Abstract: A high voltage insulator has a polymeric core that forms a mechanical strength member and an outer covering of a heat-shrinkable polymeric tube that is electrically insulating and non-tracking and that has sheds on its outer surface.

Abstract: A high voltage porcelain insulator has a plurality of sheds extending laterally thereof at spaced apart locations therealong. The creepage path length of the shedded insulator is extended by mounting polymeric insulating creepage extenders on the porcelain sheds. The creepage extenders do not extend completely around the periphery of the sheds but leave a gap. Preferably the gaps of adjacent creepage extenders along the insulator are not aligned.

Abstract: The termination of a high voltage electric cable includes a rigid heat shrinkable tube that extends between the cable jacket and a connector mounted on the cable conductor. The tube is made from an engineering plastic material and has a Flexural Modulus and a Young's Modulus high enough so as to ensure that the termination is self supporting. The termination may be used in the transmission of power from one carriage to another of an electric train.

Abstract: Electrical wire and cable is provided with a layer of insulation or jacketing material which comprises a mixture of: (1) a polyester based on tetramethylene terephthalate, preferably polytetramethylene terephthalate; and (2) more than 40%, based on polymer (1), of a block copolymer preferably having polytetramethylene terephthalate hard blocks and poly(polytetramethylene oxide terephthalate) soft blocks. Polymer (2) has a flex modulus of at least 69 MPa preferably at least 138 MPa. The insulation or jacketing material exhibits improved resistance to stress crazing in a number of solvents.