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
避雷器第4部分:交流系统用无间隙金属氧化物避雷器(IEC 60099-4-2004 修改+A1-2006+A2-2009);德文版EN 60099-4:2004+A1:2006+A2:2009