How does icing affect insulator performance?

• A. Can create conductive paths, heightening flashover risk; de-icing may be required.
• B. Ice reduces surface conductivity and lowers flashover risk.
• C. Ice has no effect on conductivity.
• D. Ice only affects color of insulator.

Answer: (C)

Icing changes the surface conditions that govern leakage across an insulator. The ice layer itself isn’t a strong conductor, but it often interacts with a thin film of liquid water and any impurities on the surface. That combination can create conductive paths along the insulator, allowing leakage current to flow more easily and reducing the insulation’s ability to withstand high voltages. As a result, the potential for flashover increases in icing conditions, making de-icing or preventive measures necessary to maintain safe operation. The idea that ice has no effect or that it only changes color isn’t consistent with how leakage paths form on moist, contaminated surfaces.