Installation of a cable line. Ways to lay cable lines

The organization of electricity supply networks involves the implementation of a wide range of activities, in which the key role is played by cable laying. In the work on the electrotechnical infrastructure, a variety of technologies and methods are involved. From workers it is required not only physical installation of control points with lines, but also a choice of optimum configurations of installation that will allow to increase an operational term of object. To date, the laying of cable lines is implemented in a variety of ways - from the arrangement of underground channels to fixing the contour in special structures. Each variant of installation assumes observance of special specifications and technical regulations.

General technology of installation of a cable line

Mounting operations with power cables basically reduce to physical fastening and the organization of systems which keep lines in the set position. Also, auxiliary technical measures, including connection and termination, are also common. The connection of wires to the electrical equipment is carried out with the help of cable couplings, closures and clamps. The main thing in this part of the work is to correctly compare the size of the fixing armature and the cable itself. The quality of the performance of the installation operations also depends on how accurately the initial preparation of the material for the same compounds was also carried out accurately. Cutting and stripping of the ends of the wire can not do without special tools, including strippers, wire cutters, clamp pliers, etc. In addition, the installation of a cable line can provide for the use of protective electrochemical compounds. These can be sealants that provide insulation barriers. The application of such materials in the process of working with wiring requires care and compliance with the technology of mounting a specific cable.

Cable laying in the trench

This is one of the most common ways of laying a cable, which is appropriate to use in non-asphalted areas, where it is also assumed a minimal risk of physical damage to the line. Begins laying with the formation of a trench, in which the wire will be immersed. To ensure that the underground cable facilities have a solid foundation in the lower part and are not frozen, the technology instructs the performers to create a cushion in the form of a small mound. It can include sand, gravel or crushed stone - the average height of the coating is 10 cm.

The prepared cable is immersed in a trench, and then isolated by special windings. If necessary, separate sections are connected with the calculation for strengthening the points of information by auxiliary reinforcement. If the conditions permit, then it is desirable to make the connection of wires and cables with an underground gasket in advance. The same applies to insulation work, although the transportation process also does not always make it possible for advance technical preparation of the cable line. The advantages of this method include the minimum financial costs and the possibility of the most profitable use of the wire section. The disadvantages of the same technology of underground laying include the lack of access to the line: for inspection and diagnosis will have to excavate the trench.

Roll-up of cables in the ground

The technique of laying the cable in a trench involves the implementation of rolling. Actually, this operation in one form or another is required for other editing technologies, but in this case the approaches to its implementation are most clearly manifested. There are two methods of rolling. In the first case, the laying of cable lines is realized by means of a special conveyor that grasps the end of the wire and, as it moves along the trench, puts it on the very bottom. Workers in the process of performing this operation monitor the correctness of the rolling and the accuracy of the wire position at the bottom of the trench.

The second way of rolling does not involve the use of moving equipment. The drum, on which the cable was previously wound, is fixed in one place so that the wire can be untwisted. For ease of rolling, special rollers with clamps are used. They are fixed on the end of the cable and its free padded part with one or another step, the distance of which depends on the severity of the wire. If in the future it is planned to install a cable line in the form of a connection with other segments, this option may not be suitable because of the risk of a line break at the attachment point. In such situations it is better to use the same conveyor.

Gasket in block constructions

By block constructions are meant different constructions. A classic example is an asbestos-tube pipe into which a cable is made, whose diameter is 1.5 times smaller than the reinforcing sheath. Another kind of unit is a cellular panel, into which lines of wires are also introduced. This option is suitable in cases where it is necessary to lay several contours in a small area. Such blocks do not provide continuous insulation, but only separate the wires at certain points of the gasket. The block technology of installation of cable lines is highly reliable, which is achieved due to effective protection against mechanical damage.

However, the resistance of the line will depend on the type of protective structure used. Obviously, the most reliable solution will be the use of tubular channels, but it is also the most expensive and difficult to perform. The same rolling in this scheme can be performed only by hand without the use of a conveyor. On the other hand, in certain installation conditions, the use of blocks becomes the only acceptable way to install the line. In particular, pipes for cable laying are used at the intersection of the contour with roads and railways. Also, without additional reinforcement, the cables can not be avoided if laying in soils with an aggressive chemical composition is planned.

Cable laying in channel construction

It has already been said that the main drawback of laying a line in a trench under the ground is the lack of the possibility of direct access to the cable without performing earthworks. Combine the advantages of laying in a trench and block technology allows installation in a channel construction. With this circuit design of the circuit, maintenance of cable lines is allowed without excavation, that is, the possibility of access to the line for performing repair and diagnostic activities remains. The canal itself is in some way a box whose walls are formed by concrete slabs or bricks. It turns out a closed structure, in which the cable is contained.

The contour is also in the ground, but closer to the surface than in the case of trenching. Moreover, this scheme is used in enterprises directly in the premises, so the upper part of the box is literally on the surface. But if the installation is carried out outside the production premises, then the implementers immerse the structure in the ground. But this does not mean that access to communications will require the implementation of large-scale land works in the form of excavations. Internal installation of the cable line in the channel is carried out with the help of special suspensions and clamps. In some cases, the traditional laying on the bottom with the use of substrates.

Gasket in collectors and tunnels

Tunnel structures are usually included in the infrastructure of industrial and production facilities. These are small rooms of the corridor type, in which communications are laid. In terms of ensuring reliability and durability, this variant of laying can be considered the best. Fastening of wires is carried out by means of special couplings. Initially, the Tunnel Tunneling Project provides for the possibility of integrating communication lines into special niches. Collector rooms in the sense of service are even more technologically advanced. The features of such facilities include the possibility of laying a large number of wires - usually up to 20. Each line is also supplied with insulating windings, but in armor protection in this case there is no need. In this case, the construction of cable lines is allowed only in those collectors and tunnels, where there are water catchments and storm sewage systems. Depending on the operating conditions of the wiring, it may be necessary to install ventilation systems, including artificial and natural circulation systems.

Special attention should be paid to the technique of rolling the cable in the tunnel. The use of conveyors, as well as massive drums, is impossible in this case. Unwinding is done manually or using a winch mechanism. If a thick cable or several wires are serviced simultaneously, roller systems are also involved. The undeniable advantages of this type of cable laying include a high degree of line protection and direct access for maintenance. However, such laying conditions are a rarity and are laid as part of the technological infrastructure in industrial projects.

Gasket in galleries

In this case it is a question of ground structures, which can be arranged outside of technological premises. Galleries are called trestles, which, according to the type of tunnel, can pass through the most important parts of the laying. If air communication lines are laid on poles by weight, then in the case of galleries, installation is carried out in enclosed structures. However, there are different versions of the execution of overpasses. Sometimes, for the sake of economy, designers develop designs without side walls. Also objects of this type differ in the possibilities of passing inside. There are structures in niches of which it is possible to carry out even transportation, and there are also facilities with limited access only for technical repairs, diagnostics and maintenance of the line itself.

This option, despite its attractiveness, is not used often because of high financial costs. Nevertheless, it is the only possible, if it is a question of laying in the enterprises, the underground channels of which are already saturated with communications. With regard to line protection, the ground structures provide the necessary level of safety. On difficult sections of the route, asbestos-concrete pipes for cable routing can also be used, which protect the contours from destructive mechanical and atmospheric influences.

Suspension of cables

This option assumes the implementation of the classical scheme for the installation of hinged lines. This method is easy execution, economic accessibility and the ability to easily perform assembly and repair operations. However, not all cable communications can in principle be carried out in this way: first of all, this applies to cases where it is necessary to install a cable line, supplemented by thick layers of insulation. Do not forget that the wiring harness is operated in open conditions with direct exposure to ultraviolet rays, high and low temperatures, precipitation, etc. Accordingly, some types of cables require an effective insulation that makes the line heavier, delivering problems during installation.

It can not be said that the air wiring significantly benefits from underground installation, but in situations where the arrangement of the same trenches is impossible, this method is quite worthy of consideration. Directly installation is carried out on the poles and poles of high-voltage lines. During installation, the insulation of electrical cables is carried out in accordance with the brand of wire. In the choice of protective equipment, specialists take into account such characteristics as dynamic stability, strength, frost resistance, ability to resist and not to deform before short-term loads, etc. Further, during maintenance at certain intervals, the insulating jacket can be replaced, cable.

Why do I need a heating cable?

As a part of sets of communication lines, technological wires and materials that are not the main conductors are often encountered, but they perform important auxiliary tasks. This includes a heating wire. Its function is to provide the optimum temperature regime in which power communications should be operated. Thus, the protection of cable lines from freezing is realized, in which the wires lose their operational properties. An electrical charge is applied to the heating circuit, which, thanks to a special alloy of the internal core, is converted into thermal energy, which heats the near wires.

Directly in cable wiring, heating conductors are rare. Usually, the heat insulation function performs the basic insulation. Most often, heating lines are used as a supplement in technological equipment. With this technique, tanks, pipelines, parts of transformers and industrial equipment are insulated. To the features that the heating cable has, it is possible to include a protective shell made of polymer materials. Also, depending on the brand manufacturers use different means of electrical shielding. For example, in this capacity a solid aluminum or copper wire mesh can be used. The main shell is made of polyvinyl chloride, which protects the veins from mechanical damage. In addition to the function of providing heating, the annealed conductors can also serve as an effective electrochemical means of corrosion protection. This kind of protection is required for metal fittings, which is used for fastening and tying communication.

Conclusion

Installation work in the work with power cables is preceded by the development of the project. The compiler of the technical plan for laying out communications takes into account a number of factors of exploitation that give him grounds to make a choice in favor of one or another method of laying. For example, air links are established in cases where there is no possibility of using more reliable ground-based assembling schemes. Underground methods of communication themselves justify in many ways, but because of the lack of direct access to the line from them, too, they often refuse. If we are talking about the organization of a network adjacent to industrial enterprises, it is more likely that part of the contour can be laid in a technological tunnel or a collector room. In addition to the external conditions of the gasket, the operational requirements for the cable itself are taken into account. Only a comprehensive analysis of the conditions for the implementation of the project task can give the right answer to the questions about choosing the optimal scheme for installing the cable line.