Laying the communication cable along the supports is a method that is resorted to when it is impossible to use the laying in the sewer or by the trench method. The main document regulating the procedure and rules for carrying out these works is VSN 116-93, an instruction developed by the Giprosvyaz Institute (Moscow) and approved by the Russian Ministry of Communications.
Support routing is described in section 6.5 of the document. When choosing a cable brand, it is recommended to be guided by its purpose (outdoor laying, load bearing capacity etc.), as well as resistance to external adverse factors that can affect the quality of the transmitted signal ( electromagnetic fields, static voltage, lightning, etc.). The document allows air laying of communication cables of two types: optical and with metal conductors.
Laying the communication cable along the supports: general requirements
Only special brands of self-supporting cables (, etc.) can be allowed to hang. Otherwise, it is necessary to provide a carrying cable fixed to the supports through special consoles. The carrier cable must be grounded every 250 m. Existing overhead power transmission towers can be used for suspension. The construction of new supports for these purposes in urban areas is prohibited by law. It is allowed to use special racks mounted on the roofs of buildings and structures. Clamps for attaching a cable or carrying cable are installed below the power electrical wires at a distance of at least 350 mm.
The laying of copper communication cables along the supports of overhead lines (overhead lines) has some limitations. In particular, clause 6.5.3 states that cables with a capacity of not more than 100 pairs can be suspended on the supports of overhead lines of urban and rural communication lines.
Communication cable: types of installation
Lack of cable ducting and the impossibility of suspension to existing buildings and facilities is one of the difficulties that signalmen often face when performing work in the city. In such cases, resort to suspension. There are 3 types of installation:
With support clips;
. using tension clamps;
. combined.
Support clamps are used on straight sections of the communication line. Although there are many various designs similar devices, all of them can be divided into 2 types: discontinuous and indissoluble. The latter are used in places where there is a risk of tall trees falling. When a tree falls on a wire, it pops out of the clamp and may remain undamaged. All clamps usually have an elastic sleeve made of dense rubber.
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Tension clamps are designed for rigid fixing of the cable to the support. It is applied both on direct, and on turning sections of the line. The combined mounting method is associated with alternating support and tension clamps.
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The laying of copper communication cables along the poles of overhead lines, as well as optical ones, has its advantages and disadvantages. Benefits include a reduction capital costs, short time installation and ease of maintenance of the line. The disadvantages include the negative impact environment, causing the communication cable to fail prematurely. Special care should be taken when working with optical fiber, due to the fragile structure of the material.
The construction of networks is associated with their installation and laying. If possible, experts prefer to use the underground (trench) method. But if there is no such possibility, all that remains is laying the telephone cable along the poles.
Pole laying: rules, facilities, amenities
Laying a telephone cable along poles is a less expensive, simple and convenient form of tensioning communication wires. Today there are several standard ways mounting:
- supporting - made using supporting clamps where the cable runs only in a straight line. The angle of rotation should not exceed 10-20 degrees;
- tension - requires the use of rigid fastening tension clamps used for rotary, ring installation sections, as well as throughout the route. The method is convenient for its efficiency, it does not require additional cleaning of the ends, allowing you to quickly and without additional tools to install;
- the combined method is used where the route is laid both on straight lines and on corners, turning, ring sections. It is most convenient in conditions of increased movement of air flows, as it provides a reliable and durable fastening.
It is worth noting that combined method significantly reduces financial expenses for repairs and construction.
The convenience of laying a telephone cable along the poles is that:
- no need to open roadbed;
- you can "hang" the system in dense urban areas,
- financial savings.
In addition, the external broach is convenient in operation and repair: you can always see where the rush occurred.
Cables for laying indoors (, TTsPPt) are designed for local networks subscriber access. Like all systems used internally, they differ:
- fire safety,
- high quality transmission,
- interference protection,
- flexibility
- increased strength.
Cables : characteristics
TTsPPt cables are telephone wires successfully used for local networks. Installation is carried out in a hanging way. Rated voltage is not more than 225V AC and up to 200V DC. Transmission speed up to 2048 kbps. Structure of the TCPT:
- conductive conductor - soft copper wire;
- isolation - polyethylene film up to 0.2 mm. thick;
- one pair of insulated cores, differing in color, is twisted in a unidirectional twist with unequal and non-multiple steps;
- galvanized steel wire - load-bearing cable;
- the overall sheath for the wire is light-stabilized polyethylene.
The system is installed at temperatures from -50 to + 60C, the minimum possible bend is 10 cable diameters, the service life is up to 25 years.
Cables TPPSHt: characteristics
Underground workings, data transmission from mines - all this is impossible without a cable of the TPPSHt brand. In addition, the wires are successfully used in the ground installation of the system. Ability to work under extreme low temperatures(up to -60С), flexibility and high reliability of communication provided the wires with popularity in conditions of increased aggressiveness of the environment. Design elements:
- copper wire,
- polyethylene insulation,
- aluminopolymer tape - screen,
- galvanized steel wire - load-bearing cable,
- PVC compound- outer shell.
The right choice of cable for communication is an uninterrupted supply where it is really needed.
During the construction of networks, communication operators often face the inability to use cable ducts or buildings. For passage through the air suspension method, in such cases, installing the cable along lighting poles or power poles can greatly facilitate the task.
There are several standard methods mounting:
1. Supportive.
2. Tension.
3. Combined.
Let's consider each of the methods in more detail.
1. Mounting the optical cable using support clips.
Support clamps are used for sections where the cable runs in a straight line, the maximum angle of rotation when using such clamps is from 10 to 20 °. Domestic and foreign manufacturers offer a variety of clip options for supporting mounting of self-supporting (ADSS) and 8-gang cables.
Clamps PPO-6.5/8.0-06 or ZP-8-1(2)
Clamps PPO or ZP can be used on routes with a risk of falling trees, damaging poles. When a tree falls on a cable or a pole is damaged, the cable breaks out of the clamp and usually remains undamaged.
Examples of using PPO clamps in combination with various nodes mounts.
Clips supporting spiral.
Spiral clamps are used for mounting self-supporting cable (ADSS) on power line poles, lighting and communication poles. Many modifications are available for various span lengths and cable termination strengths. The fastener consists of a protector - to protect the cable sheath from damage, a power spiral and a thimble.
Support clamp SC30/34 or CS
Universal clamp for hanging "8-shaped cables", can be fastened with a steel tape, or with a bolt to wooden supports. Allows you to install a cable with a cable diameter of 4 to 9 mm.
Differs in simple and quick installation, but has some limitations. When using such clamps, it is important to accurately select the diameter of the cable, in practice there have been cases of cable slipping through the clamp, it is also important to strictly observe the recommended span length. The practice of using such clamps has shown that it is best to use them in combined version installation (Alternating anchor and support clamps).
Supporting clamp HC 10/15.
clamps NS 10/15 are used for mounting ADSS cable, up to 20 mm in diameter, it is recommended to use it on straight sections of the route.
According to the experience of use, we can say that such clamps are good for small spans - up to 60-70m, installation during rain is practically impossible, since the cable slips through the sleeve.
2. Mounting the optical cable using tension clamps.
Tension (anchor) clamps are used for rigid cable fastening, they are used both on rotary, branch, end sections of installation, and along the entire length of the route.
Tension anchor clamps AN-250(500,700,800), AC 6(7), PA 06(07),
Anchor clips can be used with both "8" and self-supporting cables. Clamps for hanging cables with bearing element from a steel cable allow you to quickly install the cable, without stripping and separating the strength element. plastic loop on the clamp cable provides isolation of the bearing element in the event of a short circuit to the mass of the support. It is NOT recommended to use such clamps when installing a cable with a steel wire strength element; with a long-term load, the teeth of the wedges begin to slip along the smooth wire, which leads to cable damage. 
Tension spiral clamps.
Tension spiral clamps are used for mounting self-supporting cables (ADSS) on power line poles, power poles, lighting, contact network Railway The fastener consists of a protector, a loop-shaped power spiral coated with a special abrasive and a thimble.
3. Installation of optical cable by the method of combined suspension.
The combined suspension method is widely used when using clamps PPO, SC30\34. The essence of the method is the alternation of supporting and tension (anchor) clamps. In this way, it is possible to increase the reliability of the line and reduce construction and operation costs. The optimal ratio is 4 support to one tension clamp.
) every year acquires more and more wide application in the construction of power and lighting air electrical lines. With the advent of this material came completely new technology construction, repair and operation electrical networks. Overhead power lines made with SIP wire are usually denoted by the abbreviation "VLI".
The actual installation process, carried out during the construction of the VLI, is preceded by the design stage. The VLI project includes full information about the location of the route of the future line, the brand of wire used, the number and type of supports, the features of the construction and installation work.
In order to carry out the installation of SIP wire on supports, facades of buildings, perform branches, connections and other operations, it is designed necessary set special fittings, and tools. The project specification should contain an exhaustive list of materials, which lists all the necessary fittings for the installation of SIP.
Wire unrolling
Installation is started after the installation of VLI supports with clamps attached to them.
Anchor clamps are installed on the anchor supports, bearing the tension force of the conductors, on the clamps located between them intermediate supports- support clamps.
Installation of the SIP cable begins with its rolling. To do this, the following steps are sequentially performed:
- On all supports of the anchor span on which the wire is mounted, special rolling rollers are installed. On the extreme, anchor supports, the rollers are fastened with a belt, on the intermediate supports, the rollers are hung on a hook in the eyelets for supporting clamps;
- Behind one of the extreme supports of the span, a drum with a wire is installed. It is located in a vertical position on special stands that allow it to rotate during the rolling process. In order for the wire to enter the roller at a shallower angle, it is recommended to install the drum from the support at a distance not less than its length;
- On the other side of the span being mounted, there is a drum on which a leader cable is wound, usually representing synthetic rope with a diameter of 10–12 mm, depending on the method of rolling (manual, mechanized);
- Next, manual rolling of the leader cable is carried out. This operation is carried out by sequential lifting to each support, threading the cable into the roller and its further pulling;
- After climbing to the last support, the leader cable is connected to the SIP by means of a special stocking and swivel, which prevents the wire from twisting during the rolling process.
This completes the preparatory procedures, and the actual rolling of the wire begins. The cable leader slowly, without jerks, is pulled in the opposite direction. During mechanized rolling, the drum winder, driven by the engine, works internal combustion with a gearbox, the leader cable can also be pulled out manually.
In the process of rolling, the wire, following the leader cable, rises to the support and takes its place on the rollers. Rollers and drums must be located so that during rolling there is no friction of the wire on the ground, support and other structures. It is unacceptable to use technology in which the wire is rolled out on the ground, and then rises to the support.
Fixing wires to poles
The rolling continues until the beginning of the wire, connected to the leader cable, passes the roller on the last support. The next step is mounting. The carrier core or the entire bundle, depending on the type of wire used, is fixed in the anchor clamp, leaving the ends long enough to make connections. Then the SIP is disconnected from the leader cable. The roller is removed. Next, on all intermediate supports, insert the cable into the lugs of the supporting clamps, and remove the mounting rollers.
The wire is stretched on the first anchor support of the span. To do this, you need a manual winch with a special compressive grip of the bundle or carrier core. Since the tension force must be strictly metered, a dynamometer is required. The amount of tensioning force can be specified in the project, otherwise, it can be taken from the installation tables in accordance with the brand of wire and the length of the anchor span.
The work is carried out from the AGP platform (“autotower”). The winch is fixed on the carrier core or on the harness, its hook is attached to the support through a dynamometer. By moving the handle, the SIP wire is pulled to the required force, controlled by the dynamometer scale. At the end of the tension, the wire is fixed and tightened in the anchor clamp, after which the winch and the dynamometer are removed.
Possibility of laying underground
The input of electrical power to electrified premises (houses, summer cottages, etc.) is often carried out using self-supporting insulated wire, sometimes this requirement is directly stated in the technical specifications for connecting the facility. In this regard, some owners of objects are interested in whether it is possible to install a SIP cable from a pole to a house underground. To answer this question, one should refer to GOST R 52373–2005, which defines that a self-supporting insulated wire designed for overhead power lines. This means that the use of SIP for underground laying is not provided for and is a violation of the Rules for the Construction of Electrical Installations, which prescribe the use of electrical materials in strict accordance with their intended use.
Carrying out the approach to the house
To perform tapping to the house, it is necessary on a support overhead line from which it is planned to carry out the input, install a bracket for attaching the anchor clamp. If the supply line is made with a bare wire, the bracket is installed below the traverse with insulators. When connected to VLI, the bracket is mounted below the line clamps.
The tap wire is fixed in the anchor clamp on the support, while leaving the ends long enough to connect to the line. The connection itself is carried out by the personnel servicing the line, after the installation work has been completed. For connection, special clamps for bare wire are used, if the overhead line is made bare wire, or piercing clamps, if the connection is made to VLI.
At the place where the SIP is attached to the facade of the house, it is also necessary to install a bracket for attaching the anchor clamp. The wire fixed in the anchor clamp on the support is inserted into the clamp on the facade of the house, pulled manually and fixed. Often, Specifications order to place the cabinet on outer wall buildings, with the stipulation that the power input is carried out by a solid, visible wire. Before entering the counter or circuit breaker, located in the metering cabinet, SIP is laid along the facade of the building. To fix the wire on the wall, special facade mounts are used.
Connection to a meter or machine
The actual input to the meter is performed in the same way as when using a conventional cable. The ends of the wires are stripped of insulation by 25–30 mm, depending on the depth of the meter terminal blocks, inserted into the terminal holes and clamped with contact screws. It should be noted that from the point of view of safety, as well as ease of installation, the more preferable option is when the SIP is connected to the machine installed in front of the meter. In the terminals of modern circuit breakers modular type the wire can be wound directly, if the switch has bolt-on terminals, it is better to use lugs.
Entering inside the house
In the case when the metering device is located indoors and the issued Technical Conditions allow this option, a dilemma arises: to bring the SIP inside the building and connect it directly to the metering cabinet, or to make the transition to the VVGng cable before entering the house? Both options are in principle possible, but the following nuances should be taken into account. The SIP sheath does not have sufficient fire resistance compared to the VVGng cable, therefore, it is undesirable to bring this wire inside, especially if the house is wooden. On the other hand, energy sales representatives are unlikely to accept a wire connection located before the meter. There are two ways to get out of this situation:
- Perform entry with a solid SIP cable using metal pipes and corrugated sleeves, having processed it with one of the flame retardants in the form of paint or paste;
- On the outer wall, before entering the inside of the house, install a circuit breaker, on the input of which to bring the SIP, and on the output, a cable that goes inside the room to the meter. The switch should be placed in a sealed box.
The second option looks preferable, because: firstly, a material with high fire resistance is used indoors, and secondly, the section of the cable hidden from the eyes, at the point of its passage through the wall, is protected by an automatic machine. In this case, the automatic input to the counter in the metering board is no longer required.
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