Some of the first implementations of monitored withstand diagnostics on utility systems

Hipot or voltage proof tests have long been used to assure the health of cable systems in the factory and when commissioning. One of the concerns with this approach is that there is no way to judge the quality of the Pass, ie did the system barely survive or was there a respectable margin. This paper shows how this problem has been practically addressed in US utilities with an approach which is termed "Monitored Withstand". The protocols and the test philosophies are discussed. A number of case studies are discussed together which some reflections on future activities in this arena.