When installing electrical wiring and cable lines, you often have to solve the problem of how to route a wire or cable through the external walls of buildings and internal partitions. There are many requirements for the passage of electrical conductors through obstacles, and it is very important to comply with each of them, because this affects not only the ease of repair and replacement of wiring, but also the safety of its use. In this article we will tell you how to lay cables through a wall made of wood, brick and concrete in accordance with the requirements of regulatory documents.

Gasket requirements

The requirements for this type of work are regulated by two main regulatory documents. The first source is the PUE, which should always be addressed when we're talking about about the design of electrical installations. The second document is SNiP 3.05.06-85, which describes the standards for the construction and installation of electrical devices. Information on this issue is also contained in Federal Law 123, which formulates the requirements fire safety.

For the production of construction and installation work a corresponding project is required. If it is intended to lay a cable or wire through walls, the project must contain an architectural and construction part. The openings that a wall or partition must have through which wires and cables are supposed to be laid must be indicated on the project drawings.

Openings (openings) made in accordance with the design in walls, partitions, ceilings and foundations should not be framed by weakened areas that may collapse during operation. In general, installations through walls must meet the following requirements:

• the laying must provide the ability to replace wires and cables during operation.
• When installing wiring, it must be ensured that fire, smoke and moisture cannot spread through the installation openings from one room to another.

Compliance with these conditions is ensured by compliance following rules:

1. Laying of cables and electrical wiring through fireproof walls and ceilings is carried out in pipes, ducts or directly in openings. At the same time, in openings, without using additional protection, only protected (armored) cable can be laid. We talked about how to conduct electrical wiring in pipes in a separate article.
2. If the wall, partition or ceiling is made of combustible material, conductor products are laid in steel pipes.
3. The space between the wires and pipes or boxes, as well as all backup openings and boxes, are sealed. We also talked about how to seal a cable gland.

The material used to seal openings must be easily removable if necessary. The fire resistance of the sealant cannot be inferior to the fire resistance of the wall, partition and ceilings. Sealing using sealing material is carried out on both sides of pipes, ducts, and openings.

If the cable passage through the wall is made in a section of pipe, its bending radius, if any, should not exceed the permissible bending radius of the conductor grade used (this parameter is indicated in technical specifications).

Installation technology

First, let's look at how to pass a power cable or wire through the wall of a wooden house or log building.

The first step is to determine the entry point where the wall is drilled. The hole diameter is determined based on the thickness steel pipe, into which the conductor will be placed. Before stretching the cable, its edges should be carefully processed with a file to remove sharp burrs that could damage the insulation. For additional protection of the cable line, it is better to lay it in corrugation.

After installation, the pipe filling requirements must be met. In this case, you can use an asbestos cord, wrapping it around the cable and driving it tightly into the pipe on both sides. The photo shows wooden wall and laying the power cable through it:

How to conduct electrical wiring through the wall and perform wiring is shown in the photo below:

1. Steel pipe.
2. Distribution box.
3. Asbestos cement lining.
4. Cable channel.
5. Corrugation.
6. Asbestos cement lining.
7. Double socket.

For example, the options for how to route a cable through a brick wall are shown:

The sequence of work is as follows:

1. IN brick wall an opening of the required dimensions is made.
2. A piece of corrugation (sleeve) is inserted into the prepared opening.
3. A heat-shrinkable seal is installed on the pipe.
4. The space between the sleeve and the opening is filled mortar.
5. A cable or wire, previously placed in a corrugated pipe, is passed through the sleeve.
6. The space between the corrugation and the sleeve is sealed with one of the materials that meets the requirements of the rules.
7. By thermal exposure (for example, using a hair dryer), the seal shrinks until the point of entry of the electrical conductor into the sleeve is completely sealed.

If the wall is made of concrete, the technology is the same as for a brick one. The photo below shows an example of laying a cable through a concrete wall:

For industrial use, inflatable cable seal technology is of interest. The seal is an inflatable chamber made of metalized laminate. The cable line is wrapped with a sealant on which a sealant is applied. The chamber is then inflated to fill the passage, after which the helium valve is securely locked. How the passage is filled is shown in the photo:

That's the whole technology of laying cable through a wall made of wood, concrete and brick. As you can see, laying a line through obstacles is not particularly difficult, the main thing is to be familiar with the requirements for electrical installation!

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How and with what can cable passages be sealed and why?

About the company » Questions and answers » How and with what can cable passages be sealed and why?

When constructing new buildings and structures, or when reconstructing old premises for various purposes, the projects must provide for the conditions and requirements for the placement of power supply communications in them. The main governing document is the PUE (electrical installation rules). The employees of our electrical laboratory are well aware of these requirements and have practically fulfilled them more than once. Constantly monitor changes in modern requirements, study additions, SNiPs, GOSTs and others regulations.

The documents detail the requirements, where and how, what cables and wires are laid. The requirements are described and take many factors into account:

• fire safety;
• operating conditions and location of buildings and structures;
• production sector, which involves electrical installations;
• power and maximum current loads;
• types of wires and cables to be laid and many other details.

Basic requirements for cable passages through the wall

Paragraph 2.1.58 of the PUE states that in order to ensure the possibility of laying additional wiring or replacing the old one, cables and wires through the walls are laid in boxes or pipe cuttings. To prevent the penetration of fire or water, the gaps between the cable and the pipe are sealed with fire-resistant material, which can be easily removed if necessary. The fire resistance of the filler must be no lower than the fire resistance of the wall in which the cable passes.

Sections of SNiP 3.05.06-85 clarify many individual details and expand the capabilities of performers; the content names specific materials used to seal cable passages. In addition, it determines specific cases that through walls made of combustible material, pipes in passages must be metal or asbestos. Examples of the composition and proportion of the sealing mass for sealing cable passages are given:

• 1:10 cement and sand;
• 1:3 clay and sand;
• 1.5:11:1 clay-sand and cement;
• 2:1 gypsum and expanded perlite, other options;
• Red foam with fire safety certificate.

The gaps between the sleeves for cable passage and the wall are sealed with cement mortar or concrete. In cases where the walls are not a fire barrier, these gaps do not need to be sealed. When organizing cable passages through ceilings and walls, provision must be made for laying backup pipes, metal, asbestos or plastic, depending on the conditions. In addition to pipe cuttings, industrially manufactured sleeves are used for transitions of cables and wires different diameters through the walls. Nuclear power plants use special sealed devices. These structures contain plates with grooves for different cable diameters.

Employees of construction companies or managers of organizations that operate buildings cannot always correctly navigate the implementation of many requirements. It is especially important to fulfill the requirements efficiently and with minimal costs, choose best option and materials for sealing gaps in cable passages, taking into account the conditions at your facility.

Thanks a lot practical experience and knowledge, technical support at a high level, the electrical laboratory can conduct high-quality tests. Our employees will tell you how, with what and why you need to seal the passages for cables, in each specific case, they will help you practically and arrange everything Required documents for the work done.

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Open electrical wiring indoors / PUE 7

2.1.52. Open laying of unprotected insulated wires directly on bases, on rollers, insulators, on cables and trays should be carried out: ¶

1. For voltages above 42 V in rooms without increased danger and for voltages up to 42 V in any rooms - at a height of at least 2 m from the floor or service area. ¶

2. For voltages above 42 V in high-risk and especially dangerous areas - at a height of at least 2.5 m from the floor or service area. ¶

These requirements do not apply to descents to switches, sockets, starting devices, panels, lamps installed on the wall. ¶

In industrial premises, descents of unprotected wires to switches, sockets, devices, panels, etc. must be protected from mechanical influences to a height of at least 1.5 m from the floor or service area. ¶

In domestic premises industrial enterprises, in residential and public buildings, the specified slopes may not be protected from mechanical influences. ¶

In rooms accessible only to specially trained personnel, the height of openly laid unprotected insulated wires is not standardized. ¶

2.1.53. In crane spans, unprotected insulated wires should be laid at a height of at least 2.5 m from the level of the crane trolley platform (if the platform is located above the crane bridge deck) or from the crane bridge deck (if the deck is located above the trolley platform). If this is not possible, then protective devices must be installed to protect personnel on the trolley and crane bridge from accidentally touching the wires. Safety device must be installed along the entire length of the wires or on the crane bridge itself within the location of the wires. ¶

2.1.54. The height of open laying of protected insulated wires, cables, as well as wires and cables in pipes, boxes with a degree of protection not lower than IP20, in flexible metal hoses from the level of the floor or service area is not standardized. ¶

2.1.55. If unprotected insulated wires intersect with unprotected or protected insulated wires with a distance between the wires of less than 10 mm, then additional insulation must be applied to each unprotected wire at the intersection points. ¶

2.1.56. When crossing unprotected and protected wires and cables with pipelines, the clear distance between them must be at least 50 mm, and with pipelines containing flammable or flammable liquids and gases - at least 100 mm. When the distance from wires and cables to pipelines is less than 250 mm, wires and cables must be additionally protected from mechanical damage for a length of at least 250 mm in each direction from the pipeline. ¶

When crossing hot pipelines, wires and cables must be protected from high temperatures or must be designed accordingly. ¶

2.1.57. When laying parallel, the distance from wires and cables to pipelines must be at least 100 mm, and to pipelines with flammable or flammable liquids and gases - at least 400 mm. ¶

Wires and cables laid parallel to hot pipelines must be protected from high temperatures or must be designed accordingly. ¶

2.1.58. In places where wires and cables pass through walls, interfloor ceilings or where they exit outside, it is necessary to ensure the possibility of changing electrical wiring. To do this, the passage must be made in a pipe, duct, opening, etc. In order to prevent the penetration and accumulation of water and the spread of fire in places of passage through walls, ceilings or exits to the outside, the gaps between wires, cables and the pipe (duct, opening) should be sealed etc.), as well as backup pipes (ducts, openings, etc.) with an easily removable mass from non-combustible material. The seal must allow replacement, additional installation of new wires and cables and ensure the fire resistance limit of the opening is not less than the fire resistance limit of the wall (floor). ¶

2.1.59. When laying unprotected wires on insulating supports, the wires must be additionally insulated (for example, with an insulating pipe) in places where they pass through walls or ceilings. When these wires pass from one dry or wet room to another dry or wet room, all wires of one line can be laid in one insulating pipe. ¶

When passing wires from a dry or damp room to a damp one, from one damp room to another damp one, or when wires exit a room outside, each wire must be laid in a separate insulating pipe. When leaving a dry or damp room into a damp or outside building, wire connections must be made in a dry or damp room. ¶

2.1.60. On trays, supporting surfaces, cables, strings, strips and other supporting structures, it is allowed to lay wires and cables close to each other in bundles (groups) various shapes(for example, round, rectangular in several layers). ¶

The wires and cables of each bundle must be fastened together. ¶

2.1.61. In boxes, wires and cables can be laid in multilayers with an ordered and random (scattered) mutual arrangement. The sum of the cross-sections of wires and cables, calculated by their outer diameters, including insulation and outer sheaths, should not exceed: for blind boxes, 35% of the clear cross-section of the box; for boxes with openable lids 40%. ¶

2.1.62. Permissible long-term currents on wires and cables laid in bundles (groups) or multilayered must be taken taking into account reduction factors that take into account the number and location of conductors (cores) in the bundle, the number and mutual arrangement bundles (layers), as well as the presence of unloaded conductors. ¶

2.1.63. Pipes, ducts and flexible metal hoses of electrical wiring must be laid so that moisture cannot accumulate in them, including from condensation of vapors contained in the air. ¶

2.1.64. In dry, dust-free rooms, in which there are no vapors and gases that negatively affect the insulation and sheath of wires and cables, it is allowed to connect pipes, ducts and flexible metal hoses without sealing. ¶

The connection of pipes, ducts and flexible metal hoses to each other, as well as to ducts, electrical equipment housings, etc. must be done: ¶

• in rooms that contain vapors or gases that negatively affect the insulation or sheathing of wires and cables, in outdoor installations and in places where oil, water or emulsion can get into pipes, boxes and hoses - with a seal;
• boxes in these cases must have solid walls and sealed solid covers or blind ones, detachable boxes must have seals at the joint points, and flexible metal hoses must be sealed;
• in dusty rooms - with sealing of connections and branches of pipes, hoses and boxes to protect against dust.

2.1.65. The connection of steel pipes and boxes used as grounding or neutral protective conductors must comply with the requirements given in this chapter and Ch. 1.7. ¶

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Is it permissible to lay a cable along wooden walls in a country house and secure it with brackets? | Elcomelectro

About the company » Questions and answers » Is it permissible to lay a cable along wooden walls in a country house and secure it with brackets?

No, it is not permissible to lay and fasten the cable openly, on a combustible base, which includes wood.

PUE clause 2.1.32. When choosing the type of electrical wiring and the method of laying wires and cables, electrical safety and fire safety requirements must be taken into account. PUE clause 2.1.37. When laying open protected wires (cables) with shells made of combustible materials and unprotected wires, the clear distance from the wire (cable) to the surface of bases, structures, parts made of combustible materials must be at least 10 mm. If it is impossible to ensure the specified distance, the wire (cable) should be separated from the surface by a layer of fireproof material protruding from each side of the wire (cable) by at least 10 mm. PUE clause 2.1.38. At hidden gasket protected wires (cables) with sheaths made of combustible materials and unprotected wires in closed niches, in voids building structures(for example, between the wall and the cladding), in furrows, etc. With the presence of combustible structures, it is necessary to protect wires and cables with a continuous layer of fireproof material on all sides. PUE clause 2.1.39. When laying pipes and ducts made of non-combustible materials openly on non-combustible and non-combustible bases and structures, the clear distance from the pipe (duct) to the surface of structures and parts made of combustible materials must be at least 100 mm. If it is impossible to ensure the specified distance, the pipe (box) should be separated on all sides from these surfaces by a continuous layer of fireproof material (plaster, alabaster, cement mortar, concrete, etc.) with a thickness of at least 10 mm. PUE clause 2.1.40. When laying pipes and ducts made of non-combustible materials hidden in closed niches, in voids of building structures (for example, between a wall and cladding), in furrows, etc. pipes and ducts should be separated on all sides from the surfaces of structures and parts made of combustible materials by a continuous layer of non-combustible material with a thickness of at least 10 mm. PUE clause 2.1.41. When crossing short sections of electrical wiring with elements of building structures made of combustible materials, these sections must be made in compliance with the requirements of 2.1.36-2.1.40.

PUE clause 2.1.58. In places where wires and cables pass through walls, interfloor ceilings or where they exit outside, it is necessary to ensure the possibility of changing electrical wiring. To do this, the passage must be made in a pipe, box, opening, etc. In order to prevent the penetration and accumulation of water and the spread of fire in places of passage through walls, ceilings or exits to the outside, gaps between wires, cables and pipes (ducts, openings, etc.), as well as backup pipes (ducts, openings, etc.) should be sealed. .p.) easily removed mass from fireproof material. The seal must allow replacement, additional installation of new wires and cables and ensure the fire resistance limit of the opening is not less than the fire resistance limit of the wall (floor).

When laying any communications, cable penetrations must be constructed - products, prefabricated structures that are designed for the passage of cables, pipelines, communication lines through walls and partitions. Their main purpose is to prevent fire from spreading into adjacent rooms through flammable materials. They are arranged on the basis of SP 2.13130.2009 and GOST R 53310-2009. Their installation is mandatory and regulated by Federal Laws.

Fire compartments and cable penetrations

According to the requirements, during the construction of buildings residential buildings they are divided into fire compartments, which block fire and smoke on their territory and prevent them from spreading beyond the compartment. However, utility lines pass through any room, which violate the integrity and tightness of the fire section. In order to maintain the fire resistance limits of the structure and penetration.

A striking example that proves the need to install such structures is the fire at the Ostankino TV tower in 2000. Here, telecommunication lines were placed in a vertical shaft, without dividing it into fire compartments and laying protective passages. As a result, the fire quickly spread throughout the building.

Design of cable penetrations

The simplest cable penetration is a metal sleeve embedded in a wall or partition. A cable or pipeline passes through the sleeve, the outer diameter of which is slightly smaller than the diameter of the fire protection structure. The gap between the communication line and the inner wall of the sleeve is filled with tow, thoroughly soaked in fat. That is why the simplest cable penetrations are also called glands. Also, along with or instead of tow, asbestos, rubberized rings, and special packings can be used.

At industrial facilities and power plants, slightly different structures are installed. They are two ends of which are connected by sleeves. To seal the gap between communications and internal walls, special diaphragms and washers are used. One such cable penetration is used to pass several utility lines.

Sealing materials

To create the possibility of laying an additional or replacing an old utility line, all other communications pass through the walls in boxes or trims metal pipes(sleeves). Therefore, the sealing of cable penetrations must be made of fire-resistant, water- and gas-tight material that is easy to remove.

In this case, the ability of the embedding to resist fire should be no lower than the fire-resistant ability of the wall.

SNiP 3.05.06-85 specifies specific mixtures that can be used to fill the gap between the cable and the penetration:

• cement-sand mixture in a ratio of 1:10;
• composition of clay and sand with a material ratio of 1:3;
• sealing mass of clay, sand and cement (1.5:11:1);
• gypsum and taken in a ratio of 2:1;
• other materials that meet fire safety requirements.

Cable penetrations are also allowed to be sealed construction foam, if it is certified in accordance with the requirements of GOST R 53310-2009. Gaps in the walls do not need to be filled if the partitions are not fire barriers.

Modular penetrations

IN modern construction Modular penetrations are used to isolate fire compartments. They are steel or plastic frames, which are equipped with blind inserts or modules with holes. To protect against electromagnetic radiation, copper gaskets are installed. The tightness is created by tension bolts.

IN general view modular cable penetrations for fire protection are complex design, assembled on site from prefabricated sealing inserts made of a polymer that is difficult to burn. Elements made of galvanized high-grade steel are used as fastenings.

In this penetration, the cable is placed in a special sealing module and crimped with an adapter for increased tightness. When the tension bolts are screwed in, the sealing inserts are compressed, tightly compressing the cable and ensuring gas- and water-tightness of the penetration.

Features of installation of cable penetrations

Installation of penetrations has its own characteristics, which depend on the type of material load-bearing structure. Thus, when laying cable systems in monolithic concrete buildings, fire-resistant structures are laid directly into the formwork before pouring the concrete mixture. When constructing prefabricated monolithic buildings, penetrations are laid into blocks at the factory during their manufacture.

In brick houses, for installation, cable systems are placed in special channels - grooves. In finished monolithic buildings, small holes are drilled with a diamond drill. The diameter of the penetration is calculated separately. During construction or temporary operation of a building, penetrations are made of special fireproof cushions.

Cable Penetration Testing

Depending on the location of operation, cable penetrations must meet established requirements. Thus, when they are installed at nuclear power plants, they must be tested for their ability to absorb, insulate or reflect radiation.

At ordinary construction sites, universal cable penetrations are tested by heating, force (mainly on bending resistance), as well as fire resistance, water and gas insulation properties.

Is fire-resistant foam in cable penetrations a crime or a blessing?

Communicating with electrical equipment installers from different regions Russia, I was surprised to learn that almost all of them, when laying power or low-current cable lines through fire barriers (walls, partitions, etc.), use fire-resistant polyurethane foam for sealing. To my questions “WHY?”, they answer that everyone does it, and it’s “FIRE RESISTANT”, and there’s even a certificate, and it’s more convenient to work with it……foamed it and that’s it…. And no one has answered how this is regulated.

Let's figure it out. What does the legislation say about this?

Federal Law of July 22, 2008 No. 123-FZ " Technical regulations on fire safety requirements." Article 137. Fire safety requirements for building structures.
clause 4. Nodes of intersection of enclosing building structures with cables, pipelines and others technological equipment must have a fire resistance rating not lower than the required limits established for these structures.

SP 2.13130.2012 “Systems fire protection. Ensuring the fire resistance of protected objects.”
clause 5.2.4 The intersections of building structures with regulated fire resistance limits of cables, pipelines, air ducts and other technological equipment must have a fire resistance limit not lower than the limits established for the structures being crossed. The fire resistance limits of intersections (penetrations) are determined according to GOST 30247, GOST R 53299, GOST R 53306, GOST R 53310.

SP 76.13330.2016 “Electrical devices. Updated version of SNiP 3.05.06-85"
clause 5.25 After execution electrical installation work the general contractor is obliged to seal holes, grooves, niches and nests, ensuring the rated fire resistance limit of the intersecting enclosing structure.

PUE 7. “Rules for electrical installations.” Edition 7. Section 2. Electricity sewerage. Chapter 2.1. Electrical wiring
clause 2.1.58. In places where wires and cables pass through walls, interfloor ceilings or where they exit outside, it is necessary to ensure the possibility of changing electrical wiring. To do this, the passage must be made in a pipe, duct, opening, etc. In order to prevent the penetration and accumulation of water and the spread of fire in places of passage through walls, ceilings or exits to the outside, the gaps between wires, cables and the pipe (duct, opening) should be sealed etc.), as well as backup pipes (ducts, openings, etc.) with an easily removable mass from non-combustible material. The seal must allow replacement, additional installation of new wires and cables and ensure the fire resistance limit of the opening is not less than the fire resistance limit of the wall (floor).

GOST R 53310-2009 “Cable penetrations, sealed entries and busbar penetrations. Fire safety requirements. Test methods for fire resistance".
4.1 Cable penetrations, sealed entries and busbar penetrations made in enclosing structures with standardized fire resistance limits or fire barriers must have a fire resistance limit not lower than the fire resistance limit of the structure being crossed.
4.2 The design of the penetrations must provide the possibility of replacing and (or) additional laying of wires and cables, and the possibility of their maintenance.

And so on….. It is not stated anywhere exactly what materials should be used. Accordingly, fire-resistant polyurethane foam “seems to be suitable” in terms of parameters.
This is where the main mistake is immediately revealed!!!
SP 2.13130.2012 says The fire resistance limits of intersection nodes (penetrations) are determined according to GOST 30247, GOST R 53299, GOST R 53306, GOST R 53310. Cable penetrations include GOST R 53310. What is cable penetration?
cable penetration: a structural element, product or prefabricated structure intended for sealing cable passages through enclosing structures with rated fire resistance limits or fire barriers and preventing the spread of fire into adjacent rooms within a regulated time. Cable penetration includes cables, embedded parts (ducts, trays, pipes, etc.), sealing materials and prefabricated or structural elements.

All fire resistant foam tested according to GOST 30247.1-94 for fire resistance, as well as according to GOST 30244-94, 30402-96, 12.1.044-89 to determine properties fire danger materials. The question is, why can’t we test fire-resistant foam in accordance with GOST 53310 and safely use it when sealing cable passages? It's all about the properties of the foam itself. Firstly: fire-resistant foams have the same flammable (polyurethane foam) base as regular ones. mounting foams. It acquires fire resistance due to special fire-retardant fire-resistant and flame-retardant additives. Those. When exposed to flame, the foam will melt, but not burn. And secondly, she is also afraid of UV radiation, from which it is destroyed. To protect it, it is plastered or sealed with special sealants.

The biggest problem with fire-resistant foam when sealing cable penetrations is that when the cable burns, it melts around it, and, accordingly, a hole is formed through which smoke and fire spread into adjacent rooms.

According to GOST 53310, tests are carried out according to three indicators of limit states - this is loss thermal insulation ability sealing material (I), loss of integrity of the sealing material (E) and achievement critical temperature heating the material of the product elements (T). The designation of the fire resistance limit of the penetration consists of symbols normalized limit states and a figure corresponding to the time to reach one of these states (the first in time) in minutes. The fire resistance limit must correspond to one of the following numbers: 15, 30, 45, 60, 90, 120, 150, 180, 240, 360.

Numerous inspections and tests have shown that without the use of additional measures and protective equipment, fire-resistant foam in cable penetrations cannot provide the required fire resistance limits, except perhaps only the very minimum.

Based on all of the above, it can be argued that fire-resistant foams cannot be used when sealing cable penetrations, because they are not tested according to GOST 53310. It is not economically profitable to test and certify according to GOST 53310 without additional protection. And finally, when additional measures and protective equipment are used, the complexity and cost increases many times.

We all must understand that during a fire, every minute is important to save people, and due to dishonesty or simple ignorance of the requirements, people can die. Use cable penetration sealing systems that comply with the regulatory and technical documentation in the field of fire safety. Don't break the law. Take care of people!!!

The material was prepared by D.P. Ovchinnikov, Development Director, ANGTS for PB Ogneza LLC.

Cable penetration - 2006

Offered to the attention of readers

the article reflects one of modern trends telecommunications market

in terms of increasing the degree

specializations. The article discusses modern solutions making entries when laying cable systems.

Alexey ZAVISTOVSKY

When constructing cable lines, it is often necessary to make transitions through the external and internal enclosing elements of the building, and when disconnecting cables in distribution devices- insert them into cabinets, cabinets and consoles. In other words, cable penetrations are an integral and full part of any cable system. Special attention they are confirmed by the fact that the production of these components even constitutes a separate branch in the cable and wire industry. Today on the market there is a number of advanced solutions in this area, optimal from the point of view of installing cable routes.

At the same time, despite the obvious progress of input and cable technology, new materials and developments have not yet become widespread in the domestic practice of installers. Moreover, designers and installers are not even always aware of these solutions, and penetrations are often carried out using traditional methods, the old fashioned way. Without pretending to comprehensively cover the extremely broad subject of input cable technologies, this review is intended to acquaint specialists with the main directions of development of products of this class, as well as with specific input equipment already available on the Ukrainian market. Let’s make a reservation right away: in the author’s field of view there are only products that are ready to be installed independently, and not as part of any devices.

The phenomenon of “penetrations” in standards

There are probably no such people who are against standards, because in fact, any official documents establish the minimum characteristics necessary to create a system at all stages - from design to installation. Cable penetrations, which are prescribed in the regulatory documents of most industries, are no exception. Such increased attention to the “entry point” is explained by the special requirements for cable penetration in various fields activities, telecommunications professionals must be knowledgeable and apply numerous industry codes and regulations.

In addition, the use of standards makes it much easier to make decisions on purchased equipment. The author knows from own practice how important it is to select the necessary elements for cable transitions at the design stage; If the products comply with the requirements of the standards, the task is significantly simplified.

One of the most important documents where penetrations are mentioned is PUE (Electrical Installation Rules). We present here the full definition, which, of course, relates more to the power supply network, but is also quite applicable to other cable systems:

« PUE 2.1.58: In places where wires and cables pass through walls, interfloor ceilings or where they exit outside, it is necessary to ensure the possibility of changing the electrical wiring. To do this, the passage must be made in a pipe, box, opening, etc. In order to prevent the penetration and accumulation of water and the spread of fire in places of passage through walls, ceilings and exits to the outside, gaps between wires, cables and pipes (ducts, openings, etc.), as well as backup pipes (ducts, openings, etc.) should be sealed. .p.) easily removable mass of fireproof material. The seal must allow replacement, additional installation of new wires and cables and ensure the fire resistance limit of the opening is not less than the fire resistance limit of the wall (floor).

More detailed information on the established requirements for cable penetrations can be found in the following standards:

SNiP 3.05.06-85 Electrical devices;

ANSI/TIA/EIA-569-A Standard for Telecommunications and Commercial Building Facilities;

OSTN-600-93 Industry construction and technological standards for the installation of structures and communication devices, radio broadcasting and television;

VSN 116-87 Instructions for the design of line-cable communication structures;

VSN 60-89 Communication, signaling and dispatching devices engineering equipment residential and public buildings;

RD 45.162-2001 Complexes of public cellular and satellite mobile communications networks;

DSTU B.V.1.1-8-2003 Cable penetrations. Fire resistance test methods.

Design of penetrations

As we have already discussed, properly designed cable penetrations must meet industry design standards as well as site-specific safety regulations. Meanwhile, achieving this is not so easy. To “shove” a cable bundle, installers usually rack their brains on the spot, inventing penetrations from scrap material. This happens because at the design stage, designers in most cases do not pay due attention to this issue. Scattering on the drawing cable routes, designers see only walls, windows and doors, as a result, entry points appear in the project based on the installation results.

Naturally, with such an approach, organizing penetrations of cable systems does not make sense for several reasons: the influence of the “human factor” (each employee represents the cable entry in his own way), the risk of using unknown or outdated components, etc. As a rule, with such an approach, even the basic parameters of “correct” penetration are not provided:

Permissible bending radius of cables when crossing walls and ceilings;

Reserve capacity of passages for development;

Free access to the penetration on both sides of the wall and ceiling;

Marking of passages (data cable, low current, electrical), both on the plan and on the penetration;

Measures to preserve the characteristics of walls and ceilings (fire resistance);

Correspondence of the location of the penetration with the drawing.

Coordinated timely actions of all subcontractors - ventilation workers, plumbers, etc. - help resolve these issues. After dividing the ceiling or underground space, a separate design document is drawn up for cable penetrations ( rice. 1). The architectural and construction plan indicates the size of the passage, its type, reference to the building plan with a height from the floor.

Such detail in a project is always useful, and in some cases simply necessary, for example: when installation team consists of unskilled workers; when the design is carried out by order of third-party specialized organizations (possibly from another country) or when the entrance to VIP premises is designed.

The importance of a careful approach to the organization of cable entries is emphasized, for example, by the fact that some manufacturers produce software products that allow even a not very trained user to form a penetration. The characteristics of the cables and their quantity are entered into the program, and after that the penetration is completed automatically or manually. The program itself generates all the necessary technical information for installation, in particular, the required size of the opening in the wall for installing the penetration, the external dimensions of the penetration itself ( rice. 2), plus a detailed specification of the required purchasing elements is provided.

When included in cable systems projects modern types input and cable equipment increases the reliability of the system and its maintainability. Let's consider various, most common cases of cable entries

Passage for home, office and production premises

Apartment modern man often plays the role of an office where a lot of communications need to be introduced, for example:

CCTV;

The local network in the front door;

Terrestrial, cable TV;

Telephone communications;

Intercom communication.

Even in new buildings, it is impossible to replace or add cables without destroying them. Therefore, when planning the introduction of subscriber wiring with stairwells In apartments, cables must be laid in hidden wiring channels, in flexible metal or PVC pipes. The transition point from external to internal wiring is located in niche cabinets recessed into the wall. For external wiring, external cabinets are used. Flexible hoses are fixed with seals.

In cottages, depending on local conditions, cables can be supplied to the building in several ways:

a) through a basement, basement or pit;

b) output to outer wall building;

c) from the nearest external pillar.

For underground entry, a small type inspection device can be provided in front of the building. Pipes extending from the inspection device ( rice. 3) and then entering the building are sealed with plugs, glands or cable yarn stuffing (OST 1705-021-90).

Aboveground inputs are made on the wall under the canopy in embedded pipes ( rice. 4). The gaps between pipes and the building structure, as well as between wires and cables laid in pipes, are sealed with easily removable

fireproof materials, for example, cement with sand by volume 1:10, clay with sand 1:3, clay with cement and sand 1.5:1:11.

When laying overhead, outlet pipes (goons - rice. 5).

When it comes to the use of cable penetrations in commercial and industrial buildings, it should be noted that compliance with cabling standards is of critical importance. Firstly, construction companies realize that when deploying any cabling systems, you need A complex approach oriented towards a demanding client. Secondly, customers representing certain industries put forward their own intra-industry requirements for penetrations - this is protection from fire, smoke, rodents, radiation, explosions, gases, noise, dust, as well as operational requirements. Accordingly, such projects must use the most modern cable entry solutions.

Fire resistance is considered one of the most important characteristics of cable penetrations at industrial facilities. Commissioning of any building is impossible without the conclusion of a fire department commission, therefore cable passages must meet the fire resistance limit ( table 1) fire barrier. Even if the passage is relatively simple, and the wall is not a fire barrier, it is still recommended to create a barrier every 20 m to prevent the spread of fire at the entry point.

Fire resistance is named the first characteristic in terms of importance, but in some production conditions other parameters may come to the fore, for example, protection against water penetration. It is known, for example, that the real scourge of underground cable communications is flooded wells. However, thanks to proper design of cable glands, this problem can be successfully combated.

And in all cases great importance It has right choice specialized equipment and materials corresponding to the type of facility and industry standards. But there is a choice on the Ukrainian market: today several companies already offer similar products, technical consultations and installation services ( table 2)

Types of cable penetrations and materials

The range of products for organizing transitions is very diverse, so in our review we will focus only on the most common materials and devices.

The method of sealing passages has become widespread

fire-fighting foam, which is a low-flammable building material.

The foam is more technologically advanced compared to the above compositions based on sand, cement and clay, moreover, they are fire resistant and do not swell ( rice. 6). It is usually applied on one side of the transition assembly and is intended for sealing single and multiple vias with obstacles to access.

Another, very inexpensive way sealing passages - use fireproof paint and putty , which do not harden or dry out, but under the influence of fire expand and turn into charred material - a gray-black crust. This crust prevents the penetration of hot toxic gases and flames. When installing in an opening, they are pre-installed on both sides mineral wool slabs and then covered with putty. These materials are excellent for filling transitions of various configurations and sizes, as well as transitions where there is a possibility of movement of building structures. It is important to add that the use of mineral wool boards is not accidental, because Compared to conventional heat-insulating materials, this material is made of a special composition that can withstand temperatures above 1000 0 C without melting ( rice. 7).

When organizing inputs using PVC pipes, a high level of fire protection is provided fireproof cuffs . This device is a ring with stripes inside made of a material with a high degree of swelling. The cuff is equipped with tabs for attaching to a wall or floor ( rice. 8a) and comes in different diameters. In case of fire, it compresses the pipe and blocks the passage ( rice. 8b). To achieve the required fire resistance limit, it can be used in conjunction with putty.

The above methods of organizing inputs are undoubtedly used by installers more often, but they have one drawback in common - difficulties with ongoing operation, for example, with laying new lines, which usually leads to the destruction and subsequent restoration of penetrations. In addition, these solutions are not very suitable for very wide transitions where insulating pipes, trays and cable harnesses accumulate. These problems can be solved by other types of cable penetration products also on the market.

A good remedy In particular, fire protection cushions or cable penetrations based on modular seals are considered. When installing new lines, the cushions and modular seals can be easily removed and rebuilt. It is also important that their installation and dismantling is not accompanied by any contamination, so they can be used in rooms with high requirements for cleanliness, for example, in telecommunications areas or computer rooms.

Fireproof pillows (rice. 9) are a cover made of specially treated fiberglass, filled with a granulate composition. When exposed to fire, the cushion expands to almost double its original volume, and then hardens and provides a complete seal, keeping fire and smoke out. In addition, it is a very good insulating material.

Modular seals (rice. 10) began to be used in our country relatively recently. This is the most expensive technology, but it opens up the widest possibilities when working on a project and provides guaranteed quality of cable sealing in the passage. Today, this type of penetration is used in all areas of industry, especially where there are increased requirements for reliability.

On the Ukrainian market, penetrations based on modular seals are today represented by products of three companies: Roxtec, HAWKE, TVD.

For all manufacturers, the modular penetration consists of three main parts. Firstly, this frames(rice. eleven), which can be embedded in the wall, bolted or welded to a metal surface. They can be made of different materials: stainless steel, galvanized, polymer, and can also be dismountable or solid. For example, a collapsible frame is convenient when the cables are already laid. Manufacturers offer frames of rectangular or round shape (for pipes in sewers), and can also produce them according to individual customer sizes.

Actually sealing modules, the second structural element, consist of two halves and a core made of a rubber-like, elastic material with a flame retardant and low smoke production. When installed, they fit tightly to pipes and cables, providing protection from fire, water, gas, pressure and vibration. Special versions have been developed for protection against electromagnetic interference (EMC) and for use in hazardous areas (EEx).

The hole diameter can vary from 3 to 100 mm. The design of sealing modules may differ between different manufacturers. For example, the HAWKE company produces a set of modules with a fixed diameter corresponding to a specific cable. The internal surface of HAWKE modules is transversely corrugated, which ensures a tight fit of the cable during installation ( rice. 12).

The Roxtec solution allows you to change the diameter of the same module due to a multilayer design (Roxtec proprietary technology - “Multi-Diameter”). Depending on the dimensions of the cable, the diameter is selected by removing the rubber layer ( rice. 13). At the same time, the “original” Roxtec modules themselves are also available in different diameters.

Note that each of these solutions has its own advantages, and their choice largely depends on specific tasks.

Another element without which cable penetration with modular seals is impossible is compression block (rice. 14). After installing all the cables into the penetration, the compression block, using a special mechanism (each company has a different mechanism), compresses the modules in the frame. The operating principle is based on a wedge-shaped spacer, which is adjusted by bolts ( rice. 15).

Concluding the conversation about penetrations based on modular seals, it is impossible not to mention domestic products of this type. Similar devices for hermetically sealed cable entry - UGVK-1 ( rice. 16) and UGVK-2 (collapsible and non-collapsible, respectively) - produced by the Ukrainian-Czech enterprise TVD.

Specialized input and cable equipment

The input and cable equipment and materials described above are used mainly in the construction of construction projects. However, there is a whole range of specialized products that are also in demand, but focused on narrower tasks. They are used mainly in the design of devices and apparatus, and can also be used when organizing a single input, when there is no need to purchase a large penetration.

These include, for example, feed-through cable clamps (glands, rice. 17), or “cable glands”, which are used when removing cables for video cameras, ATM power cords, various sensors from walls, cases and furniture. They are installed in a wall or metal partition, and their main purpose is still the same - cable fixation and protection according to the IP index.

On rice. 18 Other, most diverse devices from the family of cable glands are also presented. These products are also used for cable entry into various equipment and are designed to perform a variety of tasks: adjusting the dimensions of the entry (for example, a Rittal sealed cable gland), protecting the cable from adverse conditions, from chafing on sharp edges of planes (edges, bushings), and also allow pulling cables with already installed connectors (furniture inputs).

Here I would like to draw special attention to special device for hermetic input, so-called. "separation seal". And that's why. If you are lucky enough to create cable system in hazardous production, you will have to strictly follow all industry rules for cable penetrations without exception. And here the most correct approach is to combine the efforts of electricians and low-current workers to ensure a single entry of cables into the hazardous area. In this case, there is a ready-made instruction for electricians on the use of separation seals (the latest edition of DNAOP 0.00-1.32-01, replacing the 7th section of the PUE), which also covers the requirements for laying low-voltage circuits.

The technology for installing separation seals can be found in VSN 332-74.

Concluding the first specialized review on cable input equipment, I would like to express the hope that all the innovations in this area will very soon enter into installation practice. And here I cannot resist giving advice to specialists: if you are going to use penetrations at domestic facilities, you need to choose from products that have a Ukrainian certificate. These nodes are very critical, and there are special requirements for them.

Alexey ZAVISTOVSKY,

design engineer

network department

and telecommunications,

"Saturn Data International"

And cable lines, you often have to solve the problem of how to route a wire or cable through the outer walls of buildings and internal partitions. There are many requirements for the passage of electrical conductors through obstacles, and it is very important to comply with each of them, because this affects not only the ease of repair and replacement of wiring, but also the safety of its use. In this article we will tell you how to lay cables through a wall made of wood, brick and concrete in accordance with the requirements of regulatory documents.

Gasket requirements

The requirements for this type of work are regulated by two main regulatory documents. The first source is one that should always be consulted when it comes to electrical installations. The passage of cables through walls is discussed in various paragraphs, for example in paragraph 2.1.58. The second document is SNiP 3.05.06-85 (in clause 3.18), which describes the standards for the construction and installation of electrical devices. Information on this issue is also contained in the Federal Law of July 22, 2008 N 123-FZ
“Technical Regulations on Fire Safety Requirements”, Article 82, which formulates fire safety requirements.

To carry out construction and installation work, it is necessary to have an appropriate project. If it is intended to lay a cable or wire through walls, the project must contain an architectural and construction part. The openings that a wall or partition must have through which wires and cables are supposed to be laid must be indicated on the project drawings.

Openings (openings) made in accordance with the design in walls, partitions, ceilings and foundations should not be framed by weakened areas that may collapse during operation. In general, cable routing through walls must meet the following requirements:

• the laying must provide the ability to replace wires and cables during operation.
• When installing wiring, it must be ensured that fire, smoke and moisture cannot spread through the installation openings from one room to another.

Compliance with these conditions is ensured by observing the following rules:

1. Laying of cables and electrical wiring through fireproof walls and ceilings is carried out in pipes, ducts or directly in openings. At the same time, only protected (armored) cable can be laid in openings, without the use of additional protection. We talked about this in a separate article.
2. If the wall, partition or ceiling is made of combustible material, conductor products are laid in steel pipes.
3. The space between the wires and pipes or boxes, as well as all backup openings and boxes, are sealed. We also talked about that.

The material used to seal openings must be easily removable if necessary. The fire resistance of the sealant cannot be inferior to the fire resistance of the wall, partition and ceilings. Sealing using sealing material is carried out on both sides of pipes, ducts, and openings.

If the cable passes through the wall in a section of pipe, its bending radius, if any, should not exceed the permissible bending radius of the conductor grade used (this parameter is indicated in the technical specifications).

Installation technology

First, let's look at how to pass a power cable or wire through the wall of a wooden house or log building.

The first step is to determine the entry point where the wall is drilled. The diameter of the hole is determined based on the thickness of the steel pipe in which the conductor will be placed. Before stretching the cable, its edges should be carefully processed with a file to remove sharp burrs that could damage the insulation. For additional protection of the cable line, it is better to lay it in corrugation.

After installation, the pipe filling requirements must be met. In this case, you can use an asbestos cord, wrapping it around the cable and driving it tightly into the pipe on both sides. The photo shows a wooden wall and laying a power cable through it:

How to conduct electrical wiring through the wall and perform wiring is shown in the photo below:

1. Steel pipe.
2. Distribution box.
3. Asbestos cement lining.
4. Cable channel.
5. Corrugation.
6. Asbestos cement lining.
7. Double socket.

For example, the options for how to route a cable through a brick wall are shown:

The sequence of work is as follows:

1. An opening of the required size is made in the brick wall.
2. A piece of corrugation (sleeve) is inserted into the prepared opening.
3. A heat-shrinkable seal is installed on the pipe.
4. The space between the sleeve and the opening is filled with mortar.
5. A cable or wire, previously placed in a corrugated pipe, is passed through the sleeve.
6. The space between the corrugation and the sleeve is sealed with one of the materials that meets the requirements of the rules.
7. By thermal exposure (for example, using a hair dryer), the seal shrinks until the point of entry of the electrical conductor into the sleeve is completely sealed.

If the wall is made of concrete, the technology is the same as for a brick one. The photo below shows an example of laying a cable through a concrete wall:

For industrial use, inflatable cable seal technology is of interest. The seal is an inflatable chamber made of metalized laminate. The cable line is wrapped with a sealant on which a sealant is applied. The chamber is then inflated to fill the passage, after which the helium valve is securely locked. How the passage is filled is shown in the photo:

That's the whole technology of laying cable through a wall made of wood, concrete and brick. As you can see, laying a line through obstacles into an apartment or house is not particularly difficult, the main thing is to be familiar with the requirements for electrical installation!