Metal-Oxide Surge Arrester With External Series Gap (EGLA) IEC
Arrester designed to protect the insulator assembly from lightning caused fast front overvoltages only; this is accomplished by raising the spark over level of the external series gap to a level that isolates the arrester from power frequency overvoltages and from the worst case slow front overvoltages due to switching and fault events expected on the line to which it is applied.