DL / T 996 — 2019 ICS  K  中华人民共和国电力行业标准 DL / T 640 — 2019
代替 DL / T 640 — 1997 高压交流跌落式熔断器 High-voltage alternating-current drop-out fuses 2019-06-04 发布 2019-10-01 实施 国家能源局 发 布 DL / T 640 — 2019 I 目 次 前 言 .............................................................. ............................................................... .................................... Ⅲ 1 概述 .............................................................. ............................................................... ........................................ 1 1.1 范围 .............................................................. ............................................................... ............................. 1 1.2 规范性引用文件 .............................................................. ............................................................... ......... 1 2 正常和特殊使用条件 .............................................................. ............................................................... ............ 1 3 术语和定义 .............................................................. ............................................................... ............................ 1 4 额定值 .............................................................. ............................................................... .................................... 6 4.1 概述 .............................................................. ............................................................... ............................. 6 4.2 额定电压（rU） .............................................................. ............................................................... ........ 6 4.3 额定绝缘水平 .............................................................. ............................................................... ............. 6 4.4 额定频率 )(rf .............................................................. ............................................................... ............. 6 4.5 额定电流和温升 .............................................................. ............................................................... ......... 7 4.6 额定短路开断电流 .............................................................. ............................................................... ..... 7 4.7 额定开合负荷电流（适用时） .............................................................. ................................................ 7 5 设计和结构 .............................................................. ............................................................... ............................ 7 5.1 结构及组件 .............................................................. ............................................................... ................. 7 5.2 接线端子 .............................................................. ............................................................... ..................... 7 5.3 绝缘子 .............................................................. ............................................................... ......................... 7 5.4 互换性 .............................................................. ............................................................... ......................... 7 5.5 机械要求 .............................................................. ............................................................... ..................... 7 5.6 爬电距离 .............................................................. ............................................................... ..................... 8 5.7 腐蚀 .............................................................. ............................................................... ............................. 9 5.8 弧前时间 -电流特性 .............................................................. .......................................