Methods, systems, and articles of manufacture consistent with the present invention provide for determining the location of a short circuit in a branched wiring system. The distance from the short circuit to an impedance measurement point is determined based on a measured impedance of the branched wiring system. The branch in which the short circuit is located is then determined by identifying a calculated high-frequency impedance phase spectrum for the branched wiring system with one of the branches short-circuited that correlates to a measured high-frequency impedance phase spectrum for the branched wiring system. The measured high-frequency impedance phase spectrum is measured from the impedance measurement point.
A method and apparatus detect arc faults. The method and apparatus may digitally detect current and voltage signals at a master node (111) positioned at a first point in a wiring system (131). At a second point in the wiring system (131), a slave node (122) may digitally detect current and voltage signals. An arc fault that develops between the first and second points in the wiring system (131) may be detected by comparing the current signals from the master node (111) and from the slave node (122), and comparing the voltage signals from the master node (111) and from the slave node (122).