SPD“3+1”接线模式及间接触电防护分析

SPD "3+1" Mode and Analysis of Protection Against Indirect Contact

介绍了TT系统中SPD的"3+1"保护模式。重点分析采用"3+1"接线模式时,其N-PE放电间隙的失效短路使TT系统暂时成为局部TN系统运行,电气设备外露导电部分可能出现的危险对地故障电压。并指出,为满足间接触电防护要求、避免电击事故的发生,应尽量降低电源端系统中性点接地电阻。

The "3+1" protected mode of TT system was introduced.The situation which might occur the dangerous to-ground-fault-voltage in the exposed conductive parts of electrical equipment was analyzed,when using the "3+1" wiring mode,the "N-PE" discharge gap short-circuit failure,TT system became partial TN system operating state temporarily.It also was pointed out that,in order to meet the requirements of protection against indirect contact and avoid the electric shock accident,it should try to reduce the neutral p...