Insulators under fire, what are we talking about?

• A line directly in the fire is considered as lost
• A line near the heat of a fire can be saved
• What is the condition of insulators on a line nearby a fire?

Reliability of insulators during or after a fire is a key consideration for T&D line design or refurbishment.
One must evaluate the risk of a line drop in the proximity of a fire as well as the possibility for a catastrophic failure afterwards resulting from a degraded insulator.

Our study on a comparison of insulators electromechanical strength after heat exposures shows

Based on “INSULATORS UNDER FIRE” – GEORGE JM / PRAT S – EDM 2019, International conference on overhead lines, Design, Construction, Inspection & Maintenance, Mar. 25-28 2019, Fort Collins, Colorado, USA / Reliability Behaviour.

For porcelain and composite insulators

During an extreme heat exposure, there will be no mechanical separation below rating for porcelain insulators but punctures induced by crack developing internally. The weakening resulting from heat exposure can become a threat for the future of the line.

Read full article in the Overhead & Underground T&D Technologies Special Edition 2022