RU2284080C1 - Multipurpose water-and-gas-tight stuffing box for telephone communication cables with plastic-covered conductors - Google Patents

Abstract

FIELD: electrical engineering.

SUBSTANCE: proposed water-and-gas-tight stuffing box designed for terminating ends of communication cable line, including plastic-sheathed telephone cables with polyethylene insulated conductors, in capacity of 100 to 600 pairs directly in switchgear cabinet on vertically mounted cables which can be or not held at gage pressure and with water-repelling material filled core has shield connector secured on aluminized polyethylene cable sheath in contact with conical surface of through hole at input end of body; plastic cable sheath is filled within stuffing box with cold-cured polyurethane sealing compound; each conductor is covered with plastic insulating layer throughout its entire length.

EFFECT: simplified design, enhanced reliability of cable box.

1 cl, 7 dwg

Description

The invention relates to the field of linear-cable communication facilities, to the section of coupling cable couplings, and more specifically to gas-tight coupling cable couplings that are mounted on the ends of cable lines of electric communication cables, namely, telephone cables with polyethylene insulation lived in a plastic sheath (GOST R 51311-99). These cables (for example, TPPep cable brand) during operation must be under excess air pressure, and cables (for example TPPepZ brand) are produced with hydrophobic filling of the cable core and therefore are not contained under excessive air pressure during operation, but require tight sealing of the ends in the distribution cabinets.

Gas tight couplings are designed to ensure that the cable lines are kept under constant excess air pressure, which is supplied through the air ducts to the inside of the cable from special compressor units, and if the cable is damaged (for example, if the outer sheath of the cable is damaged), the air pressure in the cable decreases and the station responds alarm (light, sound), indicating damage to the cable. According to the values of pressure reduction, the place of damage is found and the corresponding cable repair is carried out.

Known (1) is a gas-tight cable assembly (DE 4005842) comprising a cylindrical body in which a ring is located, in the opening of which a sealant is placed through which the cable passes. In the gap between the ring and the housing, sectional elements of a special shape are located, which ensure the use of cables with different outer diameters. The disadvantage of this device is the design complexity, lack of means for sealing the conductors located inside the cable.

Also known (2) is a gas-tight sleeve (RU 2035814) for cables during operation under excessive air pressure, comprising a metal casing, an insulating disk with holes installed in the casing, and conductors passing through an insulating compound filling the space inside the metal casing, and holes in the disk, with each conductor on the part of the length provided with tubular insulation.

Known gas-tight coupling has a complex structure, large dimensions and time-consuming to manufacture (manufactured under production conditions). In addition, it cannot be used for cables with a large number of conductors.

The closest analogue to the invention (3; 4) is a polyethylene sleeve on a cable of type TP, for example a small-sized gas-tight sleeve with a self-expanding sealant VILAD-31 (MGNMs). This coupling also has a complex structure, consists of two cones and a cylinder, is mounted over a cable section with a remote outer sheath and fluffy insulated copper conductors with a horizontal cable arrangement, and the joints of the coupling parts between themselves and with the cable sheath are sealed with three heat-shrinkable tubes (TUT); while the coupling is filled with a self-expanding polyurethane sealant VILAD-31.

The technical result of the invention is:

- simplification of the design,

- expanding the arsenal of technical means by creating a reliable universal water and gas tight coupling for telephone cables with an external plastic sheath and with polyethylene insulation of conductors installed on the end of a cable trunk with a capacity of 100 to 600 pairs directly in a control cabinet on vertically passing cables that may be under excessive pressure or without it, but with hydrophobic core filling.

The specified technical result is achieved by the fact that the water-tight cable sleeve, comprising a housing with a through hole, hermetically filled with a compound, and conductors passing through the compound outside the housing, contains a screen connector located in the through hole of the housing, mounted on an aluminum-polyethylene cable sheath located inside the outer plastic cable sheaths, and connected to the screen wire of the cable and the ground wire extending beyond the housing made of polyethylene, the diameter of the through hole at the inlet end of the case through which the plastic sheath of the cable is inserted inside the case is smaller than the diameter of the specified hole at the outlet end of the case through which conductors and the ground wire are taken out of the case, the compound used is cold-hardened polyurethane sealant that fills the plastic cable sheath, and the screen connector is located in the housing in contact with the conical surface of the through hole at the input end of the housing, and on the plastic oic cable sheath and adjacent the inlet end of the housing is installed shrinkable tube, each conductor along the entire length has a plastic insulation layer.

The invention is illustrated using figures 1-6, which depict:

Figure 1 "a" - Mounted coupling using shrinkage HERE open flame of a gas burner (hot method).

Figure 1 "b" - Mounted coupling using adhesive sealing tapes LG-2, tapes 88T and reinforcing bandage "Armoplast" (cold method).

Figure 2 - Longitudinal section of the coupling

Figure 3 - Location of the coupling in the control cabinet

Figure 4 - Assembly of the screen connector

Figure 5 - Sealing the input end of the housing

6 - Sealant filling

The universal water-tight coupling (UVGNM) contains a housing 1 with a through hole, a compound 2, hermetically filling the opening of the housing 1, cable conductors 3, each of which has an insulating layer hermetically passing through compound 2, a screen connector 4, mounted on an aluminum-polyethylene sheath 5 of the cable, to which the ground wire 6 is attached, facing the outside of the housing 1, and the screen wire of the cable (not shown in FIG.). The housing 1 is made of polyethylene, while the diameter of the through hole at the input end of the housing into which the plastic sheath 7 of the cable is inserted is smaller than the diameter of the hole at the output end of the housing, in which the conductors (wires) 3 of the cable and the ground wire are located 6. V as compound 2, a non-expanding polyurethane sealant is used during hardening, for example, VILAD-13, which has high flow rates, due to which it penetrates into the plastic sheath containing the core of the cable from water workers with insulation, thereby creating an additional shutter. The use of this sealant prevents the appearance of bubbles during hardening, which lead to a decrease in electrical strength.

Screen connector 4, made according to US Patent No. 5617501 with a priority of April 1, 1997 (for example, in the form of two "crocodile-like" plates with curly teeth, on one of the plates of which (the base of the connector) a threaded rod is welded to the end and onto which through the hole is installed on the second plate and when screwing the nuts on the rod of the plate are compressed, making electrical contact with the aluminum-polyethylene sheath of the cable), is located in compound 2 in contact with the conical surface of the through hole at the input end of the housing 1. To seal the junction of the cable and the housing on the plastic sheath 7 of the cable and adjacent to the input end of the housing 1 installed heat-shrinkable tube (TUT) 8.

The coupling 9 is mounted as follows:

- on the end of the cable vertically located in the control cabinet, pull the length of the HERE 8 and the housing 1,

- at the end of the cable remove the outer protective alumina-polyethylene sheath 7,

- departing from the place of cut of the sheath by 10 mm, on the belt insulation 5 cables make a bandage of threads 12,

- between the aluminum-polyethylene sheath 7 and the waist insulation 5, the base of the screen connector 4 is inserted, then the upper part of the connector is installed and both parts are tightened with a nut, and thus the screen connector 4 is fixed on the insulating (aluminum-polyethylene) sheath 7, for example, using a threaded connection (see figure 4)

- remove the belt insulation 5 from the end of the cable, produce fluffing of wires 3 (insulated cores),

- to the screen connector 4 connect the screen cable wire (not shown in Fig.) and the ground wire 6,

- push the housing 1 onto the fluffy core of the cable all the way into the screen connector 4,

- seal the junction of the housing 1 with the outer aluminum-polyethylene sheath 7 of the cable with a heat-shrinkable tube 8 (see Fig. 5) by heating it with an open flame of a gas burner.

In explosive rooms where it is impossible to use an open flame of the burners, the sealing of the junction of the housing 1 with the outer aluminum-polyethylene sheath 7 is carried out in a "cold way", i.e. by winding with 50% overlap of the surfaces to be sealed, initially with LG-2 tapes, then 88T tapes and then with two layers of Armoplast bandage, followed by wetting with water so that the bandage hardens;

- at a distance of about 20-30 mm from the housing 1, the core of the cable, which contains the conductors 3, is pulled together with a tie or tied with thread 11,

- fill the sealant 2 in the opening of the housing 1 (see Fig.6) and maintain until it completely hardens, which occurs within 12 hours.

Figure 3 shows the coupling 9 installed in the base of the distribution cabinet 10. The disassembled bundles of conductors 3 (cores) are attached to the cabinet metal structures with straps or dressings. The ground wire 6 is connected to the earth bus (not shown in FIG.).

Advantages of the proposed coupling:

- simpler and cheaper design;

- simplified installation technology;

- the cost of construction works is reduced;

- provides control over the cable line in the area from the closet well to the distribution cabinet, as branched conductors are located at the output of the coupling;

- there is no need to install a branch coupling in the cabinet well;

- the problem of eliminating moisture condensate from entering the cable core arising in the control cabinet due to the location of the sealant in the plastic sheath of the cable is solved.

Information sources

1. Patent DE 4005842;

2. Patent RU 2035814;

3. "General instruction for the construction of linear structures of the GTS", approved by order of the Minister of Communications of the USSR of May 6, 1977 No. 220, Moscow Publishing House "Communication", 1978 (section 12.3.)

4. Technological map for the installation of small-sized gas tight couplings MGNMs on cable TPPep., Moscow, 2003

5. "Guidelines for the construction of linear structures of local communication networks", part II, Moscow, SSKTB-TOMASS, 1995

Claims (1)

A water-tight cable sleeve containing a housing made of polyethylene with a through hole sealed with a compound, and conductors passing through the compound outside the housing, characterized in that it comprises a screen connector located in the through hole of the housing, mounted on an aluminum-polyethylene cable sheath and connected to the screen a cable wire and a ground wire extending beyond the housing, the diameter of the through hole at the input end of the housing through which inside the plastic sheath of the cable is given, smaller than the diameter of the indicated hole on the outlet end of the case, through which conductors and the ground wire are led outside the case, a cold-cured polyurethane sealant is used as a compound, filling the aluminum-polyethylene sheath of the cable, the screen connector is located in the case in contact with the conical surface of the through openings at the inlet end of the case, on the aluminum-polyethylene sheath of the cable and the inlet end of the case adjacent to it, is installed May winding tube or the sealing tapes and bandages "Armoplast" and each conductor along its entire length has a plastic insulation layer.

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