What does "flashover" refer to in the context of insulators?

Flashover refers to a voltage discharge that occurs across an insulator as a result of the breakdown of air. This phenomenon typically happens when the voltage applied to the insulator exceeds its dielectric strength, causing the surrounding air to ionize and allowing electric current to arc across the insulator. This can lead to a rapid and uncontrollable transfer of electrical energy, which can damage the system and compromise the integrity of the insulator.

In practical terms, flashover can occur during conditions of high humidity, pollution, or when the insulator becomes contaminated, leading to an increase in conductive paths through the air. Understanding this concept is crucial for designing effective insulators that can withstand various environmental conditions and maintain performance without allowing flashover to occur.