UK experience of MV paper insulated cables

The author´s observations are based upon experience of 11 kV and 33 kV cables in Manweb, and on the last 3 years experience of examining cables from several other electricity company and industrial networks. Every installed cable is an individual, and behaves as an individual. A paper cable is itself a very complex system of inter-related components and processes, and when installed in the ground, the complexity is increased. The behaviour of any particular cable is therefore determined by many factors-who made it, when it was made, the quality of manufacture (conductors, paper, paper lapping, impregnant type, impregnation quality, etc.), installation conditions, installation quality, loading history-all play a part in determining the life of a paper cable, and need to be considered when determining the cause of a failure, assessing the present condition of the cable, or making predictions about it´s future reliability. The author discusses the UK experience of both 11 and 33 kV cable networks