TN接地型式中有关问题的探讨

Discussion on Issues of TN Earthing Type

主要论述了低压配电系统接地型式的定义和概念,提出了公共电网系统接地问题,以及一些新的母排设置方法,对国际标准进行了简单介绍,希望有关部门对现行设计规范的名词术语、图示等进行统一。提出在TN系统中,应放弃使用零线、接零系统、接零保护等老的工程语言;依据规范,并没有三相五线制和单相三线制的概念和定义,这种说法将PE导体也纳入了带电导体的范畴;N线和PEN线的颜色要严格区分;将国家规范和国际标准中对接地型式的表示方法总结成两类;否定了TN—S系统中,给变压器所在建筑物以外的建筑物供电时,N线和PE线不相独立和绝缘分开的做法,并给出了正确做法。

Concept of low-voltage distribution system earthing type are presented. Earthing of public power system and new busbar setting way are put forward. International standard are also introduced. In TN system, the term of ＂ zero＂ line and connecting ＂zero＂ protection should be abandoned. According to code, there are no ＂ three term. Colour of neutral line phases five lines system and PEN line should be distinguish strictly. Expressing ways are divided into two classes in national and international code separately. In TN system, when transformer inside one building supplying to other buildings, practice way of neutral line and PE line not separated are denyed, the fight way is given.