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).