A method determines a location of a single-phase-to-ground fault in an ungrounded power distribution system. The method detects the faulty phase of the distribution system having the fault and compares a difference between an angle of a voltage and an angle of a current measured at a root of a faulty feeder and boundaries of each section of the faulty feeder to determine a faulty section of a faulty feeder having the fault. A line segment of the faulty section is tested for a change of a sign of a voltage on the faulty phase in the faulty section to determine a faulty line segment. The location of the fault is determined based on a distance from a terminal bus of the faulty line segment to a location along the faulty line segment having a value the voltage on the faulty phase equals zero.