NF C61-744-21/A1*NF EN 61643-21/A1:2009 低压电涌保护装置 第21部分:与电信和信号传送网络连接的电涌保护装置 性能要求和试验方法
Low voltage surge protective devices - Part 21 : surge protective devices connected to telecommunications and signalling networks - Performance requirements and testing methods