Best option for Cable TV Bonding

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ldavisfl

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Location
Denver, CO
I am looking for any opinions on the best option for grounding a relocated Cable TV drop. The current drop is a classic scenario where the drop is near the electrical service drop. The cable runs down house surface, is grounded via an IBT on the grounding electrode conductor, and then enters house. No problems.

Trouble is, I've built a detached shop and the cable drop must move (because it's literally on the roof of the new building). The NEW drop will be on the back of the shop, and the coax cable enters the shop through the wall, runs through the walls, enters a PVC conduit passing down through the slab, runs underground in a dedicated conduit back to the original service location.

The issue here is that the new cable drop location at the shop building is not coincident with the subpanel inside the shop building where I will bond it. It's about a 22 ft run inside the walls to get a grounding conductor from the shop's subpanel to the new cable drop location.

What's the best grounding method. The options I can think of are:

(1) Put new IBT near new cable drop, run AWG6 cable through walls and bond to grounding bar in panel (about 22 ft).
(2) Put new IBT on shop exterior, near the subpanel, and then run AWG outside around to the cable drop location (about 22 ft).
(3) Put new IBT near new cable drop, run AWG6 cable over about 10 ft and bond/clamp it to the shop's second grounding electrode (about 10 ft away from IBT) which itself connects to grounding panel.
(4) Something else I haven't though of

Option 1 would be the tidiest (hidden) but 22 ft is a long run and exceeds the 20 ft required by 800.100(A)(4). Option 3 strikes me as the best. Although the run would still be effectively 22 ft from the IBT to the subpanel, it would pass by 2 grounding electrodes on the way to the sub panel.

Second question, unrelated to the above, I'd like to have the coax cable's conduit come up, turn, and enter through the sill plate into the basement. I was thinking that I would bond the coax cable back to the main panel just inside the house as it is now. The coax would be bonded twice, in other words: once where it first drops to the shed, and again where it enters the main house. Does this seem like a correct grounding solution for a coax cable that is "running though" an accessory building on its way to a 1-family dwelling? Is the second bonding even required, or possibly a bad idea?

I have attached a sketch.

cable_drop_grounding.jpg

Thank you,
LDavisFL
 

hbiss

EC, Westchester, New York NEC: 2014
Location
Hawthorne, New York NEC: 2014
Occupation
EC
Option 4- let the cable company worry about it. Not your responsibility.

The only thing you do need to do is get the RG6 from the old location to the new before the cable company arrives to run the new drop. Let them connect it up.

-Hal
 
Last edited:

hbiss

EC, Westchester, New York NEC: 2014
Location
Hawthorne, New York NEC: 2014
Occupation
EC
That's what I would do too. Bury it around the house. I would probably drive another ground rod at the drop location and bond that around to the ground rod around the corner. That way the cable guy has the rod right there to connect his ground to and he shouldn't have to think too hard.

Beyond that I wouldn't do anything more because those guys have their own rules and ways of doing things and you would only be wasting your time. Like if you put fittings on the RG6- guaranteed they will cut them off and install their own.

-Hal
 
I am looking for any opinions on the best option for grounding a relocated Cable TV drop. The current drop is a classic scenario where the drop is near the electrical service drop. The cable runs down house surface, is grounded via an IBT on the grounding electrode conductor, and then enters house. No problems.

Trouble is, I've built a detached shop and the cable drop must move (because it's literally on the roof of the new building). The NEW drop will be on the back of the shop, and the coax cable enters the shop through the wall, runs through the walls, enters a PVC conduit passing down through the slab, runs underground in a dedicated conduit back to the original service location.

The issue here is that the new cable drop location at the shop building is not coincident with the subpanel inside the shop building where I will bond it. It's about a 22 ft run inside the walls to get a grounding conductor from the shop's subpanel to the new cable drop location.

What's the best grounding method. The options I can think of are:

(1) Put new IBT near new cable drop, run AWG6 cable through walls and bond to grounding bar in panel (about 22 ft).
(2) Put new IBT on shop exterior, near the subpanel, and then run AWG outside around to the cable drop location (about 22 ft).
(3) Put new IBT near new cable drop, run AWG6 cable over about 10 ft and bond/clamp it to the shop's second grounding electrode (about 10 ft away from IBT) which itself connects to grounding panel.
(4) Something else I haven't though of

Option 1 would be the tidiest (hidden) but 22 ft is a long run and exceeds the 20 ft required by 800.100(A)(4). Option 3 strikes me as the best. Although the run would still be effectively 22 ft from the IBT to the subpanel, it would pass by 2 grounding electrodes on the way to the sub panel.

Second question, unrelated to the above, I'd like to have the coax cable's conduit come up, turn, and enter through the sill plate into the basement. I was thinking that I would bond the coax cable back to the main panel just inside the house as it is now. The coax would be bonded twice, in other words: once where it first drops to the shed, and again where it enters the main house. Does this seem like a correct grounding solution for a coax cable that is "running though" an accessory building on its way to a 1-family dwelling? Is the second bonding even required, or possibly a bad idea?

I have attached a sketch.

View attachment 23431

Thank you,
LDavisFL

I would recommend option 3 and run your bare copper bonding conductor, direct buried outside of the conduit.

Doing so will help you create an equipotential with the structures grounding system reducing the possibility of damage to any devices involved with the CATV.

By the way if your screen name indicates you are in FL which is a lighting capitol of the U.S. proper grounding and more importantly proper bonding is key to prevent surge or lightning induced damaged.

Wayne
 

hbiss

EC, Westchester, New York NEC: 2014
Location
Hawthorne, New York NEC: 2014
Occupation
EC
At the end of the day it doesn't really matter what you do because the cable company will do whatever they want or have been instructed to do. They don't have to use anything you provided nor can you require it. If you tamper with their grounding after they leave it can leave you liable for damages to their cable boxes and them not liable for any related damage to your house, wiring or electronics.

Every time a cable guy comes to my house little makes sense in the way they ground. If I say something they say that this is the way they have to do it. Just do what I do and walk away shaking your head. :slaphead:

-Hal
 
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