Patent attributes
A method and apparatus for determining a location of a phase-to-earth fault on a three-phase electric line of an electric network, comprising determining, when the ratio of a fault current and load current has a first value, a first fault distance line which indicates an estimate of a distance of the fault from the measuring point in relation to an equivalent load distance, determining, when the ratio of the fault current and load current has a second value which differs from the first value, at least one second fault distance line, determining a distance at which the determined fault distance lines intersect when superimposed and determining the distance between the measuring point and the point of fault on the basis of the determined distance or distances of intersection.