RU52249U1 - COMMUNICATION CABLE SYMMETRIC HIGH FREQUENCY WITH FILM-PORO-FILM POLYETHYLENE INSULATION IN A LEAD SHELL - Google Patents

Abstract

A symmetric high-frequency communication cable with a film-porous-film polyethylene insulation in a lead sheath contains in its design polyethylene insulation superimposed on conductive wires in the form of three concentric layers: the inner layer is made of solid polyethylene, the middle layer is made of porous (foamed) polyethylene, the outer layer - from continuous polyethylene; reduced insulation thickness and twisting pitch of insulated conductive wires into fours (ranging from 100 to 200 mm). Symmetric high-frequency communication cables with a film-porous-film polyethylene insulation in a lead sheath are used for laying in telephone conduits, in pipes, blocks, collectors tunnels and indoors without mechanical influences on the cable, in an environment that is neutral with respect to the sheath, in conditions not characterized by increased electromagnetic influence; for laying in a telephone sewer, in pipes, blocks in the absence of mechanical influences on the cable, in an environment aggressive to the sheath, in conditions not characterized by increased electromagnetic influence; for laying in soils that are neutral with respect to the sheath, if the cable is not subjected to significant tensile or compressive forces, in areas that are not characterized by suspended electromagnetic influence; for laying in fire hazardous areas, in mines, tunnels, channels and collectors, if the cable is not subjected to large tensile forces, in areas not characterized by increased electromagnetic influence. The cable is used for cable trunking, zone communication lines and connecting lines in the frequency range up to 552 kHz or when using secondary digital transmission systems in the frequency range up to 8448 kHz and operating with an alternating voltage of remote power supply up to 690 V or constant voltage up to

1000 V. The cable is designed for operation at ambient temperature from minus 50 to plus 50 ° С. The development of a symmetric high-frequency communication cable with a film-porous-film polyethylene insulation in a lead sheath can significantly increase the reliability and quality of information transfer and the stability of the electrical characteristics of the communication cable, since porous (foamed) polyethylene as the inner layer of insulation of conductive wires leads to a decrease in the dielectric constant of the material isolation, reducing the dielectric loss tangent and reducing material consumption. The quality of information transfer is also ensured by reducing the pitch of the twisted insulated conductive wires in fours and twisting them with different steps ranging from 100 to 200 mm. Reducing the outer diameter, and hence the mass of the cable, greatly facilitates its installation and operation.

Description

Symmetric high-frequency communication cables with a film-porous-film polyethylene insulation in a lead sheath are designed for cable trunking, zone communication lines and connecting lines used in the frequency range up to 552 kHz or when using secondary digital transmission systems in the frequency range up to 8448 kHz and operating at AC voltage of remote power supply up to 690 V or DC voltage up to 1000 V.

The main areas of application of symmetric high-frequency communication cables with film-porous-film polyethylene insulation in a lead sheath of grades:

MKPSpG - for installation in telephone conduits, in pipes, blocks, collectors tunnels and indoors, in the absence of mechanical stress on the cable, in an environment neutral to the sheath, in conditions not characterized by increased electromagnetic influence.

MKPPSShp - for installation in telephone conduits, in pipes, blocks in the absence of mechanical impacts on the cable, in an environment that is aggressive with respect to the sheath, in conditions not characterized by increased electromagnetic influence.

MKPSpSB, MKPSpSBShp - for laying in soils that are neutral with respect to the sheath, if the cable is not subjected to significant tensile or compressive forces, in areas that are not characterized by increased electromagnetic influence.

MKPSpSBG - for laying in fire hazardous areas, in mines, tunnels, channels and collectors, if the cable is not subjected to great tensile forces, in areas that are not characterized by increased electromagnetic influence.

Closest to essential features analogue of utility model

- a symmetric high-frequency communication cable with cord-polystyrene insulation in a lead sheath (Belorussov NI et al. Electrical cables, wires and cords: Reference book. - M .: Energoatomizdat, 1988).

Symmetric high-frequency communication cables with cord-polystyrene insulation in a lead sheath are designed for operation in cable trunk lines, zone communication lines and connecting lines, sealed with K-60P systems in the frequency range up to 252 kHz, Kama systems in the frequency range up to 552 kHz or secondary digital transmission systems in the frequency range up to 8448 kHz and operating with alternating voltage remote power supply up to 690 V or up to 1000 V DC.

Design elements of a symmetrical high-frequency communication cable: conductive conductors, insulation, zone insulation, sheath.

Signs of an analogue that coincide with the essential features of the claimed utility model:

- copper single-wire veins;

- the system of twisting lived in fours, fours - in the core;

- the number of fours - 4 or 7;

- belt insulation;

- lead sheath.

The use of cord-polystyrene insulation of conductive conductors in analog cables does not allow to obtain stable electrical characteristics of the communication cable. Frequently generated interference currents reduce the quality of information transmission over communication lines, and sometimes make it impossible. The formation of these interference currents consumes electromagnetic energy transmitted through the circuits that have an effect, which also leads to an increase in losses (attenuation) when transmitting signals over communication cables. In addition, the existing structural elements of the cable with cord

polystyrene insulation, its dimensions (outer diameter and weight of the cable) complicate its installation and operation.

The essential features of the claimed utility model are a three-layer film-porous-film insulation made of polyethylene, a smaller twisting step of insulated conductive cores in fours, a reduced nominal insulation thickness.

When using a three-layer film-porous-film insulation made of polyethylene in the cable, the reliability, quality and stability of the electrical characteristics of the communication cable are significantly increased. The foamed insulation layer (porous polyethylene) leads to a decrease in the dielectric constant of the insulation material and a decrease in the dielectric loss tangent, a decrease in material consumption, and the like. The process of applying film-porous-film polyethylene insulation is less complicated and time-consuming, does not require constant attention from the employee and the level of qualification required when applying cordon-polystyrene insulation, which reduces the human factor in production. Reducing the pitch of the twisted insulated conductors in the quadruples in the range from 100 to 200 mm also positively affects the stability of the electrical characteristics of the cable (the twisting steps in all fours are different). The use of film-porous-film insulation reduces the outer diameter, which makes the cable lighter, which makes its installation and operation easier and more convenient. In addition, the use of the specified insulation of the claimed utility model significantly reduces the cost of the communication cable.

The technical result - improving the reliability, stability and quality of the specified electrical characteristics of the cable, reducing the weight of the cable, reducing the complexity in its manufacture, installation and operation - is achieved by using a symmetrical high-frequency three-layer film-porous-film-polyethylene insulation in the communication cable design, reducing the insulation thickness and pitch twisted insulated conductive cores in fours.

The drawing shows:

Figure 1 - symmetric high-frequency communication cable with film-porous-film polyethylene insulation in a lead sheath of grade MKPSPS 7 × 4 × 1.2.

Description of the design of the utility model - a symmetric high-frequency communication cable with film-porous-film polyethylene insulation in a lead sheath:

- Single-wire conductive conductors made of soft copper wire, made of copper wire rod according to TU 16-705.491-2001 (Fig. 1, item 1). Serve to direct the flow of electrical energy. Must not have burrs, cutting edges, breaks, leading to damage to the insulation. The nominal diameter of the conductive core is 1.2 mm.

- Three-layer insulation of film-porous-film-polyethylene is applied to the conductive conductors (Fig. 1, item 2): the inner layer is made of solid polyethylene of the LE 8706 brand, the middle layer is made of porous (foamed) polyethylene of the HE 1102 brand, the outer layer is made of solid polyethylene of mark NOT 3366. Insulation must not have gaps, impurities and inclusions; there shall be no dents, sag or bulge on the outer surface of the insulation. The insulation must be airtight. The total insulation thickness is 0.82 mm.

- Four insulated cores, dramatically different in color, are twisted into a star four around the central element of a round synthetic thread (figure 1, pos. 3). The twisting steps of the isolated conductors in different fours vary, and should be in the range from 100 to 200 mm.

- The nominal number of fours in the cables is 4 or 7. In the four, two conductors located diagonally form a working pair. The core insulation of the first pair of four should have red and yellow (white) colors, the second pair - blue (blue) and green.

- Twisted four wrapped in an open spiral with a distinctive synthetic ribbon or thread (figure 1, position 4). The colors of ribbons and threads (distinctive elements) of all fours should be

different and are shown in table 1. Two adjacent fours (counting and guide) should be wrapped with synthetic tape or synthetic thread of red and green, respectively. The bright colors of the insulation of the cores are used to ensure compliance with electrical safety requirements and facilitates the work when installing the cable.

Table 1. The number of fours in the cable four 7 Conventional number four The color of the distinctive elements Conventional number four The color of the distinctive elements one Red one Yellow 2 Green 2 Red 3 Blue 3 Green four yellow four White 5 Brown 6 The black 7 Blue

- Fours are twisted into the core of the cable with a twisting step of no more than 600 mm. A belt insulation of polymer tapes is applied to the core (Fig. 1, pos. 5). The use of paper tapes is not allowed, since when pumping with air and installing the cable, the paper absorbs moisture, which significantly degrades the electrical characteristics of the cable.

- On top of the belt insulation, a lead sheath is applied that meets the requirements of GOST 24641-81 (Fig. 1, pos. 6). The thickness of the lead shell must comply with that specified in GOST 24641-81.

- The lead sheath of the MKPPSG brand cable is protected by a layer of technical petroleum jelly of the VTV-1 brand according to TU 38.101-180-76 or industrial oil according to GOST 20799-88. Protective covers in accordance with GOST 7006-72 types are applied to the lead sheath in cables of the MKPSPSB, MKPSPSBG, MKPSPSShp, MKPSPSBSHp grades: for cables with type B protective sheath - from a pillow, two steel strips with a nominal thickness of 0.5 mm and an outer protective cover; for cables with a protective cover like BG - from a pillow and two steel tapes with previously applied zinc coating; for cables with protective cover of Шп type - from a protective hose made of polyethylene; for cables with a protective cover like BShp - from a pillow, two steel galvanized tapes 0.3 mm thick or from corrugated steel tape clad with polymeric materials on both sides, with a minimum thickness of a steel layer of 0.1 mm and a protective hose made of polyethylene. The cable protection hose must be tight. There should be no dents, cracks or marks on the surface of the protective hose leading the thickness of the protective hose beyond the limit deviations.

The way to use the utility model.

Description of structural elements, due to which it becomes possible to obtain a technical result.

Structural elements to achieve the desired technical result: three-layer film-porous-film insulation made of polyethylene, a reduced pitch of twisted insulated conductive cores in fours ranging from 100 to 200 mm, a reduced nominal insulation thickness.

Thanks to the developed utility model, the reliability, quality and stability of the electrical characteristics of the communication cable are significantly increased. The inner continuous layer of polyethylene allows you to control the adhesion between the conductor and the insulation and eliminates the ingress of moisture between the conductor and the insulation (due to the absence of open pores around the conductor). Foaming of the insulation material (porous polyethylene) leads to a decrease in the dielectric constant of the insulation material, a decrease in the dielectric loss tangent, a decrease in material consumption, and the like. A less time-consuming and more advanced process of applying film-porous-film polyethylene insulation reduces the human factor in production. Reducing the pitch of the twist of conductive wires positively affects the quality of the cable, and reducing the mass of the cable greatly facilitates its installation and operation.

Claims (5)

1. A symmetric high-frequency communication cable with a film-porous-film polyethylene insulation in a lead sheath, consisting of copper single-wire insulated conductors twisted into 4 or 7 star quadruples, twisted into a fours core, with a belt insulation of polymer tapes, in a lead sheath, characterized in that a three-layer film-porous-film insulation of polyethylene is applied to the conductive wires, while the outer and inner layers are made of continuous polyethylene, the middle layer is made of porous ennogo) polyethylene, and steps stranding insulated conductors in quadruples are different and are in the range of from 100 to 200 mm. 2. The cable according to claim 1, characterized in that a cushion, armor of two steel tapes and an outer protective cover are applied over the shell. 3. The cable according to claim 1, characterized in that on top of the shell impose a pillow, armor of two steel strips with pre-applied zinc coating. 4. The cable according to claim 1, characterized in that a protective hose made of polyethylene is applied over the sheath. 5. The cable according to claim 1, characterized in that a cushion, armor of two steel galvanized tapes or of corrugated steel tape clad with polymeric materials on both sides, and a protective hose made of polyethylene are laid over the shell.