Re: Soon to arrive my HDTV

On Apr 4, 10:18 pm, Cinderl...@[EMAIL PROTECTED]
 (Cinder Lane) wrote:
> W_tom, you have stated many times in this thread that wall receptacles
> do not have earth grounds.  What about wall receptacles in concrete and
> steel buildings?  Aren't they in direct contact with earth ground?
>
> Also, for the sake of arguement, let's assume that you are correct --
> that because of high inductance, wall outlets do not have a "true" earth
> ground according to the IEEE definition.  Are you saying that ALL
> plug-in surge suppressors offer NO protection whatsoever?

   One technique to 'layer' protection is to integrate concrete into
protection.  Connect everything inside a 'chamber' or ring so that all
conductors - AC electric, communication lines, air ducts, water pipes
- create a unified conductive room or structure.  Same principle used
to construct a 'nuclear hardened' Norwegian maritime communication
facility.  But the facility still suffered lightning damage.  van der
Laan and van Deursen in an IEEE paper discuss how station damage was
eliminated.  All conductors were integrated, moved or unified to a
single point ground.

  Whereas concrete is conductive, also im****tant is high current
conductors be even more conductive - less impedance.   As noted in
their 4 Nov 1998 IEEE paper:
> A highly reliable lightning protection can be obtained by
> providing a path for lighting or lightning-induced current
> around the circuit to be protected.  The shape of the
> conductors used in of particular im****tance; the choice
> is based on the required low transfer impedance Zt.

  Walls integrated into the system using better conductors (not just
concrete).  All tubes and ****elds grounded at both ends.  Two ground
rings were installed around both the tower and building so that tubes,
walls, and conductors had an even better earth grounds.

  Protection involves two fundamental concepts - conductivity and
equipotential.  Conductivity into earth was improved by better
connecting (lower impedance) all conductive materials to an also more
conductive earthing electrode.  But we can never make conductivity
sufficient.  So each structure is encircle with a halo ground (buried
ground ring) and connect all incoming conductors to a same point
causing any surge  voltage to remain more constant inside that
facility - equipotential.  However we can never create sufficient
equipotential.  So we make that connection to earth more conductive.
An Ufer or halo ground also makes the earthing electrode more
conductive.   No plug-in protector even discussed. The paper is about
surge protection.   As so many IEEE papers makes obvious, earthing
defines protection.

  Yes, integrating an entire concrete wall, floor, etc into the
protection system means better protection; which is what all telcos do
to slightly improve protection.  If only one wire or pipe enters that
facility without a most conductive connection (via hardwire or via
surge protector) to the single point, then a protection system is
compromised.

  We accomplish same in residential buildings by making earth part of
a conductive single point ground.  Or better make earth more
equipotential.  Pictures demonstrate how better Florida homes utilize
Ufer grounds in poor conductive soil:
    http://members.aol.com/gfretwell/ufer.jpg

  If grounding carries higher currents, then rebar inside concrete
must be electrically interconnected.  Since earthing determines surge
protection, then rebar inside footings is electrically connected to
rebar in the foundation, and interconnected to rebar inside concrete
floor.   Often interconnected using cadwelding for lower impedance.
Performed so that massive earthing means a decreasing better
protection.


  Plug-in protectors protect from one type of surge.  A surge often
made irrelevant by protection already inside all appliances.  Another
type of surge that overwhelms protection inside appliances, instead,
seeks earth ground.  This type can be created even by utility
switching.  But the most common and typically most destructive source
- lightning.  Lightning striking down the street can be a direct
strike to household appliances.  Protection is installed to make
lightning surges irrelevant; therefore makes other (less common)
surges also irrelevant.  That same 'whole house' protector also
provides protection from that first type surge.  In short, one 'whole
house' protector makes plug-in protectors (for only one type of surge)
irrelevant especially when plug-in protectors cost tens of times more
money per protected appliance.

  One 'whole house' protector properly earthed is for all types of
surges.  If a plug-in protector spec defined protection, then obvious
is 'no protection' from a typically destructive surge.  So plug-in
protectors don't claim any protection.  Worse, being too close to
appliances, that same plug-in protector can provide the typically
destructive surge with more destructive paths to earth via
appliances.  We saw same when two plug-in protectors earthed surges
through an entire network of powered off computers.

   Better is to direct money on a larger 'whole house' protector
(better conductivity, conducts even larger surges, and longer life
expectancy) and use that money to upgrade earthing (better
conductivity and equipotential).

  Earthing must meet and exceed post 1990 NEC earthing requirements.
A house built before 1990 probably needs significant earthing
improvements. Older homes are sometimes missing any earth ground.
Homes built after 1990 may need that earthing upgraded so that, for
example, ground wire from breaker box to earth is shorter, separated
from other wires, no sharp bends, etc.   All incoming utilities must
make that short (ie 'less than 10 foot') connection to the same earth
electrode.  One utility discusses this in:
    http://www.cinergy.com/surge/ttip08.htm

  Above is called secondary protection.  Inspection of the primary
protection system is also recommended:
   http://www.tvtower.com/fpl.html

  No earth ground means no effective protection.  Even a 'whole house'
protector is ineffective without earthing.  Many confuse a 'box' with
protection.  That 'box' is only a connecting device.  Cable TV needs
no 'box'.  Cable TV uses 12 AWG wire and a $2 ground block (visit any
hardware store to view it) connected directly to earth ground.  No
'box' required for protection.  Conductivity and equipotential (ie
single point earth ground) provides protection.  Too many view
protection in terms of that 'box' rather than in what provides
protection - earth ground.


  Typical lightning strikes are 20,000 amps.  Strikes of 60,000 amps
means a surge incoming on a residence might be as high as 20,000
amps.  Most will probably never see a 100,000 amp strike in their
lifetime.  A minimally sized 'whole house' protector is for 50,000
amps.  Those numbers define a protector's life expectancy.  A larger
'whole house' protector means even more surge can seek earth ground
via the protector.  These numbers mostly define a protector's life
expectancy.  More im****tant - an earthing electrode makes that current
irrelevant by providing even better conductivity and equipotential.
Both functions are what makes Bud's posts irrelevant.  Those functions
also state why "a protector is only as effective as its earth
ground",  why "no earth ground means no effective protection", and why
"connection to earth ground must be low impedance - ie 'less than 10
feet' ".  Principles that must be ignored to recommend a plug-in
protector.