w_tom wrote:

(a lot)

But, Dubya Tom, I think you're missing the most important point: Earth
ground. Earth ground is what's really, really, really, really, really
important. Earth ground. It's important. The most important thing is
earth ground. And humans. And earth ground.

Yes, an improperly installed lightning rod can cause damage
... because the human has failed to install or maintain the
most critical component in a lightning protection system:
earth ground. So what is Michael's point? Whether it be
lightning rod or radio station or telephone central office
switching station. They all suffer direct lightning strikes
and must not suffer damage. Protection is defined by quality
of and connection to earth ground which is why properly
earthed facilities need not suffer damage.

Bulldozers rip out a ground system for a radio station.
That proves that lightning damage cannot be avoided? That
demonstrates why lightning damage is due to human failure.
Yes grounding systems can also deteriorate with age. If a
human does not maintain it, then lightning damage can occur.
Human failure. Protection is only as good as its earth
ground. So what is your point? That one should quit because
lightning damage is unavoidable?

I was building surge protectors decades ago. Some
unfortunate failures. Some spectacular successes. One never
resolved mystery. One fact was consistently demonstrated and
repeated by industry professionals even in IEEE papers.
Protection is only as effective as its earth ground. By your
own examples, inferior earth grounds can result in damage.
Improper connections of a lightning rod to its earth ground
caused failure. So what? Inferior earth grounds are examples
of human failure. Earthing defines protection from lightning.

Michael Terrell demonstrates that damage occurs when the
human does not install or maintain sufficient earthing.
However since protection might not be large enough for the
rare 200K amp lightning strike, then we should never bother
with any protection? What kind of reasoning is that?

Most all lightning strikes do so little damage as to not
even leave indications on trees. Even 12 AWG wire (20 amp
wire inside walls) is more than sufficient to earth most
direct lightning strikes. But we install even heavier wire
and earthing grounds to lightning rods so that even larger
direct strikes cause no damage. In many locations, human do
not install protection for the 200,000 amp strike because such
strikes just don't happen. Where it does happen, the earthing
system is enhanced. Even in Central FL, professionals have
installed earthing systems to make damage irrelevant. Humans
also fix the earthing systems when bulldozers rip it out
because proper earthing is that essential to protection.

For locations with no protection, even a single 8 foot earth
ground rod is a massive improvement. Again repeating the
point. Protection is only as good as the earth ground.
Damage from lightning is directly traceable to human failure.
In locations where a human will never see a 200K lightning
strike in his lifetime (which is most places), then even a
simple eight foot earth ground rod is sufficient. But should
earthing need be marginally improved, then size and cost of
that earthing system increases quickly.

Others fixed their earthing systems and stopped suffering
damage in Central FL. That is the point. Eliminating damage
starts with and is defined by the quality of earth ground and
connections to it. Even 25 strike per year to TV and FM
stations on the Empire State Building need not cause damage -
which is where much of the original research was conducted.
Michael Terrell says that is wrong because humans will not
maintain their earthing systems? Quitters logic.

Michael promotes a quitters attitude. Yes, a lightning
protection system may fail to earth an extremely rare 200,000
amp strike. Yes, most locations don't protect from the 200K
lightning strike because such lightning never occurs. So
what? Therefore he advocate no protection? Why advocate a
quitters attitude? Protection is defined by earth ground.
Properly installed earthing systems can even earth 200K
lightning strikes. But a damaged earth ground system means
damage can occur. Damage avoided if the earthing system been
repaired and was sufficient.

Other radio stations in central FL addressed earthing
problems and don't experience repeated failures. Central FL
requires even better earthing systems. Maybe they also
maintain their earthing systems? How can that be? Well some
humans accept failure as situation normal. Others fix problems
before failure occurs. Some may even insult to prove their
point. But those other radio stations fixed their problems
rather than just repeatedly replace the phone system. They
did not take on a quitter's attitude. They addressed the
solution starting with a most critical system component -
earth ground. One that was sufficient for Central FL.