reduce the flammability of the material. The abbreviation NG in the name means “non-flammable”.

Smooth rigid PVC pipes used in open wiring - on walls and ceilings. The format is three meters long. To solve in corners and projections, you should use fasteners and other accessories that are convenient and easy to use. The pipes have high degree protection IP65, prevent moisture penetration, protect against mechanical damage.

Smooth HDPE pipes provide additional insulation for networks and protect against mechanical damage. They are durable - service life is over 50 years. Resistant to temperature extremes, withstand severe frosts.

Plastic pipes allow you to collect all cables in one place and provide equal access to each of them.

When reconstructing the wiring or installing a new one, it is recommended to "pack" it in a protective sheath. The most commonly used corrugated electrical pipes, which are usually called "corrugation for cables and wires." It is a round hose with a ribbed surface. Due to the ribbing, its flexibility is significantly increased.

Why do you need corrugation

In general, from mechanical destruction of a corrugation, even a metal one, does not best protection... One can only hope that having felt that the drill has failed, it will be possible to stop in time. And in order not to get into the wiring for sure, it is better to have an accurate plan for laying it with measurements and reference to the corners. After all, not everyone determines a cable in a corrugation, even under load. So do not forget to take pictures, sketch and mark the distances before pouring the screed, before finishing.

Types of corrugations for cable routing

The corrugation for the cable is of different strength:

As you can see, the classification is based on strength properties, which determines the area of ​​use.

Varieties

In addition to all this, there is also a corrugation with and without a broach. A pull-through is a thin cable or wire that makes it easier to pull the cable into a corrugation. The cable is tied to the end of the cable, pulled by its other end, tucking the cable inward. It is problematic to cope with this task without a broach - with sufficient rigidity, several meters of cable can simply be pushed inside, but if the route is long, it will be too difficult.

The cable corrugation can be with a broach (the correct name is "probe") and without

If we talk about the types of plastic corrugation, it should be mentioned that there is a two-layer corrugation. On the outside, it has the same ribbed surface, but on the inside it is smooth. A corrugation for a cable of this type is expensive, but if necessary, you can really stretch a new cable into it. In those types where the inner wall is ribbed, this is far from always possible - if the track has a minimum of turns, and even those along a wide radius.

The metal corrugation for cables is also different. It is made of galvanized or stainless steel. In addition, there is a metal corrugation with polymer coating... She has best performance for protection from dust, moisture ingress. This protective shell is also called metal-polymer.

What materials

Corrugation for cable and electrical wires made of plastic and metal. The materials used are different, with different characteristics... They must be chosen based on the tasks that they must perform.

When it comes to compliance fire safety when installing the gasket in combustible walls, perfect option — metal pipe... It saves from the stresses that can arise when the size of the building changes. Rodents cannot cope with it either. Also this the best way from the point of view of fire safety: even in the event of short-circuit currents and non-operation, the probability of burning through a pipe with a wall thickness of 2 mm is very small. This means that the fire will not start. If laying electrical cables in pipes does not appeal to you at all, then you can use metal or stainless steel or galvanized corrugations.

Corrugation for cable, dimensions, prices

Corrugated pipes for power grids are available in sizes from 16 mm to 65 mm. When choosing a size, it must be borne in mind that these products have two diameters - outer and inner. If you are going to lay several conductors - wires or cables - the diameter must be selected so that there is a gap of at least half the radius. This requirement is based on the fact that when laying in a group (it is necessary, by the way, to take a special cable), it will heat up more and the presence of an air gap will contribute to better heat dissipation.

Size selection

The choice of the diameter of the corrugation also depends on the section on which it will be laid:

The diameter of the corrugation for cable laying is selected depending on the number and cross-section of wires. Data for copper conductors are given in the table.

This information is for reference, but you can focus on it. You can take a larger, but not smaller diameter.

Prices

Generally speaking, the cheapest is corrugation for PVC cable, in the middle range - PP and HDPE, the most expensive is metal corrugation. Moreover, the option with a broach is slightly more expensive than without it. When buying, you need to pay attention to the same wall thickness, color uniformity.

A corrugation for a cable is sold in coils of 50 and 100 meters, less often it can be found by meters, but the price is then slightly higher. In general, the price depends not only on the material, but also on the wall thickness. The cheapest is a light PVC corrugation for a cable, but sometimes it looks more like just a film. From what this can protect, it is difficult to say. If you are concerned about quality, it is better to purchase everything related to electrics not in building supermarkets such as Leroy, etc. but in specialized ones. The quality is usually better there, and the prices, if higher, are reasonable. So that you have an idea of ​​the possible range of prices, in the table we will summarize several types of corrugations with a brief technical description.

Name	A type	External diameter	Inner diameter	Broach	Price per meter	IP	Appointment
PVC corrugation	easy	16 mm	11.4 mm	Yes	2.4 rbl
	BCS	15.7 mm	11.3 mm	Yes	from 7.5 rubles / m	55	for hidden laying
Black HDPE corrugated pipe	BCS	19.5 mm	14.5 mm	Yes	from 8.9 rub / m	55	for hidden wiring
Red double-walled HDPE pipe	tough	50 mm	41.5 mm	Yes	78.5 rub / m	44	for hidden laying
HDPE pipe heavy	heavy	31 mm	23.4 mm	Yes	from 9.7 rubles / m	55	hidden gasket
PPL (polypropylene) corrugated pipe	easy	19.7 mm	14.8 mm	Yes	from 28 rub / m	55	open, hidden gasket
Corrugated pipe polyamide	black	21.2 mm	16.8 mm	No	from 52 rub / m	68	open, hidden gasket, UV resistant
Corrugated pipe polyamide	gray	21.2 mm	16.8 mm	Yes	from 48 rub / m	68	open, hidden gasket

Installation of corrugated pipes

For outdoor (open) installation, special plastic clips are used to fasten the corrugations for cables and wires, which are selected for outside diameter pipes. Clips are attached every 20-30 cm to self-tapping screws or dowels - depending on the type of wall. A corrugation for kbalay is inserted into the installed clips, pressed until it clicks. When mounted in a groove, it is fastened with plastic ties or dowel ties. You can also use homemade fasteners- strips of sheet metal with nails or self-tapping screws in the middle.

When designing a route, the following recommendations should be taken into account. It is assumed that the route should be without sharp turns so that, if necessary, you can tighten a new piece of cable. That's why:

These rules relate to the development of a track for ground (suspension) and including. If the route is long and you want to be able to pull the cable “in case of something” without replacing the corrugation, design the route with these rules in mind.

Corrugated wiring

When installing wiring in a house or apartment, pieces of corrugation are fixed between junction boxes, from them to switches / sockets, to lighting fixtures... Here the sections are usually small, straight, with a maximum of one or two turns. So there are no problems with the cable tightening.

If you tighten several conductors into the corrugation for the cable, they are folded, they are fastened along the entire length with tape or electrical tape in increments of 30-50 cm (depending on the stiffness). Rigid insulation is stripped 10-15 cm from one edge, the wires are twisted into a common bundle, a loop is formed from it (secure the loop with tape or electrical tape). If the tourniquet turns out to be too thick, you can form loops separately, just stretch the twine through everything. A rope is tied to this loop, and then they begin to pull it with opposite side pulling the sheath over the cables. In this case, it is necessary to pull without jerks, smoothly - so as not to damage the cable or cable.

During installation, make sure that the broach does not slip out. To be sure, you can secure the cable with a piece of tape. There are two approaches to editing:

• First, fix the corrugation, then tighten the cable or wires into the finished piece.
• First stretch the cable, then mount.

The first method is good when installing internal wiring, where the distances are small - from box to box, from box to outlet, etc. The second method is more suitable when installing long sections.

Features of open laying on the street

When wiring outdoors, it is usually suspended from a cable. For outdoor use, metal stainless steel is suitable, and better - metal-polymer corrugation for the cable, as well as plastic polyamide (black or blue). All these materials are resistant to ultraviolet light and remain flexible at subzero temperatures.

During installation, the cable stretched into the corrugation is suspended on a cable. The cheapest mounts are ordinary plastic ties. There are also special suspensions.