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Install Grounding when you Trench.

Nov 23rd 2019, 13:02

W3TDH

Joined: Feb 26th 2007, 14:48
Total Topics: 0
Total Posts: 0
Any trench you dig, such as for running coaxial cable antenna feed lines or conduit that will contain them, that begins at the building were your Shack is located can be an opportunity to markedly improve your Shack's Grounding System.

20+ feet of any trench can be a good location to install a Grounding Electrode Array. Dig the first 20 to 30 feet of the trench to a depth of 30 inches or more. Drive in a ground rod through the bottom of the trench at least the rod's own length away from any underground structure such as a basement wall. In order to be maximally effective the rod needs to have a shell of earth around it that has a radius of the length of the rod. Drive the second rod the combined length of both rods further out along the trench. Join the 2 rods to each other and the termination point using #2 American Wire Gage (AWG) or larger bare copper wire as the Grounding Electrode Conductor (GEC). Connect the GEC to the driven rods using testing laboratory listed Ground Rod Clamps.

For even greater effectiveness use 2 inch wide or wider copper strap as the GEC. That can be made from a roll of copper roof flashing cut to the desired width. The pieces can be joined using pieces of copper plate held together over the joint and connected through the strap to each other using stainless steel hardware. Connect the copper strapping to the rods using copper plates which you have formed around the rod by clamping both in a vice. Such splicing and rod connection kits can also be purchased from amateur radio equipment dealers.

Remove any copper oxide from any surface that will be part of a connection between the parts of the Grounding Electrode System (GES) and cover the joining surfaces with copper antioxidant paste. This can be done with "Emery Cloth" abrasive tape or with a wire brush.

To avoid your new Grounding Electrode System becoming a problem instead of a solution make sure that it is bonded to the existing electrical service Grounding Electrode System. By bonding the 2 systems together you avoid any marked difference in potential between them and thus avoid any destructive current flow between the 2 separate systems through your radio equipment and accessories. Missing this step could leave you hating me and life in general. Since, like most people I'd rather be liked than hated I ask that you not skip this important step.

If you have to dig a trench anyway why miss the opportunity that the excavation offers to install a highly effective Grounding Electrode Array for your Shack.

--
Tom Horne W3TDH

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