A previous discussion between engineers about earthing was
in two discussions in the newsgroup misc.rural entitled:
Storm and Lightning damage in the country 28 Jul 2002
Lightning Nightmares!! 10 Aug 2002
http://tinyurl.com/ghgv and
http://tinyurl.com/ghgm
If your building does not, at minimum, meet post 1990
National Electrical Code (NEC) requirements, then sufficient
earthing may exist. Connection to cold water pipe is no
longer sufficient to earth for human safety reasons. Earthing
for transistor safety typically exceeds what the NEC requires.
Distance to that earth ground is critical. Plug-in 'shunt
mode' protectors are too far from earth ground; not
sufficiently earthed to provide secondary protection.
Therefore those ineffective (and so grossly undersized)
protectors avoid all discussion about earthing.
Earthing a building is for secondary protection. Also
inspect earthing for your primary protection:
http://www.tvtower.com/fpl.html
Ham radio operators would disconnect the antenna, place the
antenna lead inside a mason jar, and still suffer damage.
Disconnecting alone was not sufficient protection. Damage
stopped when the antenna lead was earthed. Do as Ben
Franklin demonstrated in 1752. Give the surge a
non-destructive path to earth. Lightning rods and 'whole
house' protector; both do same. Earth before lightning can
enter a building.
finalquest wrote:
w_tom - I do believe you make a very valid and important point. After
reading up on it a bit, one point grounding is one of the most
important things that need to be checked. As you mentioned the
cheaper surge protectors need that good ground to work properly. I'm
still researching this and have to agree at this point, the best
protection is to disconnect everything but there are times that's not
practical. Once again, THANKS to everybody that's helping out.