Cable identification

Abstract

 This invention relates to cables including at least three primary elongated elements (1,1A,1B) and a number of secondary elongated elements (5,5A,5B). The basic idea is that at least one of the primary elements - cable cores - should be identifiable by coding of neighboring or adjacent secondary elements - filler elements. The coded secondary elements are usually arranged in interstices between the primary elements. The primary elements can then be substantially identical in crossection and surface configuration.

Description

[0001] The present invention relates to cables including at least three primary elongated elements and a number of secondary elongated elements. The invention relates in particular to 3-core power cables in the voltage range up to 60 kV, - where the cores and filler elements are enclosed within a common outer cover or sheaths.

[0002] It is usually a requirement that the cores of such cables can be distinguished from each other. Such identification is used for simplifying installation work.

[0003] The common existing methods for core identification are by means of a) direct marking with inks, or b) marking with engraved - or embossed - characters on the insulation screen. These methods have certain deficiencies. Marking with ink may have detrimental effects related to water treeing, - whereas marking with engraved - or embossed - characters requires a thicker insulation screen layer.

[0004] The object of the present invention is to provide a unique core identification which effects neither the electrical nor the mechanical properties of the cable. The features of the invention are defined in the claims. The basic idea is that at least one of the primary elements - cable cores - should be identifiable by coding of neighboring or adjacent secondary elements - filler elements. The coded secondary elements are usually arranged in interstices between the primary elements. The primary elements can then be substantially identical in crossection and surface configuration.

[0005] Above mentioned and other features and objects of the present invention will clearly appear from the following detailed description of embodiments of the invention taken in conjunction with the drawing.

[0006] In a preferred embodiment of the invention the filler elements are colour coded. There are however also other methods for coding the filler elements. The core identification maybe obtained by using three different filler colors and any one of the cores is therefore uniquely identified by its adjacent fillers. An advantage of the invention is that the core insulation is mechanically and chemically unaffected. Another advantage is that no special tools are required for making the products.

[0007] In the figure is illustrated a 6350/11000 three core XLPE water tree retardant cable, - each conductor being 150 sq.mm. The cable has three conductors 1, 1A and 1B, each with a conductor screen 2, insulation layers 3 and an insulation screen 4. The appearance of these three conductor cores is identical. The cable has at least two filler elements 5 and 5A which are distinguishable from each other by colors, by imprints, by different materials or by different configuration.

[0008] The elongated elements of the cable are enclosed within outer covers and sheaths such as a semiconductive tape 6, a copper wire screen 7, a tape winding 8 and an outer sheath 10.

[0009] It will be clear from the drawing that if filler element 5 is red and filler element 5A is green, the cable core 1 may be identified by these two neighbor elements - or adjacent fillers -if you look at either end of the cable. It also appears that the cable core 1A can be identified from either end of the cable by 'counting': red filler - cable core - green filler - core 1A. Similarly the core 1B can be identified from either side by 'counting': green filler - cable core - red filler - core 1B.

[0010] However, by introducing also a yellow filler 5B in the interstice between the cores 1A and 1B, all cores are easily identified from both ends of the cable: Core 1 is the one adjacent to fillers 5 (red) and 5A (green), - core 1A is the one adjacent to fillers 5A (green) and 5B (yellow), - whereas the core 1B is the one adjacent to the yellow and red fillers.

[0011] The above detailed description of embodiments of this invention must be taken as examples only and should not be considered as limitations on the scope of protection. The invention is useful also for cables not having outer covers and for cables having more than three cores or primary elements.

[0012] Beside this the cores 1A, 1B and 1C can be optical fiber elements, e.g. loose or tight buffered fibers, metal or plastic tubes containing optical fiber ribbons or slotted core elements containing optical fibers and/or optical fiber ribbons in its grooves. In the case of optical elements the coloured fillers 5 can be used as an additional marking element for such fibers and/or each group of fibers which have already a first marking.

Claims

1. Cable including at least three primary elongated elements (1,1A,1B) and a number of secondary elongated elements (5,5A,5B),
characterized in that
at least one of the primary elements is identifiable by coding of neighboring or adjacent secondary elements.

2. Cable according to claim 1,
characterized in that
the secondary elements are arranged in interstices () between the primary elements.

3. Cable according to claim 1,
characterized in that
the primary elements are substantially identical in crossection and surface configuration.

4. Cable according to claim 1,2 or 3,
characterized in that
at least two of the secondary elements are coded by colors.

5. Cable according to claim 1,2 or 3,
characterized in that
at least two of the secondary elements are coded by imprints.

6. Cable according to claim 1,2 or 3,
characterized in that
at least two of the secondary elements are coded by different materials.

7. Cable according to claim 1,2 or 3,
characterized in that
at least two of the secondary elements are coded by different configuration.

Drawing