An outdoor investigation on hydrophobicity of silicone rubber insulators in the Temperature Zone

This paper summarizes the common hydrophobicity change characteristics of silicone rubber insulators in the North Temperature Zone, according to the results of a series of outdoor tests. The tests were conducted for over a year on an outdoor experimental flat roof in Beijing, China, which belongs to the North Temperature Zone. All samples were not energized and suffered from the various natural environmental stresses. The samples were investigated using the HC method. The test results show that the hydrophobicity of SIR insulators can decrease and even lose in winter. After winter, with the change of season, different samples have the different hydrophobic recovery capacity. The influences of several typical environmental stresses such as ambient temperature, precipitation and ultraviolet radiation, to the hydrophobicity of silicone rubber insulators are also analyzed. Finally, based on the test results, the dynamic hydrophobicity monitoring method of silicone rubber insulators in the North Temperature Zone is discussed.