EA007171B1 - Coupling for connecting up to 1o kv power cables - Google Patents

Abstract

The technical task provides designing a coupling for up to 10 KV power cables with no breakdowns and protection against corrosion. An isolating tape is applied on cables sheath cut overlapping the sheath and insulation. A dielectric with high permitivity is applied on the insulating tape edge. Conductors are connected by sleeves, spacing between the sleeves and insulation is filled with mastic, upon each sleeve the dielectric with high permitivity is applied, above it an insulating dielectric is applied. An insert-spacer is arranged between the conductors. A volume netting is wound around the conductors , over it a vinyl tape and a conducting screen are wound, the spacing between the conductors is filed with a compound. A ground wire fastened to the armor and casings as applied over the screen. The conductor is impregnated with a compound in areas close to the armor cut. The conductor is placed into a shrink tube, the tube overlaps the jute cover. A polyethylene housing made from split elements is arranged above the tube the joints of the split elements are tightly sealed using shrink tubes.

Description

The invention relates to cable technology, namely, devices for connecting power cables and can be used when laying, repairing and operating cable power lines with voltage up to 6/10 kV.

Known coupler brand SEF (TU 3599-028-01403993-200) for cables with voltage of 6/10 kV produced by JSC Mikhnevsky plant of electrical products (installation instructions). In this clutch, the cable cores, stripped of belt insulation, semiconducting paper, cladding, armor and jute cover, are connected by connecting sleeves, the sleeves are wrapped with an LETSAR insulating tape, a cross-shaped strut is installed between the wires, a metal case filled with a compound, shells and armor is installed on the body they are interconnected and with the casing with flexible copper conductors fixed on the shells, armor and casing with steel wire bandage and soldered tin-lead solder, the connection with the body is made on the outer surface, for which the conductors are brought out, thus, the armor and the sheath of one cable are connected to another cable by means of the coupling housing.

The disadvantage of this coupling is the absence of any mechanisms to regulate, reduce or redistribute the field strength inside the coupling, which leads to frequent breakdowns of the coupling. Grounding conductors removed from the coupling housing to the outside during operation of the coupling have direct contact with the ground, as a result of which they are intensively destroyed by corrosion, after which the sheath and armor of one cable lose contact with the sheath and armor of another cable, and when both grounding conductors are destroyed loses contact with both cables.

Known coupling for connecting power cables with voltage of 6/10 kV, brand 8so1sNsa51 types 92OT 411-3 and 92-OT 421-3 produced by 3M E1ss1g1sa1 Prgoisk taken as a prototype (installation instructions for couplings 92-OT 411-3, 92-OT 421- 3, 3M of the Axis + sYapb Osh, 14.04.2003). In this clutch, the cables are stripped of belt insulation, semiconducting paper, sheath, armor and jute cover, and a high dielectric strength and high resistance tape is wound on the stripped portion of the belt insulation of cables close to the shells (on the backs of the cables) the sheath is wound up with Elastosil sealing mastic, a tape of 8с1с11 23 is wound over the mastic. The cable cores are connected by crimping sleeves, the bare sections of the cores between the sleeves and the insulation are filled with mastic tape 8с1СН 2221 с ahodom the insulation veins 10 mm, the liner wound semiconductive tape 8so1s11 13, on top of it 8so1sN insulating tape 23 with a stop at 20 mm insulation on insulated sleeve worn mesh tape-tube 8so1sN R3R. All cable cores are wrapped together with a mesh tape 8so1SN P3P from the sheath of one cable to the sheath of the other, a metal mesh tape 8So1SH 24 is wound from the sheath to the cable sheath, and a copper jumper is installed along the splicing, which is fixed on the edges of the mesh tape 8с1сН 24 with ring springs and on. armor of cables with copper wire, ring springs wrapped with 8с1с11 23 tape, splice wrapped with 8cm1c11 P3P mesh tape from the jute cover of one cable to the jute cover of another cable; the coupling is wrapped with a tape with fiberglass reinforcing threads 8с1с11 45 and filled with a two-component compound 8соcсНса51 2140И or 8с1сНса51 4.

This device has a number of drawbacks, the main one being the breakdown of the 8с1с11 23 tape, wound on the roots of cables and insulation of conductors at the point of shearing of cable sheaths due to pushing of insulation of conductors when they are moved apart during installation of the coupling. Partially, the problem is solved by winding the 8с1с11 23 tape around the cores close to the shell, which prevents the insulation from being pushed through, however, the absence of field strength control mechanisms in the cable spine does not reduce the high probability of breakdown. In addition, the breakdown of this coupling has a high probability due to incomplete filling of the coupling with the compound and the formation of air cavities, which cannot be monitored during the installation of the coupling, since the coupling is opaque. The contact of the copper lintel with the armor is of poor quality, the contact of the copper mesh with the aluminum sheath is unacceptable by the relevant rules of EIR, in addition, the contacts are not sealed. During the operation of the coupling due to changes in the load and temperature of the soil during the day, coupling elements and cables experience repeated expansion / contraction, due to which the compound is peeled off from the cable sheaths and moisture penetrates from the jute to the unpressurized jumper contacts with the armor and the jumper to the grid and mesh with a shell, leading to acceleration of oxidation of the contacting surfaces.

An object of the invention is to create a coupling, not subject to breakdown in the roots of cables, having reliable, non-corrosive contacts of grounding elements with surfaces of armor and shell.

The solution of the technical problem is achieved by the fact that the spliced cables are stripped of belt insulation, semiconducting paper, metal sheath, armor and jute, and the semiconducting paper is cut at a distance of 5 mm from the sheath cut. A layer of insulating tape is applied to the sheath (spine) of each cable, with a distance of about 10 mm onto the cable sheath and about 20–30 mm to the insulation of the cable. A dielectric layer with a high dielectric constant with a width less than the width of this section is superimposed on the edge of the section of the layer of this tape that overlaps the core insulation. Stripped cable conductors are connected via shells. The exposed areas of the veins between each sleeve and the insulation of the connected cores are filled with mastic, ensuring a smooth transition from the diameter of the sleeve to the diameter of the insulation of the cores. A regulating dielectric layer with a high dielectric constant is applied to each sleeve, which extends over the core insulation, over which an insulating dielectric layer with a width not less than the width of the regulating layer is applied. Between the connected conductors there is a mesh insert-spreader with a length of at least insulating dielectric of the sleeves, having a three-pointed star shape in the section. A volumetric grid with a length of winding from the sheath of one to the sheath of another cable is wound around the splicing. A filler valve is installed in the central part of the coupling, and a layer of transparent vinyl tape is wound over the splicing over the bulk mesh and over the sheaths of cables. The splice of the cores is filled with a compound and wrapped around a vinyl tape with a tape conductive screen from the shell to the shell, a multicore ground wire from armor to cable armor is laid over the screen, which, in places imposed on the shell close to the armor, has locking wire sections impregnated with a compound. Between the blocking areas and cable sheaths there is a layer of mastic tape. The ground wire is fixed on the armor and cable sheaths with ring springs, the springs are protected with tape or tubes each longer than the width of the ring spring, on top of the springs and blocking sections on each cable from jute cut to winding transparent vinyl tape a layer of mastic is applied over it or a two-layer mastic length less than the width of the mastic layer; a heat-shrinkable tube overlooking the jute covers of the cables is seated on the splice. A plastic case of two or three detachable elements with a transverse connector line, whose joints between each other and with jute cable covers are sealed with heat-shrinkable tubing, can be mounted on an splice.

The invention is illustrated in the drawing, where in FIG. 1 shows a clutch, longitudinal section. The cables were stripped using standard technology from jute 1, armor 2, sheath 3 and semiconducting paper 4. The stubs of the cables are wrapped with insulating tape 5, at the edges of which a tape with a high dielectric constant is wound from the side of the sleeves. The cable conductors are connected by sleeves 8. The exposed areas of the conductors between the sleeves and the insulation 5 are filled with mastic 9, creating a smooth transition from the diameter of the sleeve to the diameter of the insulation. A dielectric layer 10 with a high dielectric constant is superimposed over the sleeves. A layer of insulating dielectric 11 is applied over it. Between the connected cores there is a grid insert 12, which has the shape of a three-beam star in cross section, a volume net 13 is wound over the cores, and a filling valve 14 is installed in the center of the splice. The splice is wrapped with transparent vinyl tape 15 and filled with compound 16. A foil 17 is wound over the vinyl tape and a ground wire 18 is installed with a blocking area impregnated with compound 19, under which There is a layer of mastic 20. The wire is fixed on the sheaths and armor of the cables by ring springs 21 wrapped with PVC tape 22. Ring springs and a blocking area from jute to transparent tape are wrapped with mastic tape 23, over which a layer of PVC tape or a two-layer mastic 24 is wound less than the length of the layer mastic 23. The splicing is protected by a heat-shrinkable tube 25 and body 26. The joints of the body are sealed with short heat-shrinkable tubes 27.

Achievable technical result is to reduce the likelihood of breakdown of the coupling in sections of the sheath of cable sheaths, the ability to control the splicing compound by using a transparent tape, reliable contact of the grounding elements of the coupling with the shell metals and armor, protection of these contacts and grounding elements from moisture and corrosive media. The winding of the ring springs with mastic tape protects them from falling under them into the ground wire and into the contacts of the wire with the sheath and armor of moisture, the penetration of moisture along the wire between the wires is blocked by a portion of the wire impregnated with compound. A layer of mastic on the cable sheath prevents the penetration of moisture from the armor into the sleeve. The distribution of the field power lines near the cable roots is achieved by arranging a material with a high dielectric constant, in which the power lines between the cable jacket and the housing are curved so that the field strength near the cut of semiconducting paper is reduced.

The type and certification tests of couplings for 10 kV cables with test voltage of 40 kV AC showed the achievement of a technical result.

Claims (2)

1. A sleeve for connecting electrical cables with insulated conductors, a layer of semiconducting paper, a sheath, protective and jute covers, including connecting sleeves, insulating, mastic and control tapes, compound, grounding and shielding elements, three-dimensional grids, inter-core spacers, heat-shrinkable tubes and case characterized in that the spliced cables are stripped of belt insulation, semiconducting paper, metal sheath, armor and jute, and semiconducting paper is cut at a distance of 5 mm from the cut about splices of each cable, a layer of insulating tape is applied to a section of the sheath of each cable with a run of about 10 mm on the cable sheath and about 20-30 mm on the insulation of the wires, a dielectric layer with high dielectric constant width less than 007171 of the width of this section, stripped cable conductors are connected by means of sleeves, bare sections of conductors between each sleeve and insulation of connected conductors are filled with mastic, creating a smooth transition from the diameter of the sleeve to the diameter core insulation of conductors, on each sleeve a control dielectric layer with a high dielectric constant is applied, going to the insulation of conductors, on top of which an insulating dielectric layer with a width of at least the width of the control layer is applied, a mesh insert-spacer with a length of at least an insulating dielectric of sleeves is installed between the connected conductors, having a cross-sectional shape of a three-beam star, a volumetric net is wound around the splicing with a winding length from the sheath of one to the sheath of another cable, a filler is installed in the central part of the sleeve th valve, a layer of transparent vinyl tape is wound on the splice over the volumetric mesh with the cable sheaths entering the cable, the splice is filled with a two-component compound and wrapped on the vinyl tape with a tape conductive screen from the sheath to the sheath, a multicore grounding wire is laid over the screen from armor to cable armor, which in places that are superimposed on the shells close to the armor sections, has blocking sections impregnated with a compound, between the blocking sections and the cable sheaths there is a layer of mastic tape, ground The conductor wire is fixed on the armor and the cable sheaths with ring springs, the springs can be protected with tape or tubes each with a length not less than the width of the ring spring, on top of the springs and blocking sections on each cable, from the jute cut to the winding of a transparent vinyl tape, a mastic layer is applied over which a layer of PVC tape is applied, a heat-shrinkable tube seated on the splice that goes into the jute covers of cables. 2. The coupling for connecting electrical cables according to claim 1, characterized in that a polyethylene housing of two or three detachable elements with a transverse connector line is installed on the splice, the joints of which are sealed to each other and to the jute covers of the cables by heat-shrinkable tubing pieces.