Multistress aging tests of polymer housed surge arresters

The combined stresses in multistress aging tests produce cumulative accelerated effects on polymer materials and surge arrester constructions that simulate typical service aging. The aging of polymer housed surge arresters is manifested by increased watts loss (internal, external or both), external flashover, or internal failure. Multistress testing is able to demonstrate deficiencies, with respect to aging, of surge arrester materials and designs, including the nature of interfaces in the insulation design. Therefore, multistress testing is believed to be a suitable test for evaluating the aging performance of surge arrester designs. Surge arrester housings made of materials other than silicone rubber are shown to age more rapidly and to require greater creepage distance than silicone rubber to maintain equivalent watts loss levels in multistress tests.