Which statement best describes aging mechanisms for porcelain/glass insulators compared with polymer insulators?

• A. Porcelain/Glass age primarily through UV exposure and loss of surface hydrophobicity, while polymer ages mainly by mechanical wear.
• B. Porcelain/Glass age through mechanical wear and glaze micro-damage; polymer ages due to UV exposure and loss of hydrophobicity, increasing leakage.
• C. Porcelain/Glass age due to chemical corrosion of glass; polymer ages solely due to thermal expansion.
• D. Porcelain/Glass age due to hydrophobicity loss; polymer age due to glass glazing damage.

Answer: (B)

Aging mechanisms depend on material type. Porcelain and glass insulators are inorganic and brittle, so their aging mainly comes from mechanical wear and glaze micro-damage caused by weathering, abrasion, and trafficing elements. Over time, the glaze can develop micro-cracks and roughness that trap moisture and create pathways that degrade performance. Polymer insulators, being organic coatings, age primarily from UV exposure that breaks surface chemical bonds and reduces hydrophobicity. Once the surface loses hydrophobicity, water spreads more easily on the surface during rain, increasing leakage current and the risk of surface tracking. So the description that porcelain/glass age by mechanical wear and glaze micro-damage, while polymer ages due to UV exposure and loss of hydrophobicity (leading to more leakage), fits the real behavior best.