Surface analysis of polymeric surge arresters under coastal Florida conditions

Polymeric materials are susceptible to aging and degradation due to environmental stresses (weathering). It is necessary to study the surface changes since they are the primary cause for failures and understanding why things fail is essential to finding ways of minimizing the likelihood of recurrence. This paper presents the surface transitions of polymeric housed surge arresters under accelerated multistress coastal Florida conditions, for six years. 9 KV ethylene propylene silicone blend (EPSB) and silicone rubber (SiR) commercial polymeric arresters were used for this purpose. The EPSB arresters showed slight discoloration, change in hydrophobicity, and reduction in CH₃ functional groups in the FTIR spectra while the SiR arrester surfaces remained almost intact. Weibull distribution was used to predict the probability of failure of these arresters using reduction in CH₃ FTIR Peak heights. Good results correlating this prediction and previous research have been obtained, which can be used by utilities for preventive maintenance or condition monitoring.