Final Report of the 2004 - 2007 International Enquiry on Reliability of High Voltage Equipment - Part 3: Disconnectors and Earthing Switches

Results from a world wide utility survey of failures and service experience with disconnectors and earthing switches rated for 60 kV and above are presented. The surveyed service experience comprises 935 204 three phase equipment-years. Statistical information about 1 959 major and 3 001 minor failures - such as origin, cause and failed subcomponent - are provided. In addition, failure frequencies as a function of voltage level, design, type of drive, location and age are presented.