fire resistant polyurethane foam in cable penetrations is it a crime or a blessing?

Communicating with electrical equipment installers from various regions of 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.), fire-resistant mounting foam is used for sealing. To my questions “WHY?”, they answer that everyone does this, and she is also “FIRE-RESISTANT”, and even has a certificate, and it’s more convenient to work with her ...... foamed and that’s it .... And no one answered how this is regulated.

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

Federal Law No. 123-FZ of July 22, 2008 "Technical Regulations on the Requirements fire safety". Article 137 Fire safety requirements for building structures.
item 4. Crossing points of enclosing building structures with cables, pipelines and other technological equipment must have a fire resistance limit not lower than the required limits established for these structures.

SP 2.13130.2012 "Systems fire protection. Ensuring the fire resistance of objects of protection.
Clause 5.2.4 Crossing points of building structures with standardized fire resistance limits for 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 (passages) 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"
p.5.25 After completion electrical work the general contractor is obliged to seal holes, furrows, niches and nests, ensuring the standardized fire resistance limit of the intersected enclosing structure.

PUE 7. "Rules for the installation of electrical installations." Edition 7. Section 2. Sewerage of electricity. Chapter 2.1. Wiring
clause 2.1.58. In places where wires and cables pass through walls, interfloor floors or their exit to the outside, it is necessary to provide the possibility of changing the 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, gaps between wires, cables and the pipe (duct, opening etc.), as well as reserve pipes (ducts, openings, etc.) with an easily removed mass from fireproof material. The seal must allow replacement, additional laying of new wires and cables and ensure the fire resistance of the opening is not less than the fire resistance of the wall (ceiling).

GOST R 53310-2009 “Cable penetrations, sealed entries and busbar ducts. fire safety requirements. Test methods for fire resistance.
4.1 Cable penetrations, hermetic bushings and busbar ducts 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 crossed structure.
4.2 The design of penetrations should provide the possibility of replacement and (or) additional laying of wires, cables, the possibility of their maintenance.

Well, and so on ... .. It is not written anywhere which materials should be used. Accordingly, the fire-resistant mounting 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 intersections (passages) are determined according to GOST 30247, GOST R 53299, GOST R 53306, GOST R 53310. GOST R 53310 refers to cable penetrations. What is a cable run?
cable penetration: structural element, a product or a prefabricated structure designed to seal the places where cables pass through enclosing structures with standardized fire resistance limits or fire barriers and prevent the spread of combustion to adjacent rooms for a standardized time. Cable penetration includes cables, embedded parts (boxes, trays, pipes, etc.), sealing materials and prefabricated or structural elements.

All fire resistant foams tested in accordance with GOST 30247.1-94 for fire resistance, as well as in accordance with GOST 30244-94, 30402-96, 12.1.044-89 to determine the properties fire hazard materials. The question is why it is impossible to test fire-resistant foam according to 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 combustible (polyurethane foam) base as conventional mounting foams. It acquires fire resistance due to special flame retardant fire-resistant and flame-retardant additives. Those. under the influence of a flame, the foam will melt, but not burn. And secondly, she is also afraid of UV radiation, from which it is destroyed. For protection, it is plastered or smeared with special sealants.

The most a big problem fire-resistant mounting 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 to neighboring rooms.

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

Numerous checks and tests have shown that without the use of additional measures opriya and means of protection, fire-resistant mounting foam in cable penetrations cannot provide the necessary limits of fire resistance, perhaps only the most minimal.

Based on all of the above, it can be argued that fire-resistant mounting foams cannot be used when sealing cable penetrations, because. they are not tested according to GOST 53310. Test and certify according to GOST 53310 without additional protection not economically viable. And, finally, when using additional measures and means of protection, the complexity and cost increase many times over.

We all must understand that during a fire, every minute is important to save people, and because of dishonesty or elementary ignorance of the requirements, people can die. Use systems for terminating cable penetrations that comply with 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 Industrial Security of Ogneza LLC.

Passages through internal and external walls, partitions and intermediate floors must be made in a pipe or opening, which would make it possible to replace the electrical wiring. The passages of unarmoured cables and wires through fireproof walls and interfloor ceilings must be carried out in metal or insulating semi-solid rubber, PVC tubes (uncut) or in segments plastic pipes, and through combustible walls - in insulating tubes enclosed in steel segments. ends metal pipes be sure to end with bushings or funnels. Installation insulating tubes necessary not only to ensure the replacement of wiring, but also to strengthen the insulation of unprotected wires.

Wires with a folded seam (APRF, PRF, PRFl) are allowed to be laid through wooden walls without additional protection.

Passages can be open and closed. open passages wires and cables are carried out in buildings with wooden walls and ceilings. In a brick building, the passage can be made hidden, in a furrow carved into the wall, but not under a layer of plaster.

When preparing passages through walls and ceilings, it is necessary to take into account the environment of the adjoining premises. If the adjoining premises are classified as dry, then the wire in the wall is laid through one hole. When passing from a dry room to a damp, damp or outside, from damp to damp, each wire must be pulled in a separate insulating pipe.

To ensure the flow of water, the holes are made with a slight slope towards a damp, damp room or outside. From the side of the dry room, the hole is framed with an insulating porcelain or plastic sleeve, and from the side of the wet, damp or outside - with a porcelain funnel. Bushings and funnels are smeared with alabaster or cement mortar so that the collar of the sleeve lies firmly on the surface of the wall, and the outlet of the funnel completely comes out of the wall and is directed downwards. The bushings are put on the insulating tube.

The connection of wires when leaving a dry, damp room in a damp or outside building must be carried out in a dry or wet room at the roller or in a junction box installed at the aisle.

To prevent the penetration of water, the spread of fire, open passages of cables and wires through the outer walls of the premises should be sealed with easily removable fireproof materials after laying electrical wiring ( mineral wool, slag, etc.). Funnels on both sides are filled with an insulating compound, such as bituminous mass. Open passages through the internal walls of normal non-explosive and non-flammable premises may not be sealed.

Open passages of wires through interfloor ceilings are made in an insulating tube with protection against mechanical damage to a height of at least 1.5 m. With hidden laying of wires through interfloor ceilings, the wires are passed in insulating tubes, the exits of which are terminated with porcelain funnels.

When making passes through interfloor ceilings, where protection of the wire from mechanical damage is required when it exits to the upper floor, it is forbidden to use wires of the PRD, PRHD brands (in steel pipes these wires are not laid).

When making a passage through the interfloor overlap, single-core insulated wires of the APR, APV, APRV, etc. brands are used. Insulated pipes in the passages should not have breaks along the length and are sealed with the outer edges of the bushings and funnels (they can protrude from them by 4-5 mm). It is forbidden to make passages in wooden walls at the joints between logs.

Intersections of wires and cables are not recommended. AT open wiring when crossing unprotected wires with unprotected or protected insulated wires(with a distance between them of less than 10 mm), additional insulation must be applied to an unprotected wire: a piece of a whole PVC tube is put on it or 3-4 layers of insulating tape are applied.

In brick buildings, wire crossings are carried out hidden in plastered furrows - twisted two-core wires of one of the intersected lines are laid in a furrow, putting an insulating or PVC tube on them. At the points of entry and exit of the wire from the groove, porcelain funnels are put on the insulating tube.

Rice. Pipeline bypass:
1 - wire; 2 - rubber tube; 3 - funnel.

In cases where wiring is carried out with single-core wires, each of them is placed in a separate insulating tube.

Around metal structures buildings, beams, pipes and especially pipelines with hot liquids, condensation and rust can form, which destroy the insulation. Therefore, when crossing protected and unprotected wires and cables with pipelines (Fig. 38), the distance between them must be at least 50 mm, or wires and cables at the intersection must be laid in insulating or metal pipes embedded in the furrow. If the distance from wires and cables to pipelines is less than 250 mm, they should be additionally protected from mechanical damage at a length of at least 250 mm in each direction from the pipeline.

With open parallel laying, the distance of wires and cables, as well as the distance from the hidden laying junction boxes to the pipelines must be at least 100 mm.

When crossing hot pipelines, wires and cables in without fail protect against high temperatures

do not "forget" about the new:
Federal Law of July 22, 2008 N 123-FZ
"Technical regulation on fire safety requirements"
Article 82. Fire safety requirements for electrical installations of buildings, structures and structures
1. Electrical installations of buildings, structures and structures must comply with the class of the fire and explosion hazardous zone in which they are installed, as well as the category and group of the combustible mixture.
2. Cables and wires of fire protection systems, means of ensuring the activities of units fire brigade, fire detection systems, warning and management of people evacuation in case of fire, emergency lighting on evacuation routes, emergency ventilation and smoke protection, automatic fire extinguishing, internal fire water supply, elevators for transporting fire departments in buildings, structures and structures must remain operational in a fire for the time necessary for the complete evacuation of people to a safe area.
3. Cables from transformer substations of backup power sources to input distribution devices must be laid in separate fire-resistant channels or have fire protection.
4. Power supply lines for buildings, structures and structures must have devices protective shutdown, preventing the occurrence of a fire in the event of a malfunction of electrical receivers. Installation rules and parameters of residual current devices must take into account the fire safety requirements established in accordance with this Federal Law.
5. Switchboards must have a design that excludes the spread of combustion outside the shield from the low-current compartment to the power one and vice versa.
6. The wiring of cables and wires from the floor switchboards to the premises must be carried out in channels made of non-combustible building structures or molded fittings that meet fire safety requirements.
7. Horizontal and vertical channels for laying electrical cables and wires in buildings, structures and structures must be protected from the spread of fire. At the places of passage cable channels, boxes, cables and wires through building construction with a rated fire resistance limit, cable penetrations with a fire resistance limit not lower than the fire resistance limit of these structures should be provided.
8. Cables laid in the open must be flame retardant.
9. Emergency lighting fixtures on evacuation routes with autonomous power sources should be provided with devices to test their performance when simulating a power outage. The service life of an autonomous power source must provide emergency lighting on evacuation routes during the estimated time of evacuation of people to a safe area.
10. Electrical equipment without means of fire and explosion protection is not allowed to be used in explosive, explosive and fire hazardous premises of buildings, structures and structures that do not have additional protection measures aimed at eliminating the risk of an ignition source in a combustible environment.
11. Fire-proof electrical equipment is not allowed to be used in explosive and fire-explosive rooms.
12. Explosion-proof electrical equipment may be used in fire hazardous and non-flammable premises, and in explosive premises - provided that the category and group of the explosive mixture in the room correspond to the type of explosion protection of electrical equipment.
13. The rules for the use of electrical equipment, depending on the degree of its explosion and fire hazard in buildings, structures and structures for various purposes, as well as the fire hazard indicators of electrical equipment and methods for their determination, are established by federal laws on technical regulations for these products and (or) regulatory documents on fire security.

In the installation of electrical wiring of an apartment and a house, it is impossible to avoid work on arranging the passage of a cable through a wall. Let's look at regulatory requirements to such works and the practice of their implementation.

But first, we note that in these works, in addition to the normative, there are organizational stage. Since from works this type(dismantling, gating, etc.) a lot of construction debris, you need to think about its disposal in advance.

For the disposal of stone waste from such works, you need to rent special garbage containers. For the disposal of rolled ferrous and non-ferrous metals, it is reasonable to look at a company that buys scrap metal, for example here https://www.metallrutorg.ru/. It will be not only convenient, but also profitable.

Norms for the passage of cable through walls

As expected, the right electrician, first we turn to regulatory documents. We begin the search for information with, electrical installation rules. You can download the PUE from the site.

In the PUE edition 7, we look at the points from 2.1.56 down. Translating an official document into everyday language, we see following rules the passage of wires and cables of electrical wiring through the walls:

• When arranging a passage, it is important to ensure the replacement of electrical wiring in case of repair or replacement (PUE, clause 2.1.58).
• If wiring is carried out with wires, then the passage of wires in the wall must be protected by a pipe, a duct, an electrical corrugated pipe.
• the wiring is carried out by cable, then the passage of the cable through the walls of dry interior spaces can be arranged in the form of an opening, without a duct or pipe.
• the cable passes through the walls of the interior with different humidity or through the wall from the street to the room, for example, entering the power supply into the house, then there are no strict recommendations in the PUE on protecting the cable in the wall passage with a pipe (sleeve). There is an indication of the need to close the gaps between the cables with non-combustible materials that can be easily removed during cable replacement work. This is necessary to close the penetration of water and moisture through the passage.

However, in practice, it is better to protect the passage of the cable through the wall of the house from the street with a pipe (sleeve) firmly fixed to the wall structure and laid with a slope to the street.

In indoor areas apartments and houses, to protect the passage of the cable through the wall, it is obligatory only in wooden houses to enhance fire safety.

Let's sum up the first result

If in practice you need to make a cable pass through a wall in an apartment and house, you need to:

First: If possible, refuse to use wires for electrical wiring and work with cables. If this is not possible, for example, retro wiring with wires on insulators, make a passage in the wall through the sleeve.

Second: Make the cable pass through the wall so that it is easy for you to replace it yourself. This criterion will be sufficient for a correct pass.

Third: Arrange passage through the wall wisely. For example, if you are making hidden (non-replaceable) wiring, then there is no justification for using a sleeve for the passage. Except if the passage is made between two walls with an air gap.

Fourthly: protect all cable passages from the street from moisture penetration. In an apartment, these are power cables for air conditioners; in a house, this is the input of a power cable into the house or the output of a cable to buildings on the site.

How to make a cable pass through a wall in practice

Let's see the practice of work. Let's start with a hole in the wall for wiring in the apartment.

Cable passage through the wall in the apartment

The first problem that arises when drilling a hole in the wall for laying the cable is the existing wiring in the walls. When drilling, it is important not to damage the existing electrical wiring, and also not to hurt possible pipes pipeline.

Special devices or folk methods can help solve this problem. I wrote about the search for hidden wiring with devices. Folk methods I list below:

• First, if you have a radio receiver, tune it to 100 kHz and scan the wall at the location of the future hole. If there are live wires, the receiver should show a background sound.
• Secondly, take a phase determiner (probe). It will show a live wire NOT running deep in the wall.
• Thirdly, for a smartphone, there are programs like "Metall Detector".
• Fourthly, it “hears” the wire in the wall, the hearing aid is in the “phone” mode. Didn't check.

Unfortunately, the proposed technical methods to find concealed wiring not always available. Therefore, we use a simple and reliable visual inspection. For this:

Look at the place of the future passage (hole) for the presence of junction boxes, sockets, switches. Never not drill through holes in the walls on the horizontal and vertical lines for the installation of boxes, sockets, switches, lamps. It is highly likely that the wiring was done according to the rules and the wiring routes were parallel to the floor and corners with standard indents from corners and slopes. About it .

Tool

To drill through holes, you will need, first of all, a puncher with a drill. The length of the drill depends on the thickness of the walls. It must be determined in advance. In the panel share it is 270-350 mm, in the "stalinka" the thickness of the walls can exceed 1 meter.

The diameter of the drill depends on the required hole and wall thickness. The thicker the wall, the larger diameter borax. A reasonable drill diameter is 25-30 mm. However, in the kit you need to have a drill of a smaller diameter of 10-16 mm, below I will explain why.

Stages of work on drilling a through hole

stone wall

Prepare the place of work: there will be a lot of garbage. Wallpaper from the wall at the drilling site, it is better to remove it. If the hole is at a height, the footing must be firm.

Start drilling with a short small diameter drill. This will reduce the crumbling of the concrete or plaster when drilling starts.

On a long drill, make a marker with electrical tape showing the thickness of the wall. He will be needed.

Continue drilling. If you have not warned the neighbors in advance, they are already ringing your doorbell. The sound from your drilling in panel house extends to the entire hallway.

Continue with careful drilling. If you feel the stop of the drill, stop immediately, it is likely that the drill will hit the rebar. The drill will not be able to drill through the panel reinforcement, so the hole must be shifted and started over.

Follow the wall thickness mark on the drill. When 5-7 cm remains to the mark, again change the thick drill (25-30 mm) to the drill 10-16 mm and, if possible, reduce the impact of the perforator.

This technique will avoid falling out of a piece of wall on the opposite side of the passage. After the passage of the drill of the entire wall, you will feel it immediately, go to adjoining room and widen the hole with a larger diameter drill.

If a hole sleeve is required, then the diameter of the pipe for the sleeve should be slightly smaller than the diameter of the hole. It is necessary to hammer the sleeve from the side of the beginning of drilling (!).

wooden wall

You need a wood drill, a simple drill and accuracy.

Drywall partition

If you need to make a cable pass through a plasterboard wall, then:

• Find a place where there are no structural profiles;
• Drill drywall sheets with a simple drill. It's 12-24mm;
• Look there is a heater in the partition;
• If there is insulation and it is soft, pass it with a thin metal rod, such as an awl, to the drywall sheets on the opposite side. Manually rotating the homemade awl, go through the sheets of the Civil Code from the opposite side;
• Expand the hole with a drill to the desired size;
• Insert a sleeve into the hole plastic pipe. In order for the pipe to pass through the insulation, sharpen the edge of the pipe with a file;
• If the insulation is hard, just drill a hole with a long drill bit.

Conclusion

The passage of the cable through the wall in the apartment and the house is quite possible to do with your own hands. The main thing to have right tool be careful and turn off the power to the apartment so as not to get hit by electric shock in case of damage to the wiring. And the puncher needs to be powered from another group or from the (apartment) shield, through the carrying.

The device of passages through walls, overlapping wiring

Passages through internal and external walls, partitions and intermediate floors must be made in a pipe or opening, which would provide the possibility of replacing electrical wiring. The passages of unarmoured cables and wires through fireproof walls and interfloor ceilings should be carried out in metal or insulating semi-solid rubber, polyvinyl chloride tubes (uncut) or in segments of plastic pipes, and through combustible walls - in insulating tubes enclosed in steel segments. The ends of metal pipes must be terminated with bushings or funnels. The installation of insulating tubes is necessary not only to ensure the replacement of wiring, but also to strengthen the insulation of unprotected wires.

Wires with a folded seam (APRF, PRF, PRFl) are allowed to be laid through wooden walls without additional protection.

Passages can be open and closed. Open passages of wires and cables are carried out in buildings with wooden walls and ceilings. If the building is brick, then the passage can be made hidden, in a furrow carved in the wall, but not under a layer of plaster. When preparing passages through walls and ceilings, it is necessary to take into account the environment of the adjoining premises.

If the adjoining premises are classified as dry, then the wire in the wall is laid through one hole. When passing from a dry room to a damp, damp or outside, from damp to damp, each wire must be pulled in a separate insulating pipe.

To ensure the flow of water, the holes are made with a slight slope towards a damp, damp room or outside. From the side of the dry room, the hole is framed with an insulating porcelain or plastic sleeve, and from the side of the wet, damp or outside - with a porcelain funnel. Bushings and funnels are smeared with alabaster or cement mortar so that the collar of the bushing lies tightly on the wall surface, and the outlet of the funnel completely comes out of the wall and is directed downwards. The bushings are put on the insulating tube.