Types of linear fittings. Overhead line fittings

Linear fittings used when fixing wires in garlands of suspension insulators can be divided according to their purpose into five main types:

1. Clamps for fixing wires and cables, subdivided into supporting, suspended on intermediate supports, and tension, used on anchor-type supports.

2. Coupling fittings (brackets, earrings, ears, rocker arms), which serves to connect clamps with insulators, for hanging garlands on supports and for connecting multi-chain garlands to each other.

3. Protective fittings (rings), mounted on garlands of lines with a voltage of 330 kV and above, designed for a more uniform distribution of voltage between the individual insulators of the garland and to protect them from damage by an arc during overlaps.

4. Connecting fittings, which serves to connect wires and cables in the span, as well as to connect wires in loops on anchor-type supports.

5. Spacersused to connect split-phase wires to each other. Support clamps consist of a boat in which the wire is placed, dies and bolts (or a bolt) for fixing the wire in the boat, springs, trunnions or brackets for attaching the clamp to the garland.

According to the strength of the wire fastening, the supporting clamps are divided into the following types:

Blind clamps, in which the strength of the seal reaches 30 - 90% of the strength aluminum wires, 20 - 30% of the strength of steel-aluminum wires and 10 - 15% of the strength of steel cables. With such termination, the wire and cable in the event of a break in one of the spans, as a rule, are not pulled out of the clamp and the tension of the wire or cable that remains unbroken is transferred to the intermediate support.

Blind clamps are the main type of clamps currently used on overhead lines.

Drop-out clips(also called releasing), throwing out a boat with a wire when the supporting garland deviates at a certain angle (about 40 °) in the event of a wire break in one of the spans. Thus, the tension of the wire remaining unbroken is not transferred to the intermediate support. This feature of the operation of the drop-down clamp allows you to slightly reduce the weight of the intermediate support. However, in operation, there were cases of ejection of wires from drop-down clamps during dancing and uneven loading with ice in adjacent spans. Therefore, drop-down clamps are not currently used and are not discussed below.

Multi-roller hangers, essentially not being clamps, since the wire can freely roll over the rollers with a difference in tension in adjacent spans. Multi-roller suspensions are used for fastening wires with a cross section equal to or greater than 300 mm2 and cables on intermediate supports of large transitions. At the same time, the protection of steel-aluminum wires is provided by special flexible couplings that are mounted on the wires in the areas of their possible movement along the rollers.

Blind terminals for a phase split into three wires consist of a body, dies, tension bolts with nuts and gaskets made of aluminum. Previously produced bolt clamps with the arrangement of bolts and dies in the side of the span are currently replaced by clamps in which the bolts are located on the hinge side. With the new clamps, limited wire movement from the span side is possible, which reduces damage to the wires from vibration.

Compressible Tension Clamps used for the installation of steel-aluminum wires with a cross section of 300 mm2 or more. They consist of a steel anchor, in which the steel core of the wire is crimped, and an aluminum housing, in which the aluminum part of the wire is crimped from the span side.

The disadvantage of pressable tension clamps with an anchor is the need to cut the wire in order to crimp it. Therefore, a pressable tension clamp for steel-aluminum wires of the "through" type is produced, in which it is possible to mount the wire without cutting it. However, clamps of this type are significantly heavier than conventional compression clamps.

For monometallic wires and steel cables, pressing clamps of a simpler design are produced, consisting of a sleeve for crimping the wire and a part for hanging the sleeve on a garland.

Wedge Tension Clamps used for suspension of steel cables. They consist of a body and a double wedge. When the cable is pulled, the wedge presses the cable against the body, which ensures a secure termination.

Coupling fittings are subdivided into brackets that serve to attach a garland to a support or to parts fixed on a support, earrings connected on one side with brackets or parts on a support, and on the other hand with insulator caps, ears used to pair insulator rods with clips or other parts of the garland from the side of the wire.

Coupling fittings also include intermediate links used to lengthen garlands, and rocker arms that serve to move from one to two or more suspension points.

Protective fittings overhead lines power transmission

Protective reinforcement can be made in the form of horns or rings. Protective rings for supporting garlands of lines with a voltage of 330 kV and above were made in the form of ovals, installed with a longer side along the line.

Currently, special support clamps are used on 330 and 500 kV lines with the wires located approximately at the level of the lower insulator skirt.

With an insulated cable suspension on lines with a voltage of 220 kV and higher, the insulators are shunted by discharge horns.

Suspension of supporting garlands on intermediate supports is carried out with the help of KGP-type attachment points, consisting of a U-shaped bolt with nuts, fixed in the holes of the traverse. The mount kit includes a bracket or an earring for hanging the garland. Tension garlands are fixed on supports with the help of KG or KGN attachment points. Sketches of attachment points are given in the catalogs of linear fittings.

Connecting fittings for overhead power lines

Connectors designed to connect wires and cables are divided into oval and pressed.

Oval connectors are used for wires up to 185 mm2 inclusive. In them, the wires are overlapped, after which the connector is crimped using special pliers. Steel-aluminum wires with a cross section of up to 95 mm2 inclusive are fixed in connectors by twisting.

Pressable connectors are used to connect wires with a cross section of more than 185 mm2 and for steel cables of all cross sections. The extruded connector for steel-aluminum wires consists of a shaped steel tube pressed onto a steel core and an aluminum tube pressed onto the aluminum part of the wire. Connectors for monometallic wires and steel cables consist of a single tube.

Spacers

The spacers installed on the split-phase wires to ensure the required distance c between the wires consist of two pairs of dies bolted to the wires and a rigid rod pivotally connected to the dies. Currently, only blind struts are used.

The operating experience of the releasing struts turned out to be unsatisfactory, since struts of this type were thrown off during the dance of the wires; therefore their use is not allowed. in loops anchor supports weighted struts with weights are installed to limit the swinging of the loops.

Power line fittings are special standard parts designed for connecting wires, connecting insulators into garlands, attaching wires to them, hanging garlands on power transmission towers and other functions.

Requirements for power line fittings - rated mechanical strength , good articulation , high corrosion resistance , high fatigue strength , good electrical conductivity (in some cases)

Classification of fittings for power lines

By purpose, fittings for power transmission lines are divided into several groups: coupling fittings for power lines, supporting fittings for power lines, tension fittings for power lines, connecting fittings for power lines, protective fittings for power lines, contact fittings, fittings for fastening pin insulators, spiral fittings, fittings for self-supporting insulated wires(SIP fittings)

Coupling fittings for power lines

Appointment of special fittings for power lines

Coupling fittings are designed to complete the suspension with attachment points of the KGP type, lugs of the U1, U1K, U2, U2K, US, USK, and UD types, SK and SKD type brackets, intermediate links of the PR, PRV, PRVU, PRT, 2PR, 2PRR, PTM types , lanyards of the PTR type, earrings of the SR, SRS, SD types and rocker arms of the KT3, 2KD, 2KU, 2KL types.

Elements of coupling fittings for power lines

knots for attaching garlands to a support, earrings, ears, staples, intermediate links, rocker arms

Supporting reinforcement for power lines

Supporting fittings are designed for supporting fastening of wires (ropes) and looping of the loop, as well as for holding the fastening points of screens of the UKE type. Support fittings include support clamps(type PG, PGG, PGN), roller hangers, spacers special(type RS) and knitting special(type VS and PVS).

Tension fittings for power lines

Tension clamps are used to fasten wires to tension garlands of anchor supports high voltage line.

Connecting fittings for power lines

Connecting fittings include oval connectors And thermite cartridge. Also includes a die clamp, etc.

Oval connectors

Oval connectors are made of aluminum and are an oval tube. Connectors are mounted by crimping and twisting. Crimping is performed on special tongs, the ends of the wires are inserted into the connector body, the connector is crimped from both sides in a checkerboard pattern. The twisting of the connector is carried out on a special machine for twisting oval connectors. To improve the electrical qualities of the connection, the ends of the wires after crimping or twisting are connected with a thermite cartridge.

Thermite cartridge

Used to connect wires in a loop. The cartridge consists of a mold, an insert and thermite mass. Thermite mass is applied to the chill mold, when welding, the wires are brought into the chill mold and fixed in special tongs. Next, the thermite mass is ignited and welding takes place.

Protective fittings for power lines

Protective fittings include protective horns, protective screens and rings, arresters, vibration dampers.

Protective horns

They are used to create a spark gap, divert an electric arc when the insulation overlaps and protect the insulation of a high-voltage line. The upper horns (РРВ) are attached to the coupling fittings at the top of the garland, the lower horns (РРН) are attached to the pestles of the insulators or the coupling fittings at the bottom of the garland.

Protective screens and rings

Protective screens and rings serve to divert the electric arc that occurs when the insulation is blocked from the surface of the insulators and improve the distribution of electrical voltage over the garland.

Dischargers

They are used to protect against lightning damage sections of overhead lines with reduced insulation compared to the rest of the line from overvoltage waves coming from the line. There are two types: tubular(RTF, RTV, RTVU) and valve. Tubular spark gaps consist of a fibrous bakelite or vinyl plastic tube and electrodes. When an arc is formed between the electrodes, the inner surface of the tube begins to evaporate, and the resulting gases, passing through the tube, stretch and extinguish the arc.

Vibration dampers

Vibration dampers are installed on wires and cables of power lines to prevent damage from fatigue stresses caused by vibration. Vibration dampers such as GV, GVN or GPG are used for installation on overhead lines. For installation on wires of large transitions - GPG-type dampers with a "blind" fastening or drop-down vibration dampers of the GPS type.

Fittings for fixing pin insulators

For fastening pin insulators are used pins And hooks.

Pins

Pins are used for fastening pin insulators to traverses of poles of 0.4-20 kV overhead lines and telegraph lines. Made from steel or preserved wood (for secondary lines). Insulators are attached to the pins with tow or special caps.

Hooks

Hooks are used for fastening pin insulators to supports of 0.4-10 kV overhead lines and telegraph lines. Made from steel. The hooks are screwed into the wooden posts of the supports. Insulators are attached to hooks using tow or special caps. Sometimes the hooks are welded to the traverses of the supports.

Spiral fittings for power lines

Description of spiral fittings for power lines

At the heart of spiral reinforcement are wire spirals covering the wire. It combines well with wires and cables due to its own flexibility and, after installation, is actually combined with the wire into a single whole.

Compared with traditional (bolted or pressed) structures used in the electric power industry and communications, spiral fittings have a number of advantages, and only they can be used for the installation of fiber-optic communication cables (self-supporting, embedded in ground wire, phase wire), as other types fittings create an unacceptably large clamping force.

Types of spiral fittings for power lines

Spiral reinforcement according to its purpose is divided into the following types: tension clamps, supporting clamps, repair clamps, connecting clamps, cable clamps, protective protectors.

Linear fittings used when fixing wires in garlands of suspension insulators can be divided according to their purpose into five main types:

Clamps used to secure wires and cables, subdivided into supporting, suspended on intermediate supports, and tension, used on anchor-type supports.
Coupling fittings (brackets, earrings, ears, rocker arms) used to connect clamps with insulators, to hang garlands on supports and to connect multi-chain garlands to each other.
Protective fittings (rings) mounted on garlands of lines with a voltage of 330 kV and above, designed to more evenly distribute the voltage between the individual insulators of the garland and to protect them from damage by an arc during overlaps.
Connecting fittings used to connect wires and cables in the span, as well as to connect wires in loops on anchor-type supports.
Spacers used to connect split-phase wires to each other. Support clamps consist of a boat in which the wire is placed, dies and bolts (or a bolt) for fixing the wire in the boat, springs, trunnions or brackets for attaching the clamp to the garland.

Clips for fixing wires and cables

According to the strength of the wire fastening, the supporting clamps are divided into the following types:

Blind clamps, in which the termination strength reaches 30 - 90% of the strength of aluminum wires, 20 - 30% of the strength of steel-aluminum wires and 10 - 15% of the strength of steel cables. With such termination, the wire and cable in the event of a break in one of the spans, as a rule, are not pulled out of the clamp and the tension of the wire or cable that remains unbroken is transferred to the intermediate support.

Blind clamps are the main type of clamps currently used on overhead lines.

Drop-down clamps (also called release clamps), which eject a boat with a wire when the supporting garland deviates at a certain angle (about 40 °) in the event of a wire break in one of the spans. Thus, the tension of the wire remaining unbroken is not transferred to the intermediate support. This feature of the operation of the drop-down clamp allows you to slightly reduce the weight of the intermediate support. However, in operation, there were cases of ejection of wires from drop-down clamps during dancing and uneven loading with ice in adjacent spans. Therefore, drop-down clamps are not currently used and are not discussed below.

Multi-roller hangers that are essentially not clamps, since the wire can freely roll over the rollers with a difference in tensions in adjacent spans. Multi-roller suspensions are used for fastening wires with a cross section equal to or greater than 300 mm2 and cables on intermediate supports of large transitions. At the same time, the protection of steel-aluminum wires is provided by special flexible couplings that are mounted on the wires in the areas of their possible movement along the rollers.

Blind clamps for a phase split into three wires consist of a body, dies, tension bolts with nuts and aluminum gaskets. Previously produced bolt clamps with the arrangement of bolts and dies in the side of the span are currently replaced by clamps in which the bolts are located on the hinge side. With the new clamps, limited wire movement from the span side is possible, which reduces damage to the wires from vibration.

Compressible tension clamps used for mounting steel-aluminum wires with a cross section of 300 mm2 or more. They consist of a steel anchor, in which the steel core of the wire is crimped, and an aluminum housing, in which the aluminum part of the wire is crimped from the span side.

For monometallic wires and steel cables, pressing clamps of a simpler design are produced, consisting of a sleeve for crimping the wire and a part for hanging the sleeve on a garland.

Wedge tension clamps used for suspension of steel cables. They consist of a body and a double wedge. When the cable is pulled, the wedge presses the cable against the body, which ensures a secure termination.

Coupling fittings for overhead power lines

Coupling fittings are subdivided into brackets that serve to attach the garland to a support or to parts fixed on a support, earrings connected on one side with brackets or parts on a support, and on the other hand with insulator caps, ears used to connect insulator rods with clips or other parts of the garland from the side of the wire.

Coupling fittings also include intermediate links used to lengthen garlands, and rocker arms that serve to move from one to two or more suspension points.

Protective fittings for overhead power lines

Currently, special support clamps are used on 330 and 500 kV lines with the wires located approximately at the level of the lower insulator skirt.

With an insulated cable suspension on lines with a voltage of 220 kV and higher, the insulators are shunted by discharge horns.

Connecting fittings for overhead power lines

Connectors designed to connect wires and cables are divided into oval and pressed.

Spacers

The operating experience of the releasing struts turned out to be unsatisfactory, since struts of this type were thrown off during the dance of the wires; therefore their use is not allowed. Weighted struts with weights are installed in the anchor support loops, which limit the swinging of the loops.

The reliability of an overhead power transmission line is determined by the quality of all elements used in its construction. In this section of our catalog you are offered information, using which you can easily select components for use in overhead lines different types– main, open lines switchgears and others.

The products offered by our company are produced in strict accordance with all the requirements of the regulatory and technical documentation governing the manufacture of products for the electric power industry. The range of products in this category consists of several types of clamps and other products, including vibration dampers, mounting thermochucks, spacers and some other elements necessary for the installation of any overhead power line.

clamps

Using the clamps offered by us, you will solve any problems that arise during the construction of an overhead line or during its repair. All products can be used on aluminum and steel-aluminum overhead lines. Since these components are usually required in large quantities, purchasing them from us will save you significant cash, as we sell these fittings at low prices. Briefly describe each type of reinforcement.

Hardware clamps are intended for fastening the wire of the overhead line to the terminals of electrical devices. They are also used to connect wires to branch fittings. There are two types of products in the product range - conventional and pin clamps used in solving a wider range of tasks.

The name of the grounding clamps in itself speaks of their purpose. With the help of these components, the installation of grounding sections of overhead lines is carried out. Specifications The grounding fittings offered by us guarantee that the parameters of the grounding scheme correspond to the calculated values, which do not change for a long time.

The use of branch clamps will allow you to configure the overhead line, refusing to perform a number of complex installation operations, for example, cutting the wire. Installation of overhead lines using fittings of this type is carried out quickly and with low labor costs with the highest quality of connection. We supply products in two types - monolithic and detachable. This greatly expands the possibilities of their application.

Tension clamps are the main element in attaching the overhead line wire to the tension insulating garland. The fittings that we offer meet all the requirements for ensuring the mechanical strength of the suspension unit. The ultimate breaking load is high enough for the use of these components in lines of various types.

With the use of flat clamps, you can easily solve the complex tasks of configuring overhead lines. This type of fitting is used, for example, when tapping. With the help of these clamps, reliable lightning protection systems are built on overhead lines up to 110 kV.

Also in the construction of lightning protection systems, as well as for attaching wires of overhead lines with a voltage of up to 220 kV to insulating garlands, another type of clamps is used - supporting. We offer several types of these fittings, designed for various nominal wire sizes and a fairly wide range of mechanical loads.

In the installation of overhead lines by twisting, which is used quite often due to the reliability of the resulting connection, the connecting clamps offered by us are used. The components are easy to use and provide required quality connection that does not deteriorate over time even under harsh operating conditions.

Loop clamps are necessary to make transitions from one section of the overhead line to another, for example, from one wire to two, or with copper wire to aluminum or vice versa. Most often, such a need arises when mounting an overhead line wire loop on a corner or anchor support.

Repair clamps, as, again, it is clear from the name, are used to repair the overhead line. Using fittings offered by our company, your staff will perform repair work quickly and with minimal labor costs.

SIP clamps are designed for fastening SIP wires. Use on: branches from the highway, highway, branches of input to the building.

Other fittings

Vibration dampeners are used to relieve excessive mechanical stresses that occur on overhead lines during the vibration of wires, for example, under wind loads. With the help of thermochucks, the wires are mounted in a monolithic indestructible connection. Fastening points are necessary for mounting insulating garlands to the overhead line support, and the lugs are designed for attaching suspension insulator rods to other overhead line fittings.

All fittings, taking into account its high quality, you will receive at very competitive prices.

The quality of overhead line fittings is the key to its stable functioning.