On 4/7/2011 10:13 PM, Bill wrote:

wrote in message
...
On Thu, 7 Apr 2011 16:50:58 -0700 (PDT), andyeverett
wrote:

I was at a home today which a while back had a lightning strike the
chimney and explode the top of the chimney off. On the drive home I
got to thinking, I have two metal chimney liners, one for a first
floor wood-stove and another for the furnace and only the furnace
liner is indirectly grounded, I guess, via the furnace ground. If TV
antennas need to be grounded should chimney liners be grounded as
well?

Thank you for your thoughts!

I would put a lightning rod on top of the chimney and run a wire down
to a rod below.

Yes install a proper lightning rod, proper size ground wire run outside
the building, and to proper ground rod(s). (Or don't do anything at all.)


I agree that if you want protection add a lightning rod. The earthing
system for a ground rod has to be tied to the earthing system of the
electrical system. For most of us the probability of being hit is quite low.

Ordinary antennas are not earthed to protect from lightning strikes -
the earthing system is not heavy enough. Hams may expect their much more
extensive antennas to be struck by lightning, which requires a more
extensive earthing system.

Earthing an antenna (or flue) will not attract lightning. As haller
wrote a lightning rod is just a safe point for lightning to strike.

--
bud--