METHOD AND DEVICE FOR MEASURING GROUNDING RESISTANCE

摘要

PROBLEM TO BE SOLVED: To easily measure grounding resistance of an individual grounding electrode without separating a grounding conductor from existing equipment or using any auxiliary electrode. SOLUTION: This grounding resistance measurement device is provided with a lead wire 2, in which one end is connected to a grounding conductor 5 connecting the existing equipment 6 to the individual grounding electrode 1 buried in the ground together, a return conductive wire 3, in which one end is opened and arranged for forming capacity coupling with the ground, and a measurement apparatus 4 measuring the grounding resistance of the individual electrode from a voltage ratio measured at a time before/after impression of an alternating current signal when the alternating current signal is impressed between the other end of the lead wire and the other end of the return conductive wire. A circuit exhibiting high impedance in the vicinity of a frequency of the alternating current signal used for measurement of the grounding resistance of the individual grounding electrode while exhibiting low impedance in the vicinity of a commercial frequency is inserted between the connection point in the grounding conductor with one end of the lead wire and the existing equipment.