The YCA11 local-display fault indicator is widely used in electric power system, ring network cabinet, high-voltage switch cabinet and cable branch box, which can accurately and reliably detect the sections where the fault occurs in the power grid and fault types, having greatly improving the operation level and the trouble removal efficiency of distribution network. The entire machine is designed with electromagnetic induction, photoelectric conversion, signal fiber transmission, single-chip microcomputer control and other technology, which has high accuracy and strong anti-interference ability.