GB1365921A - Joints and terminations for electric cables - Google Patents

Abstract

1365921 Cable joints and terminations BRITISH INSULATED CALLENDERS CABLES Ltd 20 Jan 1972 [21 Jan 1971] 2885/71 Heading H2E Oil Rowing between a channel in the core of a cable and the interior of a cable joint or termination passes through a filter 16 which removes particles of metal or other materials which would encourage electrical breakdown. In one embodiment (Fig. 1) a metallic connector 3 comprises ferrules 2 which receive the ends of the cores 1 of two cables (only one shown). A central portion 4 of the connector prevents oil flow between the two cables. The connector 3 is clamped by a nut 9 to a stress relief ring electrode 6 embedded in an epoxy insulator 7, an 0-ring 5 providing an oil seal. The oil flows from each cable core through a filter 16, through ports 10 in the ferrule and ports 11 in the clamping nut, through the gap 12 between the insulator 7 and lapped paper insulation 13, and through a gap 15 between the insulator 7 and an end insulator 14, to the space between the insulators and the outer metal casing (not shown) or may flow in the opposite direction. The filter 16, which is of metal, paper, glass fibre or a sintered material, is clamped inside the ferrule by an externally threaded nut 18. Other embodiments (Figs. 2 and 3, not shown) are similar except that the filter is in the form of a ring located between the clamping ring 9 and the paper insulation 13 or at the outer end of space 15. In a termination (Fig. 4, not shown) the filter is inside the ferrule, and the oil passes through ports (44) in the ferrule to the space (45) between the cable and a tubular insulator (46). In all embodiments the filter is preferably located near the oil-entry end of the oil path.