# cable line grounding



## joecaption (Nov 30, 2011)

I have my cable, phone and cords for my TV and computer plugged into a surge protector now that I picked up at Wal Mart. I had lighting hit a tree about 10' from my house right were my phone and cable run and it came in and blew out my computer and phones so I figured I'd play it safe and not go through that again.
And yes my old cable was grounded. I would not suggest just attaching it to a water pipe. Any break such as any plastic pipe, tape on a joint, oxadation and there is no ground. A ground rod in the ground would be best.


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## amakarevic (Apr 12, 2007)

Comcast definitely does not go that far. At least not in my case. I can try to drive a grounding rod in a foot wide strip of dirt between the house and the concrete walkway but if I hit a rock I'll just have to try a different spot, I.e. can't dig. But I will make an extra hole on the box for the ground wire.

Thanks


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## bobelectric (Mar 3, 2007)

All utilites : electric, phone, cable, satellite, water ect. must be bonded at the same point.The days of little ground rods are done


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## AllanJ (Nov 24, 2007)

I suggest that the first box to which the incoming cable TV cable attaches be grounded. A sure fire way of doing this is to have a #14 copper wire fastened to the stud to which the cable screws or presses on (or to some other part of the chassis of that equipment). The other end of this wire is connected to a known ground

All ground rods for a building need to be bonded together (using #6 copper wire). (Two objects are considered bonded if they are both bonded to the same third object for example two rods with separate wires going to the same panel).

A problem that is seen once in a blue moon is incorrect connection or bonding of cable company equipment up on the utility pole, resulting in the cable itself having voltage on it relative to ground. The ground wires I mentioned prevent energizing of exposed metal parts of your equipment that is passive (such as splitters) or that has 2 prong power cords.


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## J. V. (Jun 1, 2007)

The NEC requires a grounding means like Bob mentions above. Cable and satellite are brought to a grounding block before they enter the structure or dwelling. This grounding block is designed with a grounding screw and is where you connect the #10 ground wire to the system ground/bond. Usually directly to the ground rod. Adding a rod or any other electrode without connecting it to the system ground is pointless.


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## amakarevic (Apr 12, 2007)

Bob, are you saying one ground rod for all, electric, phone, cable, etc.?

If electric was added to the house 60 yrs ago from the street and cable 20 yrs ago from the alley, as well as the phone, how is that possible???

I think that's a nice idea in case you are building a new house but how is that feasible when you're adding utilities as you go?

To summarize, are you saying it won't work if I ground the cable and phone to a new ground rod?

Finally, if that is the case, I wonder why Comcast and Verizon certainly don't do it like that...


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## Yoyizit (Jul 11, 2008)

Grounding in more than one place can result in electrical currents in the shield of coaxial cable. You probably want a Single Point Ground.


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## gregzoll (Dec 25, 2006)

amakarevic said:


> Bob, are you saying one ground rod for all, electric, phone, cable, etc.?
> 
> If electric was added to the house 60 yrs ago from the street and cable 20 yrs ago from the alley, as well as the phone, how is that possible???
> 
> ...


Yes, all communication lines (ie catv, satellite, telco), must be bonded as of the 2008, to a single point, which means the common ground point for the home, whether it is a Ufer, or rod driven into the ground. Now, if the install was done prior, it falls under older rules, and can be attached to the inside cold water pipe, but there is no telling if that is still good, due to who knows if it goes far enough out into the ground, or especially in places like Florida, sand is not a good ground.

For incoming telco, catv, satellite, it should be attached to a common ground block, that then has a wire grounding it to the ground point for the structure. I got smart and moved my telco & catv to the back of the house, ripped of the strap on the side of my meter pan that Comcast had installed, and properly ran the ground wires from the block for the catv & ground point in the telco NID, to the ground rod, that sits two feet from the house.


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## amakarevic (Apr 12, 2007)

Physically impossible in my case. It is a city row house with attached houses on both sides. The electricity comes from the street front, and that's where its ground rod is, the cable and phone from the back alley pole. You'd have to drill a tunnel under the house to connect the two ground rods.


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## Jim Port (Sep 21, 2007)

Where does your water line enter the house?


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## amakarevic (Apr 12, 2007)

Jim Port said:


> Where does your water line enter the house?


Street side. There is a spigot near where the other 2 utils come from the pole.

It is the case with, I'm sure, well over 85% of homes around here... So they must have a workaround


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## gregzoll (Dec 25, 2006)

amakarevic said:


> Physically impossible in my case. It is a city row house with attached houses on both sides. The electricity comes from the street front, and that's where its ground rod is, the cable and phone from the back alley pole. You'd have to drill a tunnel under the house to connect the two ground rods.


Can you bond to the cold water pipe where it comes into the structure, then in turn have the cold water pipe bonded to the panel Neutral/Ground bus bar? That is a possibility.


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## amakarevic (Apr 12, 2007)

gregzoll said:


> Can you bond to the cold water pipe where it comes into the structure, then in turn have the cold water pipe bonded to the panel Neutral/Ground bus bar? That is a possibility.


I think that's how it's currently done through the spigot


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## gregzoll (Dec 25, 2006)

amakarevic said:


> I think that's how it's currently done through the spigot


Take a picture and post of this attachment for ground. You can not attach to the spigot outside, due to it is not a proper ground. You may end up having to have telco and cable ran around the side of the house to enter where power does, so that it can be properly bonded to the ground rod.


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## AllanJ (Nov 24, 2007)

For bonding ground rods (and all qualifying grounding electrodes) you must use #6 copper wire or equivalent (or in a few instances better). Run that wire around the building perimeter if needed.xxxxx Drill a hole in the rim joist or something and run the ground wire across the basement ceiling if needed.

You can get away with informal grounds such as wires running loose and exposed to pieces of equipment being bonded to the nearest pipe although you need to make sure that the pipe provides a continuous electrical path to another bonding wire going to the panel i.e. does not have a plastic section in the middle.

(Between buildings the ground wire accompanying the feed wires, even if smaller than #6, suffices to bond grounding electrodes.)

The grounding block pictured several replies above can result in some video signal loss, given that the coax cable has to be cut and joined there.


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## amakarevic (Apr 12, 2007)

gregzoll said:


> Take a picture and post of this attachment for ground. You can not attach to the spigot outside, due to it is not a proper ground. You may end up having to have telco and cable ran around the side of the house to enter where power does, so that it can be properly bonded to the ground rod.


Dude, there is no "side of the house", it is a city row house with attached city row houses on both sides


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## amakarevic (Apr 12, 2007)

What y'all are saying sounds beautiful and makes sense and I'm sure it's doable with SFHs. However, refer to my description of the property and utility entry points above for why that is not possible. However, since I am positive 85% of homes in my area are like mine exactly in all aspects, I am sure the utilities cos have an established workaround...


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## gregzoll (Dec 25, 2006)

amakarevic said:


> What y'all are saying sounds beautiful and makes sense and I'm sure it's doable with SFHs. However, refer to my description of the property and utility entry points above for why that is not possible. However, since I am positive 85% of homes in my area are like mine exactly in all aspects, I am sure the utilities cos have an established workaround...


There is no such thing as a work around.


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## gregzoll (Dec 25, 2006)

amakarevic said:


> Dude, there is no "side of the house", it is a city row house with attached city row houses on both sides


There is a way to do it, but it requires more info as to showing a picture of the area (ie google maps, with relevant info blacked out), or picture that you have taken to give all of us an idea of what you are dealing with.


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## amakarevic (Apr 12, 2007)

gregzoll said:


> There is no such thing as a work around.


Well how do you think it's done in this exact use case scenario??? By drilling a tunnel under the house?


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## amakarevic (Apr 12, 2007)

The Comcast dude is coming tomorrow, this will be the first question to ask him. And will relay to yall.


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## gregzoll (Dec 25, 2006)

amakarevic said:


> Well how do you think it's done in this exact use case scenario??? By drilling a tunnel under the house?


It has already been explained what to do.


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## gregzoll (Dec 25, 2006)

amakarevic said:


> The Comcast dude is coming tomorrow, this will be the first question to ask him. And will relay to yall.


And you know the first question that he/she will ask is "What is the problem, because I am not seeing one.", or they will never even come to your house, but check at the pole or pedestal, and close the ticket as no problem.

It is not something that they will take their time to do, unless the ground is missing, or you get someone anal, and they do not like how it is currently grounded, and redo it, which will pretty much be how it is now.

From the 2011 NEC:

Exception: In one- and two-family dwellings where it is not
practicable to achieve an overall maximum bonding conduc-
tor or grounding electrode conductor length of 6.0 m (20 ft), a
separate grounding electrode as specified in 250.52(A)(5),
(A)(6), or (A)(7) shall be used, the grounding electrode con-
ductor shall be connected to the separate grounding elec-
trode in accordance with 250.70, and the separate
grounding electrode shall be connected to the power
grounding electrode system in accordance with 820.100(D).

The 20-ft limitation on length results in a lower imped-
ance, which in turn limits the potential difference between
CATV systems and other systems during a lightning strike.
Large potential differences between grounding conductors
can result in increased damage if a lightning strike were to
occur.

The informational note to 820.100(A)(4) provides guid-
ance for the treatment of the cable and primary protector
grounding conductor length at apartment and commercial
buildings that is consistent with the 20-ft rule for one- and
two-family dwellings. However, a specific length is not
specified in the Code, because such a limitation may not be
practical in some installations.

Section 820.100(D) requires bonding of CATV and power
grounding electrodes at the same building or structure. A
common error made in grounding CATV systems is con-
necting the coaxial cable sheath to a rod-type grounding
electrode driven by the CATV installer at a convenient loca-
tion near the point of cable entry to the building, instead of
bonding it to the electrical service grounding electrode sys-
tem, service raceway, or other components that make up the
grounding electrode system. A separate grounding electrode
is permitted only if the building or structure has none of the
grounding means described in 820.100(B)(1) or (B)(2),
which is rare.

Section 250.94 requires that a bonding means with not
less than three termination points that is accessible and ex-
ternal to the service equipment be provided for making the
bonding and grounding connection for other systems. One
of the following means is permitted for existing installa-
tions:

1. Exposed nonflexible metallic raceways
2. An exposed grounding electrode conductor
3. An approved means for the external connection of a
conductor (A 6 AWG copper conductor with one end
bonded to the service raceway or equipment with about
6 in. exposed is acceptable.)

Proper bonding of the CATV system coaxial cable
sheath to the electrical power grounding electrode is needed
to prevent potential fire and shock hazards. The earth cannot
be used as an equipment grounding conductor or bonding
conductor, because it does not have the required low-
impedance path. (See 250.54.)

Both CATV systems and power systems are subject to
current surges as a result of, for example, induced voltages
from lightning in the vicinity of the usually extensive out-
side distribution systems. Surges also result from switching
operations on power systems. If the grounded conductors
and parts of the two systems are not bonded by a low-
impedance path, such line surges can raise the potential dif-
ference between the two systems to many thousands of volts.
This can result in arcing between the two systems — for
example, wherever the coaxial cable jacket contacts a
grounded part, such as a metal water pipe or metal structural
member — inside the building.

If a person is the interface between the two systems and
the bonding has not been done in accordance with the Code,
the high-voltage surge could result in electric shock. More
common, however, is burnout of a television tuner, a part
that is almost always an interface between the two systems.
The tuner is connected to the power system ground through
the grounded neutral of the power supply, even if the televi-
sion set itself is not provided with an equipment grounding
conductor.

Also see the commentary following 250.92(B) and
820.100(E).

The bonding requirement of 250.94 addresses the diffi-
culties sometimes encountered by communications and
CATV installers trying to properly bond their respective sys-
tems together and to the electrical supply system. These dif-
ficulties arise from the increasing use of nonmetallic
materials for water pipe, fittings, water meters, and service
conduit. In the past, bonding between communications,
CATV, and power systems was usually achieved by connect-
ing the communications protector grounds or cable shield to
an interior metallic water pipe, because the pipe was often
used as the power grounding electrode. Thus, the require-
ment that the power, communications, CATV cable shield,
and metallic water piping systems be bonded together was
easily satisfied. If the power was grounded to one of the
other electrodes permitted by the Code, usually by a made
electrode such as a ground rod, the bond was connected to
the power grounding electrode conductor or to a metallic
service raceway, since at least one of these was usually ac-
cessible.

With the proliferation of plastic water pipe and the ser-
vice equipment sometimes being installed in finished areas
(often flush-mounted), where the grounding electrode con-
ductor is typically concealed, as well as the increased use of
nonmetallic service-entrance conduit, communications and
CATV installers often do not have access to a suitable point
for connecting bonding jumpers or grounding electrode con-
ductors. For further information, see the commentary fol-
lowing 820.100(D), Informational Note No. 2.


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## rrolleston (Oct 17, 2011)

I have seen some cable installers install this silly little clip on the meter for a ground. Don't make sense when all that is in the meter socket is the neutral and that has to pass all the way back to the main service for a ground.

I really don't understand how that makes a good ground.


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## gregzoll (Dec 25, 2006)

rrolleston said:


> I have seen some cable installers install this silly little clip on the meter for a ground. Don't make sense when all that is in the meter socket is the neutral and that has to pass all the way back to the main service for a ground.
> 
> I really don't understand how that makes a good ground.


Mine has a ground running from it, to ground the can to the grounding rod. I thought that the strap was silly also, since there is usually paint on the box, or they scrape it off, if they are wise, and in turn causes the box to rust over time.


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## amakarevic (Apr 12, 2007)

gregzoll said:


> It has already been explained what to do.


It was explained assuming you can connect the power and phone/cable ground rods. But it is impossible because they are on two unconnectable sides of the house


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## amakarevic (Apr 12, 2007)

I just spoke with a friend who is an elec engineer and he says the ground rod for the phone and cable should be separate from power and not even connected cause a connection can disrupt the phone/cable signal. Just relaying what he said, verbatim.


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## Jim Port (Sep 21, 2007)

The electrical engineer apparently does not know the electrical code requirements.

Is there a reason a conductor cannot be run through the ceiling of the house in the basement from front to back to connect the rods?


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## amakarevic (Apr 12, 2007)

Jim Port said:


> Is there a reason a conductor cannot be run through the ceiling of the house in the basement from front to back to connect the rods?


Is this a joke? Well, I will ask the dude tomorrow. In fact, to be sure, I will show him this thread first hand to avoid lost in translation. But I appreciate everyone's input. Sounds like a stalemate from the code Nazi points of view. I will ask my neighbor if I can take his house down in order to run wire underground to connect the two rods...


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## gregzoll (Dec 25, 2006)

amakarevic said:


> Is this a joke? Well, I will ask the dude tomorrow. In fact, to be sure, I will show him this thread first hand to avoid lost in translation. But I appreciate everyone's input. Sounds like a stalemate from the code Nazi points of view. I will ask my neighbor if I can take his house down in order to run wire underground to connect the two rods...


No it is not a joke. The joke will be, when the catv contractor either shows up or not. If they do, they will look at it, state no problem and leave.

I have been there, when I tried to get Comcast to fix their shoddy grounding. I ended up taking matters into my hand and doing it myself, the correct way.


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## diy'er on LI (Jul 6, 2009)

I have no idea how to properly ground cable wires... just going to say that like Joecaption, the crappy grounding job that cablevision did ultimately caused the destruction of 3 TVs and a DVD player. Mercifully, this was years ago... before we had internet.

Cable companies really don't give a crap about grounding. Definitely do 'overkill' on the grounding the best you can. Just to be super safe, we never have a computer hardwired into the modem. Everything runs on secured WiFi because of our distrust of cable grounding.


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## rrolleston (Oct 17, 2011)

gregzoll said:


> Mine has a ground running from it, to ground the can to the grounding rod. I thought that the strap was silly also, since there is usually paint on the box, or they scrape it off, if they are wise, and in turn causes the box to rust over time.



Yeah once it rusts you won't even have a ground since they put it right on top where the water sits. Here they will not allow me to ground to the can. Even though the power company said it is OK. Inspectors are strange sometimes I don't understand and sometimes I fully agree with what they say.


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## Jim Port (Sep 21, 2007)

As they say on "Shark Tank" " I'm Out."


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## gregzoll (Dec 25, 2006)

rrolston, by 250.24, as long as it can be grounded either at the rain head, meter can, or main panel, it is acceptable. Here, they ground at the meter, then bond the main panel to the inside cold water copper, which is copper out to the water meter. If you have PEX, they bond the main panel out to the ground rod, or use a Ufer.


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## AllanJ (Nov 24, 2007)

Once in a blue moon incorrect grounding results in damage to cable company equipment and the cable company blames the customer for improper grounding. If you run proper grounds yourself you should avoid problems although I believe that the cable company has to prove its case with more than just the fried equipment itself.


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## J. V. (Jun 1, 2007)

amakarevic said:


> I just spoke with a friend who is an elec engineer and he says the ground rod for the phone and cable should be separate from power and not even connected cause a connection can disrupt the phone/cable signal. Just relaying what he said, verbatim.


He's does not know what he is talking about. 



Jim Port said:


> As they say on "Shark Tank" " I'm Out."


I don't blame you. This OP deserves no help. Smart ass to say the least.



AllanJ said:


> Once in a blue moon incorrect grounding results in damage to cable company equipment and the cable company blames the customer for improper grounding. If you run proper grounds yourself you should avoid problems although I believe that the cable company has to prove its case with more than just the fried equipment itself.


Lightning causes these issues and I don't care how good a job anyone did of grounding/bonding of the system, a direct strike is going to cause damage. There is little you can do to stop a direct hit.

Our cable and satellite companies are very diligent about grounding the dish or cable system. However, they used the wrong size wire in my instance.


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## amakarevic (Apr 12, 2007)

What if I run the ground wire into the main panel ground rod through the basement?


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## gregzoll (Dec 25, 2006)

We already stated that is one option. It will have to be at least min. #8, with the ground wired clamped or bonded to the wire, that gets bonded to the ground on the panel. Better, if you can get that wired out to the ground rod, and clamped to it, vs. landing it in the panel.


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## amakarevic (Apr 12, 2007)

panel would be way easier than going to the rod.

but here is another option: i have a shed close to the where the cable anchors into the house that has its own subpanel and a ground rod next to it, for power. it's wired legit, i.e. the subpanel is grounded to the ground inside the house from where it feeds and its own ground rod. so, if i go to this rod, and in this case i can actually access the rod and not go through the subpanel, that should do, right ?? however, that subpanel connects ground also to the ground bus inside the house, not going all the way to the original ground rod.

the trench i'd need to dig would be about 15-20 ft, no big deal. the alternative for the inside house panel ground bus would require drilling through a thick brick wall, something i don't look forward to doing.

thanks


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## gregzoll (Dec 25, 2006)

I do not see a problem, as long as you are bring the feeds to that structure, grounding them to the ground, which as long as it is interconnected to the main structure. Now the catch is, that if you get a lightening strike, it can use the telco or catv to get into the main structure, since it would be "shortest path to ground". Do what you wish, but if it was me, I would be using gas discharges on them, or installing a whole house surge, with telco & catv protection, at the main panel in the house, vs just expecting that the ground will never fail out in that secondary structure.

(4) Grounding Electrode. The grounding electrode shall
be as near as practicable to, and preferably in the same area
as, the grounding electrode conductor connection to the sys-
tem. The grounding electrode shall be the nearest of one of
the following:
(1) Metal water pipe grounding electrode as specified in
250.52(A)(1)
(2) Structural metal grounding electrode as specified in
250.52(A)(2)
Exception No. 1: Any of the other electrodes identified in
250.52(A) shall be used if the electrodes specified by
250.30(A)(4) are not available.
Exception No. 2 to (1) and (2): If a separately derived sys-
tem originates in listed equipment suitable for use as ser-
vice equipment, the grounding electrode used for the service
or feeder equipment shall be permitted as the grounding
electrode for the separately derived system.
Informational Note No. 1: See 250.104(D) for bonding re-
quirements for interior metal water piping in the area served
by separately derived systems.
Informational Note No. 2: See 250.50 and 250.58 for re-
quirements for bonding all electrodes together if located at
the same building or structure.

250.54 Auxiliary Grounding Electrodes
One or more grounding electrodes shall be permitted to be
connected to the equipment grounding conductors specified
in 250.118 and shall not be required to comply with the elec-
trode bonding requirements of 250.50 or 250.53(C) or the
resistance requirements of 250.53(A)(2) Exception, but the
earth shall not be used as an effective ground-fault current
path as specified in 250.4(A)(5) and 250.4(B)(4).


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## amakarevic (Apr 12, 2007)

Thanks a lot. BTW, how deep do I have to bury conduit. Is 6" enough or should I go deeper. I've buried conduit before but it was with a water line side by side 3' because of the frost line for water, I imagine I won't have to go nearly that deep.


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## gregzoll (Dec 25, 2006)

What does your local state? If you can get 24" or deeper, even better. Six inches is only good, if you plan on just using it for temp purposes, and pulling up at the end of the season. Not good for the long term.


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## amakarevic (Apr 12, 2007)

I dunno, I can ask the county. It is a very narrow strip between the house and the walkway, if I can reach to dig a foot i'll be happy


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## amakarevic (Apr 12, 2007)

If I have to go 2' I might as well drill a hole in the wall and go through the basement to the main panel


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## amakarevic (Apr 12, 2007)

Here is how narrow it is


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## amakarevic (Apr 12, 2007)

Oops, forgot the photo.


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## gregzoll (Dec 25, 2006)

amakarevic said:


> If I have to go 2' I might as well drill a hole in the wall and go through the basement to the main panel


That is how I would do it. In MDU's, and office buildings, the grounding is done inside the structure, not at point of entry. Cables come in through conduit or raceway, then get bonded to structure ground at the closet, or place of demarc inside the structure.


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## amakarevic (Apr 12, 2007)

How do I clamp connect a single wire coming into the panel? It is too skinny for a 3/8" clamp connector, which is designed for 14/2 romax cable or fatter


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## amakarevic (Apr 12, 2007)

OK, so i am running the ground green wire solid NM AWG 10 from the 2nd floor through the house into the basement.

2 questions:

1. are there any issues with this wire being tied together with the phone and coaxial cables, which also need to go from the same spot in the 2nd floor into the basement? my concern is whether the surge in the ground wire can damage the other two cables despite the insulations. maybe i am just paranoid...

2. on its way through the 1st floor, this wire will go through an exposed framing area of the washer/dryer alcove. there is an old galvanized steel 1.5" pipe that is used for venting the washer drain pipe to which i can conveniently cable tie the ground and the other two cables. the question is similar to #1, are there any issues with tying a ground wire to a steel pipe (which itself is not connected to the ground) ?

thanks


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## gregzoll (Dec 25, 2006)

Yes, you would have a "Floating Ground", and also cause a "Ground Loop", due to the isolated ground.


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## amakarevic (Apr 12, 2007)

gregzoll said:


> Yes, you would have a "Floating Ground", and also cause a "Ground Loop", due to the isolated ground.


yes to what?


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## gregzoll (Dec 25, 2006)

Yes to the fact, that if you ground to the pipe that you are thinking about, that is for venting, which is not grounded.


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## amakarevic (Apr 12, 2007)

gregzoll said:


> Yes to the fact, that if you ground to the pipe that you are thinking about, that is for venting, which is not grounded.


i am not grounding "to the pipe" -- just **securing** the insulated solid gauge 10 ground wire so it doesn't dangle loose -- on its way to the basement to be grounded into the ground bus bar in the main panel.

so the steel pipe is just for tie to it, much like you would staple the cable to a 2x4 stud...

is this OK and is it OK that this green insulated ground wire be tied up for convenience with the phone and coax cables? my concern is that the high surge from a thunfer strike could fry the other two cables in its proximity despite the insulation on both sides. 

thanks


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## gregzoll (Dec 25, 2006)

That should be fine. Worst case scenario, if there ever is a lightening strike, and the pipe gets energized, it can burn the insulation on the wire, then continue onwards. I would just probably stick with it attached as best at the top & bottom on wood, or if you can pull a smurf tube or conduit, that may be the better option.

Even if you can not secure, floating in the air along that channel that you are running it in, would not be a problem, due to if there is no way anyone can mess with the wire, and no plans later to run anything else through there, I would not worry.


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## amakarevic (Apr 12, 2007)

oh there is a lot of wood attaching both before and after the pipe attachment.

thanks


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## rrolleston (Oct 17, 2011)

It seems it would be nuch easier to install the cable tv wire and grounding block somewhere inside where it's easier to run a ground wire to it. Or install another one inside and leave the other one alone.


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