The ac clean-fog test for contaminated insulators

The paper* summarizes the results of clean-fog tests conducted by eleven task force laboratories on a common suspension insulator, IEEE insulator.** The test series done according to a specific set of guidelines, show considerable dispersion in the fifty per cent flashover voltage between the laboratories. The significant parameters of the clean-fog method that influence the fifty per cent flashover voltage are discussed. More controls in testing are needed before the formalization of the clean-fog method as a standard contamination test for high voltage ac insulators can be made.