小电流选线全称小电流接地选线装置，简称小电流。是一种电力行业使用的保护设备。该设备适用于3KV－66KV中性点不接地或中性点经电阻、消弧线圈接地系统的单相接地选线，用于电力系统的变电站、发电厂、水电站及化工、采油、冶金、煤炭、铁路等大型厂矿企业的供电系统，能够指示出发生单相接地故障的线路。
The small current selection line is called the small current grounding line selection device, which is called small current. It is a kind of protection equipment used in the electric power industry. The equipment is suitable for the single phase grounding line selection of 3KV 66KV neutral point ungrounded or neutral point through resistance and arc suppression coil grounding system. It can be used in power system substation, power plant, hydropower station and power supply system of large factories and mines, such as chemical industry, oil production, metallurgy, coal, railway and other large factories and mines, and can indicate the line that occurs single-phase grounding fault.
小电流接地故障选线，又称小电流接地保护，选出带有接地故障的线路，给出指示信号。 小电流接地故障选线难，主要难在故障特征不显著，谐振接地系统选线难
Small current grounding fault line selection, also known as small current grounding protection, selects the line with ground fault and gives the indication signal. Small current grounding fault is difficult to select, and the main reason is that the fault feature is not significant.