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Old November 15th 06, 10:07 PM posted to microsoft.public.windowsxp.basics
w_tom
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Posts: 373
Default Earthgrounding

Pappion wrote:
Is the answer then to literally unplug the surge suppressor from the wall
outlet???


A plug-in protector can be a kludge solution. First, building
earthing should be upgraded to post-1990 code which means an earthing
electrode is connected typically 'less than 10 foot' to AC breaker box.
Second, cut power cord short and connect it to AC receptacle on
breaker box. Now that AC phase has a short connection to earth - can
provide some protection.

Again, this is a kludge solution. One reason is because the power
strip protector is typically so undersized (and yet costs so much
money). Minimally sized protectors earth a nearby and direct strike -
and remain functional. That is but another reason why a 'whole house'
protector from Siemens, Cutler-Hammer, Leviton, Intermatic, GE, etc are
so effective.

Bud promotes plug-in protector manufacturers. Therefore he will avoid
some facts. His 'recommendation' is really a technical discussion
of how different protectors can and fail to protect. Recommendations,
instead, are found in standards. Bud will not challenge that blunt
IEEE statement from the Red Book:
In actual practice, lightning protection is achieve by the
process of interception of lightning produced surges,
diverting them to ground, and by altering their
associated wave shapes.


To convert a plug-in protector to something useful, plug it into a
wall receptacle that makes a short connection to earth - as IEEE says
is necessary for protection. IOW cut that six foot power strip cord
short so that entire connection from power strip to earth ground is
'less than 10 feet'. A shorter connection to earth means even better
protection.

Earthing is the protection. Therefore each protected and incoming
utility wire makes a 'less than 10 foot' connection to same earth
ground. Defined above is 'secondary' protection.

Also confirm integrity of your 'primary' surge protection:
http://www.tvtower.com/fpl.html

Finally, as a ham, then appreciate this figure from industry
professionals:
http://www.erico.com/public/library/...es/tncr002.pdf
Two structures (antenna and building): each has a single point earth
ground. To make both earthings more effective, a ground wire
interconnects both earthing electrodes. Yes, even the underground
phone wire is earthed where it enters a building - as the figure
indicates. Every incoming wire on every cable must connect to a common
earthing electrode - either directly or via a 'whole house' protector.

Effective protection is a building wide solution. Each protection
'layer' is defined by a common earthing electrode. Earthing should be
upgraded to meet and exceed post-1990 National Electrical Code
requirements because earthing provides appliance protection from direct
lightning strikes.

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