On 4/12/2012 11:26 AM, Drax Felton wrote:
> How come few houses of modern construction have lightning rods if they were
> such an important invention?
Virtually all industrial installations have them on all buildings and
Where I worked *all* the buildings (except single story offices)
including new construction had them. There's over a Billion (Yes that's
with a "B")dollars of facility recently finished that has them.
When I put my 45G up about 10 years ago, nearly all
tutorials/instructions on grounding, including grounding kits suggested
that the ground cable be gently curved (dressed) away from the base of
the tower and said to avoid any sharp bends. I think they recommended a
minimum bend radius of 6 to 8 inches. I don't see that listed any more.
However, even a tiny increase in inductance should be avoided. I've
seen lightning get off a grounded tower part way down. I've seen it
jump to the guy wire and then get off after only 20 or 30 feet.
The high amperage builds a tremendous magnetic field with an opposing
EMF. Combined with the rapid rise time it quenches the current flow and
the lightning seeks an easier path, not necessarily physically shorter.
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