Covered cable comparative testing: HDPE and XLPE evaluation

Hendrix Cabos e Acessorios Ltda and CEMIG, in Brazil, have signed a technical cooperation document in order to perform tests on medium voltage covered cable used in spacer cable system. Hendrix Cabos e Acessorios Ltda is a joint-venture company between Hendrix Wire & Cable, USA (the pioneer in spacer cable systems in the world) and Procable Energia e Telecomunicaoes Ltda (a Brazilian Co. of power and telecommunication cable systems). CEMIG, which is the largest Brazilian Power Utility, has changed its distribution line construction standard used in urban areas, from overhead bare construction to spacer cable construction, due to the latter's reliability and, more importantly, attractive cost-benefit relationship. In order to evaluate the medium voltage covered conductors used in spacer cable systems, a testing program was performed on samples of covered cable with high-density polyethylene (HDPE) and crosslinked polyethylene (XLPE). The tests were performed at CEMIG (Brazil) and Hendrix W&C (USA) laboratories. The program goals were: (1) to determine the performance of different insulation compounds; (2) to compare test procedures and results between American and Brazilian standards, applicable to covered conductors; (3) to suggest improvement in covered cable standards to be discussed in technical events. This paper describes test requirements, results and performance comments.