A method for detecting earth faults in three-phase electric power distribution networks comprising a coil connected to a neutral point of a power transformer, including continuously measuring at least currents in feeders (16A, 16B, 16C) of all phases and a voltage appearing at the neutral point, and initiating fault detection if any measured quantities exceed a predefined threshold value, characterised by the steps: if transient current exceeds fundamental frequency current, use the steps: a) estimating capacitance and conductance of each feeder, b) estimating capacitance and conductance of the neutral point, c) determining a feeder as faulty, either when the capacitance of the feeder is lower than the capacitance of the neutral point device, or when the conductance of the feeder is lower than the conductance of the neutral point device and lower than the conductance of all other feeders; if transient current does not exceed fundamental frequency current, use the steps: d) determining active power of each feeder e) determining a feeder as faulty when the active power of said feeder exceeds a predefined value, f) determining the magnitude of the neutral point voltage phasor, g) determining a derivative of said magnitude, h) using active power to determine a fault direction of each feeder, if said magnitude exceeds a preset threshold and if said derivative is positive and i) producing a resulting report signal. if transient current exceeds fundamental frequency current, use the steps: a) estimating capacitance and conductance of each feeder, b) estimating capacitance and conductance of the neutral point, c) determining a feeder as faulty, either when the capacitance of the feeder is lower than the capacitance of the neutral point device, or when the conductance of the feeder is lower than the conductance of the neutral point device and lower than the conductance of all other feeders; a) estimating capacitance and conductance of each feeder, b) estimating capacitance and conductance of the neutral point, c) determining a feeder as faulty, either when the capacitance of the feeder is lower than the capacitance of the neutral point device, or when the conductance of the feeder is lower than the conductance of the neutral point device and lower than the conductance of all other feeders; if transient current does not exceed fundamental frequency current, use the steps: d) determining active power of each feeder e) determining a feeder as faulty when the active power of said feeder exceeds a predefined value, f) determining the magnitude of the neutral point voltage phasor, g) determining a derivative of said magnitude, h) using active power to determine a fault direction of each feeder, if said magnitude exceeds a preset threshold and if said derivative is positive and i) producing a resulting report signal. d) determining active power of each feeder e) determining a feeder as faulty when the active power of said feeder exceeds a predefined value, f) determining the magnitude of the neutral point voltage phasor, g) determining a derivative of said magnitude, h) using active power to determine a fault direction of each feeder, if said magnitude exceeds a preset threshold and if said derivative is positive and i) producing a resulting report signal.