GROUND FAULT DETECTION DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a ground fault detection device capable of determining the presence of a ground fault in a DC circuit as well as a ground fault location in the DC circuit using an AC voltage application method.SOLUTION: A ground fault detection device 4 detects a ground fault of a solar cell string 2 in an ungrounded state. The ground fault detection device 4 includes: a ground wire 21 for connecting a predetermined point A in the solar cell string 2 to the ground GND; an AC voltage source 22 connected to the ground wire 21; an ammeter 23 for detecting AC and DC current components on the ground wire 21; and an arithmetic unit 24 to which a detection result from the ammeter 23 is inputted. The arithmetic unit 24 determines the presence of a ground fault on the basis of the AC current component, and determines a ground fault location in the DC circuit on the basis of the DC current component.