Vacuum Disconnector And Continuous Vacuum Monitoring On A 2sis Medium Voltage Distribution System

An extended summary is given about aspects dealing with the application of vacuum disconnectors. Discussed are normative requirements, dielectric considerations in new and aged condition, failure mode analysis in case of loss of vacuum and vacuum monitoring. The influence of vacuum monitoring on the availability of the disconnector application in "open ring" and "closed ring" distribution networks as well as in the fast transfer switch application is discussed. It is shown that the continuous vacuum monitor improves the availability of the disconnector function to 99.99998 %.