Performance comparison of silicone rubber and EPDM insulators in humid and contaminated environments

This paper investigates the effect of pollution severity and relative humidity on the performance of silicone rubber and ethylene propylene diene monomer (EPDM) insulators. Rectangular samples of silicone rubber and EPDM were used for the tests. The ramp test method was used to measure flashover voltage and leakage current at different climate conditions. Flashover voltage, arc inception voltage, as well as surface resistance of silicone rubber and EPDM coating materials were measured at various pollution severity and relative humidity levels in a fog chamber. Experimental results showed a decrease in flashover voltage, arc inception voltage and surface resistance with an increase in pollution severity and relative humidity. The result of this study can be used in the selection of polymeric insulators for contaminated and humid environments.