Polymer insulating materials and insulators for high voltage outdoor applications

The authors discuss the characterization, evaluation and performance of polymer weathershed materials and insulators used for high-voltage outdoor applications. Ethylene propylene diene monomer (EPDM), ethylene propylene monomer (EPM), silicone rubber (SR), and an EPDM/silicone rubber alloy were tested. The tests considered most pertinent for these materials and applications are described. Test results for some of the materials evaluated are presented. A compound that successfully passes these tests should perform satisfactorily during its intended service life. The effects of aging on insulators were studied. The tests that are needed to determine the extent of insulator aging are discussed.< >