Supertension (66-500 kV) polymeric cables and their accessories

Among the different types of joints the prefabricated designs are nowadays the more extensively used, due to their intrinsic higher reliability, as they are factory moulded and factory routine tested at HV before installation on site. In addition, the prefabricated concept allows a reduction in jointing time and jointing skill which can however differ according to the design and fitting concept. Two main types of prefabricated joints are used: (a) the composite type, and (b) the premoulded type. The composite type joint includes two premoulded rubber stress cones, which are pressed by a spring system against the cable core, and a conically shaped central insulator of cast thermoset resin. The premoulded type joint includes a moulded EPR or silicone rubber one piece or three pieces sleeve, which is (are) interference fitted over the prepared cable core. The author describes these types of joint.