In-shop switchgears and transformer substations. In-shop switchgears and transformer substations Application area

Electrical installation rules

7th edition

Section 2 Power transmission

Chapter 2.4 Overhead power lines with voltage up to 1 kV

Date of introduction 2003-10-01

Foreword

Designed with the requirements in mind state standards, building codes and regulations, recommendations of scientific and technical councils for the consideration of draft chapters. The draft chapters were considered by the working groups of the Coordination Council for the revision of the PUE

Prepared by OJSC "ROSEP", co-executor - JSC "Firm ORGRES"

AGREED in accordance with the established procedure with Gosstroy of Russia, Gosgortekhnadzor of Russia, RAO "UES of Russia" (OJSC "VNIIE") and submitted for approval by the State Energy Supervision Authority of the Ministry of Energy of Russia

From October 1, 2003, chapter 2.4 of the "Rules for the Installation of Electrical Installations" of the sixth edition becomes invalid.

The requirements of the Electrical Installation Rules are mandatory for all organizations, regardless of ownership and organizational and legal forms, as well as for individuals employed entrepreneurial activity without forming a legal entity.

Application area. Definitions

2.4.1. This chapter of the Rules applies to overhead power transmission lines of alternating current with a voltage of up to 1 kV, carried out using insulated or uninsulated wires.

Additional requirements for overhead lines up to 1 kV are given in Ch. 2.5, 6.3 and 7.7.

Cable inserts into the line and cable branches from the line must be made in accordance with the requirements of Chapter 2.3.

2.4.2. An overhead transmission line (OHL) with a voltage of up to 1 kV is a device for the transmission and distribution of electricity through insulated or non-insulated wires located in the open air and attached by linear fittings to supports, insulators or brackets, to the walls of buildings and to engineering structures.

An overhead power line with a voltage of up to 1 kV using self-supporting insulated wires (SIP) is designated VLI.

Self-supporting insulated wire - insulated conductors twisted into a bundle, and the carrying conductor can be either insulated or uninsulated. The mechanical load can be absorbed either by the carrier conductor or by all conductors of the harness.

2.4.3. The overhead line is a section of the line from the supply transformer substation to the end support.

Linear branches or branches to the input can be connected to the overhead line.

Linear branch from the overhead line - a section of the line connected to the overhead line, which has more than two spans.

Branch from the overhead line to the input - the section from the support of the main line or linear branch to the clamp (bushing insulator).

A branch from VLI is allowed to be performed in the span.

2.4.4. The state of the overhead line in the calculations of the mechanical part:

normal mode - mode with unbroken wires;

emergency mode - mode with broken wires;

assembly mode - mode in conditions of mounting supports and wires.

Mechanical calculation of overhead lines up to 1 kV in emergency mode is not performed.

General requirements

2.4.5. The mechanical calculation of the elements of the overhead line should be carried out according to the methods described in Chapter 2.5.

2.4.6. Overhead power lines should be located so that the supports do not obstruct the entrances to buildings and entrances to courtyards and do not impede the movement of vehicles and pedestrians. In places where there is a danger of traffic collisions (at entrances to courtyards, near exits from roads, when crossing roads), the supports must be protected from collisions (for example, by bollards).

2.4.7. On the overhead line supports at a height of at least 2 m from the ground after 250 m on the overhead line mains, the following should be installed (applied): the serial number of the support; posters showing the distances from the overhead line support to the cable communication line (on the supports installed at a distance of less than 4 m to the communication cables), the width of the security zone and the phone number of the overhead line owner.

2.4.8. When the VLI passes through forests and green spaces, cutting of glades is not required. In this case, the distance from the wires to trees and bushes with the largest SIP sag arrow and their greatest deviation should be at least 0.3 m.

When passing overhead lines with bare wires through forests and green spaces, cutting a clearing is not necessary. In this case, the distance from the wires with the largest sag arrow or the greatest deviation to trees and bushes should be at least 1 m.

The distance from insulated wires to green spaces should be at least 0.5 m.

2.4.9. Overhead line support structures must be protected from corrosion, taking into account the requirements of 2.5.25, 2.5.26 and building codes and regulations.

2.4.10. Protection of overhead lines from electrical overloads should be performed in accordance with the requirements of Chapter 3.1.

Climatic conditions

2.4.11. Climatic conditions for the calculation of overhead lines up to 1 kV in normal mode should be taken as for overhead lines up to 20 kV in accordance with 2.5.38-2.5.74. In this case, for overhead lines up to 1 kV, you should take:

when calculating according to 2.5.52: = 1.1 - for self-supporting insulated wire, free or covered with ice;

when calculating according to 2.5.54 and 2.5.55:

0.8 - for single-circuit overhead lines;

0.9 - for single-circuit overhead lines with suspension on PV supports;

1.0 and 1,2 - for double-circuit and multi-circuit overhead lines, as well as when suspended on supports of overhead lines of a self-supporting non-metallic optical cable (OCSN);

1.0 and 1.0 - in all cases.

2.4.12. The calculation of the length of the branch span from the overhead line to the input according to 2.4.20 should be carried out in ice mode for two cases:

1) wind direction at an angle of 90 ° to the axis of the overhead line, the overhead line wires are covered with icebNS, the thickness of the ice wall on the branch wiresb0 =0,5 bNS;

2) wind direction along the overhead line (angle 0 °), ice wall thickness on the branch wiresb0 = bNS.

In this case, in both cases, the reduction of the tension of the branch wires should be taken into account when the top of the support is deflected.

Wires. Linear fittings

2.4.13. On overhead lines, as a rule, self-supporting insulated wires (SIP) should be used.

The self-supporting insulated wire must belong to the category of protected, have insulation from a light-stabilized flame retardant synthetic material UV and ozone resistant.

2.4.14. According to the conditions of mechanical strength on the overhead lines, on the linear branch from the overhead line and on the branches, wires with the minimum cross-sections indicated in Tables 2.4.1 and 2.4.2 should be used to the inputs.

Table 2.4.1

Minimum allowable cross-section of insulated wires

bNS, mm	Carrying conductor cross-section, , on the VLI highway, on a linear branch from the VLI	The cross-section of the conductor on the branches from the VLI and from the overhead line to the inputs,
	35 (25) *
15 and more	50 (25) *

________________

* The cross-section of the self-supporting insulated wires, twisted into a bundle, without the carrying wire is given in brackets.

Table 2.4.2

Minimum allowable cross-sections of bare and insulated wires

Standard ice wall thicknessbNS, mm	Wire material	Wire cross-section on the trunk and linear branch, mm
	Aluminum (A), untreated aluminum alloy (AN)
	Steel-aluminum (АС), heat-treated aluminum alloy (АЖ)
	Copper (M)
15 and more	A, AN АС, АЖ М

2.4.15. When constructing overhead lines in places where operating experience has established the destruction of wires from corrosion (seashores, salt lakes, industrial areas and areas of saline sands), as well as in places where, on the basis of these surveys, it is possible to use self-supporting insulated wires with an insulated core ...

2.4.16. The overhead line, as a rule, should be carried out with wires of constant cross-section.

It is recommended to take the cross-section of the phase conductors of the high-pressure line at least 50 .

2.4.17. Mechanical calculation of wires should be carried out according to the method of permissible stresses for the conditions specified in 2.5.38-2.5.74. In this case, the voltages in the wires should not exceed the permissible voltages given in Table 2.4.3, and the distances from the wires to the earth's surface, crossed structures and grounded elements of supports must meet the requirements of this chapter.

Table 2.4.3

Permissible mechanical stress in overhead lines up to 1 kV

The wire	Allowable stress,% tensile strength
The wire	at the highest load and lowest temperature	at average annual temperature
SIP with a section of 25-120
Aluminum cross-section, :
25-95

From heat-treated and non-heat-treated aluminum alloy with cross-section, :
25-95

Steel-aluminum section, :

35-95

The calculation uses the parameters of the wires given in table 2.5.8.

2.4.18. All types of mechanical loads and influences on a self-supporting insulated wire with a carrier conductor must be perceived by this core, and on a self-supporting insulated wire without a supporting wire, all the cores of the twisted bundle must be perceived.

2.4.19. The length of the branch span from the overhead line to the input should be determined by calculation depending on the strength of the support on which the branch is performed, the height of the branch wires on the support and at the input, the number and cross-section of the branch wires.

At distances from the main overhead line to the building that exceed the calculated values of the branch span, it is established required number additional supports.

2.4.20. The choice of the cross-section of current-carrying conductors for the long-term permissible current should be carried out taking into account the requirements of Chapter 1.3.

The cross-section of current-carrying conductors should be checked for the heating condition in case of short circuits (SC) and for thermal resistance.

2.4.21. Fastening, connecting the self-supporting insulated wire and connecting to the self-supporting insulated wire should be done as follows:

1) fastening the wire of the VLI line on intermediate and corner intermediate supports - using supporting clamps;

2) fastening the wire of the VLI main line on anchor-type supports, as well as the end fastening of the branch wires on the VLI support and at the input - using tension clamps;

3) connection of the VLI wire in the span - using special connecting clamps; in the loops of anchor-type supports, it is allowed to connect an uninsulated carrier wire using a ram clamp. Connecting clamps designed to connect the carrier wire in the span must have mechanical strength not less than 90% of the breaking strength of the wire;

4) connection of the phase conductors of the VLI line - using connecting clamps with an insulating coating or a protective insulating sheath;

5) the connection of wires in the branch span to the input is not allowed;

6) connection of grounding conductors - using ram clamps;

7) branch clamps should be used in cases:

branches from the phase conductors, with the exception of the self-supporting insulated wire with all the carrying conductors of the harness;

branches from the carrier.

2.4.22. Fastening of supporting and tension clamps to VLI supports, walls of buildings and structures should be performed using hooks and brackets.

2.4.23. The design forces in the supporting and tension clamps, attachment points and brackets in normal operation should not exceed 40% of their mechanical breaking load.

2.4.24. Connections of wires in the spans of overhead lines should be made using connecting clamps that provide mechanical strength of at least 90% of the breaking strength of the wire.

In one span of overhead lines, no more than one connection is allowed for each wire.

In the spans of the intersection of overhead lines with engineering structures connection of overhead lines is not allowed.

The connection of the wires in the loops of the anchor supports should be done using clamps or welding.

Wires of different brands or cross-sections should be connected only in the loops of the anchor supports.

2.4.25. Fastening of bare wires to insulators and insulating traverses on overhead line supports, with the exception of supports for intersections, is recommended to be single.

Fastening of bare wires to pin insulators on intermediate supports should be performed, as a rule, on the neck of the insulator from its inner side with respect to the support post.

2.4.26. Hooks and pins should be calculated in the normal mode of operation of the overhead line using the method of destructive loads.

In this case, the efforts should not exceed the values given in 2.5.101.

Arrangement of wires on supports

2.4.27. On the supports, any arrangement of insulated and non-insulated wires of overhead lines is allowed, regardless of the area of climatic conditions. The neutral wire of overhead lines with bare wires, as a rule, should be located below the phase wires. Insulated outdoor lighting wires laid on VLI supports can be placed above or below the self-supporting insulated wire, and also be twisted into a self-supporting insulated wire harness. Uninsulated and insulated outdoor lighting wires laid on overhead line supports should be located, as a rule, above PEN (PE) conductor of overhead lines.

2.4.28. Devices installed on supports for connecting electrical receivers must be located at a height of at least 1.6 m from the ground surface.

The protective and sectioning devices installed on the supports should be located below the overhead lines.

2.4.29. The distances between the bare wires on the support and in the span, according to the conditions of their convergence in the span with the largest sag arrow up to 1.2 m, must be at least:

with a vertical arrangement of wires and an arrangement of wires with a horizontal displacement of no more than 20 cm: 40 cm in areas I, II and III on ice, 60 cm in IV and special areas on ice;

with other locations of wires in all areas on ice at wind speed during ice: up to 18 m / s - 40 cm, more than 18 m / s - 60 cm.

With the largest sag arrow of more than 1.2 m, the indicated distances should be increased in proportion to the ratio of the largest sag arrow to the sag arrow equal to 1.2 m.

2.4.30. The vertical distance between insulated and non-insulated wires of overhead lines of different phases on a support when branching off from overhead lines and when crossing different overhead lines on a common support should be at least 10 cm.

The distance from the overhead line wires to any support elements should be at least 5 cm.

2.4.31. With joint suspension on common supports of VLI and overhead lines up to 1 kV, the vertical distance between them on the support and in the span at an ambient temperature of plus 15 ° C without wind should be at least 0.4 m.

2.4.32. When two or more VLIs are jointly suspended on common supports, the distance between the self-supporting insulated wire harnesses must be at least 0.3 m.

2.4.33. With joint suspension on common supports of overhead lines up to 1 kV and overhead lines up to 20 kV, the vertical distance between the nearest overhead lines of different voltages on a common support, as well as in the middle of the span at an ambient temperature of plus 15 ° C without wind, should be at least:

1.0 m - when suspending self-supporting insulated wire with insulated carrier and with all carrier wires;

1.75 m - when suspending self-supporting insulated wire with an uninsulated carrier wire;

2.0 m - when suspending bare and insulated wires of overhead lines up to 1 kV.

2.4.34. When suspended on common supports wires of overhead lines up to 1 kV and protected wires of overhead lines 6-20 kV (see 2.5.1), the vertical distance between the nearest wires of overhead lines up to 1 kV and overhead lines 6-20 kV on the support and in the span at a temperature of plus 15 ° С without wind should be at least 0.3 m for self-supporting insulated wire and 1.5 m for uninsulated and insulated wires of overhead lines up to 1 kV.

Insulation

2.4.35. Self-supporting insulated wire is attached to the poles without the use of insulators.

2.4.36. On overhead lines with bare and insulated wires, regardless of the material of the supports, the degree of atmospheric pollution and the intensity of thunderstorm activity, insulators or traverses made of insulating materials should be used.

The selection and calculation of insulators and fittings are carried out in accordance with 2.5.100.

2.4.37. On the supports of branches from overhead lines with bare and insulated wires, as a rule, multi-neck or additional insulators should be used.

Grounding. Overvoltage protection

2.4.38. On the overhead line supports, grounding devices must be made designed for re-grounding, protection against lightning surges, grounding of electrical equipment installed on the overhead line supports. The resistance of the grounding device should be no more than 30 ohms.

2.4.39. Metal supports, metal constructions and reinforcement of reinforced concrete elements of the supports must be attached to PEN-conductor.

2.4.40. On reinforced concrete supports PEN- the conductor should be connected to the reinforcement of reinforced concrete racks and struts of the supports.

2.4.41. Hooks and pins of wooden poles of overhead lines, as well as metal and reinforced concrete poles, when suspended on them a self-supporting insulated wire with an insulated carrying conductor or with all carrying conductors of the harness, are not subject to grounding, with the exception of hooks and pins on the supports, where repeated grounding and grounding are performed to protect against atmospheric overvoltage.

2.4.42. Hooks, pins and fittings of overhead lines with a voltage of up to 1 kV, limiting the span of the intersection, as well as supports on which joint suspension is made, must be grounded.

2.4.43. On wooden poles of overhead lines, when switching to a cable line, the grounding conductor must be connected to PEN- the conductor of the overhead line and to the metal sheath of the cable.

2.4.44. Protective devices installed on overhead transmission line supports for protection against lightning overvoltages must be connected to the ground electrode by a separate descent.

2.4.45. The connection of grounding conductors to each other, their connection to the upper grounding outlets of the racks of reinforced concrete supports, to hooks and brackets, as well as to grounded metal structures and to grounded electrical equipment installed on the overhead transmission line supports, must be performed by welding or bolted connections.

The connection of the grounding conductors (slopes) to the ground electrode in the ground must also be carried out by welding or have bolted connections.

2.4.46. In populated areas with one- and two-story buildings, overhead lines must have grounding devices designed to protect against atmospheric overvoltages. The resistances of these grounding devices should be no more than 30 ohms, and the distance between them should be no more than 200 m for areas with up to 40 thunderstorm hours per year, 100 m for areas with more than 40 thunderstorm hours per year.

In addition, grounding devices must be performed:

1) on supports with branches to the inputs to buildings in which a large number of people can be concentrated (schools, nurseries, hospitals) or which are of great material value (livestock and poultry premises, warehouses);

2) on the end supports of lines with branches to the inputs, while the greatest distance from the adjacent grounding of the same lines should be no more than 100 m for areas with the number of thunderstorm hours per year up to 40 and 50 m - for areas with the number of thunderstorm hours per year more than 40.

2.4.47. At the beginning and end of each VLI line, it is recommended to install clamps on the wires for connecting voltage monitoring devices and portable grounding.

It is recommended to combine grounding devices for lightning surge protection with re-grounding PEN-conductor.

2.4.48. Requirements for grounding re-grounding devices and protective conductors are given in 1.7.102, 1.7.103, 1.7.126. It is allowed to use round steel with an anti-corrosion coating with a diameter of at least 6 mm as grounding conductors on overhead line supports.

2.4.49. The guy wires of the overhead line supports must be connected to the grounding conductor.

Support

2.4.50. Supports made of various materials can be used on overhead lines.

For overhead lines, the following types of supports should be used:

1) intermediate, installed on straight sections of the overhead line route. These supports in normal operating modes should not perceive the efforts directed along the overhead line;

2) anchor, installed to limit the anchor span, as well as in places where the number, brands and cross-sections of overhead lines change. These supports should perceive, in normal operating modes, the forces from the difference in the tension of the wires directed along the overhead line;

3) angular, installed in places where the direction of the overhead line route changes. Under normal operating conditions, these supports must perceive the resulting load from the tension of the wires of adjacent spans. Corner supports can be intermediate and anchor type;

4) terminal, installed at the beginning and end of the overhead line, as well as in places limiting cable inserts. They are anchor-type supports and must perceive in normal operating modes of overhead lines one-sided tension of all wires.

The supports on which the branches from the overhead line are made are called branching; the supports on which the intersection of overhead lines of different directions or the intersection of overhead lines with engineering structures is performed are cross. These supports can be of all types indicated.

2.4.51. Support structures should provide the ability to install:

street lighting fixtures of all types;

cable end sleeves;

protective devices;

sectioning and switching devices;

cabinets and shields for connecting electrical receivers.

2.4.52. Supports, regardless of their type, can be free-standing, with struts or braces.

Guy braces can be attached to anchors installed in the ground, or to stone, brick, reinforced concrete and metal elements buildings and structures. The section of the guys is determined by calculation. They can be multi-wire or round steel. The cross-section of single-wire steel braces must be at least 25 .

2.4.53. Supports of overhead lines should be calculated according to the first and second limit states in the normal operation of overhead lines for climatic conditions according to 2.4.11 and 2.4.12.

Intermediate supports must be designed for the following load combinations:

the simultaneous effect of a transverse wind load on wires, free or covered with ice, and on the structure of the support, as well as loads from the tension of the branch wires to the inputs, free from ice or partially covered with ice (according to 2.4.12);

on the load from the tension of the branch wires to the inputs covered with ice, while taking into account the deflection of the support under the action of the load;

for a nominal design load equal to 1.5 kN, applied to the top of the support and directed along the axis of the overhead line.

Corner supports (intermediate and anchor) must be designed for the resultant load from wire pulling and wind load on the wires and support structure.

Anchor supports should be designed for the difference in tension between wires of adjacent spans and transverse load from wind pressure with ice and without ice on the wires and the structure of the support. Per smallest value the difference in gravity should be taken 50% the greatest value unilateral tension of all wires.

End supports must be designed for one-sided pulling of all wires.

Branch supports are designed for the resulting stress from all wires.

2.4.54. When installing supports on flooded sections of the route, where soil erosion or ice drift is possible, the supports must be strengthened (adding earth, paving, installing banquettes, installing ice cutters).

Dimensions, intersections and convergence

2.4.55. The vertical distance from the VLI wires to the earth's surface in populated and uninhabited areas to the ground and the roadway of streets should be at least 5 m.It can be reduced in hard-to-reach areas to 2.5 m and in inaccessible (mountain slopes, rocks, cliffs) - up to 1 m.

When crossing the impassable part of the streets with branches from the VLI to the inputs to the buildings, the distance from the self-supporting insulated wire to the sidewalks of the pedestrian paths may be reduced to 3.5 m.

The distance from the self-supporting insulated wire and insulated wires to the ground surface on the branches to the input should be at least 2.5 m.

The distance from bare wires to the ground surface at the branches to the inputs must be at least 2.75 m.

2.4.56. The distance from the wires of overhead lines in populated and uninhabited areas with the largest sag of the wires to the ground and the roadway of streets should be at least 6 m.The distance from the wires to the ground can be reduced in hard-to-reach areas to 3.5 m and in inaccessible areas (mountain slopes , rocks, cliffs) - up to 1 m.

2.4.57. The horizontal distance from the self-supporting insulated wire with their greatest deviation to the elements of buildings and structures should be at least:

1.0 m

0.2 m - to the blank walls of buildings, structures.

It is allowed to pass overhead lines and overhead lines with insulated wires over the roofs of buildings and structures (except as specified in Chapters 7.3 and 7.4), while the vertical distance from them to the wires must be at least 2.5 m.

2.4.58. The horizontal distance from the wires of the overhead line with their greatest deviation to buildings and structures should be at least:

1.5 m - to balconies, terraces and windows;

1.0 m - to blank walls.

The passage of overhead lines with bare wires over buildings and structures is not allowed.

2.4.59. The smallest distance from the self-supporting insulated wire and the wires of the overhead line to the surface of the earth or water, as well as to various structures when the overhead line passes over them is determined when highest temperature air without taking into account the heating of the wires of the overhead line by electric current.

2.4.60. When laying along the walls of buildings and structures minimum distance from the self-supporting insulated wire should be:

when laying horizontally

above the window, the front door - 0.3 m;

under the balcony, window, cornice - 0.5 m;

to the ground - 2.5 m;

with vertical laying

to the window - 0.5 m;

to the balcony, front door - 1.0 m.

The clear distance between the self-supporting insulated wire and the wall of a building or structure must be at least 0.06 m.

2.4.61. Horizontal distances from underground parts of supports or grounding conductors of supports to underground cables, pipelines and ground columns for various purposes should be no less than those given in table 2.4.4.

Table 2.4.4

The smallest permissible horizontal distance from underground parts of supports or grounding devices of supports to underground cables, pipelines and ground columns

Approach object	Distance, m
Water, steam and heat pipelines, gas distribution pipelines, sewer pipes
Fire hydrants, wells, sewer hatches, water columns
Cables (excluding communication, signaling and wire broadcasting cables, see also 2.4.77)
The same, but when laying them in an insulating pipe

2.4.62. When crossing overhead lines with various structures, as well as with streets and squares settlements the intersection angle is not standardized.

2.4.63. The intersection of overhead lines with navigable rivers and canals is not recommended. If it is necessary to perform such an intersection, overhead lines must be constructed in accordance with the requirements of 2.5.268-2.5.272. When crossing non-navigable rivers and canals, the smallest distance from the overhead line wires to the highest water level should be at least 2 m, and to the ice level - at least 6 m.

2.4.64. Intersections and convergence of overhead lines with voltages up to 1 kV with overhead lines with voltages above 1 kV, as well as joint suspension of their wires on common supports must be performed in compliance with the requirements given in 2.5.220-2.5.230.

2.4.65. The intersection of overhead lines (VLI) up to 1 kV with each other is recommended to be performed on cross supports; their intersection in the span is also allowed. The vertical distance between the wires of intersecting overhead lines (VLI) must be at least: 0.1 m on the support, 1 m in the span.

2.4.66. At the intersection of overhead lines up to 1 kV, intermediate supports and anchor-type supports can be used.

When crossing overhead lines up to 1 kV with each other in the span, the crossing point should be chosen as close as possible to the support of the upper crossing overhead line, while the horizontal distance from the supports of the crossing overhead line to the wires of the overhead line being crossed, with their greatest deviation, should be at least 2 m.

2.4.67. With parallel passage and convergence of overhead lines up to 1 kV and overhead lines above 1 kV, the horizontal distance between them must be at least as specified in 2.5.230.

2.4.68. Joint suspension of wires of overhead lines up to 1 kV and bare wires of overhead lines up to 20 kV on common supports is allowed subject to the following conditions:

2) wires of overhead lines up to 20 kV should be located above the wires of overhead lines up to 1 kV;

3) wires of overhead lines up to 20 kV, fixed on pin insulators, must have double fastening.

2.4.69. When suspended on common supports of wires of overhead lines up to 1 kV and protected wires of overhead lines 6-20 kV, the following requirements must be observed:

1) Overhead lines up to 1 kV must be carried out according to the calculated climatic conditions Overhead lines up to 20 kV;

2) wires of overhead lines 6-20 kV should be located, as a rule, above the wires of overhead lines up to 1 kV;

3) the fastening of 6-20 kV VLZ wires on pin insulators should be reinforced.

2.4.70. When crossing an overhead line (VLI) with an overhead line with a voltage higher than 1 kV, the distance from the wires of the crossing overhead line to the crossed overhead line (VLI) must comply with the requirements given in 2.5.221 and 2.5.227.

The cross-section of the wires of the crossed overhead line should be taken in accordance with 2.5.223.

Intersections, convergence, joint suspension of overhead lines with communication lines, wire broadcasting and RK

2.4.71. The angle of intersection of the overhead line with the LS * and LPV should be as close to 90 ° as possible. For confined conditions, the intersection angle is not standardized.

_______________

* LAN should be understood as communication lines of the Ministry of Communications of the Russian Federation and other departments, as well as signaling lines of the Ministry of Railways.

LPV should be understood as wire broadcasting lines.

Overhead communication lines, according to their purpose, are divided into long-distance telephone lines (MTS), rural telephone lines (STS), city telephone lines (GTS), wire broadcasting lines (LPV).

By importance, overhead communication lines and wire broadcasting are subdivided into classes:

MTS and STS lines: MTS trunk lines connecting Moscow with republican, regional and regional centers and the latter among themselves, and the lines of the Ministry of Railways passing along railways and on the territory of railway stations (class I); intrazonal MTS lines connecting republican, regional and regional centers with regional centers and the latter among themselves, and STS connecting lines (class II); subscriber lines STS (class III);

GTS lines are not subdivided into classes;

wire broadcasting lines: feeder lines with rated voltage above 360 V (class I); feeder lines with rated voltage up to 360 V and subscriber lines with voltages of 15 and 30 V (class II).

2.4.72. The vertical distance from the wires of the overhead line to the wires or overhead cables of the LAN and LPV in the span of the intersection with the largest sag of the overhead line wire should be:

from self-supporting insulated wire and insulated wires - at least 1 m;

from bare wires - at least 1.25 m.

2.4.73. The vertical distance from the wires of the overhead line up to 1 kV to the wires or overhead cables of the LAN or LPV when crossing on a common support should be:

between the self-supporting insulated wire and the drug or LPV - at least 0.5 m;

between the uninsulated wire of the overhead line and the LPV - at least 1.5 m.

2.4.74. The place of intersection of overhead lines with wires or overhead cables of drugs and power lines in the span should be as close as possible to the overhead line support, but not less than 2 m from it.

2.4.75. The intersection of overhead lines with drugs and LPV can be performed according to one of the following options:

1) wires of overhead lines and insulated wires of drugs and LPV;

2) wires of overhead lines and underground or overhead cables of drugs and power supplies;

3) wires of overhead lines and bare wires of drugs and LPV;

4) an underground cable insert in overhead lines with insulated and non-insulated LS and LPV wires.

2.4.76. When crossing overhead lines with insulated wires of drugs and power supplies, the following requirements must be observed:

2) the intersection of bare wires of overhead lines with LAN wires, as well as with LPV wires with a voltage higher than 360 V should be performed only in the span. The intersection of bare wires of overhead lines with wires of LPV with a voltage of up to 360 V can be performed both in the span and on a common support;

3) overhead line supports limiting the span of intersection with the LAN of main and intra-zone communication networks and connecting lines of STS, as well as LPV with a voltage higher than 360 V, must be of an anchor type. At the intersection of all other drugs and LPV, supports of intermediate-type overhead lines, reinforced with an additional attachment or strut, are allowed;

4) the wires of the overhead line should be located above the wires of the LAN and LPV. On the supports limiting the span of the intersection, bare and insulated wires of the overhead line must have a double fastening, the self-supporting insulated wire is fixed with anchor clamps. The LAN and LPV wires on the supports limiting the crossing span must have double fastening. In cities and urban-type settlements, newly constructed drugs and power lines are allowed to be located above the wires of overhead lines with a voltage of up to 1 kV.

2.4.77. When crossing overhead lines with an underground or overhead cable of a LAN and LPV, the following requirements must be met:

1) the distance from the underground part of the metal or reinforced concrete support and the ground electrode wooden support to the underground cable of drugs and LPV in a populated area, as a rule, there should be at least 3 m. In confined conditions, it is allowed to reduce these distances to 1 m (provided that interfering influences on drugs and LPVs are permissible); in this case, the cable must be laid in steel pipe or covered with a channel or angle steel along the length on both sides of the support at least 3 m;

2) in an uninhabited area, the distance from the underground part or the ground electrode of the overhead line support to the underground cable of the LAN and LPV should be at least the values given in Table 2.4.5;

Table 2.4.5

The smallest distance from the underground part and the ground electrode of the overhead line support to the underground cable of the LS and LPV

in uninhabited area

Equivalent resistivity earth, Ohm m	The smallest distance, m, from the underground cable LAN and LPV
	to the ground electrode or the underground part of the reinforced concrete and metal support	to the underground part of a wooden support without a grounding device
Up to 100
More than 100 to 500
More than 500 to 1000
Over 1000

3) the wires of the overhead line should be located, as a rule, above the overhead cable of the LAN and LPV (see also 2.4.76, clause 4);

4) the connection of the overhead lines in the span of the intersection with the overhead cable of the LS and LPV is not allowed. The cross-section of the supporting core of the self-supporting insulated wire must be at least 35 ... Overhead lines must be stranded with a cross-section of at least: aluminum - 35 , steel-aluminum - 25 ; cross-section of the self-supporting insulated wire with all carrying conductors of the bundle - at least 25 ;

5) the metal sheath of the overhead cable and the cable on which the cable is suspended must be grounded on the supports limiting the span of the crossing;

6) the horizontal distance from the base of the cable support of the LAN and LPV to the projection of the nearest overhead line wire on the horizontal plane should be not less than the maximum height of the support of the intersection span.

2.4.78. When crossing VLI with uninsulated wires of drugs and LPV, the following requirements must be observed:

1) the intersection of VLI with LS and LPV can be performed in the span and on the support;

2) VLI supports, limiting the span of intersections with the LAN of the main and intra-zone communication networks and with the connecting lines of the STS, must be of the anchor type. At the intersection of all other drugs and LPV on the VLI, the use of intermediate supports, reinforced with an additional attachment or strut, is allowed;

3) the bearing core of a self-supporting insulated wire or a bundle with all bearing conductors at the intersection must have a tensile safety factor at the highest design loads of at least 2.5;

4) the VLI wires should be located above the LAN and LPV wires. On the supports limiting the span of the intersection, the supporting wires of the self-supporting insulated wire must be fixed with tension clamps. VLI wires are allowed to be placed under LPV wires. In this case, the LPV wires on the supports limiting the span of the intersection must have a double fastening;

5) the connection of the bearing core and the bearing conductors of the self-supporting insulated wire harness, as well as the LAN and LPV wires in the intersection spans is not allowed.

2.4.79. When crossing insulated and uninsulated wires of overhead lines with uninsulated wires of LS and LPV, the following requirements must be observed:

1) the intersection of the overhead line wires with the LAN wires, as well as LPV wires with a voltage higher than 360 V should be performed only in the span.

The intersection of overhead lines with subscriber and feeder lines of LPV with a voltage of up to 360 V is allowed to be performed on overhead lines;

2) the overhead line supports limiting the span of the intersection must be of the anchor type;

3) drugs wires, both steel and non-ferrous metal, must have a safety factor for tensile strength at the highest design loads of at least 2.2;

4) the wires of the overhead line should be located above the wires of the LAN and LPV. On the supports limiting the span of the intersection, the wires of the overhead line must have a double fastening. The wires of overhead lines with a voltage of 380/220 V and below are allowed to be placed under the wires of the LPV and GTS lines. In this case, the wires of the LPV and GTS lines on the supports limiting the span of the intersection must have a double fastening;

5) the connection of the overhead line wires, as well as the LAN and LPV wires in the intersection spans is not allowed. Overhead line wires must be multi-wire with cross-sections of at least: aluminum - 35 , steel-aluminum - 25 .

2.4.80. When crossing an underground cable insert in an overhead line with uninsulated and insulated wires of drugs and power supplies, the following requirements must be observed:

1) the distance from the underground cable insert in the overhead line to the support of the LS and LPV and its ground electrode must be at least 1 m, and when laying the cable in an insulating pipe - at least 0.5 m;

2) the horizontal distance from the base of the cable support of the overhead line to the projection of the nearest LAN and LPV wire on the horizontal plane should be not less than the maximum height of the support span of the intersection.

2.4.81. The horizontal distance between the VLI wires and the LAN and LPV wires with parallel passage or approach should be at least 1 m.

When approaching overhead lines with airborne drugs and LPV, the horizontal distance between insulated and non-insulated wires of overhead lines and wires of drugs and LPV should be at least 2 m.In confined conditions, this distance can be reduced to 1.5 m.In all other cases, the distance between the lines should be at least the height of the highest support of overhead lines, drugs and LPV.

When approaching overhead lines with underground or overhead cables of drugs and power supplies, the distances between them should be taken in accordance with 2.4.77 clauses 1 and 5.

2.4.82. The convergence of overhead lines with antenna structures of transmitting radio centers, receiving radio centers, dedicated receiving points for wire broadcasting and local radio centers is not standardized.

2.4.83. The wires from the overhead line support to the entry into the building should not intersect with the branch wires from the LAN and LPV, and they should be located at the same level or above the LAN and LPV. The horizontal distance between the wires of the overhead line and the wires of the LAN and LPV, television cables and slopes from radio antennas at the inputs should be at least 0.5 m for self-supporting insulated wires and 1.5 m for uninsulated wires of overhead lines.

2.4.84. Joint suspension of an overhead cable for rural telephone communication and VLI is allowed if the following requirements are met:

1) the zero core of the self-supporting insulated wire must be insulated;

2) the distance from the self-supporting insulated wire to the STS overhead cable in the span and on the VLI support must be at least 0.5 m;

3) each VLI support must have a grounding device, while the grounding resistance must be no more than 10 ohms;

4) on each VLI support, re-grounding must be performed PEN-conductor;

5) the carrying rope of the telephone cable together with the metal mesh outer cover of the cable must be connected to the ground electrode of each support by a separate independent conductor (descent).

2.4.85. Joint suspension on common supports of bare wires of overhead lines, LS and LPV is not allowed.

On common supports, joint suspension of bare wires of overhead lines and insulated wires of LPV is allowed. In this case, the following conditions must be met:

1) the rated voltage of the overhead line should be no more than 380 V;

3) the distance from the lower wires of the LPV to the ground, between the LPV circuits and their wires must comply with the requirements of the current rules of the Ministry of Communications of Russia;

4) bare wires of overhead lines should be located above the wires of LPV; at the same time, the vertical distance from the lower wire of the overhead line to the upper wire of the LPV should be at least 1.5 m on the support, and at least 1.25 m in the span; when the LPV wires are located on the brackets, this distance is taken from the bottom wire of the overhead line located on the same side as the LPV wires.

2.4.86. On common supports, a joint suspension of the VLI SIP with bare or insulated LS and LPV wires is allowed. In this case, the following conditions must be met:

1) the rated voltage of the VLI should be no more than 380 V;

2) the rated voltage of the LPV should be no more than 360 V;

3) the nominal voltage of the LAN, the calculated mechanical stress in the wires of the LAN, the distance from the lower wires of the LAN and LPV to the ground, between the circuits and their wires must comply with the requirements of the current rules of the Ministry of Communications of Russia;

4) VLI wires up to 1 kV should be located above the LAN and LPV wires; at the same time, the vertical distance from the self-supporting insulated wire to the upper wire of the LS and LPV, regardless of their relative position, should be at least 0.5 m on the support and in the span. It is recommended to locate the VLI and LS and LPV wires on different sides of the support.

2.4.87. Joint suspension on common supports of bare wires of overhead lines and LAN cables is not allowed. Joint suspension on common supports of overhead lines with a voltage of no more than 380 V and LPV cables is allowed subject to the conditions specified in 2.4.85.

Optical fibers OKNN must meet the requirements of 2.5.192 and 2.5.193.

2.4.88. Joint suspension on common supports of overhead lines with a voltage of no more than 380 V and telemechanics wires is allowed subject to the requirements given in 2.4.85 and 2.4.86, and also if telemechanics circuits are not used as wired telephone communication channels.

2.4.89. On the supports of overhead lines (VLI), it is allowed to suspend fiber-optic communication cables (OK):

non-metallic self-supporting (OCSN);

non-metallic, wound on a phase wire or a self-supporting insulated wire harness (OKNN).

Mechanical calculations of supports of overhead lines (VLI) with OKSN and OKNN should be made for the initial conditions specified in 2.4.11 and 2.4.12.

Supports of overhead lines, on which the OK is suspended, and their fastening in the ground should be calculated taking into account additional loads arising in this case.

The distance from the OKSN to the earth's surface in populated and uninhabited areas must be at least 5 m.

The distances between the wires of overhead lines up to 1 kV and OKSN on the support and in the span must be at least 0.4 m.

Intersections and convergence of overhead lines with engineering structures

2.4.90. When crossing and parallel following overhead lines with railways and highways, the requirements set out in Ch.2.5 must be met.

Intersections can also be performed using a cable insert in the overhead line.

2.4.91. When the overhead line approaches by road the distance from the overhead line wires to the road signs and their supporting cables must be at least 1 m. The supporting cables must be grounded with a grounding device resistance of no more than 10 ohms.

2.4.92. When crossing and approaching overhead lines with contact wires and supporting cables of tram and trolleybus lines, the following requirements must be met:

1) Overhead lines should, as a rule, be located outside the area occupied by the structures of contact networks, including supports.

In this area, the overhead line supports must be of the anchor type, and the bare wires must be double fastened;

2) the wires of the overhead line must be located above the carrying cables of the contact wires. Overhead lines must be stranded with a cross section of at least: aluminum - 35 , steel-aluminum - 25 , bearing core SIP - 35 , cross-section of the self-supporting insulated wire (SIP) core with all carrying conductors of the bundle - at least 25 ... The connection of overhead lines in the intersection spans is not allowed;

3) the distance from the wires of the overhead line with the largest sag should be at least 8 m to the rail head of the tram line and 10.5 m to the carriageway of the street in the zone of the trolleybus line.

Moreover, in all cases, the distance from the overhead line wires to the carrying cable or contact wire must be at least 1.5 m;

4) the intersection of overhead lines with contact wires at the locations of the crossbars is prohibited;

5) joint suspension on the supports of trolleybus lines of overhead lines and wires of overhead lines with a voltage of not more than 380 V is allowed provided the following conditions are met: the supports of trolleybus lines must have mechanical strength sufficient for hanging overhead lines, the distance between the wires of the overhead line and the bracket or device for fastening the supporting cable of the contact wires must be at least 1.5 m.

2.4.93. When crossing and approaching overhead lines with cable cars and overhead metal pipelines, the following requirements must be met:

1) The overhead line must pass under the cable car; the passage of overhead lines over the cable car is not allowed;

2) cable cars should have a walkway or nets at the bottom for fencing overhead lines;

3) when the overhead line passes under the cable car or under the pipeline, the overhead line wires must be at a distance from them: at least 1 m - with the smallest sag of the wires to the walkways or fencing nets of the cable car or to the pipeline; not less than 1 m - with the largest sag arrow and the greatest deviation of the wires to the elements of the cable car or to the pipeline;

4) when crossing the overhead line with the pipeline, the distance from the overhead line wires with their largest sag to the pipeline elements must be at least 1 m. The overhead line supports limiting the span of the intersection with the pipeline must be of an anchor type. The pipeline in the crossing span must be grounded, the resistance of the ground electrode must be no more than 10 ohms;

5) when the overhead line runs parallel with the cable car or pipeline, the horizontal distance from the overhead line wires to the cable car or pipeline must be at least the height of the support, and on confined sections of the route with the greatest deviation of the wires - at least 1 m.

2.4.94. When approaching overhead lines with fire and explosive installations and with aerodromes, the requirements given in 2.5.278, 2.5.291 and 2.5.292 should be followed.

2.4.95. The passage of overhead lines up to 1 kV with insulated and non-insulated wires is not allowed in the territories of sports facilities, schools (general education and boarding schools), technical schools, children's preschool institutions(nurseries, kindergartens, children's complexes), orphanages, children's playgrounds, as well as in the territories of children's health camps.

In the above territories (except for sports and playgrounds), the passage of VLI is allowed, provided that the zero core of the self-supporting insulated wire must be insulated, and its total conductivity must be at least the conductivity of the phase conductor of the self-supporting insulated wire.

The vertical distance from the VLI wires to the earth's surface in populated and uninhabited areas to the ground and the roadway of streets should be at least 5 m.It can be reduced in hard-to-reach areas to 2.5 m and in inaccessible (mountain slopes, rocks, cliffs) - up to 1 m.

The distance from the self-supporting insulated wire and insulated wires to the ground surface on the branches to the input should be at least 2.5 m.

The distance from bare wires to the ground surface at the branches to the inputs must be at least 2.75 m.

2.4.56. The distance from the wires of overhead lines in populated and uninhabited areas with the largest sag of the wires to the ground and the roadway of the streets should be at least 6 m.The distance from the wires to the ground can be reduced in hard-to-reach areas to 3.5 m and in inaccessible areas (mountain slopes , rocks, cliffs) - up to 1 m.

2.4.57. The horizontal distance from the self-supporting insulated wire with their greatest deviation to the elements of buildings and structures should be at least:

1.0 m - to balconies, terraces and windows;

0.2 m - to the blank walls of buildings, structures.

It is allowed to pass overhead lines and overhead lines with insulated wires over the roofs of buildings and structures (except for those specified in Ch. 7.3 and 7.4), while the vertical distance from them to the wires must be at least 2.5 m.

2.4.58. The horizontal distance from the wires of the overhead line with their greatest deviation to buildings and structures should be at least:

1.5 m - to balconies, terraces and windows;

1.0 m - to blank walls.

The passage of overhead lines with bare wires over buildings and structures is not allowed.

2.4.59. The smallest distance from the self-supporting insulated wire and the overhead line wires to the surface of the earth or water, as well as to various structures when the overhead line passes over them, is determined at the highest air temperature without taking into account the heating of the overhead line wires by electric current.

2.4.60. When laying along the walls of buildings and structures, the minimum distance from the self-supporting insulated wire should be:

when laying horizontally

above the window, the front door - 0.3 m;

under the balcony, window, cornice - 0.5 m;

to the ground - 2.5 m;

with vertical laying

to the window - 0.5 m;

to the balcony, front door - 1.0 m.

The clear distance between the self-supporting insulated wire and the wall of a building or structure must be at least 0.06 m.

2.4.61. The horizontal distances from the underground parts of the supports or grounding conductors of the supports to underground cables, pipelines and ground columns for various purposes must be at least as shown in Table. 2.4.4.

Table 2.4.4

The smallest allowable horizontal distance

from underground parts of supports or grounding devices

supports to underground cables, pipelines and ground speakers

Approach object	Distance, m
Water, steam and heat pipelines, gas distribution pipelines, sewer pipes
Fire hydrants, wells, sewer hatches, water columns
Cables (excluding communication, signaling and wire broadcasting cables, see also 2.4.77)
The same, but when laying them in an insulating pipe

2.4.62. When crossing overhead lines with various structures, as well as with streets and squares of settlements, the intersection angle is not standardized.

2.4.63. The intersection of overhead lines with navigable rivers and canals is not recommended. If it is necessary to perform such an intersection, overhead lines must be constructed in accordance with the requirements of 2.5.268 - 2.5.272. When crossing non-navigable rivers and canals, the smallest distance from the overhead line wires to the highest water level should be at least 2 m, and to the ice level - at least 6 m.

2.4.64. Intersections and convergence of overhead lines with voltage up to 1 kV with overhead lines with voltages above 1 kV, as well as joint suspension of their wires on common supports must be performed in compliance with the requirements given in 2.5.220 - 2.5.230.

2.4.66. At the intersection of overhead lines up to 1 kV, intermediate supports and anchor-type supports can be used with each other.

2.4.67. With parallel passage and convergence of overhead lines up to 1 kV and overhead lines above 1 kV, the horizontal distance between them must be at least as specified in 2.5.230.

2.4.68. Joint suspension of wires of overhead lines up to 1 kV and bare wires of overhead lines up to 20 kV on common supports is allowed subject to the following conditions:

2) wires of overhead lines up to 20 kV should be located above the wires of overhead lines up to 1 kV;

3) wires of overhead lines up to 20 kV, fixed on pin insulators, must have double fastening.

2.4.69. When suspended on common supports of wires of overhead lines up to 1 kV and protected wires of overhead lines 6-20 kV, the following requirements must be observed:

1) Overhead lines up to 1 kV must be performed according to the calculated climatic conditions of overhead lines up to 20 kV;

2) wires of overhead lines 6-20 kV should be located, as a rule, above the wires of overhead lines up to 1 kV;

3) the fastening of 6-20 kV VLZ wires on pin insulators should be reinforced.

The requirements given in 4.2.123-4.2.132 reflect the features of transformer substations outdoor installation complete (KTP), pole (STP), mast (MTP) with high voltage up to 35 kV and low voltage up to 1 kV, as well as network sectioning points (SSP) with voltage up to 35 kV.

In all other respects not specified in 4.2.123-4.2.132, the requirements of other paragraphs of this chapter should be followed.

4.2.123

The connection of the transformer to the high voltage network must be carried out using fuses and a disconnector (load switch) or a combined device "fuse-disconnector" with a visible open circuit.

The switching device must be controlled from the ground. The switching device drive must be padlocked. The switching device must have earthing switches on the transformer side.

4.2.124

The switching device MTP and STP, as a rule, should be installed on the end (or branch) support of the overhead line.

The switchgear KTP and SSP can be installed both on the terminal (branch) support of the overhead line, and inside the KTP and SSP.

4.2.125

At substations and SSPs without fencing, the vertical distance from the ground surface to non-insulated live parts in the absence of traffic under the terminals should be at least 3.5 m for voltages up to 1 kV, and for voltages 10 (6) and 35 kV - according to table. 4.2.7 size.

At substations and SSP with a fence with a height of at least 1.8 m, the indicated distances to non-insulated live parts with a voltage of 10 (6) and 35 kV can be reduced to the size indicated in Table 4.2.5. In this case, in the plane of the fence, the distance from the busbar to the edge of the outer fence must be at least the size indicated in the same table.

For air inputs crossing passages or places where traffic is possible, the distance from the lowest wire to the ground should be taken in accordance with 2.5.111 and 2.5.112.

4.2.126

To service the MTP at a height of at least 3 m, a platform with a handrail must be arranged. To climb to the site, it is recommended to use stairs with a device that prohibits climbing on it when the switching device is on.

For STP, the device of platforms and stairs is not necessary.

4.2.127

Parts of the MTP that remain energized when the switching device is off must be out of reach (1.7.70) from the platform level. The disconnected position of the apparatus must be visible from the platform.

4.2.128

On the low voltage side of the transformer, it is recommended to install a device that provides a visible break.

4.2.129

The electrical wiring in the MTP and STP between the transformer and the low-voltage board, as well as between the board and the low-voltage overhead line, must be protected from mechanical damage and carried out in accordance with the requirements given in Chapter 2.1.

4.2.130

For substations with a capacity of 0.25 MVA and less, it is allowed not to provide illumination of the low-voltage switchboard. Lighting and sockets for switching on portable devices, tools at substations with a capacity of more than 0.25 MVA must be powered with a voltage not exceeding 25 V.

4.2.131

By condition fire safety substations must be located at a distance of at least 3 m from buildings of I, II, III degrees of fire resistance and 5 m from buildings of IV and V degrees of fire resistance.

It is also necessary to be guided by the requirements given in 4.2.68.

The distance from residential buildings to transformer substations should be taken at least 10 m, provided that the permissible normal levels of sound pressure (noise) are ensured.

4.2.132

In places of possible collision of transport, substations must be protected by bumpers.

Locks in the doors of premises of switchgear of the same voltage must be opened with the same key; keys from entrance doors The switchgear and other premises should not come close to the camera locks, as well as to the door locks in the enclosures of electrical equipment.

The requirement to use self-locking locks does not apply to switchgears of urban and rural distribution electrical networks voltage of 10 kV and below.

4.2.97. Enclosing structures and partitions for switchgear and transformer substations own needs power plants should be made of non-combustible materials.

It is allowed to install switchgear and transformer substations for own needs in the technological rooms of substations and power plants in accordance with the requirements 4.2.121 .

4.2.98. In one room of the switchgear with a voltage of 0.4 kV and above, it is allowed to install up to two oil transformers with a capacity of up to 0.63 MVA each, separated from each other and from the rest of the switchgear room by a partition made of non-combustible materials with a fire resistance limit of 45 minutes, at least the height of the transformer, including the high voltage bushings.

4.2.99. Apparatus related to launchers electric motors, synchronous compensators, etc. (switches, starting reactors, transformers, etc.) may be installed in a common chamber without partitions between them.

4.2.100. Voltage transformers, regardless of the mass of oil in them, are allowed to be installed in fenced RU chambers. In this case, a threshold or ramp must be provided in the chamber, designed to hold the full volume of oil contained in the voltage transformer.

4.2.101. The switch compartments should be separated from the service corridor by solid or mesh fences, and from each other by solid partitions made of non-combustible materials. These switches must be separated from the drive by the same partitions or shields.

Under each oil switch with an oil mass of 60 kg or more in one pole, an oil receiver device for the full volume of oil in one pole is required.

4.2.102. In closed free-standing, attached and built-in industrial premises Substation, in the chambers of transformers and other oil-filled devices with an oil mass in one tank up to 600 kg when the chambers are located on the ground floor with doors going out, oil collecting devices are not performed.

When the mass of oil or non-combustible environmentally friendly dielectric in one tank is more than 600 kg, an oil receiver must be arranged, designed for the full volume of oil or for holding 20% of the oil with a drain to the oil sump.

4.2.103. When building cells above the basement, on the second floor and above (see also 4.2.118 ), as well as when the exit from the chambers into the corridor is arranged under the transformers and other oil-filled devices, oil receivers must be performed in one of the following ways:

1) with an oil mass in one tank (pole) up to 60 kg, a threshold or ramp is performed to hold the full volume of oil;
2) with an oil mass of 60 to 600 kg, an oil receiver is installed under the transformer (apparatus), designed for the full volume of oil, or at the exit from the chamber - a threshold or ramp to hold the full volume of oil;
3) with an oil mass of more than 600 kg:

Oil receiver containing at least 20% of the total oil volume of the transformer or apparatus, with oil drainage into the oil sump. The oil drain pipes from the oil receivers under the transformers must have a diameter of at least 10 cm. On the side of the oil receivers, the oil drain pipes must be protected with nets. The bottom of the oil receiver should have a slope of 2% towards the sump;
oil receiver without oil drainage into the oil sump. In this case, the oil receiver should be covered with a grating with a 25 cm layer of clean washed granite (or other non-porous rock) gravel or crushed stone with a fraction of 30 to 70 mm and should be designed for the full volume of oil; the oil level should be 5 cm below the grate. The upper level of gravel in the oil receiver under the transformer should be 7.5 cm below the air inlet opening. ventilation duct... The area of the oil receiver should be larger than the area of the base of the transformer or apparatus.

4.2.104. Ventilation of the premises of transformers and reactors must ensure the removal of the heat generated by them in such quantities that, under their load, taking into account the overload capacity and the maximum design temperature environment, the heating of transformers and reactors did not exceed the maximum permissible value for them.

Ventilation of the premises of transformers and reactors should be performed in such a way that the temperature difference between the air leaving the room and entering it does not exceed: 15 C for transformers, 30 C for reactors for currents up to 1000 A, 20 C for reactors for currents over 1000 A.

If it is impossible to provide heat exchange natural ventilation it is necessary to provide for compulsory, while control of its operation with the help of signaling devices should be provided.

4.2.105. Supply- exhaust ventilation with a fence at floor level and at the level of the upper part of the room should be performed in the room where the switchgear and SF6 gas cylinders are located.

4.2.106. Ventilation of the switchgear room must ensure the removal of the generated heat to maintain the temperature permissible for electrical devices. If it is impossible to provide heat exchange with natural ventilation, forced ventilation should be provided with control of its operation.

The rooms of the switchgear, in which there are places of possible accumulation of substances (for example, SF6 gas) in quantities hazardous to workers, must be provided with exhaust ventilation with a fence at the lowest point.

In places with low winter temperatures supply and exhaust ventilation openings must be opened and closed from the outside.

4.2.107. In rooms in which the personnel on duty is 6 hours or more, the air temperature must be at least 18 C and not higher than 28 C.

In the repair area of the closed switchgear at the time of the renovation works the temperature must be at least 5 C.

When heating rooms in which there is gas-insulated equipment, heating devices with a heating surface temperature exceeding 250 C (for example, heaters of the TEN type) should not be used.

4.2.108. Openings in the enclosing structures of buildings and premises after laying conductors and other communications should be sealed with a material that ensures fire resistance not lower than the fire resistance of the enclosing structure itself, but not less than 45 minutes.

4.2.109. Other openings in the outer walls to prevent the entry of animals and birds must be protected with nets or gratings with cells of 10x10 mm.

4.2.110. Overlapping cable channels and double floors should be made of removable plates of non-combustible materials level with the clean floor of the room. The mass of an individual floor slab should be no more than 50 kg.

4.2.111. Laying in chambers of devices and transformers of transit cables and wires, as a rule, is not allowed. In exceptional cases, it is allowed to lay them in pipes.

Electrical wiring for lighting and control and measurement circuits located inside chambers or located near non-insulated live parts may only be allowed to the extent necessary for making connections (for example, to instrument transformers).

4.2.112. Laying of heating pipelines related to them (not transit) into the premises of the switchgear is allowed provided that one-piece welded pipes are used without valves, etc., and welded ventilation ducts - without valves and other similar devices. Transit laying of heating pipelines is also allowed, provided that each pipeline is enclosed in a continuous waterproof shell.

4.2.113. When choosing a switchgear circuit containing SF6 devices, more than simple schemes than in an air-insulated switchgear.

In-shop switchgears and transformer substations

4.2.114. Requirements given in 4.2.115 - 4.2.121 , take into account the peculiarities of in-house switchgears and substations with voltage up to 35 kV industrial enterprises, which must also meet the other requirements of this chapter insofar as they have not been changed.

Switchgears and substations, special electrical installations of industrial enterprises, including those in explosive and fire hazardous areas, electrothermal installations must also meet the requirements of the relevant chapters of Sec. 7.

Distances from openly installed electrical devices to water coolers of the substation must be at least the values given in Table 4.2.6.

Table 4.2.6 The smallest distance from openly installed electrical devices to water coolers of the substation

For areas with design outside air temperatures below minus 36 ° C, the distances given in Table 4.2.6 should be increased by 25%, and with temperatures above minus 20 ° C, reduced by 25%. For reconstructed objects, the distances given in Table 4.2.6 are allowed to be reduced, but not more than by 25%.

4.2.67

The distances from the equipment of the switchgear and substation to the buildings of the closed switchgear and other technological buildings and structures, to the KB, STK, SK are determined only by technological requirements and should not increase due to fire conditions.

4.2.68

Fire-prevention distances from oil-filled equipment with an oil mass in a piece of equipment of 60 kg or more to industrial buildings with the category of premises B1-B2, D and D, as well as to residential and public buildings, there must be at least:

16 m - with the degree of fire resistance of these buildings I and II;

20 m - for grade III;

24 m - for grade IV and V.

When installing oil-filled transformers with an oil mass of 60 kg or more near the walls of industrial buildings with a room category G and D, electrically connected to the equipment installed in these buildings, distances less than indicated are allowed. At the same time, at a distance of more than 10 m from them and outside the boundaries of sections with a width (Figure 4.2.13), there are no special requirements for walls, windows and doors of buildings.

Figure 4.2.13. Requirements for open installation of oil-filled transformers near buildings with production facilities of categories D and E

With a distance of less than 10 m to transformers within sections with a width, the following requirements must be met:

1) windows are not allowed up to a height (up to the level of transformer bushing);

2) at a distance of less than 5 m and degrees of fire resistance of buildings IV and V, the wall of the building must be made according to the I degree of fire resistance and rise above the roof made of combustible material by at least 0.7 m;

3) at a distance of less than 5 m and degrees of fire resistance of buildings I, II, III, as well as at a distance of 5 m or more, without restriction on fire resistance at a height from to, non-opening windows filled with reinforced glass or glass blocks with frames made of fireproof material are allowed; above - windows opening to the inside of the building, with openings provided from the outside with metal grids with cells of no more than 25x25 mm;

4) at a distance of less than 5 m at a height of less than, and at 5 m or more at any height, doors made of non-combustible or hardly combustible materials with a fire resistance limit of at least 60 minutes are allowed;

5) ventilation inlets in the wall of the building at a distance of less than 5 m are not allowed; exhaust openings with the release of uncontaminated air within the specified limit are allowed at a height;

6) at a distance of 5 to 10 m, ventilation openings in the enclosing structures of cable rooms from the side of transformers on a section with a width are not allowed.

The dimensions shown in Fig. 4.2.13 are and are taken up to the most protruding parts of the transformers at a height of no more than 1.9 m from the earth's surface. With a unit power of transformers up to 1.6 MVA, a distance of 1.5 m; 8 m; more than 1.6 MVA 2 m; 10 m. The distance is taken according to 4.2.217, the distance should be at least 0.8 m.

The requirements of this clause also apply to outdoor package transformer substations.

4.2.69

To prevent oil spreading and fire propagation in case of damage to oil-filled power transformers (reactors) with an amount of oil more than 1 ton per unit, oil receivers, oil outlets and oil collectors must be made in compliance with the following requirements:

1) the dimensions of the oil receiver should protrude beyond the dimensions of the transformer (reactor) by at least 0.6 m with an oil mass of up to 2 tons; 1 m with a mass of 2 to 10 tons; 1.5 m with a mass of 10 to 50 tons; 2 m with a mass of more than 50 tons. In this case, the size of the oil receiver can be taken less than 0.5 m from the side of the wall or partition located from the transformer (reactor) at a distance of less than 2 m;

2) the volume of the oil receiver with the oil drain should be calculated for a one-time reception of 100% of the oil poured into the transformer (reactor).

The volume of the oil receiver without oil drainage should be expected to receive 100% of the volume of oil poured into the transformer (reactor), and 80% of water from fire extinguishing means based on irrigation of the areas of the oil receiver and side surfaces of the transformer (reactor) with an intensity of 0.2 l / s m within 30 minutes;

3) the arrangement of oil receivers and oil outlets should exclude the flow of oil (water) from one oil receiver to another, oil spreading through cable and other underground structures, the spread of fire, clogging of the oil outlet and clogging it with snow, ice, etc .;

4) oil receivers for transformers (reactors) with an oil volume of up to 20 tons can be performed without oil drainage. Oil receivers without oil drainage should be made of a buried structure and covered with a metal grate, on top of which a layer of clean gravel or washed granite crushed stone with a thickness of at least 0.25 m, or non-porous crushed stone of another rock with particles from 30 to 70 mm must be poured. The level of the total volume of oil in the oil receiver must be at least 50 mm below the grate.

Removal of oil and water from the oil receiver without oil drainage should be provided by mobile means. At the same time, it is recommended to perform the simplest device for checking the absence of oil (water) in the oil receiver;

5) oil receivers with oil drainage can be performed both buried and not buried (the bottom is at the level of the surrounding layout). When performing a buried TV receiver, the installation of side fences is not required if this ensures the volume of the oil receiver specified in clause 2.

Oil receivers with oil drainage can be performed:

with the installation of a metal grate on the oil receiver, on top of which gravel or crushed stone with a layer thickness of 0.25 m is poured;

without a metal grate with gravel filling on the bottom of the oil receiver with a layer thickness of at least 0.25 m.

An unsubmerged oil receiver should be made in the form of side fences of oil-filled equipment. The height of the side fences should be no more than 0.5 m above the level of the surrounding layout.

The bottom of the oil receiver (buried and not buried) should have a slope of at least 0.005 towards the pit and be covered with purely washed granite (or other non-porous rock) gravel or crushed stone with a fraction of 30 to 70 mm. The backfill thickness must be at least 0.25 m.

The upper level of gravel (crushed stone) should be at least 75 mm below the upper edge of the side (when installing oil receivers with side fences) or the level of the surrounding layout (when installing oil receivers without side fences).

It is allowed not to backfill the bottom of the oil receivers over the entire area with gravel. At the same time, it is necessary to provide for the installation of flame arresters on oil drainage systems from transformers (reactors);

6) when installing oil-filled electrical equipment on a reinforced concrete floor of a building (structure), an oil drain device is mandatory;

7) oil outlets should ensure that oil and water used to extinguish a fire are removed from the oil receiver by automatic stationary devices and hydrants to a safe fire-fighting distance from equipment and structures: 50% of oil and the total amount of water should be removed in no more than 0.25 hours Oil drains can be made in the form of underground pipelines or open cuvettes and trays;

8) oil sump should be provided closed type and must contain the full volume of oil of a single piece of equipment (transformers, reactors) containing the largest number oil, as well as 80% of the total (taking into account the 30-minute reserve) water consumption from fire extinguishing media. Oil collectors should be equipped with a water alarm with a signal output to the control panel. The internal surfaces of the oil receiver, oil receiver fencing and oil sump must be protected by an oil-resistant coating.

4.2.70

At substations with 110-150 kV transformers with a unit capacity of 63 MVA and more and 220 kV and higher transformers with a unit capacity of 40 MVA and more, as well as at substations with synchronous compensators for extinguishing a fire, a fire-fighting water supply system should be provided with power from an existing external network or from an independent source of water supply. Instead of a fire-fighting water pipeline, it is allowed to provide for the intake of water from ponds, reservoirs, rivers and other reservoirs located at a distance of up to 200 m from the substation using mobile fire fighting equipment.

At substations with 35-150 kV transformers with a unit capacity of less than 63 MVA and 220 kV transformers with a unit capacity of less than 40 MVA, fire-fighting water supply and a reservoir are not provided.

4.2.71

KRUN and KTP outdoor installation should be located on a planned site at a height of at least 0.2 m from the level of planning with the execution of a platform for maintenance near the cabinets. In areas with a calculated snow cover height of 1.0 m and above and a duration of its occurrence for at least 1 month, it is recommended to install outdoor switchgear and transformer substations at a height of at least 1 m.

The location of the device should ensure convenient rolling out and transportation of transformers and the withdrawable part of the bays.

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