Re: Surge / Ground / Lightning

On May 3, 4:38=A0am, Franc Zabkar <fzab...@[EMAIL PROTECTED]
> wrote:
> Can you elaborate on this by showing us the path taken by the strike
> through the TV?

  See many posts that describe this same failure to a network of
powered off computers.  Surge incoming on wires that typically carry
most surges into buildings: black (hot) AC wire.  Surge arrived two
plug-in protectors - each adjacent to powered off computers.  Often
that surge is trivial; does not overwhelm protection inside a
computer's power supply.  Maybe - but irrelevant due to the adjacent
protector.

  Protector did its job - MOVs shunted (connected, diverted) surge
current into all other AC wires including the green safety ground
wire.  Green wire connects directly to motherboard and network cards -
still seeking earth ground.

  Path to earth was through the network and into a third computer.
Through that third computer's motherboard, through modem, and to earth
via phone lines.  Semiconductors in these paths were damaged.

  We literally traced this path by replacing ICs.  Some ICs (ie
network interface chips) even had cracks on packages where surge
current entered or exiting those ICs.  Absolutely no doubt as to how
surge currents found earth ground, destructively, via adjacent
computers.

  Plug-in protector is not for and does not claim to protect from this
typically destructive type of surge.  Often surges are too trivial to
overwhelm power supply circuits.  But because that protector was too
close to powered off computers and too far from earth ground, then
surge was given an alternative and destructive path to earth ground
via networked computers.

  Plug-in protectors are for surges that typically don't cause
damage.  When the essential 'whole house' protector is not earthed,
then plug-in protectors may earth surges destructively through
adjacent appliances.  Every time?  Of course not.  But the same
ineffective protection is demonstrated in Bud's citation - 8000 volts
destructively on  Page 42 Figure 8.  That surge was permitted inside
the building.  Plug-in protector did nothing to avert 8000 volts
destructively via the adjacent TV.  Bud says otherwise by denying Page
42 Figure 8.

  Page 42 Figure 8 eliminated by properly earthing a 'whole house'
protector.  Surges that seek earth ground destructively through
household appliances must be earthed at the service entrance.

  What would have avoided above network damage?  Homeowner later
installed and earthed a 'whole house' protector.  Solution necessary
so that plug-in protectors do not earth surges, destructively, though
adjacent appliances, even on Page 42 Figure 8.  Solution necessary so
that protection from a typically destructive surge exists.