MINISTRY OF ENERGY AND ELECTRIFICATION OF THE USSR

REGULATIONS
FULFILLMENT OF FIRE REQUIREMENTS
BY FIRE-RESISTANT SEAL
CABLE LINES

RD 34.03.304-87

The validity period is set from 01.01.88 to 01.01.98

DEVELOPED: by the Department of Fire Safety, Paramilitary Security and Civil Defense and V.O. "Soyuzelektromontazh" Ministry of Energy of the USSR

PERFORMERS: Zamyslov D.A., Skorikov V.V. (Department of fire safety, VOKhR and GO)

Korshunov S.E. (Trust "Elektrotsentrmontazh") Poedintsev I.V. (VNIIPO USSR Ministry of Internal Affairs)

APPROVED: USSR Ministry of Energy and Electrification 12/18/87

Deputy Minister S.I. Sadovsky

These Rules have been developed on the basis of operating experience, separate current directives of the USSR Ministry of Energy and regulatory documents on fire safety, as well as fire tests conducted at VNIIPO of the USSR Ministry of Internal Affairs to study fire-resistant seals (penetrations) from various materials for cable lines and accepted recommendations on this issue.

The rules define the basic requirements for project documentation, organization of installation work and the implementation of fire-resistant penetrations of cable lines to prevent the penetration of fire hazards through building structures, as well as localize a fire in a limited compartment of a given fire zone and reduce damage if it occurs.

With the release of these Rules, the "Guidelines for the development of project documentation in terms of ensuring fire safety of the cable industry during construction and installation work" and "Temporary fire safety requirements for construction, installation and commissioning work in the cable industry" (Order of the USSR Ministry of Energy of April 23 .84 No. 156 chipboard).

1. GENERAL REQUIREMENTS

1.1. The rules are subject to obligatory compliance with the development of project documentation, the performance of construction and installation, repair and maintenance work in the cable industry of power plants, substations and in auxiliary buildings and structures, as well as when laying cable lines at other facilities of the USSR Ministry of Energy.

1.2. Construction and installation work in cable structures should be carried out in accordance with the design documentation issued for production, as well as in the scope of the construction organization project (COS) and the production work project (PPR). The specified design documentation and organization of work should provide for the advanced installation of a fixed fire extinguishing installation in cable structures before the start of laying cable lines.

1.3. Scheme of water supply for the installation of fire extinguishing cable structures before putting it into permanent operation, i.e. for the period of laying cables, must provide the necessary water pressure, as well as manual control of shut-off valves until the complex testing of process equipment.

1.4. By order of the construction management, the installation organization and the directorate of the enterprise, responsible persons for the fire-prevention condition of specific buildings, structures and premises under construction, as well as for the operation of the installed fire extinguishing installations, should be appointed.

1.5. Acceptance of the building part of the premises and cable structures for the installation of equipment and structures should be carried out by commissions with the preparation of an appropriate act, presentation of executive documents for foundations, supports, building and electrical structures and embedded elements, as well as with the implementation of the required level of cleanliness, finishing, waterproofing, ensuring normal temperature and humidity conditions in the premises and with the mandatory installation of a fire extinguishing installation (if it is provided for in accordance with the current norms of the document).

1.6. The personnel of the customer, general contracting and subcontracting organizations during construction, installation, commissioning and repair work must comply with the Fire Safety Rules when performing construction and installation work at the facilities of the USSR Ministry of Energy.

1.7. Before putting the cable facilities into permanent operation, all commissioning and testing of a stationary fire extinguishing installation must be completed to transfer it to automatic operation with the execution of acts, in accordance with the requirements of the "Typical Instructions for the Operation of Automatic Water Fire Fighting Installations" (TI 34-00-046-85 ) and "Standard Instructions for the Operation of Automatic Fire Alarm Installations at Energy Enterprises of the USSR Ministry of Energy" (TI 34-00-039-85).

1.8. It is forbidden to take into operation cable rooms and facilities of power enterprises:

1.8.1. In the presence of construction and installation defects.

1.8.2. In case of non-compliance with the norms for laying cable lines or their implementation with a deviation from the project, as well as in the absence of coordination of these deviations from regulatory and technical documents in the prescribed manner.

1.8.3. Without complete sealing of all cable lines.

1.8.4. Without operable drainage devices and fire extinguishing systems (if they are available according to the standards).

1.8.5. Without fire belts and partitions, closing doors and other fire prevention measures provided for by the project.

2. BASIC FIRE REQUIREMENTS IN THE DESIGN DOCUMENTATION OF THE CABLE FACILITY

2.1. Design documentation for the cable facilities of enterprises under construction, issued by the customer for production, as well as POS and PPR must comply with current building codes and regulations (SNiP), Electrical Installation Rules (PUE), Instructions for designing fire protection for energy enterprises (RD 34.49.101-87 ) and these Rules.

2.2. Design documentation should contain the following basic fire safety requirements:

2.2.1. Organization of construction and installation works to ensure the advanced input of the external and internal fire water supply of the facility and stationary fire extinguishing installations in cable structures.

2.2.2. The sequence of general construction, installation and finishing works of cable structures, taking into account the launch complex.

2.2.3. Volumes and sequence of cable laying (after the commissioning of a fixed fire extinguishing installation).

2.2.4. Mechanization of work during vertical and horizontal movement of structures and cable products in the installation area and cable laying along structures, namely: determination of transportation routes and places for making construction openings, as well as accumulation sites for the installation area, establishing places and types of embedded parts for electrical structures, fastening hoists, crane beams, hoists and other mechanisms for performing installation work.

2.2.5. The procedure for sealing with fire-resistant materials the places where cable lines pass through building structures, partitions and ceilings, as well as the implementation of fire-resistant belts in cable ducts during installation work and before putting them into operation.

2.2.6. Completion of final finishing works and other activities necessary for the day of commissioning of cable structures.

2.3. For the passage of cable lines through construction openings, through walls, partitions and ceilings, it is necessary to provide:

2.3.1. Embedded pipes made of non-combustible materials for laying single cables with mandatory sealing with non-combustible material.

2.3.2. For bundles of control cables with maximum dimensions in height and width of not more than 100 mm and for single cables, asbestos-cement pipes or modular cable penetrations with a fire resistance of 0.75 h with overall dimensions along a length of at least 200 mm and a cross section:

100 100 mm - single section;

100 200 mm - two-section;

100 300 mm - three-section;

100 400 mm - four-section.

2.4. For the main flows of cable lines of objects, the following should be provided:

2.4.1. In cable structures (cable floors, tunnels, channels, galleries) and electrical rooms - cable structures and lightweight perforated and lattice metal trays.

It is forbidden to use metal trays with a solid bottom and boxes.

2.4.2. In technological rooms and on overpasses - open laying of cables, and in places of possible mechanical damage, as a rule, in channels, mines - in lightweight perforated and lattice trays.

It is allowed to use metal boxes on combined overpasses with flammable and combustible liquids, as well as on minor flows and in places of their possible mechanical damage, justified by the project.

When installing metal boxes of the KKB and KP types, make partitions and seals in them with a fire resistance of at least 0.75 hours in the following places: cable passages through walls and ceilings; on horizontal sections and overpasses every 30 m of the length of the boxes; on vertical sections every 20 m of height and when passing through ceilings; in the branching points in the boxes of the main cable flows.

2.4.3. On the territory of outdoor switchgear and substations - reinforced concrete trays, channels and tunnels.

2.5. The laying of power cables along structures, in channels, trays and boxes should be provided in a single row, and control cables in layers or bundles, in accordance with the requirements of the Electrical Installation Code, with a maximum diameter of not more than 100 mm, or in separate cells of special cable structures with a size of 100´ 100 mm.

2.6. The specified cable structures, trays and boxes should only be used factory-made.

2.7. To perform installation work, operation and repair of cable routes outside special cable structures (tunnels, cable floors, etc.), when they are located at a height of 2.5 m or more of the service mark, and also taking into account the number of cables in the stream (10 power cables and more, 50 control cables and more) service platforms should be provided.

2.8. To ensure fire safety, it is necessary to provide for multiple sealing of cable penetrations in the design and estimate documentation, namely: during the period of the cable laying program before they are put into operation - with non-combustible materials (super-thin basalt fiber, special intumescent materials, sealing fire-resistant packages, etc. .).

3. BASIC REQUIREMENTS FOR FIRE-RESISTANT SEALS

3.1. The implementation of fire-resistant cable penetrations through building structures, the installation of fire partitions and belts in cable and other rooms, structures, on open routes, in trays and boxes must be carried out in accordance with the current technological instructions.

Passages of cable lines through walls, partitions and ceilings must be sealed with any non-combustible materials, according to the appendix, to ensure a minimum fire resistance of 0.75 h.

During the installation work, multiple sealing of the cable passage points with the same fire resistance limit should be performed.

3.2. Multiple sealing of cable lines in the main cable rooms (tunnels, floors, walk-through shafts and galleries) during the installation period should be carried out from materials that allow them to be used several times (i.e. inventory sealing products), as well as from materials that can be easily disassembled to continue laying cables during the following periods of installation work:

3.2.1. During breaks in the laying of cable lines for more than 1 day.

3.2.2. By the time of testing the cables and supplying voltage for their own needs with the delivery of these premises for operational maintenance by operation and the introduction of work permits.

3.2.3. Comprehensive testing of technological equipment.

3.3. Before putting the cable facilities into operation, it is recommended to cover the ends of cable penetrations with fibrous materials and packages with fire-retardant materials with a thickness of at least 5 mm.

3.4. When using metal boxes of types KKB, KP and others in industrial premises (in places of possible mechanical and other damage), the exit of individual cables from them should be carried out using protective products (pipes, fittings, pipes, glands, etc.).

3.5. Cable lines laid in shafts and metal boxes of KKB, KP and others should be sealed with a fire resistance of at least 0.75 hours in the following places:

3.5.1. At the entrance to cable structures.

3.5.2. When passing through each mark of the main floor, as well as every 20 m on long vertical sections of cable ducts.

3.5.3. Every 30 m of horizontal sections of cable ducts, as well as at the junction (branch) of other ducts.

3.6. It is not allowed to make bundles of cables with a diameter of more than 100 mm.

When cable bundles pass through partitions, walls and ceilings, to ensure cable sealing, they should be laid out, as a rule, in one layer, separating each one from the other with a fire-resistant sealing material with a thickness of at least 20 mm.

3.7. If the thickness of the wall, partition and ceiling is greater than the values ​​​​of sealing terminations of cables specified in the appendix, they should be made on both sides (at each end) with the standard thickness of termination of cables.

If the thickness of the partition (floor) is less than the specified sealing values ​​for cable penetrations, the total thickness of the seal must correspond to the specified values, while it is allowed to make protrusions on both sides of the partition.

3.8. Holes (openings) in building structures around cable penetrations, ducts and pipes must be sealed with cement mortars for the entire thickness of building structures up to the standard fire resistance limit.

Notes:

1. OZS fire retardant composition and FK-75 foam plastic () are used at facilities according to the list agreed in the prescribed manner with Soyuzelectromontazh and GUKS of the USSR Ministry of Energy.

2. Developers may make additions and changes to the List as new fire-resistant materials are developed for sealing cable lines and conducting fire tests.

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 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. 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 a dry room, the hole is framed with an insulating porcelain or plastic sleeve, and from the side of a wet, damp or outside - 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.

The connection of wires when leaving a dry, damp room to a damp or outside building should be carried out in a dry or damp 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 (mineral wool, slag, etc.) after laying the electrical wiring. 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. When wires are laid hidden through interfloor ceilings, 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 (these wires are not laid in steel pipes).

When making a passage through an interfloor ceiling, 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. In open electrical 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 the 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 the metal structures of 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 with hot pipelines, wires and cables must be protected from high temperatures

PUE: . Laying a cable through a pue wall

2006. Rules for the installation of electrical installations. Section 2. Sewerage of electricity (41439)

PUE PUE: 2006. Rules for the installation of electrical installations. Section 2. Sewerage of electricity

1 The lining of non-combustible materials must protrude from each side of the wire, cable, pipe or conduit by at least 10 mm.

2 The plastering of the pipe is carried out with a continuous layer of plaster, alabaster, etc. at least 10 mm thick above the pipe.

3 A continuous layer of non-combustible material around the pipe (box) can be a layer of plaster, alabaster, cement mortar or concrete with a thickness of at least 10 mm.

In museums, art galleries, libraries, archives and other repositories of national importance, only wires and cables with copper conductors should be used.

2.1.50. To power portable and mobile electrical receivers, cords and flexible cables with copper conductors, specially designed for this purpose, should be used, taking into account possible mechanical effects. All cores of the specified conductors, including the grounding conductor, must be in a common sheath, braid or have a common insulation.

For mechanisms with limited movement (cranes, mobile saws, gate mechanisms, etc.), it is necessary to use such current supply structures that protect the cores of wires and cables from breaking (for example, flexible cable loops, carriages for movable suspension of flexible cables).

2.1.51. In the presence of oils and emulsions in the places where the wires are laid, wires with oil-resistant insulation should be used or the wires should be protected from their effects.

EXPOSED INDOOR WIRING

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

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

2. At voltages above 42 V in areas with increased danger and especially dangerous - at a height of at least 2.5 m from the floor level or service platform.

These requirements do not apply to descents to switches, sockets, starting devices, shields, wall-mounted lamps.

In industrial premises, the descents of unprotected wires to switches, sockets, devices, shields, etc. must be protected from mechanical impacts up to a height of at least 1.5 m from the floor level or service platform.

In domestic premises of industrial enterprises, in residential and public buildings, these 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 provided to protect the personnel on the trolley and crane bridge from accidentally touching the wires. A protective 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 the open laying of protected insulated wires, cables, as well as wires and cables in pipes, boxes with a degree of protection of at least IP20, in flexible metal hoses from the floor level or service platform 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.

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. If the distance from wires and cables to pipelines is less than 250 mm, wires and cables must be additionally protected from mechanical damage at a length of at least 250 mm on each side of 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 in 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 of an appropriate design.

2.1.58. In places where wires and cables pass through walls, interfloor ceilings or exit to the outside, it is necessary to provide the possibility of changing the 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, gaps between wires, cables and a pipe (duct, opening, etc.), as well as backup pipes (ducts, openings, etc.) .p.) easily removed mass from non-combustible 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).

2.1.59. When laying unprotected wires on insulating supports, the wires must be additionally insulated (for example, with an insulating pipe) at the points of passage 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 wires pass from a dry or damp room to a damp one, from one damp room to another damp one, or when wires exit a room to the outside, each wire must be laid in a separate insulating pipe. When exiting 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 one another in bundles (groups) of various shapes (for example, round, rectangular in several layers).

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

2.1.61. It is allowed to lay wires and cables in ducts in a multi-layer ordered and arbitrary (loose) mutual arrangement. The sum of cross sections of wires and cables, calculated according to their outer diameters, including insulation and outer sheaths, should not exceed: for deaf ducts 35% of the duct cross section in the light; for boxes with opening lids 40%.

2.1.62. Permissible long-term currents for wires and cables laid in bundles (groups) or multilayered should be taken into account with reduction factors that take into account the number and location of conductors (cores) in the bundle, the number and relative position of bundles (layers), as well as the presence of unloaded conductors.

2.1.63. Pipes, boxes and flexible metal sleeves of electrical wiring must be laid in such a way that moisture cannot accumulate in them, including from the condensation of vapors contained in the air.

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

Connection of pipes, ducts and flexible metal hoses to each other, as well as to ducts, electrical equipment cases, etc. must be done:

in rooms that contain vapors or gases that adversely affect the insulation or sheaths of wires and cables, in outdoor installations and in places where oil, water or emulsion can get into pipes, boxes and sleeves - with a seal; boxes in these cases should be with solid walls and with sealed solid covers or deaf, split boxes - with seals at the split points, and flexible metal sleeves - sealed;

in dusty rooms - with sealing of joints and branches of pipes, sleeves and ducts to protect against dust.

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

HIDDEN WIRING INDOOR

2.1.66. Hidden electrical wiring in pipes, ducts and flexible metal hoses must be made in compliance with the requirements given in 2.1.63-2.1.65, and in all cases - with a seal. The box of hidden electrical wiring must be deaf.

2.1.67. Electrical wiring in ventilation ducts and shafts is prohibited. It is allowed to cross these channels and shafts with single wires and cables enclosed in steel pipes.

2.1.68. The laying of wires and cables behind false ceilings should be carried out in accordance with the requirements of this chapter and Ch. 7.1.

ELECTRICAL WIRING IN ATTIC ROOMS

2.1.69. The following types of electrical wiring can be used in attic rooms:

open;

wires and cables laid in pipes, as well as protected wires and cables in sheaths made of non-combustible or slow-burning materials - at any height;

unprotected insulated single-core wires on rollers or insulators (in the attic of industrial buildings - only on insulators) - at a height of at least 2.5 m; if the height to the wires is less than 2.5 m, they must be protected from touch and mechanical damage;

hidden: in walls and ceilings made of non-combustible materials - at any height.

2.1.70. Open electrical wiring in the attic should be carried out with wires and cables with copper conductors.

Wires and cables with aluminum conductors are allowed in attic spaces: buildings with fireproof ceilings - when they are laid open in steel pipes or hidden in fireproof walls and ceilings; industrial buildings for agricultural purposes with combustible floors - when they are laid open in steel pipes with the exception of dust penetration into the pipes and junction (branch) boxes; threaded connections must be used.

2.1.71. The connection and branching of copper or aluminum cores of wires and cables in attic spaces should be carried out in metal junction (branch) boxes by welding, crimping or using clamps corresponding to the material, cross section and number of cores.

2.1.72. Electrical wiring in attic spaces made using steel pipes must also meet the requirements given in 2.1.63-2.1.65.

2.1.73. Branches from lines laid in the attic to electrical receivers installed outside the attics are allowed provided that the lines and branches are laid openly in steel pipes or hidden in fireproof walls (ceilings).

2.1.74. Switching devices in the circuits of lamps and other electrical receivers installed directly in attic spaces must be installed outside these premises.

OUTDOOR WIRING

2.1.75. Unprotected insulated wires of external electrical wiring must be located or fenced in such a way that they are inaccessible to touch from places where people can often stay (for example, a balcony, a porch).

From these places, these wires, laid openly along the walls, must be at a distance of at least, m:

For horizontal laying:

under the balcony, porch, and also above the roof

industrial building 2.5

under the window 0.5

under the balcony 1.0

under the window (from the window sill) 1.0

With vertical laying up to the window 0.75

The same, but up to the balcony 1.0

From the ground 2.75

When hanging wires on supports near buildings, the distance from the wires to balconies and windows must be at least 1.5 m with a maximum deviation of the wires.

External wiring on the roofs of residential, public buildings and entertainment enterprises is not allowed, with the exception of inputs to buildings (enterprises) and branches to these inputs (see 2.1.79).

Unprotected insulated wires of external wiring should be considered as uninsulated with respect to contact.

2.1.76. Distances from wires crossing fire lanes and ways for transporting goods to the surface of the earth (road) in the carriageway must be at least 6 m, in the impassable part - at least 3.5 m.

2.1.77. The distances between the wires must be: for a span of up to 6 m - not less than 0.1 m, for a span of more than 6 m - not less than 0.15 m. The distances from wires to walls and supporting structures must be at least 50 mm.

2.1.78. Laying of wires and cables of external electrical wiring in pipes, ducts and flexible metal hoses must be carried out in accordance with the requirements given in 2.1.63-2.1.65, and in all cases with a seal. Laying wires in steel pipes and ducts in the ground outside buildings is not allowed.

The distance from the wires in front of the input and the input wires to the ground surface must be at least 2.75 m (see also 2.4.37 and 2.4.56).

The distance between the wires at the input insulators, as well as from the wires to the protruding parts of the building (roof overhangs, etc.) must be at least 0.2 m.

Entries are allowed to be made through roofs in steel pipes. In this case, the vertical distance from the branch wires to the input and from the input wires to the roof must be at least 2.5 m.

For buildings of small height (shopping pavilions, kiosks, container-type buildings, mobile booths, vans, etc.), on the roofs of which people are excluded, the clear distance from the branch wires to the input and the input wires to the roof is allowed to be taken at least 0 .5 m. In this case, the distance from the wires to the surface of the earth must be at least 2.75 m.

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Wiring | power engineer

Wiring and cable lines

1. Electrical installations of different organizations, separated in administrative and economic terms, located in the same building, can be connected by branches to a common supply line or fed by separate lines from the ASU or MSB.
2. It is allowed to connect several risers to one line. On branches to each riser supplying apartments of residential buildings with more than 5 floors, a control device combined with a protection device should be installed.
3. In residential buildings, luminaires in stairwells, lobbies, halls, floor corridors and other indoor premises outside apartments should be powered by independent lines from the ASU or separate group shields powered by the ASU. The connection of these lamps to floor and apartment shields is not allowed.
4. For staircases and corridors with natural light, it is recommended to provide automatic control of electric lighting depending on the illumination created by natural light.
5. It is recommended to supply electrical installations of non-residential stock with separate lines.

7.1.34. In buildings, cables and wires with copper conductors* should be used.

Supply and distribution networks, as a rule, should be made with cables and wires with aluminum conductors if their calculated cross section is 16 mm2 or more.

The power supply of individual electrical receivers related to the engineering equipment of buildings (pumps, fans, heaters, air conditioning units, etc.) can be carried out with wires or cables with aluminum conductors with a cross section of at least 2.5 mm2.

In museums, art galleries, exhibition spaces, it is allowed to use lighting busbars with IP20 protection degree, in which branch devices to lamps have detachable contact connections located inside the busbar trunking at the time of switching, and busbars with IP44 protection degree, in which branches to lamps are made with using plug-in connectors that ensure that the branch circuit is interrupted until the plug is removed from the socket.

In residential buildings, the cross-sections of copper conductors must correspond to the calculated values, but not less than those indicated in Table 7.1.1.

* Until 2001, according to the existing construction reserve, it is allowed to use wires and cables with aluminum conductors.

It is allowed to lay fire-resistant laying in a common pipe, common duct or channel of building structures made of non-combustible materials, wires and cables of the supply lines of apartments together with wires and cables of group lines of working lighting of staircases, floor corridors and other indoor premises.

Table 7.1.1. The smallest permissible sections of cables and wires of electrical networks in residential buildings

The cross-sections of conductors must meet the requirements of clause 7.1.45.

7.1.38. Electrical networks laid behind impassable suspended ceilings and in partitions are considered as hidden electrical wiring and they should be carried out: behind ceilings and in the voids of partitions made of combustible materials in metal pipes with localization ability and in closed boxes; behind ceilings and in partitions made of non-combustible materials * - in pipes and ducts made of non-combustible materials, as well as cables that do not spread combustion. At the same time, it should be possible to replace wires and cables.

*False ceilings made of non-combustible materials are understood to mean such ceilings that are made of non-combustible materials, while other building structures located above the suspended ceilings, including interfloor ceilings, are also made of non-combustible materials.

In saunas for zones 3 and 4 according to GOST R 50571.12-96 “Electrical installations of buildings. Part 7. Requirements for special electrical installations. Section 703 Rooms containing sauna heaters must use wiring with an insulation temperature rating of 170°C.

7.1.41. Electrical wiring in attics must be carried out in accordance with the requirements of Sec. 2.

Three-phase four- and five-wire lines when supplying three-phase symmetrical loads must have a cross section of zero working (N) conductors equal to the cross section of the phase conductors, if the phase conductors have a cross section of up to 16 mm2 for copper and 25 mm2 for aluminum, and for large cross sections - at least 50 % section of phase conductors.

The cross section of the PEN conductors must be at least the cross section of N conductors and not less than 10 mm2 for copper and 16 mm2 for aluminum, regardless of the cross section of the phase conductors.

The cross section of PE conductors should be equal to the cross section of the phase conductors with a cross section of the latter up to 16 mm2, 16 mm2 with a cross section of phase conductors from 16 to 35 mm2 and 50% of the cross section of phase conductors for large cross sections.

The cross section of PE conductors that are not part of the cable must be at least 2.5 mm2 - in the presence of mechanical protection and 4 mm2 - in its absence.

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PUE: Wiring and cable lines

Wiring and cable lines

7.1.32. Internal wiring must be carried out taking into account the following:

1. Electrical installations of different organizations, separated in administrative and economic terms, located in the same building, can be connected by branches to a common supply line or fed by separate lines from the ASU or MSB.

2. It is allowed to connect several risers to one line. On branches to each riser supplying apartments of residential buildings with more than 5 floors, a control device combined with a protection device should be installed.

3. In residential buildings, luminaires in stairwells, lobbies, halls, floor corridors and other indoor premises outside the apartments must be powered through independent lines from the ASU or separate group panels powered by the ASU. The connection of these lamps to floor and apartment shields is not allowed.

4. For staircases and corridors with natural light, it is recommended to provide automatic control of electric lighting depending on the illumination created by natural light.

5. Power supply of non-residential electrical installations is recommended to be performed by separate lines.

7.1.33. Supply networks from substations to VU, ASU, MSB must be protected from short circuit currents.

7.1.34. In buildings, cables and wires with copper conductors should be used 1

Supply and distribution networks, as a rule, should be made with cables and wires with aluminum conductors if their calculated cross section is 16 mm 2 or more.

The power supply of individual electrical receivers related to the engineering equipment of buildings (pumps, fans, heaters, air conditioning units, etc.) can be carried out with wires or cables with aluminum conductors with a cross section of at least 2.5 mm 2.

In museums, art galleries, exhibition spaces, it is allowed to use lighting busbars with IP20 protection degree, in which branch devices to lamps have detachable contact connections located inside the busbar trunking at the moment of switching, and busbar trunkings with IP44 protection degree, in which branches to lamps are made with using plug-in connectors that ensure that the branch circuit is interrupted until the plug is removed from the socket.

In these premises, lighting bus ducts must be fed from distribution points by independent lines.

In residential buildings, the cross sections of copper conductors must correspond to the calculated values, but be not less than those indicated in table 7.1.1.

1 Until 2001, according to the existing construction reserve, it is allowed to use wires and cables with aluminum conductors.

The smallest allowable sections of cables and wires of electrical networks in residential buildings.

7.1.35. In residential buildings, the laying of vertical sections of the distribution network inside apartments is not allowed.

It is forbidden to lay from the floor shield in a common pipe, common duct or channel of wires and cables feeding the lines of different apartments.

It is allowed to lay fire-resistant laying in a common pipe, common duct or channel of building structures made of non-combustible materials, wires and cables of the supply lines of apartments together with wires and cables of group lines of working lighting of stairwells, floor corridors and other indoor premises.

7.1.36. In all buildings, group network lines laid from group, floor and apartment shields to general lighting fixtures, socket outlets and stationary electrical receivers must be three-wire (phase - L, zero working - N and zero protective - PE conductors).

It is not allowed to combine zero working and zero protective conductors of various group lines.

Zero working and zero protective conductors are not allowed to be connected on shields under a common terminal.

The cross-sections of the conductors must meet the requirements of clause 7.1.45.

7.1.37. Electrical wiring in the premises should be replaced: hidden - in the channels of building structures, embedded pipes; open - in electrical skirting boards, boxes, etc.

In technical floors, undergrounds, unheated basements, attics, ventilation chambers, damp and especially damp rooms, electrical wiring is recommended to be carried out openly.

In buildings with building structures made of non-combustible materials, non-replaceable monolithic laying of group networks in the grooves of walls, partitions, ceilings, under plaster, in the floor preparation layer or in the voids of building structures is allowed, performed by a cable or insulated wires in a protective sheath. The use of non-replaceable monolithic laying of wires in panels of walls, partitions and ceilings, made during their manufacture at construction industry plants or performed in the assembly joints of panels during the installation of buildings, is not allowed.

7.1.38. Electrical networks laid behind impassable suspended ceilings and in partitions are considered as hidden electrical wiring and they should be carried out: behind ceilings and in the voids of partitions made of combustible materials in metal pipes with localization ability and in closed boxes; behind ceilings and in partitions made of non-combustible materials 2 - in pipes and ducts made of non-combustible materials, as well as cables that do not spread combustion. At the same time, it should be possible to replace wires and cables.

Note 2 to entry: Suspended ceilings made of non-combustible materials are understood to mean such ceilings that are made of non-combustible materials, while other building structures located above suspended ceilings, including interfloor ceilings, are also made of non-combustible materials.

7.1.39. In the premises for cooking and eating, with the exception of the kitchens of the apartments, open laying of cables is allowed. Open laying of wires in these rooms is not allowed.

In the kitchens of apartments, the same types of electrical wiring can be used as in living rooms and corridors.

7.1.40. In saunas, bathrooms, toilets, showers, as a rule, hidden wiring should be used. Open laying of cables is allowed.

In saunas, bathrooms, toilets, showers, it is not allowed to lay wires with metal sheaths, in metal pipes and metal sleeves.

In saunas for zones 3 and 4 according to GOST R 50571.12-96 "Electrical installations of buildings. Part 7. Requirements for special electrical installations. Section 703. Premises containing heaters for saunas" electrical wiring with a permissible insulation temperature of 170 o c must be used.

7.1.41. Electrical wiring in attics must be carried out in accordance with the requirements of Sec. 2.

7.1.42. Through the basements and technical undergrounds of building sections, it is allowed to lay power cables with voltage up to 1 kV, which feed the electrical receivers of other sections of the building. These cables are not considered as transit cables, the laying of transit cables through the basements and technical undergrounds of buildings is prohibited.

7.1.43. Open laying of transit cables and wires through storerooms and warehouses is not allowed.

7.1.44. The lines supplying the refrigeration units of trade and public catering enterprises must be laid from the ASU or MSB of these enterprises.

7.1.45. The choice of the cross section of conductors should be carried out in accordance with the requirements of the relevant chapters of the PUE.

Single-phase two- and three-wire lines, as well as three-phase four- and five-wire lines when supplying single-phase loads, must have a cross section of zero working (N) conductors equal to the cross section of phase conductors.

Three-phase four- and five-wire lines when supplying three-phase symmetrical loads must have a cross section of zero working (N) conductors equal to the cross section of the phase conductors, if the phase conductors have a cross section of up to 16 mm 2 for copper and 25 mm 2 for aluminum, and for large cross sections - not less than 50% of the cross section of the phase conductors.

The cross section of PEN conductors must be at least the cross section of N conductors and not less than 10 mm 2 for copper and 16 mm 2 for aluminum, regardless of the cross section of the phase conductors.

The cross section of PE conductors should be equal to the cross section of the phase conductors with a cross section of the latter up to 16 mm 2. 16 mm 2 with a cross section of phase conductors from 16 to 35 mm 2 and 50% of the cross section of phase conductors for large cross sections.

The cross section of PE conductors that are not part of the cable must be at least 2.5 mm 2 - in the presence of mechanical protection and 4 mm 2 - in its absence.

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

A vivid example that proves the need to install such structures is the fire at the Ostankino television tower in 2000. Here, the telecommunications lines were placed in a vertical shaft, without breaking 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 passes through the sleeve, a pipeline, the outer diameter of which is slightly smaller than the diameter of the fire-fighting structure. The gap between the communication line and the inner wall of the sleeve is filled with tow, soaked through with fat. That is why the simplest cable penetrations are also called glands. Also, asbestos, rubberized rings, special packings can be used together or instead of tow.

At industrial facilities and power plants, several other structures are arranged. 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 engineering lines.

Termination materials

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

At the same time, the ability to resist fire at the seal should not be lower than the fire-resistant ability of the wall.

SNiP 3.05.06-85 indicates specific mixtures that are allowed 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 ratio of materials 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.

It is also allowed to seal cable penetrations with building foam if it is certified in accordance with the requirements of GOST R 53310-2009. Gaps in walls may not be filled if partitions are not fire barriers.

Modular penetrations

In modern construction, modular penetrations are used to isolate fire compartments. They are steel or plastic frames that are equipped with blind inserts or modules with holes. To protect against electromagnetic radiation, copper gaskets are installed. Tightness is created by tension bolts.

In general, modular fireproof cable penetrations are a complex structure 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 fasteners.

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

Features of installation of cable penetrations

The installation of penetrations has its own characteristics, which depend on the type of material of the supporting structure. So, when laying cable systems in monolithic concrete buildings, fire-retardant structures are laid directly into the formwork before pouring the concrete mixture. During the construction of prefabricated-monolithic type buildings, penetrations are laid in blocks at the factory during their manufacture.

In brick houses for laying, cable systems are placed in special channels - strobes. In finished monolithic structures, small holes are drilled with a diamond drill. The penetration diameter is calculated separately. During construction or temporary operation of buildings, penetrations are made of special fire-retardant cushions.

Cable penetration test

Depending on the place of operation, cable penetrations must meet the established requirements. So, when they are laid down at nuclear power plants, they must be tested for their ability to absorb, isolate or reflect radiation.

At ordinary construction sites, universal cable penetration is tested by heat, force (mainly bending resistance), as well as fire resistance, water and gas insulating properties.

6.5 In places where openly laid and protected cables pass through building structures, cable penetrations with a fire resistance rating not lower than the fire resistance rating of these structures (Article 82 TR), providing the required smoke and gas tightness (clause 37 of PPB 01-03) and corresponding requirements of GOST R 50571.15 and 2.1 PUE.
To do this, in places where pipes with cables pass:
-- through fire walls, ceilings and partitions with a rated fire resistance limit or their exit to the outside in rooms with a normal environment, lay electrical circuits in pipe sections for electrical wiring, smooth, made of PVC D = 25 (clause 3.18 of SNiP 3.05.06-85 * ). Seal the gaps between the cables and the pipe with cable glands for PVC pipes. Sealing should be done on each side of the pipe;
- through building structures with a non-standardized fire resistance limit, lay electric circuits in corrugated PVC pipes d=16. Seal the gaps between the cables and the pipe with TFLEX plugs.
Through combustible walls and partitions - in steel pipes (clause 3.18 of SNiP 3.05.06)
When passing through floors, the cable at the passage point is protected from mechanical damage by casings or boxes to a height of 2 m from the floor.
- for the passage of single cables through the walls between industrial premises with a class of explosive zone - 2 (according to TRoTPB) and V-1a (according to PUE) and rooms with a normal environment, use steel water and gas pipes according to GOST 3262-75 and pipe cable glands, installed from the side of the room with an explosive zone of a higher class. The gaps between pipes and cables must be sealed with asbestos cord SHAON - 3.0 (according to GOST 1779-83) to a depth of 100-200 mm from the end of the pipe, with a total thickness that ensures fire resistance of building structures. See sheet 16 of the RF project for the execution of single cable penetrations.
-- for the passage of cable assembly through the walls of industrial premises with a class of explosive zone - 2 (according to TRoTPB) and V-1a (according to PUE), use mortar universal cable penetrations designed for fire protection of cable line passages and consisting of:
- sealing flame retardant composition Formula KP - for sealing cable passage points;
- flame retardant composition Phoenix CE - for additional fire retardant treatment of cables;
- embedded parts - straight all-metal perforated tray LM 500x50.
Install cable penetrations in compliance with the requirements of technological regulations TRP-10/06 and "Recommendations for the installation and operation of fire-prevention cable penetrations of the KP type" (R5.04.067.10) of Stroytekhnorm RUE.

The places where pipes pass through building structures should be sealed with fireproof materials (mortar, cement with sand by volume 1:10, clay with sand - 1:3, clay with cement and sand - 1.5:1:11, expanded perlite with building gypsum - 1: 2 or other non-combustible materials) over the entire thickness of the wall or partition immediately after laying cables or pipes (SNiP 3.05.06-85, clause 3.65). Gaps in passages through walls may not be sealed if these walls are not fire barriers.
- cable entry from trenches into buildings is carried out through sections of concrete, reinforced concrete or asbestos-cement pipes or through holes in reinforced concrete structures.
- the ends of the pipes should protrude beyond the walls of the building into the trench by at least 0.6 m (Fig. 1). When removing cables from the ground and climbing the wall, they are protected from mechanical damage by a pipe, angle, channel or box to a height of 2 m (Fig. 2).
- passages through wooden walls and partitions are made in segments of steel or asbestos-cement pipes with a diameter of at least 100 mm, protruding on both sides of the wall or ceiling by 50 mm, or through a fireproof seal measuring 150x150 mm.