First appreciate what Franklin taught us in 1752. Lightning
seeks earth ground. Franklin demonstrated how to keep
lightning from seeking earth through church steeples. He gave
lightning a better, electrically shorter path to earth. We
call them lightning rods. However the rods really are not
protection. It is just that we humans tend to associate what
we see with the solution. Those lightning rods were only as
effective as their earth ground. And that is the point.
Protection from a direct lightning strike is defined by the
most critical component of a protection 'system' - earth
ground.

Today we give lightning many more paths to earth. Antenna
and utility wires. The most common source of a direct
lightning strike to a building is AC electric. Lightning
seeks earth ground. The shortest path to earth may be on AC
wire down the block, into your house, through houshold
appliances (destructively), to earth ground.

Just a Franklin demonstrated, damage from a direct lighting
strike is avoided IF it is earthed before it can enter a
building. CATV and satellite dish wires are suppose to
provide that protection. They are suppose to connect to
central earth ground before wire enters building. This is
required by code for human safety. It just also provides
direct strike lightning protection - if earth ground is
properly installed.

AC electric and phone wires cannot connect to earth
directly. So they make a connection to earth during the surge
via a surge protector. Again, the surge must be earthed
before it enters the building which is why telcos install such
protectors, for free, at the service entrance. However the
source of most destructive surges is also the one utility that
has no earth ground connection. AC electric is the most
common source of surges. And yet effective 'whole house'
protectors can be purchased for about $1 per protected
appliance.

Again, the surge protector really is not protection. It is
just that we humans tend to associate what we see with the
solution. The protector is made effective by the surge
protection it connects to - earth ground.

All this assumes the most critical component of a surge
protection 'system' exists. That means homes must meet and
typically should exceed post 1990 NEC requirements. The NEC
required ground should also be central earth ground to which
all incoming utilities connect.

Antennas also must be earthed for surge protection AND to
meet NEC requirements. A direct ground from antenna to earth
must be installed as required by human safety specifications
of the NEC (National Electrical Code). Also the antenna wire
should have some direct and short (less than 10 foot)
connection to central earth ground where it enters a
building. Damage from direct strikes to antennas also made
redundant by the quality of that earth ground and connection
to it.

Surge protectors are simple science. They are not always
required since some incoming wires can be connected to earth
ground without surge protectors. Either way, the
effectiveness of protection is defined by that central earth
ground. This art is discussed in two thread 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 or http://tinyurl.com/ghgm

Many have posted misconceptions or irrelevant information.
For example, the surge from a direct strike is a radio
frequency transient - not some DC voltage. Connection to
central earth ground must be short (less than 10 feet),
direct, and independent because transient is RF. Details
described in that misc.rural discussion.

As you read this, that other newsgroup, and other posts,
always remember this fundamental point. A surge protector is
only as effective as its earth ground. Earthing is so
critical that any surge protector not discussing earthing is
not effective and often sold using urban myth or junk science
reasoning. Furthermore, effective surge protection has been
repeated proven effective since the 1930 meaning that surge
damage is directly traceable to human failure.


Dave or Debby wrote:
Will it blow your modem, even if the phone line is NOT connected
to it?

Will it make your answering machine act like it is on drugs?

Will it short out a caller ID box?

Will it cause an OPEN in in 1 line of a 4 conductor phone wire?

Will it losen the ground clamp from the phone wire gnd to the
electrical wire GND ?

Any thoughts from those who know?
Dave!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!