[husker5]

Be kind - this is post #2 - actually a repost of #1 in the Dish forum.

I've read many of the grounding threads and still have a question. I have an install coming this week and I'm a little concerned about the grounding of the dish.

My house is a 2 story colonial (salt box) with an attached 3 car garage (no living space above the garage).

The dish will need to go on the 2nd story roof for LOS. My utility service enters through the the far wall of the garage so that's probably around 30 feet from the house itself.

Here's where I get confused. If the dish is mounted on the roof, it's my understanding that it and the coaxial needs to be connected to a grounding block where the cabling enters the house. Also, the grounding block needs to be connected to the grounding rod used for the electrical utility and this should be no more than 20 feet to meet NEC code.

So, the dish is probably 30' away and about 10' higher than where the grounding block would be. Is this a problem?

I'm also a little concerned about losing about 60' of RG-6 run to go from the house to the outer wall of the garage and back again, but that's what it is.

Just wondering if I'm understanding this right. Any thoughts? The install is being done by Dish but the grounding seems a generic question so please forgive my posting this on the Directv forum also.

Thanks and yes, I'm a noob.

 

[techrep]

One solution would be to drive a ground rod as close to the dish location as is reasonable. This ground rod should then be connected to the house main ground. Run from the new ground rod to the dish, grounding block, and (if used) the multiswitch. The grounding block can be located near the dish or not.

 

[bb37]

Techrep's solution solves the problem of grounding the dish and it's feedlines, but I think there may still be an NEC problem.

The NEC pushes for single-point grounding. In other words, every grounded device should be connected to the same ground rod. If you have multiple grounds, then it's possible for the potential of one ground to be different from the other grounds and that could cause some problems.

If single-point grounding is not possible, then I believe NEC indicates that all ground rods on a house should be connected together. In other words, you are allowed to have a ground rod at the electrical service entrance and another ground rod at the telco, CATV, or satellite demarc, but those two ground rods need to be connected together outside the house.

 

[BattleZone]

bb37 is correct; any secondary ground rod is to be back-bonded to the main ground rod with 6 gauge solid-copper wire. Further, an additional 8' ground rod is to be driven every 10' between the two. Obviously no satellite installer is ever going to do this as a free install.

Both Dish and DirecTV only consider grounding a system to be a requirement if the dish can be mounted within 30' of a valid ground source. Normally techs will try to mount your dish near your electrical service entrance, which is where your house ground is located, so that this can be accomplished. If Line-Of-Site or asthetic requirements dictate that the dish is mounted elsewhere, and a valid secondary ground source isn't available, then the system will not be grounded. Essentially, both satellite companies tacitly concluded that they would rather get a customer installed than to cancel a new install because it can't be properly grounded. Besides, they can always blame the installer for not finding a way to do the impossible for free.

I'd guess that half of all DBS satellite dish installations are not grounded. It's rarely ever an issue, though, certainly, in an ideal world, all dishes would be grounded.

 

[2dogz]

At the point where the electric service enters the garage, is there not an electric meter box on the outside wall? If so, that is an acceptable ground point.

Also, look at the telephone network interface box and see how the phone company grounded their stuff, same requirements.

 

[techrep]

Techrep's solution solves the problem of grounding the dish and it's feedlines, but I think there may still be an NEC problem.

The NEC pushes for single-point grounding. In other words, every grounded device should be connected to the same ground rod. If you have multiple grounds, then it's possible for the potential of one ground to be different from the other grounds and that could cause some problems.

If single-point grounding is not possible, then I believe NEC indicates that all ground rods on a house should be connected together. In other words, you are allowed to have a ground rod at the electrical service entrance and another ground rod at the telco, CATV, or satellite demarc, but those two ground rods need to be connected together outside the house.

That is correct. Multiple grounding points are allowed but, any additional grounding source must be connected to the main grounding source. I mentioned this as "connected to the house main ground."

One solution would be to drive a ground rod as close to the dish location as is reasonable. This ground rod should then be connected to the house main ground.

 

[husker5]

bb37 is correct; any secondary ground rod is to be back-bonded to the main ground rod with 6 gauge solid-copper wire. Further, an additional 8' ground rod is to be driven every 10' between the two. Obviously no satellite installer is ever going to do this as a free install.

Both Dish and DirecTV only consider grounding a system to be a requirement if the dish can be mounted within 30' of a valid ground source. Normally techs will try to mount your dish near your electrical service entrance, which is where your house ground is located, so that this can be accomplished. If Line-Of-Site or asthetic requirements dictate that the dish is mounted elsewhere, and a valid secondary ground source isn't available, then the system will not be grounded. Essentially, both satellite companies tacitly concluded that they would rather get a customer installed than to cancel a new install because it can't be properly grounded. Besides, they can always blame the installer for not finding a way to do the impossible for free.

I'd guess that half of all DBS satellite dish installations are not grounded. It's rarely ever an issue, though, certainly, in an ideal world, all dishes would be grounded.

So, it sounds like I have a lot of options for placing the dish - it's just a matter of how much trouble and cost is involved with adding additional grounding rods and connecting them all back to the main ground rod rod with 6 gauge copper wire?

As is, the dish most likely has to go on the 2nd story roof for LOS which is more than 30 feet from the wall of the garage where the electrical utility enters and where the main ground rod is. I'll keep the additional grounding rods in mind as an option.

Based on what you say and the distance involved, the installer may opt to put up the dish ungrounded or to ground incorrectly (I'm sure that will depend on the installer). I will have this discussion up front and if the ground is not according to code then I assume I could refuse the install? I've seen a lot of opinions on grounding but I guess I wouldn't be comfortable accepting something that wasn't NEC code.

I sure hope this all works out because I really want to drop my cable - but I also want it done to code.

Thanks.

 

[Johnnie5000]

So, it sounds like I have a lot of options for placing the dish - it's just a matter of how much trouble and cost is involved with adding additional grounding rods and connecting them all back to the main ground rod rod with 6 gauge copper wire?

As is, the dish most likely has to go on the 2nd story roof for LOS which is more than 30 feet from the wall of the garage where the electrical utility enters and where the main ground rod is. I'll keep the additional grounding rods in mind as an option.

Based on what you say and the distance involved, the installer may opt to put up the dish ungrounded or to ground incorrectly (I'm sure that will depend on the installer). I will have this discussion up front and if the ground is not according to code then I assume I could refuse the install? I've seen a lot of opinions on grounding but I guess I wouldn't be comfortable accepting something that wasn't NEC code.

I sure hope this all works out because I really want to drop my cable - but I also want it done to code.

Thanks.

Copper isn't cheap these days. Suck it up and put the ground block near the electric meter -or- if your circuit breaker panel is closer put it near that. Both would have acceptable common household ground points to use. 60' of cable to ground block won't hurt a thing.

 

[bb37]

...but, any additional grounding source must be connected to the main grounding source. I mentioned this as "connected to the house main ground."

Sorry about that. I interpreted "house main ground" as the ground bus in the breaker panel, i.e. inside the house, not as the existing ground rod at the electrical service entrance.

 

[bb37]

So, let me toss out another question. I have a production house starting construction next month. I'm getting it pre-wired for a satellite dish installation and I've told the builder approximately where I think the dish needs to be to get LOS. I believe that the RG6 cables I'm getting in the pre-wire will poke out of the wall near the dish which will be 10-14" feet above grade. My understanding of good grounding practice is that the cables should be grounded before they go into the house which means the ground blocks will be high on the wall. That means the ground wire will need to run up the side of the house to the ground blocks. Does this sound right to you guys?

 

[techrep]

Sorry about that. I interpreted "house main ground" as the ground bus in the breaker panel, i.e. inside the house, not as the existing ground rod at the electrical service entrance.

It is a very important point which you make much clearer.

Grounding sources not sharing a common bond can cause the potential difference, you mentioned, and can be the cause of electronic problems.

 

[flipptyfloppity]

Based on what you say and the distance involved, the installer may opt to put up the dish ungrounded or to ground incorrectly (I'm sure that will depend on the installer). I will have this discussion up front and if the ground is not according to code then I assume I could refuse the install? I've seen a lot of opinions on grounding but I guess I wouldn't be comfortable accepting something that wasn't NEC code.

I sure hope this all works out because I really want to drop my cable - but I also want it done to code.

Thanks.

NEC isn't necessarily the code in your area, just so you know.

In the end, it's up to you, but as was noted on here, about half of satellite dishes aren't grounded correctly and you don't hear about houses burning down en masse because of it.

 

[flipptyfloppity]

So, let me toss out another question. I have a production house starting construction next month. I'm getting it pre-wired for a satellite dish installation and I've told the builder approximately where I think the dish needs to be to get LOS. I believe that the RG6 cables I'm getting in the pre-wire will poke out of the wall near the dish which will be 10-14" feet above grade. My understanding of good grounding practice is that the cables should be grounded before they go into the house which means the ground blocks will be high on the wall. That means the ground wire will need to run up the side of the house to the ground blocks. Does this sound right to you guys?

You can run the ground wire inside the wall if you want. Otherwise, yes.

 

[joe diamond]

So, let me toss out another question. I have a production house starting construction next month. I'm getting it pre-wired for a satellite dish installation and I've told the builder approximately where I think the dish needs to be to get LOS. I believe that the RG6 cables I'm getting in the pre-wire will poke out of the wall near the dish which will be 10-14" feet above grade. My understanding of good grounding practice is that the cables should be grounded before they go into the house which means the ground blocks will be high on the wall. That means the ground wire will need to run up the side of the house to the ground blocks. Does this sound right to you guys?

The standard cable run from the dish to the ground block is rg6 with ground. A 12 ga ground wire is attached to the single or double cable along it's length. Run two doubles with ground.......solid copper is the current spec. $$$$ a little. Leave enough to wire the dish and a service loop.

This should end up near where the main bond for the building. The telco NID is there and the electric box is there. Bonf (clamp) a ground wire from the main bond to the ground block. Some codes even ask for a separate lug for accessory grounds.

Joe

 

[BattleZone]

Based on what you say and the distance involved, the installer may opt to put up the dish ungrounded or to ground incorrectly (I'm sure that will depend on the installer).

Correct. I'd bet a month's pay that at least half of all satellite installers don't know what I wrote in my first post. Of the ones that do, many choose not to ground, or not ground properly, anyway. Ground materials are expensive, and grounding takes time. Many installers will skip grounding if they can get away with it. That's the reality.

I will have this discussion up front and if the ground is not according to code then I assume I could refuse the install?

You can *always* refuse the install. Having said that, you need to be realistic in what you expect the installer to do, given that most of they are paying for the grounding materials out of their install pay, not to mention their time and labor. Example: the cost of an 8' ground rod and 30' of 6 gauge copper cable is more than most techs make to do the entire install. Not to mention the labor. Ever try to drive an 8' ground rod? You have to rent a pole setter in order to drive it down the first 5' or so, and then finish with a sledgehammer. As I said, that's something that virtually NO installer is prepared to do (high-end custom installers excepted).

What they are expected to do is use a ground block, and either use coax with a bonded 17ga wire attached, to run from the dish to the ground block, OR run 10ga solid copper wire from the dish to the ground block. Then, 10ga solid copper wire is run from the ground block to a valid ground source, ideally to your power meter, house ground rod, or the 6ga copper wire that connects the two. The ground block should be within 10' of the ground source, max.

I've seen a lot of opinions on grounding but I guess I wouldn't be comfortable accepting something that wasn't NEC code.

As I said, at least half of all installs aren't grounded AT ALL. Of the rest, I'd bet far less than 5% fully meet NEC code, and many areas require a higher standard than NEC.

The main reason to ground your dish is to provide a drain for static buildup on the dish. The main reason to ground your coax cables (which is done via the ground block) is so that the shield can actually SHIELD the center conductor from stray RF radiation by draining it to the ground. This can be accomplished adequately without full NEC compliance. The real world is far from ideal, and on many houses, it would be easy to spend $500 or more to bring the grounding up to NEC specs. That just isn't done.

 

[2dogz]

Another major reason to ground the coax properly is that in case of major damage to the house, falling tree, fire, tornado, etc. the firemen that enter your house would prefer not to be electrocuted by your TV wiring should it become energized.

 

[husker5]

Correct. I'd bet a month's pay that at least half of all satellite installers don't know what I wrote in my first post. Of the ones that do, many choose not to ground, or not ground properly, anyway. Ground materials are expensive, and grounding takes time. Many installers will skip grounding if they can get away with it. That's the reality.

You can *always* refuse the install. Having said that, you need to be realistic in what you expect the installer to do, given that most of they are paying for the grounding materials out of their install pay, not to mention their time and labor. Example: the cost of an 8' ground rod and 30' of 6 gauge copper cable is more than most techs make to do the entire install. Not to mention the labor. Ever try to drive an 8' ground rod? You have to rent a pole setter in order to drive it down the first 5' or so, and then finish with a sledgehammer. As I said, that's something that virtually NO installer is prepared to do (high-end custom installers excepted).

What they are expected to do is use a ground block, and either use coax with a bonded 17ga wire attached, to run from the dish to the ground block, OR run 10ga solid copper wire from the dish to the ground block. Then, 10ga solid copper wire is run from the ground block to a valid ground source, ideally to your power meter, house ground rod, or the 6ga copper wire that connects the two. The ground block should be within 10' of the ground source, max.

As I said, at least half of all installs aren't grounded AT ALL. Of the rest, I'd bet far less than 5% fully meet NEC code, and many areas require a higher standard than NEC.

The main reason to ground your dish is to provide a drain for static buildup on the dish. The main reason to ground your coax cables (which is done via the ground block) is so that the shield can actually SHIELD the center conductor from stray RF radiation by draining it to the ground. This can be accomplished adequately without full NEC compliance. The real world is far from ideal, and on many houses, it would be easy to spend $500 or more to bring the grounding up to NEC specs. That just isn't done.

I think I understand where the grounding block needs to be in relationship to the main grounding rod.

I'm still a little confused whether there is any issue with there being a 35-40' run of RG6 from the dish to the grounding block. Also, If I understand things, there will be a ground coming off the dish and should that be attached directly to the main grounding rod or can it be attached to the grounding block (is it a big deal if done incorrectly).

As for the lucky (unlucky) installer that comes to my house, I'm more than happy to work with them on the cost of doing this right. I have no problems with that. I realize my situation will not be a standard install - very little about it will be and I have no dreams of getting a "free" professional install. I'm just hoping I get someone who is willing to work with me or direct me in what needs to be done. In a way, I kind of wish they did a little pre-install visit but I'm sure we'll get this all figured out.

Thanks everyone for your responses.

 

[BattleZone]

This is just a pic I found on the 'net, but it gives you some idea. The ground wire from the dish goes to the ground block. In this picture, the ground wire is a 17ga wire that is bonded (i.e., "attached" or "twinned") to the coax cable. At the dish and at the ground block, it is pulled apart and attached. You can see the black wire going to the top of the ground block in this pic. If the ground wire is not bonded to the coax, then it must be 10ga solid copper wire.

From the ground block to the ground source, 10ga solid copper wire must be used. In this pic, it is the green wire, and green jacket is preferred (required in some offices) to make it easily identifiable as a ground line. Obviously, by looking at the pic, we assume that there's a ground source inside the building that the other end of the green wire is attached to.

The body of the ground block grounds the shield braid of the coax cables, assuming, of course, that the ground block itself is attached to a ground source.

In my area, we most commonly use a meter panel clamp to provide a grounding point:

In older areas, a grounding strap on the periscope that runs up from the meter to the aerial power lines is also common.

Another common method is to use a split bolt to bond the ground wire to the house's main ground wire:

Dish requires a grounding lug be mounted on the dish's mast foot, while DirecTV uses a green ground screw directly screwed into the foot.

When unable to connect directly to something at the main house ground, a secondary ground source may be used, with certain restrictions. For example, if the house uses solid copper cold water pipes that are grounded to the house ground, they can be used as a secondary ground source. A copper ground strap or clamp must be used; you can't mix steel and copper.

You can also put meter clamps on hot tub or AC cut-off switch boxes (not the compressor itself), or ground straps or clamps on solid steel conduit that visibly runs back to the ground source.

Still, grounding requirements can vary with local areas, so I may have missed something, or something I do here may not be allowed there.

 

[Johnnie5000]

Another major reason to ground the coax properly is that in case of major damage to the house, falling tree, fire, tornado, etc. the firemen that enter your house would prefer not to be electrocuted by your TV wiring should it become energized.

Don't think grounding will help much if the house is on fire. :nono:

 

[2dogz]

Don't think grounding will help much if the house is on fire. :nono:

Well, think about it. Fire burns, insulation melts, walls/roof collapse, wires tangle, firefighter enters with hose dousing fire with water, ZAP.

The NEC was designed over the last 100 years for safety, period, the end.