Extra-high-voltage power cable

摘要

An extra-high-voltage power cable is provided with extruded insulation 3 over a conductor 1 thereof. The insulation comprises a layer 5 of unfilled high density polyethylene or polypropylene having a higher electric strength than the material of the insulation in layer 6. In the embodiment layer 5 may or may not be cross-linked, has an electric strength fifty times greater than layer 6 and a thickness a third of the extruded insulation. The outer insulation layer 6 may be cross-linked low density polyethylene. Semiconductive screening layers 2, 4 are provided. Since the layer 5 is unfilled it is translucent thereby assisting inspection of the integrity of layer 2 prior to extrusion of the outer layer 6. IMAGE