Behaviour of high-voltage solid-type cable accessories in service

A description is given of the conditions discovered when high-voltage solid-type cable accessories have been dismantled after many years of service. In several instances compound migration had occurred, followed by secondary effects such as collapse of lead sleeves and ingress of moisture. A reconditioning technique used successfully to prolong the useful life of installed joints and sealing ends exhibiting these defects is described. An explanation of the phenomenon of compound migration is also suggested. The basic principles for new designs, together with typical illustrations of cable joints and end terminations, are given, which in the authors´ opinion should prevent compound migration occurring in future installations.