Assessment of in-service Composite Insulators by using Diagnostic Tools

This TB of Working Group B2.21 is an analysis of the situation seventeen years after WG 22.03 published an ELECTRA paper entitled “In service diagnostic testing of composite insulators” to provide information on the status quo of inspection tools for installed and energized composite insulators. The document includes experiences of both utilities and laboratories. It can be shown that the diagnostic tools that were first introduced in the 1990's have been further developed and that if correctly used, these tools can provide sufficient information to evaluate the status of an insulator as well as identify potential risks of those insulators, which are subjected to Live Line Work.