低压厂用电TN-S系统接地保护及开关特点解析

Analysis of the Characteristic of Grounding Protection and Breakers at TN-S Low Voltage Auxiliary Power System

低压厂用电接地方式多样,TN–S系统具有较高的安全性,同时其接地保护也有其自身特点。文章结合工程实践,针对低压厂用电TN–S接地系统常见的多电源点接地时所出现的问题,通过分析TN–S接地方式的低压厂用电系统特点,阐述其接地保护的配置原则,以及TN–S系统和TN–C系统在接地故障下的不同表现以及保护配置上的差异,提出在这种情况下包括开关、保护、接地等方面的解决措施。

Various grounding systems are adopted in low voltage auxiliary power system. TN-S grounding system is safety and has its own grounding protection characteristic. Based on the engineering practice, this paper focus on issues under multi-power grounding condition of LV auxiliary power supply TN-S grounding system. It analyzes the characteristics of TN-S grounding mode and the criteria of ground protection in TN-S system, as well as the different ground fault performance and protection configuration in TN-S and TN-C grounding systems. Several suitable solutions are proposed including breaker configuration, protection, and grounding etc.