Thoughts on Grounding

Ground the main strike at the tower base.  Worry about protecting your equipment (and people) from what’s left over.

My tower and my equipment shack are 100 feet apart.  Bonding the two would be fruitless because of the inductance of the bonding conductor.   So don’t bond when the two are that far apart.  Ground the tower.   Ground the shed.  Worry the most about protecting the equipment in the shed.

Accomplish the first part by putting a ufer ground* in the concrete base and spacing ground rods around the tower, all bonded in a wagon wheel ring.  That should divert just about any lightning strike.  Do not bond to the equipment shed when it’s 100 feet away.

At the shed install spaced ground rods and bond them in a wagon wheel ring.  Install protection on all cables at their entry point, coax, Internet, power, rotator, etc. and bond together.

 

 

*The Ufer Ground is an electrical earth grounding method developed during World War II. It uses a concrete-encased electrode to improve grounding in dry areas. The technique is used in construction of concrete foundations.   –Wikipedia

More…

The principle of the Ufer ground is simple, it is very effective and inexpensive to install during new construction. The Ufer ground takes good advantage of concrete’s properties. Concrete absorbs moisture quickly and loses moisture very slowly. The mineral properties of concrete (lime and others) and their inherent pH means concrete has a supply of ions and free electrons to conduct current. The soil around concrete becomes “doped” by the concrete, as a result, the pH of the soil rises and reduces what would normally be 1000 ohm soil conditions (hard to get a good ground). The moisture present, (concrete gives up moisture very slowly), in combination with the “doped” soil, make a good conductor for electrical energy or lightning currents.   —psihq.com

Cable entrance cabinet with single point ground plate and protectors.  All cables pass through this box before entering the shed in an attempt to stop all strike current from going inside.  The copper plate is bonded to a ground rod and eventually a ground ring around the shed with spaced ground rods.

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June 28, 2017: John picked up 100 feet of No. 2 Solid Copper today to serve as the ground ring.  Yay.

 

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