A study and development of high water pressure hot-line insulator washing equipment for 500-kV substation

High water pressure hot-line insulator washing equipment has been developed and in service in Japan as an effective measure to prevent the contamination flashovers of apparatus insulators at 500-kV class substations. This paper presents the results of studies on the development of the equipment, including selection of a suitable water pressure, developments of a nozzle suited for high water pressure washing and of section valves capable of minimizing water hammer, the safety of contaminated insulators against flashover during washing and electrical safety clearance between nozzles and energized parts.