Innovative HV System & Design

Cable Lying

HV cable requires special laying method and intensive care to avoid any damage during the laying which might result in to heavy losses. To achieve a safe and damage free installation, special types of cable laying tools need to be used. Promax owns wide range of state-of-art equipments like cable rollers, pulling winches, drum stands etc. These equipments are utilized as per typical specification; pulling forces withstand capacity and minimum bending radius of a particular cable.

The finalization of design part should be followed by cable pulling and laying plan and the location of drum stands and winch should be determined. Changes in the elevations, locations of bends and offsets should be considered as an important part of cable laying plan, since these factors result into increase in the pulling forces. . To minimize their effect, pulls should begin at the end having lowest
elevation.

Rollers are to be used in drawing heavy cables for safe installation; the cable can be drawn out manually or with a winch. If the cable is pulled out solely by its end, guide rollers should be placed at the corners to ensure that the cable is not bent at less than the minimum bending radius. In all these methods, the drum stand should be placed so that the cable is unreeled from the top, i.e. the cable is unreeled in the opposite direction to that shown by the arrow.

After lying is complete, the cables are to be fixed with the right clamp having adequate strength to bear forces generated due to short circuit fault. The XLPE cable is to be further commissioned and tested in accordance with the relevant test specifications for XLPE high and extra-high voltage cable systems. These include DC voltage tests on the cable sheath or AC voltage tests on the main insulation. For extra-high voltage systems, particularly, they may be supplemented by partial discharge tests on the accessories installed.