Tackling Earthing and Earth Testing in Difficult Installations

摘要

Bachelor of Science in Biology and Chemistry, Ursinus College, Collegeville, PA (USA). Twenty-five years experience with Megger, formerly under the names James G. Biddle Co., Biddle Instruments, and AVO International. Author of journal articles for numerous trade publications, including regular column on grounding and ground testing for NETA World, the publication of the Inter National Electrical Testing Association. Presenter at numerous industry functions, including this year's NETA Conference in San Antonio, TX. Good grounding and proper ground testing are so intertwined that they can readily become confused, one with the other. Good grounding is typically, though not exclusively, the establishment of an electrical connection with the soil at acceptably low impedance. This connection is commonly thought of in terms of a ground "rod", but a broad range of structures are employed to meet the challenges presented by widely differing soil conditions and site configurations. Whether simple or complex, these buried metal structures serve the same purpose, to act as electrodes in providing a low impedance path for fault current into the surrounding soil. This all seems fairly obvious, but in fact deserves further reflection.