Ground fault detection and interruption is required by the NEC as a safety precaution. The OutBack PV Ground-Fault Detection and Interruption System protects wiring and system components for one, two or four PV arrays when used in a GSLC, FLEXware 250, FLEXware 500 or FLEXware 1000. Front panel mount with stud terminals on the back. Ring Terminals.