A system of earth fault protection in which the fault current is limited by design to a low value which generally requires amplification in order to operate an earth fault relay. In the case of three-phase alternating-current systems, the limitation of the leakage current may be effected by either (1) inserting a current-limiting device between the neutral point of the system and earth (single-point earthing), or (2) connecting, in each circuit to be protected, all phases, in star, through current-limiting devices, each star point being connected to earth through an earth leakage protective device (multipoint earthing).