Here is a building grounding system consisting of qty 20 – 3/4″ ground rods each 10 feet long bonded together with a woven 14/28 copper cable using a Cad weld mold and electric igniter. The 14/28 cable goes from ground rod to ground rod around the entire building foundation perimeter. Enough of each rod is left protruding to fit the Cad weld mold on top of a brick for stability on the loose wet soil. In the video you can see that just below the proper weld is an older faulty weld that never bonded properly. The wrong size mold was used originally. The original mold was too large for the 14/28 cable, it was for 4/0 stranded copper. It ended up letting in too much oxygen. When the welding reaction started the cable heated up too much and completely melted. To ensure acceptable resistance the proper size mold was used to weld the rod to a 5 foot length of 14/28 to be used as a jumper to the existing perimeter cable using the proper size copper clamps rated for this application.
Executive Committee, meeting 7, July 4, 2019 – Part 2 of 2
Agenda and background materials:
https://app.toronto.ca/tmmis/decisionBodyProfile.do?function=doPrepare&meetingId=15470
Part 1: https://www.youtube.com/watch?v=0jePuISoHP0
Meeting Navigation:
0:07:02 – Meeting resume