Surge arresters - Part 8: Metal-oxide surge arresters with external series gap (EGLA) for overhead transmission and distribution lines of a.c. systems above 1 kV

IEC 60099-8:2011 covers metal-oxide surge arresters with external series gap (externally gapped line arresters (EGLA) that are applied on overhead transmission and distribution lines, only to protect insulator assemblies from lightning-caused flashovers. This standard defines surge arresters to protect the insulator assembly from lightning-caused overvoltages only. Designs with the EGLA's external series gap installed in parallel to an insulator are not covered by this standard.