Contamination Testing of Arresters for 500-kV Systems

The effects of external surface contaminants and moisture on the internal sparkover of lightning arresters is of prime concern in the design of extra high voltage (EHV) stations. This paper describes the design and acceptance sparkover and contamination tests performed on several different ratings of a multiunit arrester designed specifically for use on 500-kV systems. The sparkover characteristics were determined for various degrees of surface contamination and several different methods of surface wetting.