Types and designations of supports

On overhead lines, supports made of various materials can be used.

For overhead lines should be used following types supports:

1) intermediate, installed on straight sections of the overhead line route. In normal operating modes, these supports should not absorb forces 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 overhead line wires change. In normal operating conditions, these supports must absorb forces from the difference in 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 absorb the resulting load from the tension of the wires of adjacent spans. Corner supports can be intermediate or anchor type;

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

Depending on the number of chains suspended on them, supports are divided into single-chain, double-chain and multi-chain.

The supports can be free-standing or with guy wires.

Intermediate supports can be of flexible or rigid design; anchor supports must be rigid. It is allowed to use anchor supports of flexible design for overhead lines up to 35 kV.

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

The support structures must provide the ability to install:

• lamps street lighting all types;
• cable terminations;
• protective devices;
• sectioning and switching devices;
• cabinets and panels for connecting electrical receivers.

Types of supports

P - intermediate;

PP - transitional intermediate:

UP - angular intermediate:

A - anchor;

PA - transitional anchor;

AK - anchor end:

K - end:

UA - corner anchor;

PUA - transitional corner anchor;

AO - anchor branch;

POA - transitional anchor branch;

O - branch.

Nomenclature of reinforced concrete supports for 10 kV power lines

Support code	Number of racks per support	Rack code	Stand height, m	Height to the lower traverse, m	Volume of reinforced concrete, m	Weight of metal structures, kg
		SV105-3.5; SV105 SV105-3.5; SV105 SV105-3.5; SV105 SV105-3.5; SV105 SV105-3.5; SV105 SV105-3.5; SV105 SV105-3.5; SV105 SV105-3.5; SV105 SV105-3.5; SV105 SV105-3.5; SV105 SV105-3.5; SV105 SV105-3.5; SV105 SV105-3.5; SV105 SV105-3.5; SV105 SV105-3.5; SV105 SV105-3.5; SV105 SV105-3.5; SV105 SV105-3.5; SV105 SV105-3.5; SV105 SV105-3.5; SV105 SV105-3.5; SV105 SV105-3.5; SV105 SV105-3.5; SV105 SV105-3.5; SV105 SV105-3.5; SV105 SV105-3.5; SV105 SV105-3.5; SV105 SV105-3.5; SV105 SV105-3.5; SV105 SV105-3.5; SV105 SV105-3.5; SV105 SV105-3.5; SV105

STATE STANDARD OF THE USSR UNION

UNIFIED SYSTEM OF TECHNOLOGICAL DOCUMENTATION

SUPPORTS, CLAMPS
AND INSTALLATION DEVICES.
GRAPHICAL SYMBOLS

GOST 3.1107-81
(C.T.CMEA 1803 -7 9)

STATE STANDARD OF THE USSR UNION

Unified system technological documentation SUPPORTS, CLAMPS AND INSTALLATION DEVICES. GRAPHICNOTATION Unified system for technological documentation. Bases, clamps and installing arrangements. Symbolic representation

GOST 3.1107-81 (C.T.CMEA 1803 -7 9) In return GOST 3.1107 -7 3

Resolution of the Statethe USSR Gift Committee on Standards dated December 31, 1981 No. 5 943 has an introduction date set

from 01.07.82

1. This standard establishes graphic designations of supports, clamps and installation devices used in technological documentation. The standard fully complies with ST SEV 1803-7 9. 2. To depict the designation of supports, clamps and installation devices, a solid thin line should be used in accordance with GOST 2.303-68. 3. Designations of supports (conditional) are given in table. 1.

Table 1

On and change support	Support symbol in views
	front and back
1. Fixed
2. Movable
3. Floating
4.Adjustable

4. It is allowed to depict the designation of movable, floating and adjustable supports in top and bottom views as the designation of a fixed support in similar views. 5. Designations of terminals are given in table. 2. 6. The designation of a double clamp on the front or rear view, when the points of application of force coincide, can be depicted as the designation of a single clamp on similar views. 7. Designations of installation devices are given in table. 3.

Table 2

Name of clamp	Clamp designation in views
	front, back
1. Single
2. Double

Note. For double clamps, the length of the arm is set by the designer depending on the distance between the points of application of forces. A simplified graphic designation of a double clamp is allowed: . 8. Installation and clamping devices should be designated as a combination of designations for installation devices and clamps (reference appendix 2). Note. For collet mandrels (chucks), the designation - should be used. 9. It is allowed to mark supports and installation devices, except for centers, on extension lines of the corresponding surfaces (reference appendices 1 and 2). 10. To indicate the form work surface supports, clamps and installation devices should use designations in accordance with table. 4. 11. The designation of the shapes of the working surfaces is applied to the left of the designation of the support, clamp or installation device (reference appendices 1 and 2). 12. To indicate the relief of the working surfaces (grooved, threaded, splined, etc.) of supports, clamps and installation devices, the designation should be used in accordance with the drawing.

Table of persons 3

Name of installation device	The installation device is indicated in the views
	front, back, top x bottom
1. The center is stationary		Without designation	Without designation
2. Center rotating
3. Center floating
4. Cylindrical mandrel
5. Ball mandrel (roller)
6. Drive chuck

Notes: 1. The designation of reverse centers should be done in a mirror image. 2. For basic mounting surfaces, it is allowed to use the designation -.

Table 4

Name of working surface shape	Designation of the shape of the working surface on all sides
1. Flat
2. Spherical
3. Cylindrical (ball)
4. Pr and zimatic
5. Conical
6. Rhombic
7. Triangular

Note. The indication of other forms of the working surface of supports, clamps and installation devices should be carried out in accordance with the requirements established by industry normative and technical documentation. 13. The designation of the relief of the working surface is applied to the designation of the corresponding clamp support or installation device (reference appendix 1). 14. To indicate clamping devices, designations should be used in accordance with table. 5.

Table 5

15. The designation of the types of clamping devices is applied to the left of the designation of the clamps (reference appendices 1 and 2). Note. For g and drop-plastic mandrels, it is allowed to use the designation e - . 16. The number of points of application of the clamping force to the product, if necessary, should be written to the right of the clamp designation (reference appendix 2, item 3). 17. On diagrams that have several projections, it is allowed on separate projections not to indicate the designations of supports, clamps and installation devices relative to the product, if their position is clearly determined on one projection (reference appendix 2, item 2). 18. On the diagrams, it is allowed to replace several designations of supports of the same name on each view with one, indicating their number (reference appendix 2, item 2). 19. Deviations from the dimensions of the graphic symbols indicated in the table are allowed. 1 - 4 and in the drawing.

APPENDIX 1

Information

Examples of marking supports, clamps and installation devices on diagrams

Name	Examples of markings for supports, clamps and installation of eyepiece devices
1. Fixed center (smooth)
2. Center grooved
3. Center floating
4. Center rotating
5. Reverse rotating center with grooved surface
6. Drive chuck
7. Movable rest

Depending on the method of hanging support wires air lines(VL) are divided into two main groups:

A) intermediate supports, on which the wires are fixed in supporting clamps,

b) anchor type supports, used for tensioning wires. On these supports, the wires are secured in tension clamps.

The distance between supports (power lines) is called span, and the distance between anchor-type supports is called anchored area(Fig. 1).

In accordance with the intersection of some engineering structures, such as railways public use, must be performed on anchor-type supports. At the angles of rotation of the line, corner supports are installed on which the wires can be suspended in support or tension clamps. Thus, the two main groups of supports - intermediate and anchor - are divided into types that have a special purpose.

Rice. 1. Scheme of the anchored section of the overhead line

Intermediate straight supports installed on straight sections of the line. On intermediate supports with hanging insulators, the wires are secured in supporting garlands hanging vertically; on intermediate supports with pin insulators, the wires are secured with wire knitting. In both cases, intermediate supports perceive horizontal loads from wind pressure on the wires and on the support, and vertical loads from the weight of the wires, insulators and the own weight of the support.

With unbroken wires and cables, intermediate supports, as a rule, do not take the horizontal load from the tension of the wires and cables in the direction of the line and therefore can be made more lightweight design than other types of supports, for example, end supports that absorb the tension of wires and cables. However, to ensure reliable operation line intermediate supports must withstand some loads in the direction of the line.

Intermediate corner supports are installed at the angles of rotation of the line with wires suspended in supporting garlands. In addition to the loads acting on intermediate straight supports, intermediate and anchor corner supports also absorb loads from the transverse components of the tension of wires and cables.

At power line rotation angles of more than 20°, the weight of the intermediate corner supports increases significantly. Therefore, intermediate corner supports are used for angles up to 10 - 20°. For large rotation angles, install anchor corner supports.

Rice. 2. Intermediate supports for overhead lines

Anchor supports. On lines with suspended insulators, the wires are secured in the clamps of tension garlands. These garlands are like a continuation of the wire and transfer its tension to the support. On lines with pin insulators, the wires are fixed to anchor supports with reinforced viscous or special clamps, ensuring the transfer of the full tension of the wire to the support through pin insulators.

When installing anchor supports on straight sections of the route and suspending wires on both sides of the support with equal tensions, the horizontal longitudinal loads from the wires are balanced and the anchor support works in the same way as an intermediate one, i.e., it perceives only horizontal transverse and vertical loads.

Rice. 3. Anchor-type overhead line supports

If necessary, the wires on one and the other side of the anchor support can be pulled with different tension, then the anchor support will perceive the difference in tension of the wires. In this case, in addition to horizontal transverse and vertical loads, the support will also be affected by horizontal longitudinal load. When installing anchor supports at corners (at the turning points of the line), the anchor corner supports also take the load from the transverse components of the tension of wires and cables.

End supports are installed at the ends of the line. Wires extend from these supports and are suspended on substation portals. When hanging wires on the line before the construction of the substation is completed, the end supports perceive full one-sided tension.

In addition to the listed types of supports, special supports are also used on lines: transpositional, used to change the order of arrangement of wires on supports, branch lines - for making branches from the main line, supporting large river crossings and bodies of water etc.

The main type of supports on overhead lines are intermediate ones, the number of which usually accounts for 85-90% of the total number of supports.

Based on their design, supports can be divided into: free-standing And guyed supports. Guys are usually made of steel cables. Wooden, steel and reinforced concrete supports are used on overhead lines. Support designs made of aluminum alloys have also been developed.
Overhead line support structures

1. Wooden support of the 6 kV LOP (Fig. 4) - single-column, intermediate. Made from pine, sometimes larch. The stepson is made of impregnated pine. For 35-110 kV lines, wooden U-shaped two-post supports are used. Additional elements of the support structure: hanging garland with hanging clamp, crossbar, braces.
2. Reinforced concrete supports are made as single-column free-standing ones, without guys or with guys on the ground. The support consists of a post (trunk) made of centrifuged reinforced concrete, a traverse, a lightning protection cable with a grounding conductor on each support (for lightning protection of the line). Using a grounding pin, the cable is connected to a ground electrode (a conductor in the form of a pipe driven into the ground next to the support). The cable serves to protect lines from direct lightning strikes. Other elements: stand (barrel), rod, traverse, cable support.
3. Metal (steel) supports (Fig. 5) are used at voltages of 220 kV and more.

Reinforced concrete power transmission line supports used in the installation of overhead power lines (VL and VLI) in populated areas and in uninhabited areas. Reinforced concrete supports are made based on standard concrete pillars: SV 95-2V, SV 95-3V, SV110-1A, SV 110-3.5A, SV110-5A.

Reinforced concrete power transmission line supports - classification by purpose

The classification of reinforced concrete supports by purpose does not go beyond the types of supports standardized in GOST and SNiP. Read in detail: Types of supports by purpose, but here I will briefly remind you.

Intermediate concrete supports needed to support cables and wires. They are not subject to longitudinal or angular tension loads. (marking P10-3, P10-4)

Anchor concrete supports provide retention of wires during their longitudinal tension. Anchor supports must be installed at the intersection of power lines with railways and other natural and engineering barriers.

Corner supports are placed at the turns of the power line route. At small angles (up to 30°), where the tension load is not large and if there is no change in the cross-section of the wires, angular intermediate supports (IP) are installed. At large rotation angles (more than 30°), corner anchor supports (CA) are installed. At the end of the power line, anchors, also known as end supports, are placed (A). For branches to subscribers, branch anchor supports (OA) are installed.

Marking of concrete supports

It is worth focusing on the markings of the supports. In the previous paragraph I used the markings for the 10-2 supports. Let me explain how to read the markings of the supports. Reinforced concrete supports are marked as follows.

• The first two letters indicate the purpose of the support: P (intermediate) UP (intermediate corner), UA (corner anchor), A (anchor-end), OA (branch support), UOA (corner branch anchor).
• The second number means for which power transmission line the support is intended: the number “10” is a 10 kV power line.
• The third number after the dash is the standard size of the support. The number “1” is a 10.5 meter support, based on the SV-105 pillar. The number “2” is a support based on the SV-110 pillar. Detailed standard sizes are in the tables at the bottom of the article.

Reinforced concrete support structures

Reinforced concrete support structures also do not go beyond standard support structures.

• Portal supports with guy ropes – two parallel supports are supported by guy ropes;
• Free-standing portal supports with crossbars;
• Free-standing supports;
• Supports with guys.

The use of supports must comply with design calculations. For calculations, various normative tables are used, the volume of which occupies several volumes.

Concrete supports according to the number of chains held

If the support crossbars allow you to hook only one line of electric power, it is called single-chain (crossbar on one side). If the crossbar is on both sides, then the support is double-chain. If you can hang many lines of wires, then this is a multi-circuit support.

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Installation of concrete supports

Calculation of supports is carried out by SNiP 2.02.01-83 and “Guide to the design of power lines and power line foundations...”. The calculation is based on deformation and bearing capacity.

To secure the intermediate support type P10-3(4), you need to drill a cylindrical pit with a diameter of 35-40 cm, to a depth of 2000 -25000 mm. An installation bolt is not needed for such a support.

Anchor corner and anchor branch supports, are usually mounted with mounting crossbars. Please note that the crossbars can be placed on the lower edge of the support and strut, buried in the ground and/or on the upper edge of the support, along the top of the pit. The crossbars provide additional stability to the support. The depth of installation of the support depends on the freezing of the soil. Usually 2000-2500 mm.

Grounding of concrete supports

Thanks to the design of the support posts, grounding the supports is very convenient. In the racks of SV supports, in the factory during their manufacture, metal reinforcement 10 mm in diameter is installed at the top and bottom of the rack. This reinforcement runs inextricably along the entire length of the rack. It is this reinforcement that serves to ground reinforced concrete supports.