RU81371U1 - COAXIAL CABLE FOR TRANSMISSION AND DISTRIBUTION OF ELECTRIC ENERGY - Google Patents

Abstract

The proposed coaxial cable is designed for transmission and distribution of electrical energy in power and lighting networks with a rated alternating voltage of up to 380 V and a frequency of 50 Hz. The objective of the utility model is to increase the reliability and safety of operation of power and lighting networks with the exception of the possibility of unauthorized connection of consumers to these networks. To solve this problem, it is proposed in the coaxial cable, consisting of an inner conductor, insulation of the inner conductor, on which the outer multicore conductor of aluminum wires and the outer insulating sheath is concentrically applied, to be additionally equipped with a steel cable, also placed in an insulating sheath connected by a jumper to the outer insulating sheath . The presence of a steel cable improves reliability and eliminates sagging and stretching of the cable. All bearing loads are assigned to the cable to which the supporting reinforcement is attached. The inner conductor is proposed to be single-core or multi-core, from aluminum or copper wires twisted together in a core.

Description

The proposed coaxial cable is designed for transmission and distribution of electrical energy in power and lighting networks with a rated alternating voltage of up to 380 V and a frequency of 50 Hz.

The cable AVT-1 (AVT-2) is known, which is 2, 3 or 4 insulated conductors twisted around an insulated steel cable, used as branches from high-voltage lines. The use of this cable does not exclude the possibility of unauthorized connection of the consumer, bypassing metering devices.

Power cables with external wire armor are known (D. Bachelis et al. Electrical cables, wires and cords (reference), under the general editorship of N.I. Belorussov. 3rd edition, revised M. "Energy ", 1971, p. 76). Known cables comprise an internal insulated conductor, with wire armor overlaid on the insulation, which is coated with an outer sheath. In this cable design, the possibility of unauthorized connection of consumers to power lines is also not ruled out.

Closest to the proposed technical solution is a coaxial cable according to RF patent No. 33669, which contains an internal single-core conductor, insulation of the internal conductor, an external multicore conductor, and insulation of an external multicore conductor. This cable design eliminates the possibility of unauthorized connection of consumers to power lines, since it is impossible to connect to the core of the inner conductor without damaging the outer conductor. A significant drawback of this cable is its significant stretching and sagging during operation on overhead lines, which reduces the reliability and safety of power and lighting networks.

The objective of the utility model is to increase the reliability and safety of operation of power and lighting networks with the exception of the possibility of unauthorized connection of consumers to these networks.

To solve this problem, it is proposed in a coaxial cable consisting of an inner conductor, insulation of the inner conductor, on which an external multicore conductor of aluminum wires and an external insulating sheath are concentrically laid

equip with a steel cable, also placed in an insulating sheath, connected by a jumper with an external insulating sheath. The presence of a steel cable improves reliability and eliminates sagging and stretching of the cable. All bearing loads are assigned to the cable to which the supporting reinforcement is attached.

It is proposed that the inner conductor be single-core or multi-core of aluminum or copper wires twisted together in a core.

To give the cable additional strength over the outer conductor, an additional fastening element in the form of threads is applied.

To protect the cable from moisture, water-blocking threads can be additionally laid between the cores of the external conductor.

The insulation of the inner and outer conductor, as well as the steel cable, can be made of polyvinyl chloride plastic compound or silanol-crosslinkable polyethylene.

To increase the fire resistance of the cable, the insulation of the internal and external conductors, as well as the steel cable, can be made of plastic compound that does not spread combustion.

An example of the design of the proposed cable with a multicore conductor is presented in figure 1 and figure 2, where:

1. Steel cable

2. The insulating sheath of the steel cable

3. Jumper

4. Inner conductor

5. Insulation of the inner conductor

6. External conductor

7. Water blocking thread

8. Fastening element in the form of threads

9. The outer insulating shell.

In the proposed cable, the inner steel cable 1 is placed in an insulating sheath 2. The inner conductor 4 is made of copper or aluminum wires twisted together in a core. On top of the inner conductor 4, insulation 5 of the inner conductor is made of polyvinyl chloride plastic compound or silanol-crosslinkable polyethylene or non-flame retardant plastic. Over insulation 5 of inner conductor 4

an external multicore conductor 6 is located, consisting of aluminum wires. Water-blocking threads 7 are laid between the veins of the outer multicore conductor 6. A fastening element 8 in the form of threads is superimposed on top of the outer conductor 6, on top of which an outer insulating sheath 9 is made of polyvinylchloride plastic compound, or a silane-crosslinkable polyethylene, or non-flame retardant plastic bonded with an insulating sheath cable 2 with jumper 3.

Cable manufacturing technology consists of the following operations:

- twisting of a steel cable from galvanized steel wires,

- drawing of aluminum or copper wires of the inner conductor,

- twisting of aluminum (copper) and steel wire into the core on a twisting machine,

- application by extrusion of the insulation of the inner conductor,

- the combined process of applying an external conductor with water-blocking threads using SZ-twisting with the application of a fastening thread (tape) by the method of winding and applying an external insulating sheath is performed on a combined line consisting of a reverse SZ-twisting device, a winding device and an extruder. When applying an external insulating sheath, a steel cable is laid parallel to the cable.

For the manufacture of cable the following materials are used:

- Aluminum wire of grades AM, APT, AT according to TU 16.K71 - 088

- Galvanized steel wire according to TU 14-4-1457 or GOST 1526

- Polyvinyl chloride plastic compound in accordance with GOST 5960

- Composition of silanol-crosslinked polyethylene according to TU 301-05-131.

The design of the proposed cable eliminates the possibility of unauthorized connection to a power line equipped with this cable. In addition, the steel cable contributes to high strength and stability of the structure to stretch and sag, which makes it possible to use the proposed cable on overhead power lines. The presence of a steel cable allows you to shift all the bearing loads onto it, which leads to an increase in cable service life. Through the use of multi-core internal

conductor increased cable flexibility compared to the prototype. The use of silanol-crosslinked polyethylene as an insulation material can reduce the weight of the cable, increase its service life, and it is also possible to operate this cable at a higher temperature. The use of non-combustible plastic compound as an insulation material increases the fire safety of cable lines equipped with a cable of the proposed design.

Claims (5)

1. Coaxial cable for transmitting and distributing electrical energy, including an inner conductor, insulation of an inner conductor, on which an outer multicore conductor of aluminum wires is concentrically applied, and an outer insulating sheath, characterized in that it further includes a steel cable placed in an insulating sheath connected a jumper with an external insulating sheath, the inner conductor being single-core or multi-core of copper or aluminum wires twisted together into the core, while a fastening element in the form of threads is superimposed on top of the outer conductor. 2. The cable according to claim 1, characterized in that between the veins of the outer conductor an additional water-blocking thread is laid. 3. The cable according to claim 2, characterized in that the insulation of the inner and outer conductors, as well as the steel cable, is made of polyvinyl chloride plastic compound. 4. The cable according to claim 2, characterized in that the insulation of the inner and outer conductors, as well as the steel cable, are made of a composition of silanol-crosslinked polyethylene. 5. The cable according to claim 2, characterized in that the insulation of the internal and external conductors, as well as the steel cable, are made of plastic compound that does not spread combustion.