2013-11-14 CADWELD in grounding systems by Ken Moak (KM8AM)
Ken Moak (KM8AM) will present…
How to use CADWELD® in grounding systems.
Following Ken’s presentation the TNG will be mounting power strips to the work benches.
We will also be collecting funds from those interested in completing the Tape Measure Yagi project complete with offset attenuator (used for foxhunting / search and rescue) so we can order the parts necessary. Please come prepared to submit funds if you wish to participate with the group build.
Cost should be ~ $35. - $40.
How to use CADWELD® in grounding systems by Ken Moak (KM8AM)
Ken Moak (KM8AM) presented a well organized briefing on the use CADWELD® in grounding systems in amateur radio. A description of his antenna farm was included as well as the plan for an extensive grounding network for lightning protection. Some of the most critical steps in construction of a good grounding system are the connections of the tower and arrestor panel to the ground rods and the connections of ground rods to other ground rods in the grounding network. Ken presented numerous photographs while detailing the step by step procedure for generating a high quality bonded connections within the grounding system. Some of the pitfalls were described as well as the work-arounds and are highlighted in the Summary and Hints section below.
Summary and Hints:
Cadweld comes in one or multi-conductor versions. For ham applications, the one time use versions (One-Shot) are cost effective.
Cadweld provides a low impedance connection for slightly higher price than a good ground clamp.
Thoroughly clean, degrease and dry the ground wires and ground rod.
Buy a few extra molds in case there are problems.
O-rings can be a problem. Use a second seal below the factory seal and secure with a hose clamp.
Clean top of rod with file.
Push wires in all the way.
Wires go on top of rod.
$30 hammer drill from Harbor Freight is a good tool to drive ground rods into soil
Prepare a ground rod installation bit for hammer drill. Cut off point of hammer drill bit. Slip hard black plastic tubing over drill bit to act as a guide for ground rod.
Reference Materials:
"Practical Guide to Electrical Grounding" Reference Book:
http://www.erico.com/public/library/fep/LT0019.PDF
One Shot Connections to Ground Brochure:
http://www.erico.com/public/library/fep/LT1229.pdf
Catalog with drawings and part numbers for various connections:
http://www.erico.com/public/library/fep/LT0355_02.pdf
Instructions:
http://www.erico.com/public/library/fep/LT30323.pdf
Inspection Guide: