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 full name of small current line selection device is small current grounding line selection device, which is short for small current. It is a kind of protection equipment used in power industry. The equipment is suitable for single-phase grounding line selection of 3kv-66kv neutral point ungrounded or neutral point grounded through resistance and arc suppression coil system. It is used in power system of substation, power plant, hydropower station and power supply system of large-scale factories and mines such as chemical industry, oil production, metallurgy, coal, railway, etc. it can indicate the line with 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 earth fault line selection, also known as small current earth protection, selects the line with earth fault and gives the indication signal. It is difficult to select the line of small current grounding fault, mainly because the fault characteristics are not obvious, and it is difficult to select the line of resonance grounding system