Also make arrangements to have other utilities grounded to that new
earth ground or make a buried interconnection so that all other
utilities share the same earth ground (as demonstrated a utility in
http://www.cinergy.com/surge/ttip08.htm ). Code recommends that all
incoming utilities use the same earthing electrode. But we do it for
an even more important reason - surge protection.
I'm not sure what you gain with another rod at that point. If I was
adding rods I would add to the system at the electric service. The water
pipe has to be bonded - a wire connection to the grounding electrode
system for the power.
I don't remember what you said about the well. If you have an accessible
pipe that attaches to the well casing, adding that to your grounding
electrode system would be a good idea. (Or connect directly to the
casing - but I remember you are not fond of the access.)
I didn't want to get into it because I don't type very well, but since
After tracking down my water piping I found that the electrical
service is being bonded at a point where the well piping enters the
house. The pump is located under the house. The piping for the well
is some kind of rubber tubing. It looks like the house was never
properly grounded. I hope there is another grounding point somewhere,
but I don't see any signs of it.
The electrical panel has 1 number 6 leaving the panel at the top. I
can only assume it goes over a door and then into the crawlspace.
Here is a sketch of what I have found.
Because the house has a partial basement, the pit is 8 ft deep under
the house which makes it the most practical place to drive a ground
6 AWG wire to water pipe 'bonds' water pipe - to remove fault
current (electricity) from water pipes. Code requires an electrode
for earthing (even if water pipe did have buried conductive pipe).
Code also says that earthing connection (for human safety) must be
less than 20 feet. Code also wants telephone protector, cable TV coax,
etc bonded 'less than 20 feet' to that new electrode.
Better is an electrode that grounds without sharp bends, 'less than
10 feet', that is easily connected to cable and telephone service,
that uses a wire separated from all other wires, and can be
inspected. Some may drill a hole and drive that electrode through
concrete floor to exceed code requirements. How far away is that
pit? More than 20 feet? Too far - would not be code acceptable.
If the water service pipe is 10 foot or more buried metal it is
*required* to be used as an *earthing electrode*. A *supplemental*
electrode is required because water pipe may be replaced with plastic in
The size of the wire to a water pipe electrode is determined by the size
of the electrical service conductors. #6 is too small for residential
services of 200A. #6 wire must be "free from exposure to physical
damage". #4 must be "protected where exposed to physical damage". #4 is
often used instead of #6.
The NEC has no requirement for length from power system to earthing
The NEC required bonding is to anywhere on the electrode *system*.
For 1 and 2 family dwellings, the wire from phone NID to power earthing
electrode *system* can be over 20 feet, but a ground rod must be add at
the phone NID. The bond wire from phone ground rod to power electrode
system must be at least #6. If less than 20 feet the wire only has to be
20 feet is too long to provide a single point ground.
Sometimes the well casing provides earthing. A closer inspection is
required. What is that wire actually attached to and how is that
connection accomplished? Device that bonds 6 AWG wire must be
'listed' to make that connection. 6 AWG wire would connect to
interior copper pipe and to well casing. If so, both connections must
use a 'listed' connecting devices as indicated by a marking on that
I am trying to digest your message a little at a time.
This seems to assume that the surge damage was in the supply lines. I
don't think this is how I took a hit.
I believe the surge came "from" the CATV during the storm. The power
supplies in the computers are good.
The damage was the modem, router, and motherboards.
Thanks for your time
NEC says cable must be earthed. Why would a surge that seeks earth
ground ignore that cable ground to enter your house and damage
electronics - then continue on to another ground?
Every incoming utility must be connected to earth where wire enters
the building. That is code required. Water pipe is no longer
considered sufficient. Install a dedicated earthing electrode (from
the NEC list in article 250.52). Water pipe is no longer sufficient
for earthing. Post 1990 code now says any other earthing electrode
must be installed. See article 250.52(D)(2) entitled "Supplemental
Electrode Required". That electode can be located so that every
earthing connection is 'less than 10 feet', etc.
Your posts imply thinking of surges like waves on a beach.
Electicity does not work that way. Did a surge enter on cable, damage
modem, then stop? Of course not. Where is the outgoing path from
modem to earth. No outgoing path means no electricity entered on
incoming path. First current must be flowing to earth. Long later is
a modem damaged. If surge was incoming on cable, then where is the
outgoing path? No current first flowing out to ground? Then no
Damage on cable side of a modem can easily be incoming on AC mains -
outgoing via that cable. Surge passes through other things while not
damaging those others. Damage would be only at a weakest point. Why
would a surge ignore cable earthing, damage a modem, then continue out
of modem (how?) to earth ground? Earthed cable is typically an
outgoing path. AC electric is most often the incoming path to damage
cable side or phone side of modems.
How modems were so often damaged: Surge on black 'hot' wire is
shunted to green safety ground wire. Now that surge connects directly
to motherboard and modem - completely bypasses power supply. Through
modem's off hook relay (destroying off hook relay's PNP transistor)
and out to earth via 'telco installed' protector. Just another
example of AC line surge that passes through everything but only
Repaired many modems by only replacing that one transistor. Modem
worked fine for years even though other parts also conducted the
surge. Only a weakest point was damaged.
Wires highest on utility poll are most often struck; most often a
source of incoming surges. Next question - how did that surge seek
earth ground? Best destructive paths to earth will only be via some
appliances. Things you have assumed not conductive (power supply or
linoleum floor tile) are possible conductors. Again, not like waves
striking a beach. First current is flowing through sky, appliance,
and earth simultaneously. Later something in the appliance fails. To
protect, first identify all possible incoming paths - circuits that
lightning would use to obtain earth ground via appliances because that
wire was not properly earthed. Surge must be earthed before it can
enter a building.
Critical earthing requirements include a 'less than 10 foot'
connection and the electrode must be single point. Violate the
requirements and lightning may seek other destructive paths to earth.
One utility demonstrates how to create a 'single point' when all
utilities foolishly enter at mutliple locations. Single point ground
is that buried interconnecting wire;
Step back. Surge protection is not about the appliance. Protection
must be viewed in terms of the entire properly. Effective protection
'systems' (so that protection already inside the appliance is not
overwhelmed) is a complete building 'solution'.
w_ has a religious belief (immune from challenge) that surge protection
must use earthing. Thus in his view plug-in suppressors (which are not
well earthed) can not possibly work. The IEEE guide explains plug-in
suppressors work by CLAMPING the voltage on all wires (signal and power)
to the common ground at the suppressor. Plug-in suppressors do not work
primarily by earthing. The guide explains earthing occurs elsewhere.
(Read the guide starting pdf page 40).
The illustration in the IEEE guide has a surge coming in on a CATV drop.
There are 2 TVs, one is on a plug-in suppressor. The plug-in suppressor
protects TV1 connected to it.
Without the plug-in suppressor, the surge voltage at TV2 is 10,000V.
With the suppressor at TV1 the voltage at TV2 is 8,000V. It is simply a
*lie* that the plug-in suppressor at TV1 in any way contributes to the
damage at TV2.
The point of the illustration for the IEEE, and anyone who can think, is
"to protect TV2, a second multiport protector located at TV2 is required."
w_ says suppressors must only be at the service panel. In this example a
service panel suppressor would provide absolutely *NO* protection. The
problem is the wire connecting the CATV entry block to the power service
is too long (not a "single point ground"). The IEEE guide says
in that case "the only effective way of protecting the equipment is to
use a multiport protector."
Needs no protector? The IEEE guide notes that the voltage between cable
center conductor and sheath is limited by the breakdown of F-connectors
which is typically 2-4,000V. The guide notes that connected equipment
can be damaged at those voltages. Plug-in suppressors are likely to
clamp the voltage to a reasonable level.
To quote w_ "It is an old political trick. When facts cannot be
challenged technically, then attack the messenger." My only association
with surge protectors is I have some.
It seems w_ must discredit those that do not agree with his bizarre ideas.
The lie repeated.
And read the responses.
And the lie again.
And the required statement of religious belief in earthing.
The question is not earthing - everyone believes in it. The question is
whether plug-in suppressors are effective. The both the IEEE and NIST
guides says they are.
w_ has never found a link that says plug-in suppressors are NOT effective.
He just twists sources, like the IEEE guide to say the opposite of what
they actually say. Read the source.
And w_ has never explained why the only 2 examples of suppression, at
the end if the IEEE guide, use plug-in suppressors.
If there is not 10 foot underground metal water service pipe (water pipe
not used as a grounding electrode), the interior metal water pipe is
still required to be bonded by 250.104-A.
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