A study on the characteristics of various conductive contaminants accumulated on high voltage insulators

In the assessment of the conductive materials of the natural contaminants accumulated on insulators in terms of equivalent salt deposit density (ESDD), not much attention has been paid to the basic consideration, such as its solubility in water, correction of the conductivity of its water solution to the standard temperature, etc. A study was made on these important factors through repeated measurements of the actual contaminants on the insulators. As a result, practical precautions for the measurement of ESDD are indicated. Also, it is pointed out that the difference in the performance of the naturally and artificially contaminated insulators even with the same ESDD may be explained by the solubility of the materials and that the ambient temperature has a significant influence on the contamination flashover voltage