Effects of biological contamination on insulator performance

Results of investigations on biological growths on different insulators, especially porcelain and silicone rubber ones, are presented. The insulators have been exposed to tropical weather under polluted and clean conditions in Sri Lanka and Tanzania since 1995. Algae contamination was found on the insulators at the clean locations. The algae were identified as green algae. After performing a series of laboratory tests, it was concluded that the effect of algae was not too strong on the contaminated silicone rubber insulators. Suggestions how to control the algae growth are presented.