A History of Grounding and Earthing Practices in the United States: Part 2: Continuing From the 1930s Onward

In the January 2019 issue of IEEE Industry Applications Magazine, the first part of this article discussed the 270-year history of using earth as an electrical conductor for man-made electricity. Starting with the 1930s, this second part of the article continues that discussion. For the first 140 years of man-made electricity, scientists and engineers used earth as a conductor to return the continuous flowing electric current back to the source. However, Edison realized the possible physical health hazards this practice entailed for humans and animals. For a brief quarter of a century, earth was not used as a conductor, and, in hindsight, perhaps it was the lack of knowledge of man-made electricity that enabled what seemed to be the correct action at the time but would later prove to be harmful to living things. The fascinating history of using the earth for conducting man-made electricity illuminates a bright future.