Assessment of basic contamination withstand voltage characteristics of polymer insulators

An artificial contamination method for hydrophobic polymer insulators was newly developed, which can provide a uniform contaminant layer similar to thc natural one neither by damaging the polymer surface nor by adding any chemical agent to the conventional contamination slurry. Using this method, basic contamination withstand voltage characteristics of polymer insulators were investigated comparing with those of porcelain insulators. The results show that although hydrophobic polymer insulators generally have exccllent contamination withstand voltage characteristics critical reduction of withstand voltage occurs sometimes undcr rapid and heavy wetting and contamination conditions.