建筑物电气接地系统问题研究

Investigation of the problems on electrical earthing system of construction

结合相关标准、规范,对实际建筑物电气接地系统中采用的接地类型、接地故障保护措施、接地装置的选用及等电位连接作法等几个问题进行了深入的分析与研究。得出了以下结论:室外低压电源供电时,建筑物低压配电系统接地类型应采用TT系统;当建筑物室内设有10/0.4KV配电变压器作供电电源时,接地类型应全部采用TN-S系统;为了克服建筑物内各电气装置之间的电位差,在电源进线处作总等电位连接,在电器设备故障时可能发生人员触电危险处作局部等电位连接。

According to the relative standards, the author analyzes and studies several problems on electrical earthing system of construction, i.e., selection of the earthing type, protected measures of earthing troubles, selection of earthing instructions. The earthing type of low voltage distribution system should use TT system when low voltage sources is used outdoor, while the TN-S system should be adopted when 10/0.4KV distribution transformer is used as power supply, this paper discusses electrocution protected instructions to be used earthing trouble protection and how to determine its current setting values, different types of earthing should select different earthing instructions, in order to overcome the difference of electric potential, equal electric potential connection should be done at entrance of power supply and somewhere, that is to say, workers are very easy to be injured when some electrical apparatus are out of control.