Accelerated environmental and electrical aging of polymer insulators

Experimental results of accelerated aging tests conducted on two types of high voltage polymeric outdoor insulators are presented. The investigated housing polymers were ethylene propylene diene monomer (EPDM) and silicone rubber (SR). The polymer performance under environmental stresses and electrical stresses were studied separately by using a programmable weather-ometer and a rotating wheel test setup, respectively. Results show a good performance for silicone rubber under some environmental stresses, but a poor resistance to surface tracking and erosion caused by dry-band associated glow or partial arc discharges.