IEC 62689-1 defines the minimum requirements (therefore performances) and consequent classification and tests (with the exception of functional and communication ones) for fault passage indicators (FPIs) and distribution substation units (DSUs) (including their current and/or voltage sensors), which are, respectively, a device or a device/combination of devices and/or functions able to detect faults and provide indications about their localization.

IEC 62689-1 定义了故障通道指示器 (FPI) 和配电变电站单元 (DSU)（包括其电流和/或电压传感器）的最低要求（因此性能）以及后续分类和测试（功能和通信除外） )，它们分别是能够检测故障并提供关于其定位的指示的设备或设备/设备和/或功能的组合。