Testing EHV Station Insulation for Performance in Contaminated Conditions

This technical paper deals with two phases of wet testing of EHV station insulators; one for conventional rainfall tests with prescribed rate of precipitation and water resistivity and the other for artificial contamination or pollution tests under wet conditions. The authors recommend a change in USA Standards for rate of precipitation and resistivity of water and offer supporting test data confirming the ability to distinguish between satisfactory and unsatisfactory insulator designs as a result of employing their new proposal. They also offer a proposed contamination test procedure which is convenient to use, which gives reproducible results, and which is sufficiently flexible for use in varying the severity of the applied artificial contaminant according to user requirements. The artificial contamination, or pollution, test may be used in rating insulator designs concerning performance under contaminated and wet conditions.