Long term wet ageing of extruded dielectric cables

Experience outside the UK with service failures of wet MV extruded dielectric cables has led to extensive worldwide studies. This article describes work carried out at BICCGeneral UK since the 1970s and reviews the results of long-term tests (up to ten years) under working conditions on cables manufactured in the 1970s and 1980s. The results are compared with data from two-year UNIPEDE tests at 2/spl middot/5U/sub o/ on 1990s cable and demonstrate the good service performance obtained with these cables. European and North American service failure data, obtained from the literature, is then used with the service survival data on these cables to estimate their expected lifetime.