I can't find a good solid ruling for this one.

Are phone lines grounded locally at the house?

The configuration at my house has the main phone line coming off the pole,
down to a junction box, where 2 phone lines leave and a single ground wire
connects to the cold water plumbing.

I can't find any definite answers as to whether or not that ground wire is
required, desired, or useless. The intent is on replacing the whole setup
with CAT 5E (seeing how it's just as cheap as CAT 3 or phone cable) and
re-routing the wires, but I don't know if I need to keep the ground wire.
It looks like pretty standard 14 gauge wire, in a grey sheath.

Eigenvector wrote:

I can't find a good solid ruling for this one.

Are phone lines grounded locally at the house?

The configuration at my house has the main phone line coming off the pole,
down to a junction box, where 2 phone lines leave and a single ground wire
connects to the cold water plumbing.

I can't find any definite answers as to whether or not that ground wire is
required, desired, or useless. The intent is on replacing the whole setup
with CAT 5E (seeing how it's just as cheap as CAT 3 or phone cable) and
re-routing the wires, but I don't know if I need to keep the ground wire.
It looks like pretty standard 14 gauge wire, in a grey sheath.


I think that ground is the phone company's. They might have something
to say about you removing it.

--
The e-mail address in our reply-to line is reversed in an attempt to
minimize spam. Our true address is of the form .

"CJT" wrote in message
...
Eigenvector wrote:

I can't find a good solid ruling for this one.

Are phone lines grounded locally at the house?

The configuration at my house has the main phone line coming off the
pole, down to a junction box, where 2 phone lines leave and a single
ground wire connects to the cold water plumbing.

I can't find any definite answers as to whether or not that ground wire
is required, desired, or useless. The intent is on replacing the whole
setup with CAT 5E (seeing how it's just as cheap as CAT 3 or phone cable)
and re-routing the wires, but I don't know if I need to keep the ground
wire. It looks like pretty standard 14 gauge wire, in a grey sheath.
I think that ground is the phone company's. They might have something
to say about you removing it.

Alright, I'd better call them then.

The whole thing started while I was sheetrocking and insulating the
basement. The previous owner/and or phone company rather than drilling
holes into the studs, took a chisel and cut a "V" notch on the surface of
the stud so that the sheetrock would lay flat. So I'm looking at their
handywork and wondering how I can re-route those wires - when I discovered
that one of those grey wires wasn't a phone line - it was a ground wire.
Now I'm wondering if I can route the ground wire to my panel instead and/or
toss it.

Alright, Qwest here I come. I'm sure it will take about a week to
sufficiently explain my question to them so that I get an intelligent
answer.

--

wrote in message
...
On Fri, 15 Dec 2006 03:45:20 GMT, CJT wrote:

I think that ground is the phone company's. They might have something
to say about you removing it.

Good point.

It might be noted this what the Mythbusters had to disconnect to make
the "lightning kills you through the phone" myth wr. With the ground
connected, nothing happened. With it disconnected they had all sorts
of fireworks.
My experience is only with computers and surge protection. I know
losing the bond between the phone and the power will blow modems,
system boards and power supplies.

I always thought phone lines were grounded internally through the wire
leading to the pole. Actually that's why I asked, I found too many people
referring back to the grounding on the pole but never mentioning the
grounding on site.

In article ,
"Eigenvector" wrote:

I can't find a good solid ruling for this one.

That's about to change. Read on...

Are phone lines grounded locally at the house?

Yes.

More accurately, the "protector unit" for the service is connected to an earth
ground. 14-gauge used to be the norm. 12 was used for years. It's now
10-gauge.

The configuration at my house has the main phone line coming off the pole,
down to a junction box, where 2 phone lines leave and a single ground wire
connects to the cold water plumbing.

That sounds right. If done to BSP (old Bell System Practice) specification,
there should be a tag attached to the ground connection at the electrode
(water pipe, ground rod, etc). It says something to the effect: On pain of
death, thou shalt not remove the ground. It is enforced by the same thugs
that enforce the mattress tag removal ban. g

I can't find any definite answers

Until now...

as to whether or not that ground wire is required

It is.

desired

Yes.

or useless.

Only until a direct, or near-direct, lightning strike.

The intent is on replacing the whole setup with CAT 5E

It doesn't make sense to connect Cat 5e wire to a "Cat 2-1/2" network. Cat 5e
works fine for POTS (Plain Old Telephone Service) but is certainly overkill.
It's NETWORKING wire (ethernet, yammer, yammer).

(seeing how it's just as cheap as CAT 3 or phone cable

Uh, Cat 3 *IS* phone cable.

I don't know if I need to keep the ground wire.

You need to KEEP IT.

It looks like pretty standard 14 gauge wire, in a grey sheath.

If re-doing the system, I'd go 10-gauge, or at least 12.

I have encountered MANY services where the ground wire had NEVER been
connected, some as old as 20-25 years. I declined to ask the customer if they
had had to replace much/any of their equipment over the years.

I have found services bearing the above-mentioned tag with the ground clamp
(and tag) "flapping in the breeze" (disconnected). Telephony gets no respect
at all.

The "protector" at the phone entrance is NOT designed to clamp most surges -
just the *HUGE* ones, like those delivered with a direct/near-direct lightning
strike or a power line coming down across a phone cable or drop.

I once encountered an old (restored, fine) farmhouse that took a direct strike
of lightning. The charge blew the protector housing off the outside of the
home. Half of the housing was 50-feet away. I never found the other half.
On the inside of the home, the bolt blew a 2-ft gaping hole in the lathe and
plaster as it passed between a phone jack and electrical outlet across the
living room.

The charge travelled along the underground "drop" (buried service wire) about
250-ft out to the road. There it blew apart a 25-pair splice module,
interrupting service to about 20 subscribers beyond.

This protector WAS grounded, for all the good it did. With a direct strike of
lightning, ALL bets are off.

You want your protector well grounded. Trust me.
--

JR

Climb poles and dig holes
Have staplegun, will travel

Eigenvector wrote:
I can't find a good solid ruling for this one.

Are phone lines grounded locally at the house?

The configuration at my house has the main phone line coming off the pole,
down to a junction box, where 2 phone lines leave and a single ground wire
connects to the cold water plumbing.

I can't find any definite answers as to whether or not that ground wire is
required, desired, or useless. The intent is on replacing the whole setup
with CAT 5E (seeing how it's just as cheap as CAT 3 or phone cable) and
re-routing the wires, but I don't know if I need to keep the ground wire.
It looks like pretty standard 14 gauge wire, in a grey sheath.


Hi,
Just remember grounding = safety issue. That's there for a reason.
You notice surge protector on your Dmark. block? Where would surge
current go? Say when lightning strikes.

In article ,
"Eigenvector" wrote:

I always thought phone lines were grounded internally through the wire
leading to the pole.

All metallic cable SHEATH is grounded - or should be. The actual pairs are
NOT, except back at the Central Office. An externally grounded cable pair is
virtually unusable.

I found too many people referring back to the grounding on the pole
but never mentioning the grounding on site.

Telephone services have been grounded AT THE STATION (home, business, etc)
since 1876.

Alright, Qwest here I come. I'm sure it will take about a week to
sufficiently explain my question to them so that I get an intelligent
answer.

Hopefully, my words have expedited your search.

I am a Network Technician (Installer/Repairman) and have worked for Qwest for
33-years. Good luck with your project.
--

JR

Mean Evil Bell System
Historical Socity

Old (older than every poster here) demanded the phone to be earthed
to a water pipe. That is no longer acceptable. Phone must now be
earthed to an electrode also used by cable TV and AC electric. Code
also says that wire must be 12 AWG. Most use 10 AWG wire. Code also
says that earthing wire must be short. That required to meet 'human
safety' code. For transistor safety, that wire from demarc (NID) must
be 'less than 10 feet', separated from all other non-earthing wires, no
sharp bends, no splices, not inside any metallic conduit, and should be
as short as practicable. These include post 1990 code requirements.

Same rules also apply to cable TV and AC mains earthing wire. All
earthing wires should remain separated until all meet at their common
earthing electrode. If it does not exist, you should install the
earthing rod (for AC electric) before the telco comes out. You want
them to use your 'better' earthing. Else they may install one that is
insufficient (too short).

Only other ground for telephone wire is where that wire enters the
telco's CO. However AC electric must be earthed at your earthing
electrode AND at utility's transformer.

While inspecting, also confirm a safety ground wire from breaker box
to water pipe is still connected. Best attached at a point where water
pipe just enters the building and so that an earthing connection does
not pass through any soldered connections. Your gas company may also
demand same connection to gas pipe; a requirement that varies with
natural gas companies.

Most important reason to confirm ground wires and to route them deep
enough so at to not be pierced by a nail - human safety. Do those
inspections while it remains convenient.

Eigenvector wrote:
Alright, I'd better call them then.

The whole thing started while I was sheetrocking and insulating the
basement. The previous owner/and or phone company rather than drilling
holes into the studs, took a chisel and cut a "V" notch on the surface of
the stud so that the sheetrock would lay flat. So I'm looking at their
handywork and wondering how I can re-route those wires - when I discovered
that one of those grey wires wasn't a phone line - it was a ground wire.
Now I'm wondering if I can route the ground wire to my panel instead and/or
toss it.

Alright, Qwest here I come. I'm sure it will take about a week to
sufficiently explain my question to them so that I get an intelligent
answer.

On 2006-12-15, w_tom wrote:

[Earthing wire] not inside any metallic conduit

Why would this be? Sometimes it might be necessary to use metallic
conduit to protect the earthing wire from physical damage.

Same rules also apply to cable TV and AC mains earthing wire. All
earthing wires should remain separated until all meet at their common
earthing electrode.

Given that the main panel/disconnect will have a grounding bar where
the Grounding Electrode Conductor terminates, is it good practice to
run the cable TV and telephone earthing wires directly to this grounding
bar?

Thanks, Wayne

w_tom wrote:
Old (older than every poster here) demanded the phone to be earthed
to a water pipe. That is no longer acceptable. Phone must now be
earthed to an electrode also used by cable TV and AC electric. Code
also says that wire must be 12 AWG. Most use 10 AWG wire. Code also
says that earthing wire must be short. That required to meet 'human
safety' code. For transistor safety, that wire from demarc (NID) must
be 'less than 10 feet', separated from all other non-earthing wires, no
sharp bends, no splices, not inside any metallic conduit, and should be
as short as practicable. These include post 1990 code requirements.

Same rules also apply to cable TV and AC mains earthing wire. All
earthing wires should remain separated until all meet at their common
earthing electrode.

Good information except the IEEE guide on surges and surge protection at:
http://www.mikeholt.com/files/PDF/Li...ion_May051.pdf
(guide page 28-29) recommends the NID (and cable protector block) be
mounted close to the electrical service, and their ground wire be
connected to the grounding electrode conductor from the electrical
service close to the panel. With high surge currents there will be
significant voltage drop on the wire to the grounding electrode (the
wire will have a much higher impedance at lightning frequencies than its
DC resistance). With separate wires to the grounding electrode, that
voltage will appear between the power wires and the telephone wires and
may damage equipment connected to both. When the NID is connected with a
short path to the power system neutral-ground bond, the phone and power
wires will rise together.

Old practice often connected the NID ground wire to a nearby water pipe.
When electronics is connected to both power and telephone wires that can
produce failures. I moved mine to the grounding electrode conductor (but
now I will be looking for thugs - thanks Jim). The NEC now allows
connection to water pipes only within 5 feet of the entrance to the
building.

--
bud--


If it does not exist, you should install the
earthing rod (for AC electric) before the telco comes out. You want
them to use your 'better' earthing. Else they may install one that is
insufficient (too short).

Only other ground for telephone wire is where that wire enters the
telco's CO. However AC electric must be earthed at your earthing
electrode AND at utility's transformer.

While inspecting, also confirm a safety ground wire from breaker box
to water pipe is still connected. Best attached at a point where water
pipe just enters the building and so that an earthing connection does
not pass through any soldered connections. Your gas company may also
demand same connection to gas pipe; a requirement that varies with
natural gas companies.

Most important reason to confirm ground wires and to route them deep
enough so at to not be pierced by a nail - human safety. Do those
inspections while it remains convenient.

Everything you said is correct, as best as I recall it. But what are you
citing? It sounds more like a local code than a national code.

Pop`


w_tom wrote:
Old (older than every poster here) demanded the phone to be earthed
to a water pipe. That is no longer acceptable. Phone must now be
earthed to an electrode also used by cable TV and AC electric. Code
also says that wire must be 12 AWG. Most use 10 AWG wire. Code also
says that earthing wire must be short. That required to meet 'human
safety' code. For transistor safety, that wire from demarc (NID) must
be 'less than 10 feet', separated from all other non-earthing wires,
no sharp bends, no splices, not inside any metallic conduit, and
should be as short as practicable. These include post 1990 code
requirements.

Same rules also apply to cable TV and AC mains earthing wire. All
earthing wires should remain separated until all meet at their common
earthing electrode. If it does not exist, you should install the
earthing rod (for AC electric) before the telco comes out. You want
them to use your 'better' earthing. Else they may install one that is
insufficient (too short).

Only other ground for telephone wire is where that wire enters the
telco's CO. However AC electric must be earthed at your earthing
electrode AND at utility's transformer.

While inspecting, also confirm a safety ground wire from breaker box
to water pipe is still connected. Best attached at a point where
water pipe just enters the building and so that an earthing
connection does not pass through any soldered connections. Your gas
company may also demand same connection to gas pipe; a requirement
that varies with natural gas companies.

Most important reason to confirm ground wires and to route them deep
enough so at to not be pierced by a nail - human safety. Do those
inspections while it remains convenient.

Eigenvector wrote:
Alright, I'd better call them then.

The whole thing started while I was sheetrocking and insulating the
basement. The previous owner/and or phone company rather than
drilling holes into the studs, took a chisel and cut a "V" notch on
the surface of the stud so that the sheetrock would lay flat. So
I'm looking at their handywork and wondering how I can re-route
those wires - when I discovered that one of those grey wires wasn't
a phone line - it was a ground wire. Now I'm wondering if I can
route the ground wire to my panel instead and/or toss it.

Alright, Qwest here I come. I'm sure it will take about a week to
sufficiently explain my question to them so that I get an intelligent
answer.

Eigenvector wrote:
I can't find a good solid ruling for this one.

Are phone lines grounded locally at the house?

The configuration at my house has the main phone line coming off the pole,
down to a junction box, where 2 phone lines leave and a single ground wire
connects to the cold water plumbing.

I can't find any definite answers as to whether or not that ground wire is
required, desired, or useless. The intent is on replacing the whole setup
with CAT 5E (seeing how it's just as cheap as CAT 3 or phone cable) and
re-routing the wires, but I don't know if I need to keep the ground wire.
It looks like pretty standard 14 gauge wire, in a grey sheath.
..
Telephone line protection here, here which AFIK follows Bell Canada
(ATT) practice is a 'Protector' mounted where the telephone line enters
the premises. Sometimes mounted outside but often inside the house.
That protector requires a ground.

The telephone company would either have driven their own ground rod or,
as in our case run a grounding wire to the incoming metal electrical
conduit which is grounded by the power company; that ground is also
bonded to metallic water pipe.

The protector (similar ones have been in use since the 1800s) provides
voltage breakdown protection from each side of the telephone pair.
Those are either repairable manually or by replacing small slide in
units; they are essentially small spark gaps that will break down to
ground if voltage exceeds a certain figure. Can't remember what that
voltage is offhand.

Also these days if one is within distance of the server, Internet
service can also be provided via the telephone pair.

The cable TV company have a coax entering the premises and it also has
a grounded protector.

Pop` wrote:
Everything you said is correct, as best as I recall it. But what are you
citing? It sounds more like a local code than a national code.

National Electrical Code now calls for all utilities to share a
common earth ground. Water pipe as earth ground is no longer
sufficient. Water pipe is bonded to breaker box. That connection
must be within five feet of where pipe leaves earth. But that
connection is electrically better if it does not pass through a solder
joint to earth. Also meter must have a bypass ground wire. These code
requirements are for human safety have changed significantly since 1970
construction.

To make the same earthing sufficient for transistor safety means both
meeting and exceeding post 1990 National Electrical Code. Therefore an
earthing wire must be even shorter than required by code - 'less than
10 feet'. Other requirements such as not inside metallic conduit,
wires separated, no sharp bends, etc are for electric currents (ie
transients) that are beyond the scope of NEC - that will not harm
humans and that can harm transistors.

Saftety ground to a gas pipe is unique to that gas company's
requirements. NEC does not require that ground. Gas companies also
typically put an electrical insulator adjacent to the gas meter so that
their outside gas pipes are not functioning as an earth ground.
Bonding a gas pipe to breaker box would only bond gas pipes inside the
building for human safety- and again only if required by that gas
company.

wrote:
On 15 Dec 2006 11:20:52 -0800, "terry"
wrote:

The telephone company would either have driven their own ground rod
That shoukld still be bonded to the PoCo service grounding elerctrode
with a #6 copper wire.

Correct: I omitted that. It should be and ours (both telephone and
cable TV company) are bonded.

Top posted for closure

I really appreciate the response for this. I wasn't sure why that ground
wire was there so I figure I'd better ask before moving it. I can leave it
in its current position, bonded to the pipes, as the pipes are bonded to the
panel ground, this would make the phone ground the shortest it can be -
otherwise I'd have to route the phone ground wire to the other side of my
house. But at least now I can drill the studs and put up nailplates for
protection and peace of mind that I'm not gonna take out my phone service
with an errant nail in the wall.

Just for comparison, the ROMEX was done in the same fashion, that was
corrected as soon as I uncovered that little piece of handywork.

As to CAT 3 being phone cable, sorry I'm a computer systems architect the
word CAT 3 means networking to me. Besides I thought CAT 1 was phone cable?


"Jim Redelfs" wrote in message
...
In article ,
"Eigenvector" wrote:

I can't find a good solid ruling for this one.

That's about to change. Read on...

Are phone lines grounded locally at the house?

Yes.

More accurately, the "protector unit" for the service is connected to an
earth
ground. 14-gauge used to be the norm. 12 was used for years. It's now
10-gauge.

The configuration at my house has the main phone line coming off the
pole,
down to a junction box, where 2 phone lines leave and a single ground
wire
connects to the cold water plumbing.

That sounds right. If done to BSP (old Bell System Practice)
specification,
there should be a tag attached to the ground connection at the electrode
(water pipe, ground rod, etc). It says something to the effect: On pain
of
death, thou shalt not remove the ground. It is enforced by the same thugs
that enforce the mattress tag removal ban. g

I can't find any definite answers

Until now...

as to whether or not that ground wire is required

It is.

desired

Yes.

or useless.

Only until a direct, or near-direct, lightning strike.

The intent is on replacing the whole setup with CAT 5E

It doesn't make sense to connect Cat 5e wire to a "Cat 2-1/2" network.
Cat 5e
works fine for POTS (Plain Old Telephone Service) but is certainly
overkill.
It's NETWORKING wire (ethernet, yammer, yammer).

(seeing how it's just as cheap as CAT 3 or phone cable

Uh, Cat 3 *IS* phone cable.

I don't know if I need to keep the ground wire.

You need to KEEP IT.

It looks like pretty standard 14 gauge wire, in a grey sheath.

If re-doing the system, I'd go 10-gauge, or at least 12.

I have encountered MANY services where the ground wire had NEVER been
connected, some as old as 20-25 years. I declined to ask the customer if
they
had had to replace much/any of their equipment over the years.

I have found services bearing the above-mentioned tag with the ground
clamp
(and tag) "flapping in the breeze" (disconnected). Telephony gets no
respect
at all.

The "protector" at the phone entrance is NOT designed to clamp most
surges -
just the *HUGE* ones, like those delivered with a direct/near-direct
lightning
strike or a power line coming down across a phone cable or drop.

I once encountered an old (restored, fine) farmhouse that took a direct
strike
of lightning. The charge blew the protector housing off the outside of
the
home. Half of the housing was 50-feet away. I never found the other
half.
On the inside of the home, the bolt blew a 2-ft gaping hole in the lathe
and
plaster as it passed between a phone jack and electrical outlet across the
living room.

The charge travelled along the underground "drop" (buried service wire)
about
250-ft out to the road. There it blew apart a 25-pair splice module,
interrupting service to about 20 subscribers beyond.

This protector WAS grounded, for all the good it did. With a direct
strike of
lightning, ALL bets are off.

You want your protector well grounded. Trust me.
--

JR

Climb poles and dig holes
Have staplegun, will travel

w_tom wrote:

I'm not disagreeing with you Tom, however....in defense of the NEC.....

Pop` wrote:
Everything you said is correct, as best as I recall it. But what are you
citing? It sounds more like a local code than a national code.

National Electrical Code now calls for all utilities to share a
common earth ground. Water pipe as earth ground is no longer
sufficient.

It's only fair to say _why_ a water pipe is no longer "sufficient." In
fact, the NEC still requires that an underground metallic water pipe in
contact with earth for at least 10 feet shall be used per (2002) NEC
250.50, if available. It's not that an underground metallic water pipe
isn't a good ground, it is, it's just that some clown may come along
and replace it with plastic pipe, rendering it ineffective as a
grounding electrode. Which leads, as to why, to the next requirement
by NEC, 250.53, that a metal underground water pipe shall be
supplemented by an additional electrode, usually a ground rod. Also,
that connection shall not depend upon the water pipe.

Water pipe is bonded to breaker box. That connection
must be within five feet of where pipe leaves earth. But that
connection is electrically better if it does not pass through a solder
joint to earth. Also meter must have a bypass ground wire.

Yes, and _that_is_ the wire (per NEC 250.94) that is intended for
intersystem grounding, such as telephone and cable, to be connected.
This is critical for "life" safety and "transistor" safety. As you
know, bonding all the systems together, thus, making them the same
potential, allows all of the interconnected systems to come up to the
same potential during a surge or nearby lightning strike, resulting in
no destructive paths for current to flow. If different systems
grounding is not at the same potential by not being bonded, a
destructive path is established during a surge or nearby lightning
strike and _will_ find it's way through phones, modems, TVs, whatever.


Here in Florida we get a lot of serious lightning and I've been called
to repair a lot of that kind of damage. Almost always the systems are
not bonded before the fact. I've think that I may have noticed a
pattern. Many times the VCRs will get blown out and the TV is OK.
I've also noted that modems got spared while the phones get fried. I'm
beginning to wonder if it isn't a good idea to leave those old, no
longer used VCR's and telephones connected first in line, to act as
sacrificial lambs, so to speak.

These code
requirements are for human safety have changed significantly since 1970
construction.

To make the same earthing sufficient for transistor safety means both
meeting and exceeding post 1990 National Electrical Code. Therefore an
earthing wire must be even shorter than required by code - 'less than
10 feet'.

The NEC actually does require, in NEC 250.30(A)(4), that the grounding
electrode to be "as near as practicable" and "preferably in the same
area" as the grounding electrode conductor.
The NEC can't dictate where a utility will bring in it's service. In
my house, for example, the electric and phone comes in on the right
side of the house, the water comes in the front, and the cable comes in
on the left side of the house, all due to the physical layout of the
utilities.

Other requirements such as not inside metallic conduit,

I believe that NEC 250.64(E) solves that problem by requiring that the
wire be bonded to the pipe at both ends.

wires separated, no sharp bends, etc are for electric currents (ie
transients) that are beyond the scope of NEC - that will not harm
humans and that can harm transistors.

I don't think Article 250 comes right out and says it, but the
implications are there if one looks in Article 285 (Transient Voltage
Surge Suppressors), specifically, 285.12 "The conductors used to
connect the TVSS to the line or bus and to GROUND shall not be any
longer then necessary and shall avoid unnecessary bends." Similar
statements are made in Article 280 (Surge Arrestors), actually, 280.12.

Saftety ground to a gas pipe is unique to that gas company's
requirements. NEC does not require that ground.

Most certainly does, in NEC 250.104(B). "Where installed in or attached
to a building or structure, metal piping system(s), including gas
piping, that may become energized shall be bonded to the service
equipment enclosure......etc."

Gas companies also
typically put an electrical insulator adjacent to the gas meter so that
their outside gas pipes are not functioning as an earth ground.
Bonding a gas pipe to breaker box would only bond gas pipes inside the
building for human safety- and again only if required by that gas
company.

That's true, some localities, persuaded by gas companies, will amend
their _local_ codes so that gas pipes are not bonded to the electric
grounding system. However, one will usually find that the gas
appliance is grounded by the equipment grounding conductor of the
circuit that supplies the power to the appliance.

For safety reason's, it's very critcal that an interior metal water
piping be bonded to the electric grounding system, even if the incoming
underground water pipe is plastic.

I would like to see the NEC require a Ufer ground, though. IMO, a
ground rod (even two, 6 to 10 feet apart) is about the worst grounding
electrode permited by NEC. A Ufer ground (concrete encased electrode)
is easily installed during new construction, and there is no real
excuse, other than laziness, NOT to install one.

Eigenvector wrote:
Top posted for closure

I really appreciate the response for this. I wasn't sure why that ground
wire was there so I figure I'd better ask before moving it. I can leave it
in its current position, bonded to the pipes, as the pipes are bonded to the
panel ground, this would make the phone ground the shortest it can be -
otherwise I'd have to route the phone ground wire to the other side of my
house.

Before plastic pipe, that's the way grounding was done. Your
installation is grandfathered. While using the interior metal water
pipe as a grounding conductor is no longer permitted by NEC today, even
for telephone or cable, as long as nobody comes along and replaces the
interior metal pipe with plastic without jumpering it, you're OK.
Check to make sure the water meter is jumpered and also the hot to cold
at the water heater. In fact, there are still a lot of houses where
the electric service grounding was done the same way as your phone
grounding. The NEC restrictions against using interior water pipes for
grounding applies to Residential only, because of the availability and
common use of plastic pipe and popularity of DIY. Industrial and
Commercial electric services are still permitted to this day to use
interior metal water pipes as a grounding electrode conductor for an
electric service.

volts500 wrote:
Here in Florida we get a lot of serious lightning and I've been
called to repair a lot of that kind of damage. Almost always the
systems are not bonded before the fact. I've think that I may
have noticed a pattern. Many times the VCRs will get blown out
and the TV is OK. I've also noted that modems got spared while
the phones get fried. I'm beginning to wonder if it isn't a good
idea to leave those old, no longer used VCR's and telephones
connected first in line, to act as sacrificial lambs, so to speak.

Why two adjacent appliances but only one damaged? Question: which is
the better path to earth? A transient first constructs a complete
electrical path from cloud, incoming on utility, through household
appliance, to earth ground, and then to charges maybe located miles
away. Then electricity flows through everything in that path. Then
something in that path fails.

The VCR could have been a better path to earth. Or internal
protection inside the TV is better than protection inside the VCR.
Therefore VCR shunted a transient that would have otherwise overwhelmed
protection inside a TV. Multiple reasons why a VCR is damaged when
adjacent TV is not. But the bottom line: transient that should have
been earthed before entering a buillding, instead, found a destructive
path via that VCR. What is that better path to earth that next time
may take out the TV?

Appliances more often damaged include fax machines, modems, base
station for a portable phone, and alarm panels. Each may be a path
incoming from any utility and outgoing to earth ground via another
utility or other conductive material. For example, incoming on AC
electric to TV and VCR. But outgoing to earth ground via cable was
easier via VCR. Or maybe that conductive path was outgoing elsewhere.
Even linoleum tile floor or other materials normally not considered
conductive may become part of a destructive and outgoing path.

Obviously, finding every interior path to earth can be difficult. So
many items inside a building normally not considered conductive can,
instead, conduct destructive electrical transents. Therefore we earth
that transient before it can even enter the building. A protection
system must accomplish two things - equipotential and conductivity.

We make that earthing electrode as conductive as possible. But we
can never make it conductive enough. So we also create equipoential -
a single point earthing electrode, bonding everything together as short
as possible, or (even better) Ufer ground that surrounds a building.
But since we never do equipotential sufficiently, then we must improve
conductivity. Earthing (for transient protection) is an attempt to
accomplish both. Both so that neither TV nor VCR become a better path
to earth.

Of course, we are human. That means testing is necessary to find
mistakes. But testing a surge protection 'system' is not possible. If
damage results, we learn where an earthing system (and protectors) has
failed - and correct that mistake.

Other requirements such as not inside metallic conduit,
I believe that NEC 250.64(E) solves that problem by requiring
that the wire be bonded to the pipe at both ends.

Bonding the metallic pipe (or metallic raceways) at both ends also
addresses why wire inside a conduit is less conductive. However that
bonding now adds two connections. An earthing wire should not even
have splices. These actions are for lowering wire impedance. Why do
we bond a ground wire to both ends of the pipe? Because electricity
mostly flows outside - through the pipe - not through inside wire.
This bonding is a concern for human safety. Problem is greater when
wire must earth transients.

In article ,
"Eigenvector" wrote:

Top posted for closure

You wish...

As to CAT 3 being phone cable, sorry I'm a computer systems
architect the word CAT 3 means networking to me.

You may be right. However, I am unaware of any computer networking
application that specifies Cat 3 cable.

Besides I thought CAT 1 was phone cable?

Some of the garbage cable cranked-out by various manufacturers for the first
5-7 years after 1984 might qualify as Cat 1, although I don't think it is THAT
good.

The good, old "light olive gray" "quad" wire (red/green/yellow/black) used for
decades would probably qualify as Cat 2 - whatever THAT means.

I have never seen any "Cat" other than 3 and 5e. Whatever happened to 1,2,
and 4?
--

JR

volts500 wrote:

To make the same earthing sufficient for transistor safety means both
meeting and exceeding post 1990 National Electrical Code. Therefore an
earthing wire must be even shorter than required by code - 'less than
10 feet'.


The NEC actually does require, in NEC 250.30(A)(4), that the grounding
electrode to be "as near as practicable" and "preferably in the same
area" as the grounding electrode conductor.
The NEC can't dictate where a utility will bring in it's service. In
my house, for example, the electric and phone comes in on the right
side of the house, the water comes in the front, and the cable comes in
on the left side of the house, all due to the physical layout of the
utilities.

The IEEE guide on surges and surge protection:
http://www.mikeholt.com/files/PDF/Li...ion_May051.pdf

starting on guide page 31 shows the problem of having power H-G bond
point and CATV protector block connected with a long wire - potentially
many thousands of volts between the power wiring and CATV lead. The fix
in the guide is to use a plug-in suppressor that has both power and CATV
wires go through it - the voltage on power and signal wires is clamped
to the common ground at the surge suppressor. Another fix would be to
route the CATV wire from the entrance ground block to the power service
and install a 2nd ground block with short earthing connection to the
power grounding electrode conductor coming out of the service. Then
distribute the CATV from that point. Same with phone, dish, .... IMHO a
single point ground is more important than the resistance to earth.


I would like to see the NEC require a Ufer ground, though. IMO, a
ground rod (even two, 6 to 10 feet apart) is about the worst grounding
electrode permited by NEC. A Ufer ground (concrete encased electrode)
is easily installed during new construction, and there is no real
excuse, other than laziness, NOT to install one.

Totally agree. Apparently 250.50 starting in the 2005 NEC is intended to
require Ufer grounds in new construction where there is a concrete
footing or foundation. IMHO the requirement is not at all clear and is
more apparent in the exception than the rule. I don't think it was noted
in code change material I read.

--
bud--

Wayne Whitney wrote:

On 2006-12-15, w_tom wrote:


[Earthing wire] not inside any metallic conduit


Why would this be? Sometimes it might be necessary to use metallic
conduit to protect the earthing wire from physical damage.

When run in steel conduit, the wire through the steel acts as a choke
and can significantly raise the impedance of the earthing wire. As volt
notes, the NEC requires the conduit to be bonded to the earthing wire at
each end so the conduit acts as a conductor in parallel to the earthing
wire.


Same rules also apply to cable TV and AC mains earthing wire. All
earthing wires should remain separated until all meet at their common
earthing electrode.


Given that the main panel/disconnect will have a grounding bar where
the Grounding Electrode Conductor terminates, is it good practice to
run the cable TV and telephone earthing wires directly to this grounding
bar?

Connect them to the grounding electrode conductor close to where it
leaves the service.

--
bud--

On 2006-12-16, Bud-- wrote:

Given that the main panel/disconnect will have a grounding bar where
the Grounding Electrode Conductor terminates, is it good practice to
run the cable TV and telephone earthing wires directly to this grounding
bar?

Connect them to the grounding electrode conductor close to where it
leaves the service.

Well, I have both a bare Cu #6 Ufer ground coming out of the concrete
foundation and a bare #6 GEC that goes to a ground rod and the
metallic water service. They are both connected to the ground bar in
the main disconnect. A few questions:

Is it OK to a use a bare #10 for the telephone/cable ground? You
suggest that this wire should be clamped to one of the bare Cu #6
conductors, which one? Why is this better than running it to the
ground bar in the main disconnect?

Thanks for the advice.

Yours, Wayne

"Jim Redelfs" wrote in message
...
In article ,
"Eigenvector" wrote:

Top posted for closure

You wish...

As to CAT 3 being phone cable, sorry I'm a computer systems
architect the word CAT 3 means networking to me.

You may be right. However, I am unaware of any computer networking
application that specifies Cat 3 cable.

Besides I thought CAT 1 was phone cable?

Some of the garbage cable cranked-out by various manufacturers for the
first
5-7 years after 1984 might qualify as Cat 1, although I don't think it is
THAT
good.

The good, old "light olive gray" "quad" wire (red/green/yellow/black) used
for
decades would probably qualify as Cat 2 - whatever THAT means.

I have never seen any "Cat" other than 3 and 5e. Whatever happened to
1,2,
and 4?
--

JR

CAT 4 was a placeholder so far as I know, it was never in use. CAT 3 I've
only seen in 10 Mbit connections, old computer networks but still widely in
use. I think CAT 2 was the same as CAT 4, basically just a placeholder.
CAT 5 is 100 Mbit connection line, CAT 5e is 1,000 Mbit connection, CAT 6 is
1,000 Mbit, plus providing power capability. Really it's all the same
cable, just better tolerances and quality - except CAT 6 which has
additional pairs. ****That's how I know it. That's not the pedantic and/or
exact definition, there are better descriptions of it out there. So if
anyone chimes in looking for an argument I won't even bother - no trolling
here please!****

Anyway the whole project is on hold until Seattle gets back to normal, I
doubt the phone company has time to worry about my home re-wiring project at
this time. Hell, the entire town of Issaquah is out of power, at least it
was when I spoke to the local Lowe's guys - and Issaquah is a BIG town, not
some podunk.

Wayne Whitney wrote:

On 2006-12-16, Bud-- wrote:


Given that the main panel/disconnect will have a grounding bar where
the Grounding Electrode Conductor terminates, is it good practice to
run the cable TV and telephone earthing wires directly to this grounding
bar?

Connect them to the grounding electrode conductor close to where it
leaves the service.


Well, I have both a bare Cu #6 Ufer ground coming out of the concrete
foundation and a bare #6 GEC that goes to a ground rod and the
metallic water service. They are both connected to the ground bar in
the main disconnect. A few questions:

Is it OK to a use a bare #10 for the telephone/cable ground?
The NEC says insulated, but not the most important issue. Minimum size
#14, #10 is good.

You
suggest that this wire should be clamped to one of the bare Cu #6
conductors, which one?
The Ufer ground, it is really good. (Underground metal water pipes are
good too, but likely farther away. Ground rods are better than nothing.)
[With a Ufer ground you shouldn't need a rod.]

Why is this better than running it to the
ground bar in the main disconnect?

I believe the ground bar is not one of the allowable points of
attachment in the NEC.
And IMHO: It is better not to run the conductor in with power wiring.
Through the ground bar requires an extra connection in the path to the
grounding electrode.

--
bud--

"Eigenvector" wrote in message
...

"Jim Redelfs" wrote in message
...
In article ,
"Eigenvector" wrote:

Top posted for closure

You wish...

As to CAT 3 being phone cable, sorry I'm a computer systems
architect the word CAT 3 means networking to me.

You may be right. However, I am unaware of any computer networking
application that specifies Cat 3 cable.

Besides I thought CAT 1 was phone cable?

Some of the garbage cable cranked-out by various manufacturers for the
first
5-7 years after 1984 might qualify as Cat 1, although I don't think it is
THAT
good.

The good, old "light olive gray" "quad" wire (red/green/yellow/black)
used for
decades would probably qualify as Cat 2 - whatever THAT means.

I have never seen any "Cat" other than 3 and 5e. Whatever happened to
1,2,
and 4?
--

JR

CAT 4 was a placeholder so far as I know, it was never in use. CAT 3 I've
only seen in 10 Mbit connections, old computer networks but still widely
in use. I think CAT 2 was the same as CAT 4, basically just a
placeholder. CAT 5 is 100 Mbit connection line, CAT 5e is 1,000 Mbit
connection, CAT 6 is 1,000 Mbit, plus providing power capability. Really
it's all the same cable, just better tolerances and quality - except CAT 6
which has additional pairs. ****That's how I know it. That's not the
pedantic and/or exact definition, there are better descriptions of it out
there. So if anyone chimes in looking for an argument I won't even
bother - no trolling here please!****

Anyway the whole project is on hold until Seattle gets back to normal, I
doubt the phone company has time to worry about my home re-wiring project
at this time. Hell, the entire town of Issaquah is out of power, at least
it was when I spoke to the local Lowe's guys - and Issaquah is a BIG town,
not some podunk.
BTW, examples of the stellar job done on the phone lines

http://photos.imageevent.com/eigenve...e/PC160076.JPG
http://photos.imageevent.com/eigenve...e/PC160077.JPG

Looks like a pretty good ground connection to me, no corrosion and the
connection is nice and tight. But that splice! Christ that's a bad job if
I ever saw one.

In article ,
"Eigenvector" wrote:

CAT 4 was a placeholder so far as I know

Thanks for taking the time to post such detail. I am more informed.

Anyway the whole project is on hold until Seattle gets back to normal

Yeah, so I've heard. Good luck to you folks. I kinda wonder if they'll
(Qwest) ask or volunteers to help. Then again, "they" asked for volunteers
for Katrina that never panned-out. Despite being one big, fat, happy company,
we still seem to stay within the original states that comprised each of the
three BOCs (Bell Operating Companies) prior to divestitu Northwestern
Bell, Mountain Bell and Pacific Northwest Bell. We'll see...
--

JR

In article ,
"Eigenvector" wrote:

But that splice! ...that's a bad job if I ever saw one.
http://photos.imageevent.com/eigenve...e/PC160076.JPG

That was NOT done by a telco employee: They wouldn't have the TIME (or desire
to TAKE that much time) to do it like that. A trip back to the truck, if the
tech had neglected to bring along the proper connectors to begin with, would
be MUCH faster, nevermind BETTER.
--

JR

"Jim Redelfs" wrote in message
...
In article ,
"Eigenvector" wrote:

But that splice! ...that's a bad job if I ever saw one.
http://photos.imageevent.com/eigenve...e/PC160076.JPG

That was NOT done by a telco employee: They wouldn't have the TIME (or
desire
to TAKE that much time) to do it like that. A trip back to the truck, if
the
tech had neglected to bring along the proper connectors to begin with,
would
be MUCH faster, nevermind BETTER.
--

JR

Yeah I didn't think it was done by a pro. More of the previous owner's
bumblings. The verdigris on the copper wires is an especially nice touch!,
as is the clipped phone cable left just hanging there rather than simply
fixing it.

Eigenvector wrote:
I can leave it in its current position, bonded to the pipes, as the
pipes are bonded to the panel ground, this would make the phone
ground the shortest it can be - otherwise I'd have to route the
phone ground wire to the other side of my house.

Connection from phone, through wires, through pipes, etc is grossly
more than 10 feet. It is make worse by pipe joints, wire junctions
etc. It does not meet 1990 NEC earthing requirements. I suspect your
connection to earth is well over 50 feet AND does not make that
earthing connection directly. It would be a prescription for
electronics damage.

There are a number of ways to fix this. But you may regard them as
too much work. The amount of work not justified by the risk. This for
the benefit of others who are at more risk to damage.

For example that phone line could be rerouted to enter at adjacent to
AC electric. Or wire is routed inside building well separated from any
other wire or pipe to first connect to a protector at earth electrode -
and only then distributing phone service to the house. Another
suggestion from a utility is demonstrated by bad, ugly, and good
figures in:
http://www.cinergy.com/surge/ttip08.htm

There is no way around a short ground connection (lower impedance)
and a common earthing electrode if electronics protection is desired.

Bud-- wrote:
volts500 wrote:

To make the same earthing sufficient for transistor safety means both
meeting and exceeding post 1990 National Electrical Code. Therefore an
earthing wire must be even shorter than required by code - 'less than
10 feet'.


The NEC actually does require, in NEC 250.30(A)(4), that the grounding
electrode to be "as near as practicable" and "preferably in the same
area" as the grounding electrode conductor.
The NEC can't dictate where a utility will bring in it's service. In
my house, for example, the electric and phone comes in on the right
side of the house, the water comes in the front, and the cable comes in
on the left side of the house, all due to the physical layout of the
utilities.

The IEEE guide on surges and surge protection:
http://www.mikeholt.com/files/PDF/Li...ion_May051.pdf

Thanks for the link! I was pleasantly surprised that there is a IEEE
publication that's free.


starting on guide page 31 shows the problem of having power H-G bond
point and CATV protector block connected with a long wire - potentially
many thousands of volts between the power wiring and CATV lead.

I read that article twice to make sure that I was reading it right.
While it is an excellent article, and the overall point is well taken,
correct me if I'm wrong, but there seems to be a discepancy in the
document. The calculation on the bottom of p. 30 uses 30 feet as the
distance between points A and B (the distance between the cable ground
block and the connection to the electric system ground.)
That being the case, it seems to me that both figures 7 and 8 are in
violation of 820.40(4) : "...the grounding conductor shall be as short
as practicable, not to exceed 20 feet." Of course, the NEC remedy is to
drive a ground rod and bond it to the electric service.

When I get calls to repair and correct wiring from lightning damage, if
the telephone and/or cable demarc is not directly next to the electric
service, I drive a ground rod at each demarc location and bond the
ground rods to the electric service with buried a #4 bare copper wire.
I then install a new (or previously non-existent) surge arrestor at the
meter. I then connect a TrippLite power/phone/cable surge protector,
as the article calls, "multiport protector," at the equipment.


The fix
in the guide is to use a plug-in suppressor that has both power and CATV
wires go through it - the voltage on power and signal wires is clamped
to the common ground at the surge suppressor. Another fix would be to
route the CATV wire from the entrance ground block to the power service
and install a 2nd ground block with short earthing connection to the
power grounding electrode conductor coming out of the service. Then
distribute the CATV from that point. Same with phone, dish, ....

That's a good idea, if one is able to do it. In my area the cable
distribution is locked up and rendered inaccessible by locks similar to
what the gas companies use to secure a valve.


IMHO a
single point ground is more important than the resistance to earth.


I would like to see the NEC require a Ufer ground, though. IMO, a
ground rod (even two, 6 to 10 feet apart) is about the worst grounding
electrode permited by NEC. A Ufer ground (concrete encased electrode)
is easily installed during new construction, and there is no real
excuse, other than laziness, NOT to install one.

Totally agree. Apparently 250.50 starting in the 2005 NEC is intended to
require Ufer grounds in new construction where there is a concrete
footing or foundation. IMHO the requirement is not at all clear and is
more apparent in the exception than the rule. I don't think it was noted
in code change material I read.

--
bud--

volts500 wrote:

To make the same earthing sufficient for transistor safety means both
meeting and exceeding post 1990 National Electrical Code. Therefore an
earthing wire must be even shorter than required by code - 'less than
10 feet'.


The NEC actually does require, in NEC 250.30(A)(4), that the grounding
electrode to be "as near as practicable" and "preferably in the same
area" as the grounding electrode conductor.
The NEC can't dictate where a utility will bring in it's service. In
my house, for example, the electric and phone comes in on the right
side of the house, the water comes in the front, and the cable comes in
on the left side of the house, all due to the physical layout of the
utilities.


The IEEE guide on surges and surge protection:
http://www.mikeholt.com/files/PDF/Li...ion_May051.pdf


Thanks for the link! I was pleasantly surprised that there is a IEEE
publication that's free.



starting on guide page 31 shows the problem of having power H-G bond
point and CATV protector block connected with a long wire - potentially
many thousands of volts between the power wiring and CATV lead.


I read that article twice to make sure that I was reading it right.
While it is an excellent article, and the overall point is well taken,
correct me if I'm wrong, but there seems to be a discepancy in the
document. The calculation on the bottom of p. 30 uses 30 feet as the
distance between points A and B (the distance between the cable ground
block and the connection to the electric system ground.)
That being the case, it seems to me that both figures 7 and 8 are in
violation of 820.40(4) : "...the grounding conductor shall be as short
as practicable, not to exceed 20 feet." Of course, the NEC remedy is to
drive a ground rod and bond it to the electric service.

Didn't notice that but I agree. I wouldn't bet a rod at the cable ground
block would lower the differential much, but I'm not a fan of ground
rods. If the cable ground block was a legal 20 feet, the CATV to
power-ground differential would drop to a mere 6700V.

An ungrelated tidbit that may be interesting - at about 6000V surge
voltage will cause an arc-over to ground at service CB panels or H-N-G
at 120V receptacles. The voltage between power system wires at any point
will limit to about 6000V.

When I get calls to repair and correct wiring from lightning damage, if
the telephone and/or cable demarc is not directly next to the electric
service, I drive a ground rod at each demarc location and bond the
ground rods to the electric service with buried a #4 bare copper wire.
I then install a new (or previously non-existent) surge arrestor at the
meter. I then connect a TrippLite power/phone/cable surge protector,
as the article calls, "multiport protector," at the equipment.

I believe you could run the bond through the building, if practical. I
was surprised that the bond size is not as critical as would seem
because impedance dominates over DC resistance. The mimimum size
earthing wire from phone NID to grounding electrode system is a mere #14.
Single point grounds - all protectors near the power service - are a
very good idea if feasable. Having them at a distance is one of the
problems a plug-in multiport suppressor can solve.



The fix
in the guide is to use a plug-in suppressor that has both power and CATV
wires go through it - the voltage on power and signal wires is clamped
to the common ground at the surge suppressor. Another fix would be to
route the CATV wire from the entrance ground block to the power service
and install a 2nd ground block with short earthing connection to the
power grounding electrode conductor coming out of the service. Then
distribute the CATV from that point. Same with phone, dish, ....


That's a good idea, if one is able to do it. In my area the cable
distribution is locked up and rendered inaccessible by locks similar to
what the gas companies use to secure a valve.

If their service ground block is distant from the power service they
may agree to run their cable to an aditional ground block near the power
service first and then distribute from there. Distant phone service can
also be routed first to a second NID at the power service and
distributed from there.



IMHO a
single point ground is more important than the resistance to earth.


I would like to see the NEC require a Ufer ground, though. IMO, a
ground rod (even two, 6 to 10 feet apart) is about the worst grounding
electrode permited by NEC. A Ufer ground (concrete encased electrode)
is easily installed during new construction, and there is no real
excuse, other than laziness, NOT to install one.


Totally agree. Apparently 250.50 starting in the 2005 NEC is intended to
require Ufer grounds in new construction where there is a concrete
footing or foundation. IMHO the requirement is not at all clear and is
more apparent in the exception than the rule. I don't think it was noted
in code change material I read.


--
bud--

volts500 wrote:
Bud-- wrote:
volts500 wrote:

To make the same earthing sufficient for transistor safety means both
meeting and exceeding post 1990 National Electrical Code. Therefore an
earthing wire must be even shorter than required by code - 'less than
10 feet'.

The NEC actually does require, in NEC 250.30(A)(4), that the grounding
electrode to be "as near as practicable" and "preferably in the same
area" as the grounding electrode conductor.
The NEC can't dictate where a utility will bring in it's service. In
my house, for example, the electric and phone comes in on the right
side of the house, the water comes in the front, and the cable comes in
on the left side of the house, all due to the physical layout of the
utilities.

The IEEE guide on surges and surge protection:
http://www.mikeholt.com/files/PDF/Li...ion_May051.pdf

Thanks for the link! I was pleasantly surprised that there is a IEEE
publication that's free.


starting on guide page 31 shows the problem of having power H-G bond
point and CATV protector block connected with a long wire - potentially
many thousands of volts between the power wiring and CATV lead.

I read that article twice to make sure that I was reading it right.
While it is an excellent article, and the overall point is well taken,
correct me if I'm wrong, but there seems to be a discepancy in the
document. The calculation on the bottom of p. 30 uses 30 feet as the
distance between points A and B (the distance between the cable ground
block and the connection to the electric system ground.)
That being the case, it seems to me that both figures 7 and 8 are in
violation of 820.40(4) : "...the grounding conductor shall be as short
as practicable, not to exceed 20 feet." Of course, the NEC remedy is to
drive a ground rod and bond it to the electric service.

When I get calls to repair and correct wiring from lightning damage, if
the telephone and/or cable demarc is not directly next to the electric
service, I drive a ground rod at each demarc location and bond the
ground rods to the electric service with buried a #4 bare copper wire.
I then install a new (or previously non-existent) surge arrestor at the
meter. I then connect a TrippLite power/phone/cable surge protector,
as the article calls, "multiport protector," at the equipment.


The fix
in the guide is to use a plug-in suppressor that has both power and CATV
wires go through it - the voltage on power and signal wires is clamped
to the common ground at the surge suppressor. Another fix would be to
route the CATV wire from the entrance ground block to the power service
and install a 2nd ground block with short earthing connection to the
power grounding electrode conductor coming out of the service. Then
distribute the CATV from that point. Same with phone, dish, ....

That's a good idea, if one is able to dno it. In my area the cable
distribution is locked up and rendered inaccessible by locks similar to
what the gas companies use to secure a valve.


IMHO a
single point ground is more important than the resistance to earth.

I would like to see the NEC require a Ufer ground, though. IMO, a
ground rod (even two, 6 to 10 feet apart) is about the worst grounding
electrode permited by NEC. A Ufer ground (concrete encased electrode)
is easily installed during new construction, and there is no real
excuse, other than laziness, NOT to install one.

Totally agree. Apparently 250.50 starting in the 2005 NEC is intended to
require Ufer grounds in new construction where there is a concrete
footing or foundation. IMHO the requirement is not at all clear and is
more apparent in the exception than the rule. I don't think it was noted
in code change material I read.

--
bud--


If that buried bonding wire is twenty or more feet in length then dig
down to thirty inches between the two electrodes and run bare number two
copper as your bond so it can behave as a partial Ground Ring. Best
practice would be to drive the rod through the bottom of the trench.
That adds the depth of the trench to the driven depth of the rod itself.
The key to getting the lowest ground impedance is to get the electrode
down into the permanent moisture level.
--
Tom Horne

Well we aren't no thin blue heroes and yet we aren't no blackguards to.
We're just working men and woman most remarkable like you.

"w_tom" writes:
Old (older than every poster here) demanded the phone to be earthed
to a water pipe. That is no longer acceptable. Phone must now be
earthed to an electrode also used by cable TV and AC electric. Code
also says that wire must be 12 AWG. Most use 10 AWG wire. Code also
says that earthing wire must be short. That required to meet 'human
safety' code. For transistor safety, that wire from demarc (NID) must
be 'less than 10 feet', separated from all other non-earthing wires, no
sharp bends, no splices, not inside any metallic conduit, and should be
as short as practicable. These include post 1990 code requirements.

We have Verizon FIOS which comes in on fiber optic cable. The ONI
(optical network interface) uses power and I believe uses a grounded
(3-prong) cord -- thus, it is no longer attached to a long
exterior metal wire (i.e. think antenna) and seems analogous to any
interior low voltage wiring system like an alarm.

So does this situation in which the interior telephone circuit is
literally optically isolated does the code still require that the
demarc be bonded directly to earth ground?


Same rules also apply to cable TV and AC mains earthing wire. All
earthing wires should remain separated until all meet at their common
earthing electrode. If it does not exist, you should install the
earthing rod (for AC electric) before the telco comes out. You want
them to use your 'better' earthing. Else they may install one that is
insufficient (too short).

Only other ground for telephone wire is where that wire enters the
telco's CO. However AC electric must be earthed at your earthing
electrode AND at utility's transformer.

While inspecting, also confirm a safety ground wire from breaker box
to water pipe is still connected. Best attached at a point where water
pipe just enters the building and so that an earthing connection does
not pass through any soldered connections. Your gas company may also
demand same connection to gas pipe; a requirement that varies with
natural gas companies.

Interestingly - our gas company specifically WARNS against bonding the
gas entrance to ground (and will remove it if they see it). I have
heard that some gas companies purposely run a small current on the
external gas pipe to prevent galvanic corrosion. In those cases, the
internal piping (which often is grounded to appliance ground) is
isolated from the street piping via a rubber gasket of sorts.


Most important reason to confirm ground wires and to route them deep
enough so at to not be pierced by a nail - human safety. Do those
inspections while it remains convenient.

Eigenvector wrote:
Alright, I'd better call them then.

The whole thing started while I was sheetrocking and insulating the
basement. The previous owner/and or phone company rather than drilling
holes into the studs, took a chisel and cut a "V" notch on the surface of
the stud so that the sheetrock would lay flat. So I'm looking at their
handywork and wondering how I can re-route those wires - when I discovered
that one of those grey wires wasn't a phone line - it was a ground wire.
Now I'm wondering if I can route the ground wire to my panel instead and/or
toss it.

Alright, Qwest here I come. I'm sure it will take about a week to
sufficiently explain my question to them so that I get an intelligent
answer.

Optical network interface electronics still connects to AC mains. AC
electric is equivalent to an antenna connected to optican network
electronics. That incoming wire must be earthed where it enter the
building to protect optical network electronics..

FIOS installations appear to have some earthing. Cannot say why with
certainty. But an optical cable has a conductive wire within it. A
conductor so that undersground optical cable can be traced before
excavating. Have observed something from optical cable connected to
earthing. But I did not inquire as to what or why.

Some gas companies want interior gas lines bonded. Others do not.
You must conform to your gas company demands. However that gas pipe
gets bonded anyway when furnace or other gas appliances also use
electricity. IOW if building earthing is not provided, then (as
happened in one dwelling) building might use gas line to obtain a
return ground - may use that pipe as an alternative neutral wire.
Fortunately no one was home when a gas line gasket eventually broke
down; house exploded. Just another (and rare) reason why all
'conductive' utilities should share a common earth ground.

blueman wrote:
We have Verizon FIOS which comes in on fiber optic cable. The ONI
(optical network interface) uses power and I believe uses a grounded
(3-prong) cord -- thus, it is no longer attached to a long
exterior metal wire (i.e. think antenna) and seems analogous to any
interior low voltage wiring system like an alarm.

So does this situation in which the interior telephone circuit is
literally optically isolated does the code still require that the
demarc be bonded directly to earth ground?
...

Interestingly - our gas company specifically WARNS against bonding the
gas entrance to ground (and will remove it if they see it). I have
heard that some gas companies purposely run a small current on the
external gas pipe to prevent galvanic corrosion. In those cases, the
internal piping (which often is grounded to appliance ground) is
isolated from the street piping via a rubber gasket of sorts.

"w_tom" writes:

Optical network interface electronics still connects to AC mains. AC
electric is equivalent to an antenna connected to optican network
electronics. That incoming wire must be earthed where it enter the
building to protect optical network electronics..

Agreed. That's why I have whole-house surge protection right at the
meter box...

FIOS installations appear to have some earthing. Cannot say why with
certainty. But an optical cable has a conductive wire within it. A
conductor so that undersground optical cable can be traced before
excavating. Have observed something from optical cable connected to
earthing. But I did not inquire as to what or why.

If that wire is connected to the chassis ground and if that in turn is
connected to the ground prong in the plug, then it should be properly
grounded (and surge protected) in the house. If that electrical signal
is just hanging there isolated from my house wiring then there is not
much I can do about it since I can't access it...

Some gas companies want interior gas lines bonded. Others do not.
You must conform to your gas company demands. However that gas pipe
gets bonded anyway when furnace or other gas appliances also use
electricity. IOW if building earthing is not provided, then (as
happened in one dwelling) building might use gas line to obtain a
return ground - may use that pipe as an alternative neutral wire.
Fortunately no one was home when a gas line gasket eventually broke
down; house exploded. Just another (and rare) reason why all
'conductive' utilities should share a common earth ground.

Agreed. I asked my utility and they said "DON'T BOND IT"...

blueman wrote:
If that wire is connected to the chassis ground and if that in turn is
connected to the ground prong in the plug, then it should be properly
grounded (and surge protected) in the house. If that electrical signal
is just hanging there isolated from my house wiring then there is not
much I can do about it since I can't access it...

Wire has impedance. That impedance is irrelevant to 60 Hz AC
electricity; grounding that is for human safety. That same ground wire
has too many sharp bends, splices, and bundled with other wires.
Impedance is excessively high for transient protection. Bundled with
other wires, it may even induce transients on those other wires.

Earthing for electronics protection demands other precautions such as
no wire splices, no sharp bends, not inside metallic conduit, separated
from other wires, and especially short distance. AC wall receptacle
safety ground violates principles required for earth ground.

However, when transients are earthed at a building entrance (ie the
'whole house' protector), then higher impedance of interior wiring adds
to appliance protection. This separation and impedance is why better
protected facilities put a protector at earth ground AND distant from
protected electronics.

For earthing each utility in a residential dwelling, each utility
should make a less than 10 foot earthing connection - that wire length
is critical. Therefore utilities enter a building at a common location
to have a short earthing connection to a common earthing electrode.
For earthing (and low impedance), the ground connection must be short -
and other factors.