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Old 28-Sep-2019, 3:40 PM   #1
Mike4565
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Grounding questions

I have some questions about how best to ground my system. GroundUrMast, I've read some of the excellent posts you've referred other users to study.

Our roof-mounted antenna is on a mast on the WEST side of the house. It presently is grounded with #10 copper wire to an 8-foot rod directly below, but not to the service ground - which is on the EAST side of the house. The coax from the antenna enters the house at the SOUTHEAST corner. For various reasons, there are limited options for connecting the existing antenna grounding rod with the service rod.

I could drape #6 wire across the roof (single story house) from the antenna to the service rod on the opposite side. The roof is metal, however, and there would be no practical way to secure the grounding wire to the roof. This inelegant solution would provide the shortest path.

Or, I could route #6 grounding wire around the house under the eaves - this would entail a number of larger-radius 90-deg turns, and would be a much longer run, but I tend to prefer this option. Instead of running the wire out of sight under the eaves I could attach the wire to the side of the house a short distance above ground level, but it would be very visible, which I don't prefer.

1. Either way, should I connect this new line to the existing grounding clamp on the mast, a separate clamp on the mast, or to the top of the existing rod (not preferred, because the grounding rod is poorly accessible)?

2. Should I attach the new line to the house along its journey using regular NM staples, or something else? Does it matter if they are plastic or metal?

3. When it eventually gets to the service rod, should it attach directly to rod, or can it be clamped to some portion of the existing service ground wire that already is exposed?

4. Do I have to be careful that the new grounding wire does not contact any metal along the way, such as existing electrical conduit, fencing, or the like?

Thanks so much...
Mike

Last edited by Mike4565; 28-Sep-2019 at 3:44 PM.
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Old 29-Sep-2019, 5:19 PM   #2
GroundUrMast
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Rather than running #6 AWG all the way around or over your house, consider abandoning the isolated ground rod and running #10 AWG from the mast to the electrical service... The electrical service ground should be the first choice in most applications.

1. Unless the clamp is rated for terminating multiple conductors, you should only land one wire per clamp. Off the top of my head, I don't know of any clamps that are rated for termination of multiple conductors per position.

2. I avoid NM staples in exposed areas due to corrosion/rust problems (more cosmetic than anything else), I have found galvanized staples occasionally but tie-wraps with screw eyelets are readily available in my local big-box stores. Example...
https://www.homedepot.com/p/NSi-Indu...00MH/303983049

3. You can add a new clamp to the electrical service ground rod, split-bolt to the grounding conductor that runs between the rod and service panel or use a clamp/connector to bond to the meter base or service panel (these connectors are designed and rated for the specific purpose). Example...
https://www.electricmotioncompany.co...ter-box-clamp/
https://www.homedepot.com/s/intersys...bonding?NCNI-5

4. I would not intentionally connect the mast bonding conductor to anything other than the mast and the electrical service... I have found that insulated #10 AWG wire is less expensive than bare (go figure) so I have always used insulated wire to bond my mast installations. All that said, in normal operation there will not be any voltage present on the mast or grounding conductor so you don't need to be worried about it.
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Old 29-Sep-2019, 5:28 PM   #3
Mike4565
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Since posting my original query above I've done more research and would like to narrow the focus of my questions...

1. Should I disconnect the existing ground wire from antenna mast to 8' grounding rod below, and instead install a new ground wire to the GES on the opposite side of the house (and a new ground wire from the coax grounding block to the GES)?

2. There is an intersystem grounding block at the GES - should both a new antenna ground wire, and separate coax ground wire, be attached to this block?

3. A big issue I've not found any good solution for, or even referenced in any post here, is the length of run of the new ground wire (about 125'), which will necessitate either one or more splices of shorter lengths of #6 ground wire, or purchasing a roll or wire much longer than I need, at a much greater cost. Yet as best as I can tell, splicing ground wire must only be done with irreversible methods, which appear to have a high cost of their own. Are there any other options?

4. Also best as I can tell, ground wire can be stapled to the wood siding on my house, or (preferred, under the eaves), using common NM staples that do not have to be insulated. Correct?

5. Finally, it seems only common sense, but the ground wire must not make contact with any metal between the mast and GES - including metal gutters, conduit, vents, etc - correct?

Thanks...

Mike
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Old 29-Sep-2019, 5:54 PM   #4
GroundUrMast
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It looks like we were both writing and posting at the same time
Quote:
1. Should I disconnect the existing ground wire from antenna mast to 8' grounding rod below, and instead install a new ground wire to the GES on the opposite side of the house (and a new ground wire from the coax grounding block to the GES)?

2. There is an intersystem grounding block at the GES - should both a new antenna ground wire, and separate coax ground wire, be attached to this block?

3. A big issue I've not found any good solution for, or even referenced in any post here, is the length of run of the new ground wire (about 125'), which will necessitate either one or more splices of shorter lengths of #6 ground wire, or purchasing a roll or wire much longer than I need, at a much greater cost. Yet as best as I can tell, splicing ground wire must only be done with irreversible methods, which appear to have a high cost of their own. Are there any other options?

4. Also best as I can tell, ground wire can be stapled to the wood siding on my house, or (preferred, under the eaves), using common NM staples that do not have to be insulated. Correct?

5. Finally, it seems only common sense, but the ground wire must not make contact with any metal between the mast and GES - including metal gutters, conduit, vents, etc - correct?

Thanks...

Mike
1. Yes, I would opt to use only the existing electrical service GES. This would allow you to avoid the need for expensive #6 AWG wire. Both the mast and coax bonding can be done properly with #10 AWG.

2. An existing Inter-system bonding connector is the ideal connection point in most applications. It's purpose is for bonding masts, coax and phone service.

3. The run length is not an issue. Under normal conditions there is no current in a bonding conductor so there is no voltage drop concern. Again, I see no need to make these bonding connections with #6 AWG... The NEC calls out #10 AWG as the appropriate size for the mast and coax bonding conductors. I would avoid splicing if at all possible.

4. I prefer to use UV stabilized nylon tie wraps & stainless screws... I don't like rust stains.

5. I take measures to avoid intentional connection to other conductors. I also take appropriate steps to protect the conductors from physical damage.
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Old 29-Sep-2019, 8:12 PM   #5
Mike4565
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You're correct about writing at the same time...sorry - and thanks for the great information.

One follow-up question/confirmation: If I use insulated wire, would it be OK if it was in contact with some existing metal object, such as an electrical conduit? I ask because a good place to run the ground wire would include a roughly ten-foot segment where it would have to be side-by-side with a horizontal conduit.

Mike

Last edited by Mike4565; 29-Sep-2019 at 8:20 PM.
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Old 29-Sep-2019, 11:25 PM   #6
GroundUrMast
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Quote:
Originally Posted by Mike4565 View Post
You're correct about writing at the same time...sorry - and thanks for the great information.

One follow-up question/confirmation: If I use insulated wire, would it be OK if it was in contact with some existing metal object, such as an electrical conduit? I ask because a good place to run the ground wire would include a roughly ten-foot segment where it would have to be side-by-side with a horizontal conduit.

Mike
I can't think of any reason not to place insulated wire against pipe or conduit. (I would caution against placing the mast or coax bonding conductor inside metal conduit though. The metal conduit will act as an inductive choke to RF making a lighting induced surge more likely to 'seek' a lower resistance path to ground. In cases where you need the protection of metal conduit, bond the conduit and bonding conductor at both end of the conduit.)
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Last edited by GroundUrMast; 29-Sep-2019 at 11:32 PM.
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