, Description:FIELD OF INVENTION
The disclosure relates high voltage cables, more specifically the disclosure relates tomulti core high voltage cable for underground cable network.

BACKGROUND
Presently single core cables for underground cable networks are used worldwide. The operating voltages for such cables are usually greater than or equal to 66000 Voltage.

However, these single core cables have inherent issue of sheath voltage induction. Further joining bays are required to provide SVL (surge voltage limiters) to the single core cables.Moreover, for balancing the sheath voltage & current, transposing of the single core cable sheath at joint boxes is required to avoid damage to cable outer sheath. Further damage to cable outer sheathmay result in very high sheath current,high losses and deterioration of cable insulation.Further the single core cables in a grid are generally tapped by loop in loop out arrangement, and this arrangement may disturb the entire sheath voltage balancing.

SUMMARY
This summary is provided to introduce aspects related to a multi core cable and the aspects are further described below in the detailed description. This summary is not intended to identify essential features of the claimed subject matter nor is it intended for use in determining or limiting the scope of the claimed subject matter.

In one implementationa multi-core cable is disclosed. The multi core cable may comprise at least three core cables 101. Further each core cable from the at least three core cables 101 may comprise a conductor 102 and the conductor 102 may further be enclosed in an insulator 103. The insulator 103 may further be enclosed in a metallic sheath 104, characterised wherein the at least core cables 101 are enclosed within an inner sheath 105.

BRIEF DESCRIPTION OF DRAWING

The detailed description is described with reference to the accompanying figures. In the figures, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The same numbers are used throughout the drawings to refer like features and components.
Figure , illustrates a multi core cable in accordance with the present disclosure.

DETAILED DESCRIPTION
The present subject matter discloses a multi core cable.

Figure 1, illustratesa multi core cable in accordance with the present disclosure. The multi core cable 100 may comprise at least three core cables 101. Further each core cable from the at least three core cables 101 may further comprise a conductor 102. The conductor 102 may have a diameter of 19.5(+/- 2) mm and may further be enclosed in an insulator 103. The insulation103 may have an inside diameter of 33 mm and a thickness of 11mm. The insulator 103 may be made of cross linked polyethylene material. The insulator 103 may further be enclosed within a metallic sheath 104. The metallic sheath 104 may provide strength and additional support to the conductor 102 and the insulator 103. The metallic sheath 104 may have a thickness of 0.1 to 0.2 mm and shall be made of copper.

In the exemplary embodiment the at least three core cables 101 may be further enclosed within an inner sheath 105. The inner sheath 105 may be configured to hold the at least three core cables 101 in a defined position. The inner sheath 105 may have thickness of 1.5 mm and made of PE compound type ST7. Further a first layer 106 may enclose the inner sheath 105. The first layer 106 may be configured to provide mechanical strength by providing galvanized steel wire followed by rubberized cotton tape with minimum area of coverage 90%

The first layer 106 may further be enclosed in an outer sheath 107.The outer sheath 107 may be configured by pressure extruded PE compound type ST-7 of minimum thickness 3 mm. Further to provide waterproofing the multi core cable in radial direction, the inner sheath 105 and the outer sheath 107 may be pressure extruded. Further for longitudinal water ingress water blocking tape may be used on the conductor 102, the metallic sheath 104, and on first layer 106.

Claims:1. A multi-core 66 KV earthed cable comprising at least three core cables101, wherein each core cable from the at least three core cables101 further comprises a conductor102 enclosed in an insulator103, and a metallic sheath104 enclosing the insulator103; characterised wherein the at least core cables101 are enclosed within an inner sheath105.

2. The multi-core cable of claim 1,further comprises a first layer106 enclosing the inner sheath.

3. The multi-core cable of claim 2,further comprises an outer sheath107 enclosing the first layer.

4. The multi-core cable of claim 2, wherein the first layer106 as a thickness between 3 mm to 5 mm.

5. The multi-core cable of claim 3, wherein the outer sheath107 as a thickness between 2 mm to 4 mm.

6. The multi-core cable of claim 3, wherein the outer sheath is extruded under pressure during fabrication.

7. The multi-core cable of claim 1, wherein each core cable from the at least three core cables as a surface area of 300 sq. mm.

8. The multi-core cable of claim 1, wherein the inner sheath is extruded under pressure during fabrication.

9. The multi-core cable of claim 1, wherein the insulator is made from cross-linked polyethylene.

10. The multi-core cable of claim 1, wherein the insulator as a thickness between 10 mm to 12 mm.

11. The multi-core cable of claim 1, wherein the conductor 102 as a thickness between 17.5 mm to 21.5 mm.

12. The multi-core cable of claim 1, wherein the metallic sheath 104 as a thickness between 0.1 mm to 0.2 mm.

13. The multi-core cable of claim 1, wherein the inner sheath 105 as a thickness between 1.2 mm to 1.8 mm.