The scope of this Standard is to define the minimum requirements for Fault Passage Indicators (FPIs) which are devices able to detect faults, on networks from 1 kV up to 52 kV, providing indications about their localization (upstream or downstream from the FPI s location) or about the direction of fault current. The localization (upstream or downstream) or the direction of the fault current may be detected directly from the FPI and/or from a central system using information from more FPIs and/or considering the features of the feeder/network where the FPI is installed (for instance in case of overcurrents in radial operated networks without DER or in case of phase to earth faults in solid earthed radial operated systems). This Part 1: System aspects, is mainly focused on Users needs, to help them in the correct choice of FPIs correctly operating in their networks, considering adopted solutions and operation rules, and also taking into account complexity of the apparatus and consequent cost.