Tracking and erosion resistance and hydrophobicity of HTV silicone rubber for outdoor insulators

The paper reports a study of the influence of silicone oils on the tracking and erosion resistance and hydrophobicity of HTV silicone rubber. Two silicone oils (A, B) having different chemical structure are selected with consideration of good hydrophobicity and processability. Tracking and erosion resistance of HTV silicone rubber are investigated by the rotating wheel dip test (RWDT). In this test, tracking and erosion areas due to glow and partial arc discharges cause an increase in leakage current with time. The leakage current of silicone rubber decreases with increasing ratio of oil A/B. HTV SR is exposed to corona discharges in air and the specimens are analyzed by contact angle measurements. It is observed that the contact angle of silicone rubber increases gradually with time. The recovery of hydrophobicity increases with increasing ratio of oil A/B.