Anti-Pollution Performance of Bell-Type Glass Insulators in Coastal Areas

In coastal and heavy-industry zones, salt and pollutant deposition on insulator surfaces causes leakage current, corrosion and eventually flashover. Bell-type (fog-resistant) glass insulators are engineered specifically for these conditions.

How the bell shed helps

The downward-facing bell apron keeps a protected dry band on the underside, increasing the protected creepage distance and breaking up the pollution layer.

Specification tips

• Use a specific creepage distance of 31–53 mm/kV per the site pollution class (IEC/TS 60815)
• Prioritize toughened glass for self-shattering fault visibility — crews spot failed discs from the ground
• Combine with regular hot-line washing schedules in the harshest zones

For most Class IV–V pollution sites, a 100 kN bell-type string delivers the best balance of cost and reliability.