Pete C. wrote:
Pop wrote:

James "Cubby" Culbertson wrote:
Hiya,
My sister recently had a bolt of lightning hit very
near to her house. She lost a number of electronic
appliances as a result. My initial thought is that
she may not have a good ground for her house. I'm
wondering if there is a way to test it or is it mostly
just a visual thing? As well, are whole house surge
protectors good for this type of application? I
suspect not but thought I'd ask. I'm in a high
lightning area (2nd highest number in this state, FL is
no. 1) and really don't have any trees nearby so I'm
beginning to think maybe a separate ground system just
for lightning protection might make sense. Obviously
I'd locate the ground rod as far away from the house
ground but I'm wondering if this makes sense? Cheers,
cc

A good resource is your local code enforcement office. We
learned the hard way that a lightning hit, IF it uses the
house wiring to get to earth, or vice-versa, can cause
the earth rod to lose its conductivity to earth.
Apparently it affects the earth for a radius ofa 6 or 8
feet or so because they moved our ground rod about twelve
feet over and drove a new one. We wouldn't have noticed
it except for 220V equipment that started acting up due
to the lack of a good earth ground reference between the
two 110 "phases" (US). The new rod fixed all the
problems. Our local code enforcement is the one referred
us to a good electrician who came out and figured it out
in about 5 minutes. That was after three guys from the
yellow pages who were just "electricians"; this guy was
an inspector and knew what to look for apparently. The
only thing he charged us for was the rod and some cable
to the meter. The other folks wanted to start tearing
things apart. I'm glad I resisted.

HTH
Pop

A lightning strike could well affect the soil conductivity
around the grounding electrode(s) aka ground rods, but that
will not cause problems with 220V appliances. The ground is
*not* the reference for the 110V power, the neutral is and
that comes from the distribution transformer on the pole
(or pad). The ground and neutral are bonded at the service
panel, but the ground is *not* a substitute in any way for
the neutral from the transformer.

Pete C.

Hmm, you're right, of course. I think, logically anyway. Maybe
he did more work than I realized or was aware of, but ... .

If there was no earth, it would float, and since it's tied to
Neutral in the box ... and since the transformer's ... ouch;
brain ache! The problems were apparent out in the barn, about
100 ft away from the box. House itself didn't show Neutral
problems per sae, but the air pump & water pump would show up in
the house incandescents but not wildley;
Oof! I quit!

O well!
Pop`