Contamination Flashover Performance of Insulators for UHV

The results of contamination tests performed on suspension insulators and posts in a fog chamber at 60 Hz voltages up to 1450/ 13 kV are reported. Data are presented on the flashover voltage of single standard and antifog insulator strings as long as 11.5m. The influence of adjacent insulators on contamination performance is shown by tests made on a quadruple string. For post insulators, the effects of diameter on the insulation strength are explored. The indoor data are supplemented by outdoor results for an artificially contaminated test line Vee-string exposed to natural wetting conditions.