低压封闭式开关设备和控制设备 第1部分：符合IEC 60947-3的封闭式隔离开关的附加要求 在特定应用的维修和维护工作中电气设备的隔离

Low-voltage switchgear and controlgear enclosed equipment—Part 1: Additional requirements for enclosed switch-disconnectors in accordance with IEC 60947-3—Isolation of electrical equipment during repair and maintenance work in specific applications