How does a ground-fault location system work?
When an Insulation Monitoring Device (IMD) (iso685-D-P for industrial applications and LIM2010 for medical applications) detects the occurrence of a ground-fault, it enables the fault location system. The basic idea of fault location is to generate a defined locating current (pulse) that flows to the ground-fault. The locating current is driven by the system voltage and can be located in the faulted circuit using a measuring current transformer (sensor). The location current flows from the IMD via the system conductor connections to the ground-fault position taking the shortest path. From there, it flows back to the IMD through the ground path. This locating current pulse is detected by a fixed or portable current transformer on the ground-fault path and then signaled back to the ground-fault location monitor (EDS Series).
