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Dish far from house ground

Discussion in 'DIRECTV Installation/MDU Discussion' started by Neurorad, Oct 18, 2012.

  1. Neurorad

    Neurorad Cool Member

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    Nov 22, 2009
    Emphatic No, not second guessing. Trying to determine what the installer will want - first guessing. I'm trying to set this up for an easier install, fewer snags. Time is money.

    I believe this will be much more expensive than free. I understand the installer will not put the dish where I would like, out of sight. I will do what I can to correct that, before he shows, and this will cost me time and money. No question.

    I WILL have the NEC compliant ground set up, ready for installation, without additional time and cost constraints to the installer. Get in, get out, get paid. I understand the installer's point of view, completely.

    To me, second guessing is questioning a decision made by someone else. I want to set this up so that there is no decision to make. I want this to be an easy job, for the installer.
     
  2. jimmie57

    jimmie57 Hall Of Fame

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    What if you just wait, let the installer install it like he has to do it to get it approved by his boss and then after it is approved, change the ground to the way you want it to be ?
     
  3. Neurorad

    Neurorad Cool Member

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    Nov 22, 2009
    Currently, the only realistic option for dish position is in close proximity to the service entrance and whole house ground, at the front corner of the house. I'm pretty sure that is where the installer would want it located. It's currently the only realistic option, with no 'proper' ground at the opposite back corner of the house.

    I want to change that, before the installer arrives.

    If a relatively straight 17 gauge messenger wire run from the dish to the service entrance or water main entrance (accessible, inspectable, listed) is all that is needed to be code compliant, I don't think the installer will balk, if I have that cable retrofitted before he arrives. I guess there is a way to find out.

    I wish a local DTV Supervisor could be consulted, before I go through the trouble.
     
  4. Neurorad

    Neurorad Cool Member

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    Nov 22, 2009
    The wiring closet is in the basement. Proposed dish location on brick, single story in that part of the house. Attic space has a plywood floor, easy access to roof sofit. I can easily have a cable there, ready for installation, run to the basement - it's about 30 feet directly, but needs to run up to the other, 2nd story attic first, down 2" conduit to the basement, and then to the wiring closet. Probably 60' total. Most TV drops have been labelled, I will ring them out and label all 5 (of the 24 drops available, 2 cables to every location, most unused). Currently running Comcast cable without any amps. All but 1 drop were prewired, before construction, so they're all pretty direct runs.

    I retrofitted 4 2" conduits, attic to basement. 2 are currently empty. House came with 2 x 15 dB drop amps at the hub, I think for a previous dish (actually in my proposed/preferred location), but they're not connected. Power outlet at the distribution hub. Hardwired LAN drops everywhere they might be needed.

    The only obstacle is an NEC-compliant ground.
     
  5. dielray

    dielray Legend

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    Aug 5, 2009
    Satellite has to comply with both 810 and 820 of the NEC.

    The ground of the antenna and not the coax must use a minimum of AWG 17 copper-clad steel or AWG 10 solid copper to comply with the NEC. Technically the NEC allows AWG 8 aluminum to be used, but DirecTV does not. The gauges seem to have more to do with integrity. This would be the wire from the dish to the ground block.

    Coax is exempted from needing an antenna discharge unit under 810 provided it is grounded with AWG 17 copper-clad steel or AWG 10 solid copper. 820 requires a minimum of AWG 14 solid copper. To comply with both, you would have to use AWG 10 solid copper to connect the ground block to ground. 820 also restricts the length of this wire to no more than 20 ft.

    The water main is a toss up on whether the installer would even use it. To ground it would have to be continuous metal under ground for at least 10 feet. It would have to be clamped on within 5 ft of where it enters. It would need to be bonded to the service ground. Techs would have to prove it is continuous underground for at least 10 feet, which they don't have a way to do, so it just isn't bonded to.

    Your only real option is to put in an addition ground rod and bond it back with AWG 6 solid copper to the service ground.
     
  6. Neurorad

    Neurorad Cool Member

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    Nov 22, 2009
    Thanks, dielray. I'm trying to determine an easier option than a 2nd ground rod located a great distance from the service entrance.

    Why can't the ground block could be located at/near the service entrance, with 17 AWG messenger wire run from the dish to the service entrance, for the mast and coax?

    And, would I need 2 runs of 17 AWG copper clad steel messenger wire?

    Yeah, I understand about the water main. I may end up calling the utility company to help locate it - enters the house below grade, behind finished drywall. If I do use it, will require that this termination be exposed/inspectable, so I have that to contend with. The 'AHJ', in this case, would be the DirecTV local supervisor. Anyone have a tip on contacting him/her?
     
  7. jimcoe

    jimcoe Cool Member

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    Jul 24, 2012
    Installing a 2nd ground rod is very rarely done because of the expense and trouble. The rod must be 8 ft in the ground and if it is more than 20 ft from house ground, a second intermediate rod would be required. Also, 20 ft is the maximum length of ground wire from the dish to ground point. The ground wire must always be shorter than the length of coax from dish to house entry point. I'm pretty sure only 8 gauge is required between the ground rods and house ground but you should check me on this. A lot of installers carry 4 ft ground rods with them but they do not meet code. In some areas, only licensed electricians are allowed to do this type work.
     
  8. jimcoe

    jimcoe Cool Member

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    Jul 24, 2012
    The ground wire must be 10 gauge and cannot be longer than the shortest run of coax. 17 ga "meeseger" wire is allowed only from the dish to the ground block at building entrance. 10 ga is required from the ground block to house and cannot be more than 20 ft long. 10 gauge wire is now running about $0.20 per foot wholesale.
     
  9. westom

    westom Mentor

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    A second ground rod may makes electronic damage easier. Code says every wire entering the buildikng must make a less than 20 foot connection to a "common ground". That is only for human safety. For electronics safety, that connection must be as short as possible and less than 10 feet.

    Dish can be anywhere. And has its own earth ground. Its coax wire must first connect to a building's single point ground (via a wire connection as short as possible, no sharp bends, seperated from other non-grounding wires) before entering the building. Satellite coax must enter at the service entrance so that is connects short to that single point earth ground.

    Code requires satellite cable to be earthed by the same electrode used by AC electric and telephone. Electronic protection means that wire must be even shorter, no sharp bends, not inside metallic conduit, etc. Electronic protection means both meeting and exceeding code requirements.

    Forget about a water pipe. Water pipe is often an inferior ground. Most important is the single point ground that should be connected as short as possible (ie 'less than 10 feet') to the AC breaker box, the telephone (installed for free) surge protector, and to your satellite dish coax cable.
     
  10. harsh

    harsh Beware the Attack Basset

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    Nine plus times out of ten, the water comes in from the street side of the home. Do you know where your meter is? Unless the house was moved into place, the water will enter on that side of the house.
     
  11. jimmie57

    jimmie57 Hall Of Fame

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    If the water pipe has been laid in the last several years, it is a good possibility that it is PVC.
    I know mine is and it was put down in 1977.
     
  12. harsh

    harsh Beware the Attack Basset

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    You're playing fast and loose with the terminology here. Common ground has nothing to do with home wiring. The correct term is bonded ground. The term "common" makes an appearance in three phase wiring, but it isn't the same as a ground.
    Another misuse of terms. "Earthing" is to drive a ground rod and connect to it with no bonding. The service entrance is also connected to the neutral "leg" of the power grid.

    The distinctions are important as there's occasionally more than one source of power in a home system and they must all be at the same ground potential. Earthing doesn't accomplish that.
     
  13. Neurorad

    Neurorad Cool Member

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    Nov 22, 2009
    Water meter is in the middle of the front yard, about 60 feet out, centered. Doesn't help me figure out the pipe entrance.

    The water pipe doesn't make a good ground because, AFAIK, it's not bonded to the house ground, and there could be a difference in potential.

    Why is a 17 AWG carrier wire adequate for connecting the dish to the Antenna Discharge Unit, according to the NEC? Politics? This would be adequate to remove static buildup from the dish, but worthless for grounding in the event of a direct strike.

    Are nearby strikes an issue with satellite dishes, like with cable TV? I don't think so, but not sure. I don't think you could get a surge with a wall-mounted dish. The only concern is a direct strike - and that is pretty rare, and nothing will protect against that.

    If this 17 AWG carrier wire is adequate, per NEC, I think it's the way to go, if the local supervisor gives the OK. If my proposed dish was on a 10 foot mast, on the roof, or 30 feet away from the structure with buried cable, I think ground would be a lot more important, and I'd go with the bonded 2nd rod.

    Don't get me wrong - a good ground is essential for redirecting surges. Westom, let it go.
     
  14. veryoldschool

    veryoldschool Lifetime Achiever Staff Member Super Moderator DBSTalk Club

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    I doubt politics has anything to do with it.
    17 AWG is adequate for the voltage/power of the dish.
    It is not intended to be a lightning suppression.
    Grounding the 17 AWG to a larger conductor turns the 17 AWG into a fusable link. What's important is having a ground path to direct the voltage away from your home. 20' of 10 AWG does this.
    A ground rod does this, but needs to be bonded to the house service ground.
     
  15. jimmie57

    jimmie57 Hall Of Fame

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    I had a nearby strike in June of this year.

    It blew out the transformers on the telephone poles on either side of me. It knocked out / killed my phones, turned one small CRT TV screen green that was hooked to an SD dish, 2 ethernet connections and killed the LNB of the HD dish on the other end of the house. My HD TVs were hooked to a Monster Power HDP2400 power center. They shut down but they did restart after unplugging them and letting them reset. Nothing that was plugged into them was damaged. According to the tech that replaced the dish, it was improperly grounded since it was hooked to the box that the AC unit was using.
    This is the only experience I have had since I came to DTV.

    My SD dish that turned the small SD CRT TV screen green was grounded to the water spigot, which was not actually grounded since the water pipes are PVC.

    I know that the first dish was not grounded at all because I installed it myself and did not know any better.

    The new dish is very close to the power coming into the house and is indeed grounded there.
     
  16. dielray

    dielray Legend

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    Aug 5, 2009
    There are 2 things you need to ground to be up to code: the antenna and the coax from the antenna.

    The wire from the antenna to the ground block can only be 17 AWG if it is copper clad steel. If it is solid copper it must be 10 AWG.

    The coax would also go to the same ground block.

    The wire from the ground block to the point you ground can not be longer than 20 feet and must be at least 10 AWG.

    For the most part, you have two places you can ground. By the power meter or a bonded ground rod near the antenna.

    Installers use coax cable with a messenger 17 AWG copper clad steel ground wire from the dish to the ground block. This is what you would want to use. You would want the RG6 to be solid copper.

    If you are going to ground by the power meter you will want to be mindful of the length of coax. Some follow the 150 foot coax max from the ODU to the furthest receiver guideline. This is about the length that can be run with an 8way in line using all 9 SWM channels and be within the values DirecTV requires. This is done so the system can be expanded in the future if need be. Some will go only by what is immediately needed, and thus would depend on your exact setup. Installers do not stock or support amplifiers.
     
  17. Neurorad

    Neurorad Cool Member

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    Nov 22, 2009
    Thank you so much for everyone's input.

    I see 2 problems:

    1. The RG6 needs to run from the ODU to the ADU/ground block (at/near the service entrance), and then halfway back to the middle of the house, to the distribution hub. That's pushing the maximum distance. I may be able to reduce it by finding an alternate path across the attics.

    2. The RG6 'should' be grounded as close to the house entrance as possible. That is not the case, with my proposed location.

    Both of these items need to be approved by the installer and/or supervisor. I think I'll run that dual RG6 (solid copper) with messenger, and sign up for DirecTV.

    Worst case scenario, the installer refuses, and I hire a local satellite installer directly, rather than via DirecTV. Will cost a lot more than free, but that's the way it is, if I want to drop Comcast for satellite. I know some good local guys who would appreciate the business.

    Thanks again, and don't hesitate to add more comments. :)
     
  18. Neurorad

    Neurorad Cool Member

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    Nov 22, 2009
    "17 AWG copper clad steel" is extraordinarily specific. Of course it was from satellite company lobbying. Which came first, 17 AWG copper clad steel messenger cable, or that exemption in the NEC?

    The 17 AWG cable will act like a fuse, with a direct strike, which is exactly why 10 AWG or larger copper is specified.
     
  19. Neurorad

    Neurorad Cool Member

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    Nov 22, 2009
    Where is that rule from? I haven't seen it mentioned elsewhere yet.

    Edited to be more specific.
     
  20. dielray

    dielray Legend

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    810 requires 10 AWG to be used when solid copper. 820 requires solid copper for the coax ground, so 10 AWG is used from the ground block to the ground location.

    I haven't seen anywhere that says it must be shorter than the shortest run of coax. Both 810 and 820 require the ground wire to be as short and straight as practical. 820 requires it to be less than 20 feet.
     

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