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Dish far from house ground


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#26 OFFLINE   Neurorad

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Posted 19 October 2012 - 06:31 AM

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?

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#27 OFFLINE   jimcoe

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Posted 19 October 2012 - 07:16 AM

The NEC correct way would be to ground the dish via it's own ground rod close to the dish and then bond that ground to the service ground. The local ground provides the path to ground for lightning and bonding it to the service ground prevents differences in ground potential between the coax and electrical outlet (important since the receivers do not have grounded plugs). The dish itself and the coax should be attached to the local rod via at least #10 wire. The wire that connects the local rod to the main service ground can be lighter gauge.


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.

#28 OFFLINE   jimcoe

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Posted 19 October 2012 - 07:28 AM

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.


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.

#29 OFFLINE   westom

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Posted 19 October 2012 - 07:44 AM

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

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.

#30 OFFLINE   harsh

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Posted 19 October 2012 - 08:21 AM

I think I need to find where my water main enters the house.

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.

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#31 OFFLINE   jimmie57

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Posted 19 October 2012 - 09:16 AM

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.

DirecTV customer since 1996 - Current :Slimline 3 SWM, HR24-100 Component cables to 46" Samsung LCD & Optical Cable to Yamaha AVR, H21-200 HDMI to Yamaha AVR & HDMI to 52" Mitsubishi LCD


#32 OFFLINE   harsh

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Posted 19 October 2012 - 09:39 AM

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".

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.

Code requires satellite cable to be earthed by the same electrode used by AC electric and telephone.

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.

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#33 OFFLINE   Neurorad

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Posted 19 October 2012 - 11:20 AM

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.

#34 ONLINE   veryoldschool

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Posted 19 October 2012 - 11:31 AM

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.

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.
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#35 OFFLINE   jimmie57

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Posted 19 October 2012 - 11:59 AM

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.

DirecTV customer since 1996 - Current :Slimline 3 SWM, HR24-100 Component cables to 46" Samsung LCD & Optical Cable to Yamaha AVR, H21-200 HDMI to Yamaha AVR & HDMI to 52" Mitsubishi LCD


#36 OFFLINE   dielray

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Posted 19 October 2012 - 02:07 PM

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.


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.
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#37 OFFLINE   Neurorad

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Posted 19 October 2012 - 02:51 PM

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. :)
Believe nothing, no matter where you read it, or who said it, no matter if I have said it, unless it agrees with your own reason and your own common sense. -Buddha

#38 OFFLINE   Neurorad

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Posted 20 October 2012 - 04:45 AM

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.


"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.
Believe nothing, no matter where you read it, or who said it, no matter if I have said it, unless it agrees with your own reason and your own common sense. -Buddha

#39 OFFLINE   Neurorad

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Posted 20 October 2012 - 04:56 AM

The ground wire... cannot be longer than the shortest run of coax.

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

Edited to be more specific.

Edited by Neurorad, 20 October 2012 - 01:39 PM.

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#40 OFFLINE   dielray

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Posted 20 October 2012 - 05:17 AM

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


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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#41 OFFLINE   jimmie57

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Posted 20 October 2012 - 05:22 AM

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


I am not an electrical guy but doesn't electricity go to ground to the shortest distance ? Would that just be common sense that the ground wire should be the shortest wire since you do not want this unwanted electricity in the other wires ?

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#42 ONLINE   veryoldschool

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Posted 20 October 2012 - 08:54 AM

"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.

The 10 AWG requirement comes from the part of the code addressing TV & Ham radio masts.
It doesn't make any direct reference to a small dish, though it does mention an LNB and a motor, which would be the 2 or 3 meter BUD.
These normally are much higher than the < 1 meter dish, that normally is only 3'.

You seem to think this comes from "lobbying", while I look at it as a "common sense" application.
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#43 OFFLINE   P Smith

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Posted 20 October 2012 - 09:10 AM

"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.


Don't assume the 10 AWG will not vaporized during direct strike.
1/2" copper wire (rod) will be destroyed too in such case.

#44 OFFLINE   harsh

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Posted 20 October 2012 - 12:49 PM

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

Unless your house was moved from somewhere else, it suggests that the water entrance is on the street side -- probably directly in from the meter.

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.

Good and code are two different things. Of course if the pipe is plastic, it doesn't matter where it comes in.

Why is a 17 AWG carrier wire adequate for connecting the dish to the Antenna Discharge Unit, according to the NEC?

As I explained above, it is good enough because the wires it is protecting your home from are smaller gauge. It will theoretically outlast the center conductor of an individual cable when it comes time to go fusible link on you.

The major failing your having in understanding this is that the grounding is not designed to sink a lightning strike. It is simply to discharge static and lower voltages that build up for more conventional reasons.

Too often we enjoy the comfort of opinion without the discomfort of thought. -- JFK


#45 OFFLINE   P Smith

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Posted 20 October 2012 - 01:08 PM

Unless your house was moved from somewhere else, it suggests that the water entrance is on the street side -- probably directly in from the meter.Good and code are two different things. Of course if the pipe is plastic, it doesn't matter where it comes in.As I explained above, it is good enough because the wires it is protecting your home from are smaller gauge. It will theoretically outlast the center conductor of an individual cable when it comes time to go fusible link on you.

The major failing your having in understanding this is that the grounding is not designed to sink a lightning strike. It is simply to discharge static and lower voltages that build up for more conventional reasons.

That is the key to get it done right.

#46 OFFLINE   Neurorad

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Posted 21 October 2012 - 06:59 AM

It appears to me that the 'mast' can be grounded with 17 AWG copper clad steel, run back to the bonded ADU, but every cable coming into the house must also be bonded (coax) with 10 AWG copper, per NEC.

Perhaps I should take a closer look at what the NEC says about my electric pet fence and irrigation system. Neither of those are bonded, and both were 'pro installed'.

I'm MUCH more likely to pick up a nearby surge from those systems. I don't think a small wall amount dish could even get a surge.

I wonder if I could hire a knowledgeable electrician or engineer to figure those out. I need to get a whole house surge protection device ASAP, at a minimum.
Believe nothing, no matter where you read it, or who said it, no matter if I have said it, unless it agrees with your own reason and your own common sense. -Buddha

#47 OFFLINE   P Smith

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Posted 21 October 2012 - 09:45 AM

I would find such man, but who is open to get thru all your concerns and discuss accepting your knowledge of NEC requirement.

#48 OFFLINE   Neurorad

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Posted 21 October 2012 - 12:53 PM

My knowledge of NEC requirements are limited, at best. I'm interested in hiring someone more knowledgeable.

I plan on putting a pool in the back yard in the next 5 years, so extending the ground properly to the dish location may not be a big deal, if the pool needs to be bonded to the house ground. Not sure if that is indicated, though, but probably. Any pool experts? ;)
Believe nothing, no matter where you read it, or who said it, no matter if I have said it, unless it agrees with your own reason and your own common sense. -Buddha

#49 ONLINE   bobnielsen

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Posted 21 October 2012 - 04:24 PM

My knowledge of NEC requirements are limited, at best. I'm interested in hiring someone more knowledgeable.

I plan on putting a pool in the back yard in the next 5 years, so extending the ground properly to the dish location may not be a big deal, if the pool needs to be bonded to the house ground. Not sure if that is indicated, though, but probably. Any pool experts? ;)


It was a requirement when I put a pool in 40 years ago and I doubt any requirements have been relaxed since then.

#50 OFFLINE   Neurorad

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Posted 21 October 2012 - 06:17 PM

Cool, thanks for that. I'll have an excellent, bonded ground very close to the dish (but not too close); I think I saw an NEC minimum distance to a pool, somewhere.
Believe nothing, no matter where you read it, or who said it, no matter if I have said it, unless it agrees with your own reason and your own common sense. -Buddha




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