Performance of ceramic and polymeric distribution insulators with mold growth on its surface

There are several studies presented on insulator contamination by biological agents and its impact on the electrical performance is not well known. This paper describes a study developed in Bogotá, Colombia on electric performance of insulators contaminated with a common mold (i.e. Asperguillus Nigger). Ceramic and polymeric (non-ceramic) insulators used in Colombian distribution systems were selected. Biological contamination was made under controlled conditions using an isolated chamber that adjusts temperature, humidity and solar (ultraviolet) radiation. Electrical tests performed include flashover voltage and leakage currents measurements to determine how insulators are affected by bio-contamination. After laboratory tests, a significant impact on electrical performance of both types of insulators due to the biological contamination was noted.