Manual Wiring Measurement of DC Deep Well Grounding Resistance

Abstract

DC deep well grounding electrode has high engineering value due to its small footprint and easy site selection. Because a single deep well grounding electrode’s maximum diagonal distance is less than one meter, it is obviously not appropriate to measure the grounding resistance directly by using the manual recommended 5 times diagonal distance from the manual wiring [1]. Therefore, we built a DC deep well grounding electrode model and calculated its grounding resistance. Moreover, studied the law of the surface potential distribution under the action of current field created by current electrode, combining the calculated grounding resistance value, we analyzed the layout requirements for voltage electrode. By changing the position of current and voltage electrode, we studied the relationship between measurement error and wiring distance, and put forward a scheme of current and voltage electrode layout for the measurement of the grounding resistance. The scheme of the research was used to measure the grounding resistance of the deep well grounding electrode, which verified it’s validity and accuracy. Finally, we analyzed the similarities and differences of resistance measurement between deep well grounding electrode and horizontal and vertical grounding, which provides a reference for the measurement of deep grounding resistance and related standards revision.