Natural insulator contamination test results on various shed shapes in heavy industrial contamination area in Shanghai under AC energized and de-energized conditions

摘要

Insulator natural contamination tests on various shed shapes were conducted at two representative sites in Shanghai for one year. Equivalent salt deposit density (ESDD) was measured periodically, under the de-energized condition. Insulators energized at two sites for one year were removed and withstand voltage tests were conducted in artificial fog. Unexpectedly high ESDD values over 1 mg/cm/sup 2/ and NSDD (non-soluble deposit density) values over 5 mg/cm/sup 2/ were measured near a steel plant. Aerodynamic type insulators showed smaller ESDD values in general compared with deep-rib type insulators. SiO/sub 2/ (quartz) and CaSO/sub 2/-1/2H/sub 2/O (bassanite) were identified as the most dominant soluble contaminants.