Anti-Pollution Design Criteria for Line and Station Insulators

This paper presents anti-pollution design criteria for line and station insulators based on investigation of performance of various insulators under artificial pollution tests. Field pollution areas were classified into six classes; AA, A, B, C, D and E according to pollution degree. Recommended leakage distance for disc insulators per 1 kV of nominal line-to- line voltage are 0.75", 0.9", 1.0" and 1.1 " for A, B, C and D areas respectively. Considerable increase in leakage distance is necessary for cylindrical post insulators and porcelain shells with increase in average diameter.