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 60099-8:2017); German version EN IEC 60099-8:2018
Surge arresters - Part 4: Metal-oxide surge arresters without gaps for a.c. systems (IEC 60099-4:2004, modified + A1:2006 + A2:2009); German version EN 60099-4:2004 + A1:2006 + A2:2009