Arrangement of wires on supports

PLAN

AIR COMMUNICATION LINES

Objectives of the lesson:

Educational - to ensure the assimilation and consolidation of knowledge on the topic studied in the previous lesson, to control the degree of mastering the basic knowledge on the topic of the previous lesson.

Developing - to develop cognitive processes (attention, imagination, memory, perception).

Educational - to develop a positive attitude towards knowledge.

Lesson Type: Combined

Security of the lesson: insulators, hooks.

Intersubject communications: Technical means of railways, Stations and nodes.

Time: 2 hours

Organizing time.

Frontal survey on the topic of the previous lesson.

Statement of new material:

1. Purpose and classification of communication lines

   Requirements for communication lines

   Classification of overhead communication lines

   Elements of VLAN

Fixing the material.

Assignment to the house: textbook LA. Kondratieva, ON Romashkova "Regulatory systems

traffic on the railway. transport "with. 297-298

AIR COMMUNICATION LINES

Purpose and classification of communication lines

LANs are designed to connect telephone or telegraph equipment installed in various locations.

Drugs by appointment  are divided into 3 classes:

I class (backbone) - connect the Ministry with the management of roads and management between each other

II class (road and intra-division lines) - link management with departments, separation between each other and with large precinct stations

III class (local) - in-station, on the territory of large stations and nodes.

All drugs are divided into 2 types:

1). aerial lines of the VLAN

2). cable communication lines

Requirements for communication lines

the wires of the communication line must be isolated from each other (in the VLAN - air);

the lines of the communication line must be isolated from the ground;

the wires of the communication line must be protected from mutual interfering influences (protection-crossing, that is, the wires of the same circuit are swapped through a certain number of spans);

the lines of communication lines should be protected from the dangerous effects of the contact network of electrified railways;

wires of the communication line must be protected from lightning discharges (lightning conductor - steel wire 5 mm in diameter above the support by 15 cm, deepened into the ground by 0,7 m)

Classification of overhead communication lines

VLS have a great mechanical strength, have long service life, allow communication over long distances (up to 250 km). The advantage of overhead communication lines is also the ease of detection and repair of damages.

Durability  depending on the weather conditions, VLANs are divided into 4 types:

1. O (light) - for southern regions with low ice intensity on wires (thickness of ice less than 5 mm)

2.N (normal) - for areas with an average glaze intensity (ice up to 10 mm)

3. U (strengthened) - for areas with a high intensity of ice (up to 15 mm)

4. OS (especially strengthened) - for areas with a particularly strong glaze ice (20 mm or more)

On the profile of the used supports  VLANs are divided into:

with hook profile (low-conductor lines, up to 12 wires)

with a traverse profile (multi-wire lines up to 40 wires)

with a mixed profile

4. ELEMENTS OF VLAN

1. Supports

wooden

Wooden supports are made of trees with sufficient mechanical strength (oak, pine, spruce, larch, fir).

Impregnation with antiseptics (zinc chloride, creosote oil) - to extend the life of wooden supports.

reinforced concrete

All supports are subdivided:

simple

complex (anchor, semi-anchor)   Used for the stability of lines with a traverse profile, for the device of transitions through railroad cars, with elongated spans, when changing from overhead communication lines to cable lines.

2. Fittings

The fittings include:

- hooks

(on the horizontal part they have a thread for screwing into the supports);

- insulators

(porcelain, glass, plastic);

- traverses

(typical eight-pin)

3. Wires.

Wire is used as a wire - steel, copper, bimetallic.

Steel  - high mechanical strength, low cost; low electrical conductivity, is susceptible to corrosion. For protection against corrosion, zinc or add 0.2 - 0.4% copper (with copper additive)

Copper  - high electrical conductivity, not subject to corrosion; high cost, less durable;

Bimetallic  - is a steel core with a diameter of 3.2 mm with an outer copper layer of 0.4 mm.

DEVELOPED taking into account the requirements of state standards, building norms and rules, recommendations of scientific and technical councils for the consideration of draft chapters. The drafts of the chapters were reviewed by the working groups of the Coordinating Council for the revision of the Council of Auditors

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" (OAO VNIIE) and submitted to the approval of the State Energy Inspectorate of the Ministry of Energy of Russia

Since October 1, 2003, Chapter 2.4 of the "Rules for the Installation of Electrical Installations" of the sixth edition

The requirements of the Rules for the installation of electrical installations are mandatory for all organizations, regardless of the form of ownership and organizational and legal forms, as well as for individuals engaged in entrepreneurial activities without the formation of a legal entity.

Application area. Definitions

2.4.1. This chapter of the Rules applies to AC power lines with a voltage of up to 1 kV, performed 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 in-line inserts and cable branches from the line must be carried out in accordance with the requirements of Ch. 2.3.

2.4.2. Overhead transmission line (VL) with voltage up to 1 kV is a device for transmission and distribution of electricity through insulated or uninsulated wires located in the open air and fixed by linear reinforcement 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 - twisted into bundle insulated conductors, the supporting vein can be either isolated or not insulated. The mechanical load can be perceived either by the supporting vein, or by all conductors of the harness.

2.4.3. The main line is a section of the line from the feeding transformer substation to the end support.

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

Linear branch from the overhead line is a section of the line connected to the overhead line, having more than two spans.

Branch from the HV to the input - a section from the support of the main line or the linear branch to the clamp (input isolator).

Branch from VLI is allowed to perform in the span.

2.4.4. The state of high-voltage lines in the calculations of the mechanical part:

• normal mode - mode with unblocked wires;
• emergency mode - mode with broken wires;
• installation mode - a mode in conditions of installation of 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 OL elements must be carried out according to the methods described in Ch. 2.5.

2.4.6. Overhead power lines should be placed so that the supports do not obstruct the entrances to the buildings and entrances to the yards and do not impede traffic and pedestrians. In places where there is a danger of travel accidents (at entrances to yards, near road exits, when crossing roads), the supports must be protected from collision (for example, bollards).

2.4.7. On the supports of overhead lines at a height of at least 2 m from the ground after 250 m on the trunk of the overhead line, the following reference numbers shall be affixed (number); Posters that indicate the distance from the support of the overhead line to the cable communication line (on supports installed at a distance of less than 4 m to communication cables), the width of the security zone and the telephone of the owner of the overhead line.

2.4.8. When VLI passes through wooded areas and green plantations, clearing of glades is not required. In this case, the distance from the wires to the trees and bushes at the maximum sip and the maximum deviation of the sip should be at least 0.3 m.

When passing overhead lines with uninsulated wires along forest tracts and green plantations, clearing of a clearing is not necessary. In this case, the distance from the wires at the maximum sagging arrow or the greatest deviation to trees and bushes should be at least 1 m.

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

2.4.9. The structures of the overhead transmission lines must be protected against corrosion, taking into account the requirements of 2.5.25, 2.5.26 and building codes.

2.4.10. Protection of overhead lines from electrical overloads should be carried out in accordance with the requirements of Ch. 3.1.

Climatic conditions

2.4.11. Climatic conditions for the calculation of overhead lines up to 1 kV in the normal mode should be adopted for both VL and 20 kV in accordance with 2.5.38 - 2.5.74. At the same time, for VL up to 1 kV one should take:

• at calculation on 2.5.52: Cx = 1,1 - for SIP, free or covered with ice;
• when calculating by 2.5.54 and 2.5.55:
• γnw = γnг = 0,8 - for single-line overhead lines;
• γnw = γnг = 0,9 - for single-circuit high-voltage lines with suspension on MF supports;
• γnw = 1,0 and γnг = 1,2 for two-chain and multi-chain overhead lines, as well as for suspension of self-supporting nonmetallic optical cable (OKSN) on the supports of VL;
• γp = 1,0 and K1 = 1,0 - in all cases.

2.4.12. Calculation of the length of the span of the branch from the overhead line to the input according to 2.4.20 should be carried out in the ice-free regime for two cases:

1. wind direction at an angle of 90º to the axis of the overhead line, the wires of the overhead line are covered with ice, the thickness of the ice wall on the branch wires is b0 = 0.5b;
2. wind direction along the overhead line (angle 0º), the thickness of the ice wall on the branch wires b0 = bе.

In both cases, it is necessary to take into account the reduction in the tension of the branch wires when the top of the support is deflected.

Wires. Linear fittings

2.4.13. As a rule, self-supporting insulated wires (SIPs) should be used on the overhead line.

The SIP must be classified as protected, insulated from a light-resistant, light-stabilized synthetic material, resistant to ultraviolet radiation and ozone.

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

Table 2.4.1 Minimum allowable cross-section of insulated wires

* In parentheses is given the cross-section of the veins of self-supporting insulated wires twisted into a bundle, without a supporting wire.

Table 2.4.2 Minimum permissible cross-sections of bare and insulated conductors

2.4.15. When constructing overhead lines in areas where the experience of operation has been established, the destruction of corrosion wires (coasts of seas, saline lakes, industrial areas and areas of saline sands), as well as in places where, on the basis of these studies, it is possible, self-supporting insulated wires with insulated conductors .

2.4.16. The VL trunk line, as a rule, should be made with wires of unchanged cross-section.

2.4.17. Mechanical calculation of wires should be made by the method of permissible stresses for the conditions specified in 2.5.38 - 2.5.74. In this case, the voltage in the wires should not exceed the permissible voltages given in Table. 2.4.3, and the distances from wires to the ground, crossed structures and grounded support elements must meet the requirements of this chapter.

The calculation uses the wire parameters shown in Table. 2.5.8.

Table 2.4.3 Permissible mechanical stress in wires of overhead lines up to 1 kV

2.4.18. All kinds of mechanical loads and impacts on self-supporting insulated wire should be perceived by this vein, and on a self-supporting insulated wire without a supporting wire - all the veins of a twisted bundle should be perceived.

2.4.19. The span length of the branch 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 suspension of the branch wires on the support and on the input, the number and cross-section of the conductors of the branch wires.

At distances from the high-voltage line to the building, exceeding the estimated span span values, the required number of additional supports is established.

2.4.20. The choice of the cross-section of current-carrying conductors over a long-time permissible current should be carried out taking into account the requirements of Ch. 1.3.

The cross section of current-carrying conductors must be checked for short-circuit (short-circuit) heating conditions and thermal resistance.

2.4.21. Mounting, connecting the SIP and joining the SIP should be done as follows:

1. fastening of the wire of the high-voltage line on the intermediate and angular intermediate supports - with the help of clamps;
2. fastening of the wire of the high-voltage line on the anchor-type supports, as well as the end attachment of the branch wires to the support of the FIR and at the input - by means of tension clamps;
3. connection of the fiber optic cable in the span - using special connecting clamps; in the hinges of anchor-type supports, the uninsulated carrying wire can be connected by means of a pin clamp. Connection clamps intended to connect the carrier wire in the span must have a mechanical strength of not less than 90% of the breaking strength of the wire;
4. connection of the phase conductors of the high-voltage line - by means of connecting clamps having an insulating coating or a protective insulating sheath;
5. connection of wires in the span of the branch to the input is not allowed;
6. connection of grounding conductors - with the help of pliable clamps;
7. tap-off clamps should be used in the following cases:
   • branching from the phase conductors, with the exception of the SIP with all the conductors of the harness;
   • branching from the core.

2.4.22. Fastening of support and tension clamps to supports of VLI, walls of buildings and constructions should be carried out with the help of hooks and brackets.

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

2.4.24. Wiring connections in overhead transmission lines should be made using connecting clamps providing mechanical strength of at least 90% of the breaking strength of the wire.

Only one connection per wire is permitted in one overhead span.

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

The connection of wires in the loops of the anchor supports must be done by means of clamps or by welding.

Wires of different brands or sections must be connected only in the loops of the anchor supports.

2.4.25. Fastening of uninsulated wires to insulators and isolating traverses on supports of overhead lines, with the exception of supports for intersections, is recommended to be performed single.

Fastening of uninsulated wires to pins on intermediate supports should be carried out, as a rule, on the neck of the insulator on its inner side in relation to the support post.

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

The forces shall 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 overhead lines is allowed, regardless of the climatic region. The neutral wire of an overhead line with uninsulated wires should, as a rule, be located below the phase conductors. Insulated outdoor lighting wires laid on the FIR supports may be placed above or below the SIP, and also be twisted into a SIP harness. Uninsulated and insulated outdoor lighting wires laid on the VL supports must be located, as a rule, above the PEN (PE) conductor of the overhead line.

2.4.28. Installed on the support devices for connecting electric receivers should be located at a height of not less than 1.6 m from the ground.

The protective and partitioning devices installed on the supports must be located below the overhead lines.

2.4.29. The distances between uninsulated wires on the support and in the span according to the conditions of their approach in the span with the largest boom of the sling to 1.2 m should be not less than:

• with vertical arrangement of wires and arrangement of wires with horizontal displacement of not more than 20 cm: 40 cm in I, II and III regions over ice, 60 cm in IV and in special areas on ice;
• at other locations of wires in all regions by ice at a wind speed of icing: up to 18 m / s - 40 cm, more than 18 m / s - 60 cm.

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

2.4.30. The vertical distance between insulated and non-isolated overhead line conductors of different phases on the support at a branch from the overhead line and at the intersection of different overhead lines on the common support should be at least 10 cm.

The distances from the wires of the OL to any supporting elements must be at least 5 cm.

2.4.31. When co-suspension on common supports of high-voltage and high-voltage 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 not less than 0.4 m.

2.4.32. When co-suspension on common supports of two or more LFLs, the distance between SIP harnesses shall be not less than 0.3 m.

2.4.33. When co-suspension on common supports of overhead lines up to 1 kV and wires of HVL to 20 kV, the vertical distance between the nearest HVL wires of different voltages on the common support, as well as in the middle of the span at ambient temperature plus 15 ºС without wind, should be not less than:

• 1,0 m - with suspension of self-supporting insulated wire with all supporting wires;
• 1,75 m - with suspension of self-supporting insulated wire with non-insulated carrying wire;
• 2,0 m - when suspending uninsulated and insulated wires of overhead lines up to 1 kV.

2.4.34. When suspended on common supports of overhead lines up to 1 kV and protected wires of VLZ 6-20 kV (see 2.5.1), the vertical distance between the nearest wires of the overhead line up to 1 kV and VLZ 6-20 kV on the support and in the span at a temperature of plus 15 ºС without wind should be at least 0,3 m for SIP 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 supports without the use of insulators.

2.4.36. On the OL with uninsulated and insulated wires, regardless of the material of the supports, the degree of air pollution and the intensity of thunderstorm activity, insulators or traverses 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 support of branches from VL with non-insulated and insulated wires, it is usually necessary to use multi-buck or additional insulators.

Grounding. Overvoltage protection

2.4.38. On the supports of the overhead line, earthing devices intended for re-grounding, protection from lightning overvoltages, grounding of electrical equipment installed on the overhead line supports must be made. The resistance of the grounding device should not be more than 30 Ohm.

2.4.39. Metal supports, metal structures and reinforcement of reinforced concrete support elements should be connected to the PEN conductor.

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

2.4.41. Hooks and pins of wooden supports of overhead lines, as well as metal and reinforced concrete supports with suspension of SIP with insulated conductor or with all conductive conductors of the ground cable are not subject to exclusion, except for hooks and pins on supports where repeated earthing and grounding are made for protection against atmospheric overvoltage.

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

2.4.43. On the wooden poles of the overhead line during the transition to the cable line, the grounding conductor must be connected to the PEN conductor of the overhead line and to the metal sheath of the cable.

2.4.44. Protective devices installed on the supports of the overhead line to protect against lightning surges must be connected to the earth electrode by a separate descent.

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

The connection of the grounding conductors (descents) to the earth electrode in the ground must also be done by welding or having bolted connections.

2.4.46. In a populated area with one- and two-storey buildings, overhead lines must have earthing devices designed to protect against atmospheric overvoltages. Resistance of these grounding devices should not be more than 30 Ohm, and the distance between them should not be more than 200 m for areas with a number of thunderstorm hours in the year to 40, 100 m - for areas with a number of thunderstorm hours per year more than 40.

In addition, the grounding devices must be made:

1. on supports with branches to the entrances to buildings in which a large number of people (schools, nurseries, hospitals) can be concentrated or who are of great material value (livestock and poultry houses, warehouses);
2. on the end supports of the lines having branches to the inputs, the maximum distance from the adjacent ground of the same lines should not be more than 100 m for areas with a number of thunderstorm hours in the year up to 40 and 50 m - for areas with a number of thunderstorm hours per year more than 40 .

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

Earthing devices for protection against lightning overvoltages are recommended to be combined with re-grounding of the PEN conductor.

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

2.4.49. The tie-downs of the OHL supports must be connected to the ground conductor.

Supports

2.4.50. On VL can be used supports from a variety of materials.

The following types of supports should be used for overhead lines:

1. intermediate, installed on the straight sections of the TL line. These supports in normal operating modes should not take efforts directed along the overhead line;
2. anchor, installed to limit the anchor span, as well as in places where the number, grades and cross sections of the overhead lines are changed. These supports should perceive in normal operating conditions the forces from the difference in the tension of the wires directed along the overhead line;
3. angled, installed in places where the direction of the VL route changes. These supports under normal operating conditions should take the resultant load from the traction of the wires of adjacent spans. Angular supports can be intermediate and anchor type;
4. end, installed at the beginning and end of the OL, as well as in the places limiting the cable inserts. They are supports of the anchor type and should perceive unilateral traction of all wires in normal modes of operation of overhead lines.

The supports on which branches from the OL are performed are called tap-offs; the supports on which the intersection of high-voltage lines of different directions or the intersection of overhead lines with engineering facilities are crossed. These supports can be of all types mentioned.

2.4.51. The support structures should provide the possibility of installation:

• street lighting fixtures of all types;
• terminal cable sleeves;
• protective apparatus;
• sectioning and switching devices;
• cabinets and shields for connecting electric receivers.

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

The supports can be attached to anchors installed in the ground, or to stone, brick, reinforced concrete and metal elements of buildings and structures. The cross-section of the braces is determined by the calculation. They can be multiwire or round steel. The cross section of single-wire steel braces should be at least 25 mm2.

2.4.53. Supports of overhead lines must be calculated according to the first and second limit state in the normal operation mode of the OL for climatic conditions according to 2.4.11 and 2.4.12.

Intermediate supports should be designed for the following combinations of loads:

• simultaneous impact of a transverse wind load on wires free or covered with ice, and on the structure of the support, as well as loads from pulling the wires of the branches to inputs free of ice or partially covered with ice (2.4.12);
• on the load from pulling the wires of the branches to the inputs covered with ice, while allowing for the deviation of the support under the action of the load;
• on a conditional design load equal to 1.5 kN, applied to the top of the support and directed along the axis of the VL.

Angular supports (intermediate and anchor) should be designed for the resulting load from wire traction and wind load on the wires and the structure of the support.

The anchor supports should be designed for the difference in traction of the wires of adjacent spans and the transverse load from the wind pressure at ice and without ice on the wires and the structure of the support. For the smallest value of the tension difference, 50% of the largest single-sided tension of all wires should be taken.

The end supports must be designed for unilateral pulling of all wires.

Deflection supports are calculated on the resulting load from the tension of all wires.

2.4.54. When installing supports in the flooded areas of the route, where soil erosion or the impact of ice drifts are possible, the supports should be strengthened (earth padding, paving, punching, installation of ice-cutters).

Dimensions, intersections and approaches

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

At the intersection of the impenetrable part of the streets, it is allowed to reduce the distance from the SIP to the sidewalks of footpaths by means of branches from the VLI to the entrances to the buildings, to 3.5 m.

The distance from the SIP and insulated wires to the ground surface on the branches to the input must be at least 2.5 m.

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

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

2.4.57. The horizontal distance from the SIP at the maximum deviation to the elements of buildings and structures should be not less than:

• 1,0 m - to balconies, terraces and windows;
• 0,2 m - to the deaf walls of buildings and structures.

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

2.4.58. The horizontal distance from the wires of overhead lines with the greatest deviation to buildings and structures should be not less than:

• 1,5 m - to balconies, terraces and windows;
• 1.0 m - to the deaf walls.

Passage of overhead lines with uninsulated wires over buildings and structures is not allowed.

2.4.59. The shortest distance from the SIP and the wires of the overhead line to the surface of the ground or water, as well as to various structures when passing overhead lines above them, is determined at a higher air temperature without considering the heating of the HVL wires by electric current.

2.4.60. When laying on the walls of buildings and structures, the minimum distance from the SIP shall be:

• when laying horizontally
• above the window, the entrance door is 0.3 m;
• under a balcony, a window, a cornice - 0,5 m;
• to the ground - 2,5 m;
• with vertical laying
• up to the window - 0,5 m;
• to the balcony, the entrance door - 1.0 m.

The distance between the SIP and the wall of the building or structure should be at least 0.06 m.

2.4.61. Distances horizontally from the underground parts of poles or grounding of supports to underground cables, pipelines and ground-based columns for various purposes should be no less than those listed in Table 2.4.4.

Table 2.4.4. The minimum permissible horizontal distance from the underground parts of the supports or grounding devices of supports to underground cables, pipelines and ground columns

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

2.4.63. Crossing overhead lines with navigable rivers and canals is not recommended. If it is necessary to perform such crossing, the overhead lines must be constructed in accordance with the requirements of 2.5.268 - 2.5.272. At the intersection of non-navigable rivers and canals, the shortest distances from the AL lines to the maximum water level should be at least 2 m, and to the ice level - at least 6 m.

2.4.64. Intersection and convergence of overhead transmission lines with voltage up to 1 kV with a voltage over 1 kV, as well as joint suspension of their wires on common supports shall be carried out in compliance with the requirements given in 2.5.220 - 2.5.230.

2.4.65. Intersection of overhead transmission line (VLI) up to 1 kV among themselves 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) should be not less than: 0.1 m on the support, 1 m in the span.

2.4.66. In the intersection of VL to 1 kV, intermediate supports and anchor-type supports may be used among themselves.

When crossing a VL to 1 kV among themselves in the span, the intersection should be chosen as close as possible to the support of the upper intersecting overhead line, while the horizontal distance from the supports of the crossing overhead line to the wires of the overhead line being crossed should be at least 2 m at their greatest deviation.

2.4.67. With parallel passage and approach of the overhead line up to 1 kV and overhead line above 1 kV, the distance between them horizontally should be not less than specified in 2.5.230.

2.4.68. Joint suspension of wires of overhead lines up to 1 kV and uninsulated wires of overhead lines up to 20 kV on common supports is allowed provided that the following conditions are met:

1. wires of overhead lines up to 20 kV should be located above the wires of overhead lines up to 1 kV;
2. wires up to 20 kV, fixed to the pin insulators, must have a double fastening.

2.4.69. In case of suspension on common supports of overhead lines up to 1 kV and protected wires of VLZ 6-20 kV the following requirements must be observed:

1. VL up to 1 kV should be performed according to the calculated climatic conditions of the VL up to 20 kV;
2. vLZ 6-20 kV wires should be located, as a rule, above the wires of the HVL to 1 kV;
3. the installation of 6-20 kV VLZ wires on pin insulators must be carried out with reinforced.

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

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

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

2.4.71. The intersection angle of the OL with the LS * and the LPV should be as close as possible to 90 °. For cramped conditions, the angle of intersection is not normalized.

According to their purpose, air communication lines are divided into long-distance telephone lines (MTS), rural telephone lines (STS), city telephone lines (GTS), and wire lines (LPV).

Significantly, air communication and wire broadcasting are divided into classes:

• mTS and STS lines: MTS trunk lines connecting Moscow with the republican, regional and regional centers and the last among themselves, and lines of the Ministry of Railways running along railways and on the territory of railway stations (class I); intra-zone MTS lines connecting the republican, regional and regional centers with regional centers and the latter among themselves, and connecting lines of STS (class II); subscriber lines of STS (class III);
• the lines of the GTS for classes are not subdivided;
• wireline lines: feeder lines with rated voltages above 360 ​​V (class I); feeder lines with nominal voltage up to 360 V and subscriber lines with voltage 15 and 30 V (class II).

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

The LPO should be understood as wireline broadcasting lines.

2.4.72. The vertical distance from the wires of the overhead line to the wires or hanging cables of the HP and LPV in the crossing intersection at the maximum sag of the overhead line wire should be:

• from self-supporting insulated wire and insulated wires - at least 1 m;
• from non-insulated wires - not less than 1,25 m.

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

• between SIP and drugs or LPV - not less than 0.5 m;
• between uninsulated wires of overhead lines and LPV - not less than 1.5 m.

2.4.74. The intersection of the wires of the overhead line with the wires or overhead cables of the LS and LPV 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. Intersection of overhead lines with LS and LP can be performed according to one of the following options:

1. wires of overhead lines and insulated wires LS and LPV;
2. wires of overhead lines and underground or suspension cable LAN and LPV;
3. wires of overhead lines and uninsulated wires of LS and LPV;
4. underground cable insert in the overhead line with insulated and non-insulated wires LS and LPV.

2.4.76. When crossing overhead lines with isolated wires of LS and LPV, the following requirements must be met:

1. the intersection of uninsulated wires of overhead lines with LAN wires, as well as with LVV leads above 360 ​​V must be performed only in the span. The intersection of uninsulated wires with OHL lines up to 360 V can be performed both in the span and on the common support;
2. vLL supports that limit the intersection with the intersection of long-distance and intra-zone communication networks and CTC connecting lines, as well as LPV with a voltage higher than 360 V, must be of the anchor type. At the intersection of all other drugs and LPV, supports of intermediate type of overhead transmission lines are allowed, reinforced with additional attachment or strut;
3. the wires of the overhead line must be located above the LAN and LPV wires. On the supports that limit the intersection, uninsulated and insulated wires of the overhead line must have a double fastening, the CIP is fixed with anchor clamps. Wires LS and LPV on the supports that limit the intersection, should have a double fastening. In cities and urban settlements, newly constructed HP and LPVs are allowed to be located above the VLT wires with a voltage of up to 1 kV.

2.4.77. When crossing overhead lines with an underground or suspension cable 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 earthing switch of the wooden support to the underground cable of LS and LPV in a populated locality should be, as a rule, not less than 3 m. In cramped conditions it is allowed to reduce these distances up to 1 m (under the condition of permissibility of interfering influences on medicines and LPO); while the cable must be laid in a steel pipe or covered with a channel or corner steel along the length in both sides of the support not less than 3 m;
2. in an uninhabited area, the distance from the underground part or the earthing switch of the OL support to the underground cable of the LS and LPV must not be less than the values ​​given in Table. 2.4.5;
3. the wires of the overhead line should be located, as a rule, above the suspension cable of LS and LPV (see also 2.4.76, item 4);
4. connection of overhead lines in the intersection with the suspension cable LAN and LPV is not allowed. The cross section of the SIP core must be at least 35 mm2. The wires of the overhead line must be multiwire cross-sections at least: aluminum - 35 mm2, steel-aluminum - 25 mm2; cross-section of the SIP conductor with all the conductors of the harness - not less than 25 mm2;
5. the metal sheath of the suspension cable and the cable on which the cable is suspended should be grounded on the supports that limit the intersection;
6. the horizontal distance from the base of the LC and LPV cable support to the projection of the nearest OHL wire to the horizontal plane must be at least the maximum height of the intersection support.

Table 2.4.5. The shortest distance from the underground part and the grounding of the support of the OL to the underground cable of LS and LPV in the uninhabited area

2.4.78. At the intersection of VLI with non-insulated wires of LS and LPV the following requirements should be observed:

1. the intersection of ULV with LS and LP can be performed in the span and on the support;
2. fIR support, limiting the span of intersection with the LANs of trunk and intra-zone communication networks and with CTC connection lines, should be of the anchor type. When crossing all other drugs and LPV on the ULV, the use of intermediate supports, reinforced by an additional attachment or a scaffold, is allowed;
3. the conductor core of a self-supporting insulated wire or strand with all supporting conductors at the intersection site shall have a safety factor for tensile strength at the greatest design loads of not less than 2.5;
4. vLI wires should be located above the LAN and LPV wires. On the supports limiting the span of intersection, the supporting wires of the self-supporting insulated wire shall be secured with tension clamps. It is allowed to place VLI wires under the LPV wires. In this case, the LPV wires on the supports that limit the intersection should have a double fastening;
5. the connection of the core and the carrying conductors of the SIP harness, as well as the wires of the LS and LPV in the intersection spans is not allowed.

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

1. the intersection of the wires of the overhead line with the LS wires, as well as the LPV wires with a voltage higher than 360 V, must 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 VL supports;
2. supports of overhead lines limiting the span of intersection should be of the anchor type;
3. lAN wires, both steel and non-ferrous metal, should have a safety factor for tensile strength at the greatest design loads of at least 2.2;
4. the wires of the overhead line must be located above the LAN and LPV wires. On the supports that limit the intersection, the wires of the overhead line must have a double fastening. Wires of VL with a voltage of 380/220 V and below are allowed to be placed under the wires of LPV and HV lines. At the same time, the wires of LPV and GTS lines on supports supporting the crossing of the intersection must have a double fastening;
5. the connection of the wires of the overhead line, as well as the wires of the LS and LPV in the intersection spans is not allowed. The wires of the overhead line must be multiwire with cross sections at least: aluminum - 35 mm2, steel-aluminum - 25 mm2.

2.4.80. When crossing an underground cable insert in a VL with uninsulated and isolated LAN and LPV wires, the following requirements must be met:

1. the distance from the underground cable insert in the overhead line to the support of the LS and LPV and its earthing switch should be at least 1 m, and when laying the cable in the insulating pipe - not less than 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 wire and LPV to the horizontal plane must be at least the maximum height of the intersection support.

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

When approaching overhead lines with airborne vehicles and LPVs, the horizontal distance between insulated and uninsulated wires of overhead lines and wires of LS and LPV must be at least 2 m. In cramped conditions, this distance may be reduced to 1.5 m. In all other cases, the distance between the lines must be not less than the height of the highest support of overhead lines, HP and LPV.

When approaching overhead lines with underground or hanging LAN and LV cables, the distances between them should be taken in accordance with 2.4.77, paragraphs 1 and 5.

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

2.4.83. Wires from the support of the OL before entering the building should not intersect with the tap wires from the LS and LPV, and they should be located on one level or higher than the HP and LPV. The horizontal distance between the wires of the overhead line and the wires of LS and LPV, television cables and descents from the radio antennas at the inputs should be at least 0.5 m for SIP and 1.5 m for uninsulated overhead lines.

2.4.84. Joint suspension of rural cable telephone cable and VLI is allowed if the following requirements are fulfilled:

1. the zero core of the SIP must be isolated;
2. the distance from the SIP to the suspension cable STS in the span and on the support of the VLI must be at least 0.5 m;
3. each VLI support must have a grounding device, and the ground resistance must be no more than 10 Ohm;
4. on each VLI support, the PEN conductor must be re-grounded;
5. the supporting cable of the telephone cable, together with the metal mesh outer cover of the cable, must be connected to the grounding of each support by a separate independent conductor (descent).

2.4.85. Joint suspension on common supports of non-insulated wires of HVL, HP and LPV is not allowed.

On common supports joint suspension of uninsulated wires of overhead lines and insulated LPV wires is allowed. The following conditions must be met:

1. the rated voltage of the overhead line must not be more than 380 V;
2. the distance from the bottom wires of the LPV to the ground, between the LPV circuits and their wires must comply with the requirements of the current regulations of the Ministry of Communications of Russia;
3. non-insulated overhead lines must be located above the LPV wires; while the vertical distance from the bottom wire of the OL to the upper LPV wire should be at least 1.5 m on the support, and in the span not less than 1.25 m; when the APV wires are placed on the brackets, this distance is taken from the lower wire of the OL located on the same side as the LPV wires.

2.4.86. On common supports, a joint suspension of the VLI SIP with uninsulated or isolated wires of LS and LPV is allowed. The following conditions must be met:

1. the rated voltage of the surge voltage must not be more than 380 V;
2. the rated voltage of the LPV must not be more than 360 V;
3. the nominal voltage of the HP, the estimated mechanical voltage in the LAN wires, the distance from the lower LS and LPV wires to the ground, between the circuits and their wires must comply with the requirements of the current regulations of the Ministry of Communications of Russia;
4. the wires of high-voltage line up to 1 kV must be located above the wires of LS and LPV; while the vertical distance from the SIP to the top wire of the LS and LBV, regardless of their mutual arrangement, should be at least 0.5 m on the support and in the span. It is recommended to place the wires of VLI and LS and LPV on different sides of the support.

2.4.87. Joint suspension on common supports of uninsulated wires of overhead lines and LAN cables is not allowed. Joint suspension on common supports of overhead lines with a voltage not exceeding 380 V and LPV cables is allowed provided that the conditions specified in 2.4.85 are met.

Optical fibers of the JCNN must satisfy 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 not more than 380 V and telemetry wires is allowed subject to the requirements given in 2.4.85 and 2.4.86, and also if the telemechanics circuits are not used as wired telephone channels.

2.4.89. On the supports of the overhead line (VLI), suspension of fiber-optic communication cables (OK) is permissible:

• nonmetallic self-supporting (OCS);
• nonmetallic, wound on a phase wire or a SIP harness (OKNN).

Mechanical calculations of the overhead lines (OVI) with OCS and OKNN should be performed for the reference conditions specified in 2.4.11 and 2.4.12.

Supports VL, which hangs OK, and their fastening in the ground should be calculated taking into account the additional loads that arise in this case.

The distance from the OCS to the surface of the earth in the populated and uninhabited areas should be at least 5 m.

The distances between the wires of the overhead line up to 1 kV and the OCS on the support and in the span must be not less than 0.4 m.

Intersection and reconnection of overhead lines with engineering facilities

2.4.90. When crossing and concurrently following overhead lines with railways and highways, the requirements laid down in Ch. 2.5.

Crossings can also be carried out using a cable insert in the overhead line.

2.4.91. When approaching overhead lines with motor roads, the distance from the overhead lines to the traffic signs and their supporting cables must be at least 1 m. The supporting cables must be grounded with a resistance of the grounding device no more than 10 Ohm.

2.4.92. When crossing and convergence of overhead lines with contact wires and carrying lines of tram and trolleybus lines, the following requirements must be fulfilled:

1. VL should, as a rule, be located outside the zone occupied by the structures of contact nets, including supports.
      In this zone, the supports of the overhead line must be of the anchor type, and the uninsulated wires must have a double fastening;
2. the wires of the overhead line must be located above the supporting cables of the contact wires. The wires of the overhead line must be multiwire with a cross section of at least: aluminum - 35 mm2, steel-aluminum - 25 mm2, carrying the core of the insulated wire - 35 mm2, the cross-section of the wire of SIP with all the conductor wires - at least 25 mm2. Connection of overhead lines in overhead crossing is not allowed;
3. the distance from the overhead lines at the maximum sagging arrow should be at least 8 m to the rail head of the tram line and 10.5 m to the roadway of the street in the trolleybus line zone.
4. In all cases, the distance from the wires of the overhead line to the supporting cable or the contact wire must be at least 1.5 m;
5. crossing of overhead lines with contact wires at the location of the cross bars is prohibited;
6. joint suspensions on trolleybus lines of contact conductors and wires of overhead lines with a voltage not exceeding 380 V are allowed provided that the following conditions are met: the trolleybus line supports must have a mechanical strength sufficient for hanging overhead lines, the distance between the wires of the overhead line and the bracket or cable carrier fixing be at least 1.5 m.

2.4.93. When crossing and convergence of overhead lines with cable cars and overhead metal pipelines, the following requirements must be fulfilled:

1. The overhead line must pass under the cable car; passage of overhead lines over the cable car is not allowed;
2. ropeways should have bottom bridges or grids to protect the wires of overhead lines;
3. when passing overhead lines under a cableway or under a pipeline, the overhead lines should be at a distance of at least 1 m from them - with the smallest sagging of wires to the bridge or the rails of the cableway or to the pipeline; at least 1 m - with the largest sagging arrow and the greatest deviation of the wires to the cableway elements or to the pipeline;
4. when crossing overhead lines with a pipeline, the distance from the wires of the overhead line at their maximum boom should be at least 1 m to the pipeline elements. Supports of overhead lines limiting the crossing of the pipeline must be of the anchor type. The pipeline in the crossing intersection must be grounded, the resistance of the earthing switch - no more than 10 Ohm;
5. if the overhead line is connected in parallel with the cable way or the pipeline, the horizontal distance from the overhead line wires to the cableway or the pipeline must be at least the height of the support, and in the cramped sections of the route with the largest deviation of the wires - not less than 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. Passage of overhead lines up to 1 kV with insulated and non-insulated wires is not allowed on the grounds of sports facilities, schools (general education and boarding schools), technical schools, children's preschools (children's day nurseries, kindergartens, children's plants), orphanages, children's playgrounds, and on the territories of children's health camps.

In the aforementioned territories (except for sports and playgrounds), the passage of VLI is allowed provided that the zero core of the SIP must be isolated and its total conductivity must be at least the conductivity of the phase conductor of the SIP

Application area

General technical requirements apply to overhead transmission lines (overhead lines) of 110-750 kV voltage of JSC FGC UES and must be accounted for by other owners of UNEG facilities.

This document is valid:

When designing, constructing newly constructed high-voltage lines;

With comprehensive reconstruction and technical re-equipment of operating overhead lines.

General technical requirements should be used in the design to approve the Norms for the technological design of overhead power lines with a voltage of 35 kV and above.

Distinctive features of HVL of the new generation

Higher reliability and economy in operation;

The use of structures, elements and equipment that ensure minimum costs for maintenance and repair during the entire service life;

Use of advanced safe methods of construction and operation;

Complex systems for monitoring and monitoring the condition of lines, basic structures and equipment;

Effective protection systems for overhead lines from ice and wind impacts and lightning overvoltages, protection of wires and cables from vibration and dancing;

Increased protection from the impact of external factors such as approaching tree wires, high-speed transport at intersections with roads and navigable water bodies, agricultural machinery in the fields, grass-roots fires and fires on the highway, vandalism and terrorism;

General requirements

New generation air lines should provide:

High maintainability and minimum costs for recovery after over-estimated impacts of climatic factors and fires;

Compliance with Russian regulations, current environmental requirements, CIGRE and IEC recommendations in the field of electric and magnetic fields, radio interference and acoustic noise;

Conformity of reliability of power supply to the requirements of the PUE and the level of responsibility of the line;

Maximum technically and economically feasible throughput;

Improvement of forms and methods of operating with the use of modern diagnostic tools and forecasting the service life of overhead lines;

High level of information technology;

Improvement of technology and quality of construction and installation works;

Economically justified energy losses;

Economical use of land;

Low operating costs;

Application of advanced methods of operation and safe working conditions, including work under stress, modern and reliable mechanisms, small-scale mechanization, tools and tools;

Overhead transmission lines should use new equipment and technologies, building structures, equipment (polyhedral supports, supports from the bent profile, compact supports, advanced technologies of installation and repair, means of mechanization, adaptation, etc.).

VL supports in technically and economically justified cases can be suspended non-metallic optical communication cables.

Suspended arresters to increase the lightning protection of overhead lines can be used as a supplement to the cable protection, and instead of lightning protection cables on the non-lead sections of the overhead line.

When designing a high-voltage line, the following must be provided:

Construction of overhead lines for individual projects;

Selection of designs, elements and assemblies on the basis of technical and economic comparison of options;

Application of standard type unification.

Requirements for elements of overhead lines

Requirements for supports

. The height of the supports should ensure compliance with environmental requirements near the overhead line, protect the wires of overhead lines from the impact of transport on roads, agricultural machinery in the fields and, with economic expediency, the maximum reduction in the width of the forest clearing.

The structures of multi-chain supports shall provide a suspension for up to two circuits of VL with a voltage of 330, 500 kV and up to four circuits of overhead lines with voltage up to 220 kV.

Typical supports, as well as supports of optimal geometric dimensions developed for specific sections of overhead lines, should be economically justified for specific conditions of passage of the route.

For the manufacture of supports, steel grades of increased strength and corrosion resistance should be used.

Anchor-angled supports must be of a rigid construction. In uninhabited and hard-to-reach terrain in economically justified cases, the use of anchor-angled supports with detents is allowed.

Intermediate and anchor-angled supports can be made on the basis of steel racks from a closed profile.

Anchor-angled transpositional supports should occupy the minimum area of ​​the earth.

All metal supports must be equipped with means to prevent their unauthorized disassembly and damage, as well as the dismantling of equipment and wires.

Use as an anticorrosive protection of metal structures of supports hot galvanizing or coating systems with the use of zinc-plated coatings ("cold" galvanizing) or special protective anticorrosion coatings, including polymer ones.

Supports should be equipped with special safety devices ensuring safe lifting and moving of the operating personnel along the posts, traverses and ropes.

Supports must meet the requirements of ease of maintenance and maintainability.

On the supports and their elements, it shall be possible to attach special devices and devices for carrying out maintenance and repair work.

The support structures should provide the possibility of production of maintenance and repair on the overhead line under voltage.

Supports should be as technologically advanced as possible in the installation and installation of wires and cables, the support parts are accessible for transportation by freight transport, which, as a rule, do not require special permission when traveling on roads.

Requirements for foundations

. The structures of the foundations of the supports must provide the necessary strength and stability of the overhead transmission lines in all cases for the entire service life.

The foundations should be designed on the basis of engineering-geological and engineering-hydrological surveys.

The foundations, as a rule, should be prefabricated reinforced concrete (mushroom-shaped pedestals, pile foundations of reinforced concrete piles with metal grilles, shallow and superficial, foundations of reinforced concrete slabs and piles, etc.). The foundations' designs should provide, as a rule, available industrial methods of production in the field.

If it is impossible to use prefabricated foundations, monolithic reinforced concrete or prefabricated monolithic reinforced concrete foundations can be used.

Constructions of foundations in permafrost soils should provide the possibility of performing work in permafrost conditions.

In the design of foundations in the undergrowth of soils, antipruritic measures should be developed or foundation designs that are resistant to abrasive soils should be applied.

The brands of reinforced concrete foundation structures for frost resistance and water permeability, resistance to aggressive environments should ensure the integrity of foundations without additional protective coatings during their entire service life.

The metal structures of foundations in the ground must be protected from corrosion by modern corrosion-resistant materials. Mobile connections of metal assemblies in the ground (loop connections) are not allowed.

Requirements for wires and lightning ropes

Wires and lightning protection ropes on new and reconstructed overhead lines must be selected and designed in accordance with the current PUE.

The wires must:

Have small losses in the transmission of electricity;

Have sufficient thermal stability;

Have a high threshold of tension beginning the crown;

Possess increased self-damping capability;

Possess reduced adhesion to snow and ice;

Have a low level of acoustic noise;

Have a low level of radio and television interference.

As wires on the overhead line can be used:

Steel-aluminum wires with a steel core filled with lubricant;

Steel-aluminum wires with reduced active resistance to alternating current, including steel core made of non-magnetic stainless steel;

Wires with steel wires clad with aluminum;

High-temperature steel-aluminum wires (aluminum heat-treated alloy);

Wires with conductive coils of high-strength aluminum alloys, compacted twists and other modern structures.

Lightning protection cables must:

Have low active resistance to alternating current;

Provide high corrosion resistance;

To have improved aerodynamic characteristics in order to reduce mechanical loads on the support and increase the length of the spans;

Possess high mechanical strength;

Possess high resistance to lightning discharges;

Possibility to organize fiber-optic communication channels.

As lightning protection cable can be used:

A steel wire rope made of galvanized wires with a grease filling of the interwire space;

Steel-aluminum wire with an increased cross-section of the steel core with core filling with lubricant;

Lightning protection cables with built-in fiber-optic cables for the organization of modern communication channels;

Lightning protection cable with stainless steel wires in the outer layer;

Thunder-proof cable with wires of stainless nitrogen-containing steel;

Lightning protection cable made of steel wires clad with aluminum.

Requirements for braces

As supports of supports it is necessary to apply:

Steel ropes made of galvanized wires of ordinary and high strength with lubrication.

Requirements for insulators

Insulators on overhead lines in all cases should be selected according to the current standards of electrical compatibility, GOST R, branch technical requirements, taking into account local conditions, including maps of the degree of insulation pollution.

Isolators of overhead lines must possess:

High mechanical strength;

High reliability in operation, low level of rejection;

High electrical strength in conditions of contamination and moistening;

High level of the beginning of electrical discharges;

Low level of radio interference;

Low level of acoustic noise;

Small mass and convenience of transportation and operation;

When choosing the types of insulators, preference should be given to isolators that do not require special instrumental monitoring of the technical condition during the entire lifetime.

The following should be applied to the overhead line:

Glass dish-type insulators with a rejection level not worse than 10-4;

Porcelain tarelchatyh advanced foreign firms with the level of rejection is not worse than 10 - 5;

Glass insulators with reduced level of radio interference with seals made of silicone rubber;

Long-term polymer insulators of a new generation of domestic and imported production, with a rejection level no worse than 10-6;

Long-term porcelain insulators of leading foreign firms with a rejection level of no worse than 10 - 6.

In areas where there are frequent damage to VL insulators from vandalism, it is necessary to give preference to the use of vandal-proof insulators (polymer, porcelain long-length).

Requirements for linear reinforcement.

Linear reinforcement must:

Possess high mechanical strength and reliability;

Possess high wear resistance;

To have the standard sizes of interfaces, which ensure universal application in garlands of insulators and interchangeability;

Possess a low mass;

Possess high corrosion resistance;

Possibility of installation;

Do not require special maintenance and monitoring during the entire lifetime of the overhead line.

The wire-mounted reinforcement must have a minimum loss of magnetization reversal and eddy currents.

The nodes of fixing the insulator strings to the supports must ensure their reliability and durability during the entire lifetime of the overhead line.

The protective armature should ensure equalization of the distribution of voltage across the garlands of insulators, have a high level of crown initiation, resistance to deformation in operation, and ease of installation.

Effective interphase struts-dampers with rubber-metal hinges on the overhead line with splitted phase wires.

Interphase insulating spacers to prevent interphase overlaps, wire splices during intense dancing and when wires oscillate inconsistently.

Disturbing pendulums for limiting vibrations of wires during dancing on high-voltage lines in areas with frequent dance of wires;

Loads-restrictors of twisting of wires and snow repellent rings for protection of wires against sticking of wet snow;

Multiresonance vibration dampers for effectively limiting the vibration of phase wires and lightning-proof cables;

For VL with a voltage of 330 kV and above, to level the electric fields and protect from the corona, rigid protective shields of aluminum coarse toroidal shapes should be used;

For steel wires and lightning protection cables, use clamping clamps as tension clamps and clamps for their connection;

For attaching lightning protection cables with built-in fiber optic cable and dielectric fiber-optic cables on the overhead line, a line armature recommended by the cable manufacturer should be used.

Operation of overhead lines

When organizing the maintenance and repair of overhead transmission lines, the operation services of grid companies should be guided by the "Rules for the Technical Operation of Electric Power Stations and Networks of the Russian Federation", M., SPO ORGRES, 2003 and "Standard Instruction for the Operation of 35-800 kV Overhead Transmission Lines" 34.20.504-94, SPO ORGRES, 1996.

When using special design solutions on VL, development and implementation of special measures for maintenance and repair of overhead lines is required.

Planning of repairs and maintenance is recommended to take into account the assessment of the actual technical condition of the overhead line.

Normative and methodical support

In the design, construction and operation of overhead transmission lines, national standards for insulators, wires and line fittings should be guided by regulatory documents in accordance with RAO UES of Russia Order No. 422 of August 14, 2003 "On the revision of normative and technical documents and the procedure for their operation in accordance with FZ "On technical regulation", including the new chapters of the PUE of the 7th edition, "Recommendations on the technological design of overhead power lines 35 kV and above" approved Order of the Ministry of Energy of Russia of June 30, 2003 No. 284. Publishing house of the Center "ENAS", Moscow, 2004, "Rules for the Technical Operation of Electric Power Stations and Networks of the Russian Federation", M., SPO ORGRES, 2003, and other current NTD, SNiP and Sanitary Norms, as well as new normative and technical documents as they are approved.