Performances of long-term coastal field aged silicone-coated ceramic insulators under clean and salt fog conditions

Ceramic insulator is a kind of insulator that is used most widely especially in Indonesia. It has good property in both electrical and mechanical strength but has hydrophilic behavior that susceptible for leakage current flowed on the surface of insulator. Based on previous research, leakage current can be a good indicator to diagnose insulator surface condition. This paper presents leakage current performance of a long-term field aged ceramic insulator with and without RTV silicone rubber coating under clean fog and salt fog condition. The insulators have been installed in the coastal field for 5 years and 4 months. The insulators were investigated in laboratory to know the effect of voltage rise to the aged insulator condition under clean fog and salt fog condition. Monitored parameters are magnitude and THD of leakage current. The result has shown that with voltage rise, coated insulator has better performance in both clean fog and salt fog condition especially to increase the flashover voltage of aged ceramic insulator.