High voltage power cable - constructed to avoid the formation of electrochemical trees in the insulation

摘要

Power cable has a stranded conductor (12) impregnated with a semi-conductive strand sealant (18), a semi-conductive stress control layer (16) about the conductor, the sealant preventing ingress of moisture between the strand and stress control layer, an extruded polyethylene insulation layer (20) tightly about the stress control layer. A semiconductive insulation shield (24) is provided so tightly about the insulation layer as to prevent ingress of moisture, a metallic shield (30) about the insulation shield with semiconductive sealant compound (26) therebetween to prevent moisture reaching the insulation shield. The sealant is a material which is physically and chemically compatible with the stress control layer and insulation shield and is a compound which maintains its physical and electrical characteristics in spite of temperature changes due to the load cycling of the cable.