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No ground required.


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94 replies to this topic

#51 OFFLINE   slice1900

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Posted 15 April 2013 - 11:37 PM

810.1 says it only covers antennas larger than 1 meter in diameter or width, so while it would cover most larger OTA antennas, it doesn't appear it would cover Directv dishes. I don't see anything that addresses antennas smaller than 1 meter.

 

From what you're saying about not requiring backbonding, would that mean that if you had a grounding block for the coax, you could run a ground wire from that block to your OTA antenna mast to cover the requirement for grounding the mast rather than running a separate grounding wire from the mast to your building ground? Or am I misunderstanding?


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#52 OFFLINE   Rickt1962

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Posted 16 April 2013 - 05:31 AM

As a Home Builder and seeing what grounding does and not does ! If your home get struck by LIGHTNING ! And you dont have the Dish Grounded ! It will follow the cable into the home and could cause a house fire or death ! So people dont be F*** N lazy and GROUND IT !


I had my township's electrical inspector look at my installation and he said it was OK. Not enough power to worry about. My system has never been grounded and I don't think it's made any difference.

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#53 OFFLINE   AntAltMike

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Posted 16 April 2013 - 07:22 AM


I had my township's electrical inspector look at my installation and he said it was OK. Not enough power to worry about.

That was a genuinely dumb comment by the inspector.  There is not enough power to worry about except when there is enough power to worry about, like when the dish gets hit by lightning, or when a storm breaks an electrical power transmission line and it lands on the antenna or contacts its coax.


Edited by AntAltMike, 16 April 2013 - 08:27 AM.


#54 OFFLINE   bobcamp1

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Posted 16 April 2013 - 12:28 PM

810.1 says it only covers antennas larger than 1 meter in diameter or width, so while it would cover most larger OTA antennas, it doesn't appear it would cover Directv dishes. I don't see anything that addresses antennas smaller than 1 meter.

 

From what you're saying about not requiring backbonding, would that mean that if you had a grounding block for the coax, you could run a ground wire from that block to your OTA antenna mast to cover the requirement for grounding the mast rather than running a separate grounding wire from the mast to your building ground? Or am I misunderstanding?

 

 

Because the receiver has two prongs that is precisely why the Dish must be grounded!  Any appliance that is not "double insulated" has to be grounded.  Your refrigerator is not double insulated, it has 3 prong cord.  Your electric drill is double insulated, it has only 2 prongs. This has nothing to do with opinions!

 

"Too many opinions" because of too many clueless, none professional people.  Professional = Electrical Engineer.

As a fellow EE, I'll comment on this post.

 

You can't count on the ground from the receiver to ground your dish or vice versa.  You're supposed to have a dedicated wire connected between the two for that, not just count on the RF shield in the coaxial cable.  

 

Also, the dish is not an appliance.  It sees no hazardous voltages during normal operation (all voltages < 50 V), nor does it directly connect to the electrical outlet.  Even if you considered the dish and receiver to be a system, a single failure in the receiver cannot generate a hazardous voltage at the dish.  And the receiver can easily be a two-pronged IEC Class II device by using a plastic chassis.

 

You generally bond to ground any large metal structure attached to your house.  To protect against overhead transmission lines, maybe your neighbor four houses down gets hit by lightning, etc. from putting 600 V or more on the dish.  You don't have to bond small metal objects, such as the nails holding your siding up, house decorations, doorbells, etc.  How big is the dish?  Pretty small, actually.  As someone else said, only antennas larger than three feet need to be bonded to ground, so the dish is technically excluded.  It doesn't hurt to bond it to ground if you do it correctly (but it is NOT done correctly half the time), and it prevents lawsuits from greedy lawyers, so D* made it their policy to bond the dish to ground.



#55 OFFLINE   n3ntj

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Posted 16 April 2013 - 02:41 PM

As a fellow EE, I'll comment on this post.

 

You can't count on the ground from the receiver to ground your dish or vice versa.  You're supposed to have a dedicated wire connected between the two for that, not just count on the RF shield in the coaxial cable.  

 

Also, the dish is not an appliance.  It sees no hazardous voltages during normal operation (all voltages < 50 V), nor does it directly connect to the electrical outlet.  Even if you considered the dish and receiver to be a system, a single failure in the receiver cannot generate a hazardous voltage at the dish.  And the receiver can easily be a two-pronged IEC Class II device by using a plastic chassis.

 

You generally bond to ground any large metal structure attached to your house.  To protect against overhead transmission lines, maybe your neighbor four houses down gets hit by lightning, etc. from putting 600 V or more on the dish.  You don't have to bond small metal objects, such as the nails holding your siding up, house decorations, doorbells, etc.  How big is the dish?  Pretty small, actually.  As someone else said, only antennas larger than three feet need to be bonded to ground, so the dish is technically excluded.  It doesn't hurt to bond it to ground if you do it correctly (but it is NOT done correctly half the time), and it prevents lawsuits from greedy lawyers, so D* made it their policy to bond the dish to ground.

 

I am also an EE.

 

Grounding the dish is to dissipate static that can accumulate on the dish simply by air movement past it.  It should be grounded per NEC part 820.  It should be grounded to the home's main electrical service electrode (where your electrical service is also grounded to) but must have it's own clamp on the grounding electrode.  If the dish is a good distance (6m or more) from the service electrode, a secondary electrode should be used at the dish location and then the two electrodes must be bonded to each other to prevent possible differences in potential (voltage).  My original dish (1998) was bonded to a nearby water spigot.. the installer never asked if my plumbing was plastic or metal.  It is plastic (PEX) so I had a floating ground when it was initially installed.  I called D* to have the installer come right back out and properly ground the system.  I had to come out and show the installer the NEC book and diagrams to show him how to properly ground my system... too bad D* doesn't train their installers properly.

 

I rarely see satellite systems (D* or E*) properly grounded while out on inspections.


Edited by n3ntj, 16 April 2013 - 02:42 PM.

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#56 OFFLINE   west99999

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Posted 16 April 2013 - 05:43 PM

I rarely see satellite systems (D* or E*) properly grounded while out on inspections.

 

You must be out on old installs cause I can tell you at least with D* quality control has gotten way better and I would say that at least 85% attempt to ground the dish properly although maybe only 60-70% actually do it right.



#57 OFFLINE   bobcamp1

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Posted 17 April 2013 - 07:30 AM

I am also an EE.

 

Grounding the dish is to dissipate static that can accumulate on the dish simply by air movement past it.  It should be grounded per NEC part 820.  It should be grounded to the home's main electrical service electrode (where your electrical service is also grounded to) but must have it's own clamp on the grounding electrode.  If the dish is a good distance (6m or more) from the service electrode, a secondary electrode should be used at the dish location and then the two electrodes must be bonded to each other to prevent possible differences in potential (voltage).  My original dish (1998) was bonded to a nearby water spigot.. the installer never asked if my plumbing was plastic or metal.  It is plastic (PEX) so I had a floating ground when it was initially installed.  I called D* to have the installer come right back out and properly ground the system.  I had to come out and show the installer the NEC book and diagrams to show him how to properly ground my system... too bad D* doesn't train their installers properly.

 

I rarely see satellite systems (D* or E*) properly grounded while out on inspections.

Yes, I mentioned ESD build up in my first post (where I talk about an unexpected zap and falling off the ladder or roof) but forgot it in my last post.  I'm getting more forgetful the older I get.   :(

 

Since my dish is on a 4' metal pole in the ground, I had to make sure it was properly bonded to the ground rod at my service entrance on the other side of the house.  My installer did it right by accident -- he bonded it to my cold water pipe.  It's clearly all copper plumbing.  But I know he didn't check to see if the copper pipe was bonded to the ground rod, because that connection is hidden very well behind insulation.  It took me an hour just to find it.

 

But I'd argue that according to the NEC, it doesn't HAVE to be grounded in certain cases.  If it's just the dish bolted to the side of the house, and it's low enough to the ground so that a fall won't cause an injury, it probably doesn't need it.  But I also don't want installers making that determination, and even if it's not required it's always a good idea, so if I were D* I'd make it company policy to bond all installations to ground.


Edited by bobcamp1, 17 April 2013 - 07:38 AM.


#58 OFFLINE   peds48

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Posted 17 April 2013 - 03:21 PM

You must be out on old installs cause I can tell you at least with D* quality control has gotten way better and I would say that at least 85% attempt to ground the dish properly although maybe only 60-70% actually do it right.

and this statistics are on what?  Is it just in your market on nationwide?  Links?  documents stating these facts?


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#59 OFFLINE   west99999

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Posted 17 April 2013 - 07:45 PM

and this statistics are on what?  Is it just in your market on nationwide?  Links?  documents stating these facts?

Check your PM.



#60 OFFLINE   Rich

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Posted 18 April 2013 - 12:26 PM

Per DirecTV the NEC is required at a minimum but local codes can be more stringent. All local municipalities are required to follow the NEC as well so your inspector is wrong.  They can add stuff to the NEC but cannot take away.

 

And yet, D* tells me the same thing.  I recently had the CMG send out a Tech and a supervisor to do something and the supervisor and I got into it about grounding the system.  He stated it did not need to be done.  I know it was in the NEC at one time, but I really didn't want to wade thru that confusing book that says one thing in one place and then contradicts itself in another place.  Don't even know if the NEC book is still like that, I had enough of trying to wade thru that book and always went to the Electrician's Handbook which is much easier to read and doesn't contradict itself.

 

As of this moment my system has been ungrounded since I joined D* in 2002 and it works quite well.  I do know how to ground it, but  I'd rather have D* do it the correct way (if they ever send someone to my home who knows the correct way, so far that hasn't happened).

 

I did call the CMG agent back and told him what the supervisor told me and he told me the supervisor was wrong.  Still, they haven't sent anyone out to do anything about it.

 

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#61 OFFLINE   Rich

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Posted 18 April 2013 - 12:39 PM

And most of those reasons are wrong.

 

You ground solely to prevent a static discharge on the dish.  Which is insanely rare.  But if you're on a ladder or a roof and you get an unexpected zap, you might fall off.  And all it takes is one senseless death.

 

The DC voltages involved with satellite are simply not dangerous and wouldn't cause a shock.  And I don't think there's a failure mechanism that exists that can get line or neutral voltage on the dish.  Grounding it INCREASES the chance of lightning damage, because you've increased the odds of a strike.

 

Having said all of that, if your code requires it, you have to get it done.  Because if some unrelated electrical disaster happens and your insurance company discovers a missing ground on your dish, they might use it to weasel out of covering the damage.

 

I'll agree with that.  I really see nothing dangerous about it or I would have grounded my system years ago.  Each of my SWM16s has a threaded hole for a screw and says quite clearly, "Ground".  I find the whole thing rather amusing.

 

Rich



#62 OFFLINE   thasatelliteguy

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Posted 09 October 2013 - 09:03 AM

HOLY COW! How can this many people be COMPLETELY WRONG! 

 

1. Grounding has nothing to do with lightning. If you think for even a second, that a number 10 wire is going to do ANYTHING productive to halt over a BILLION VOLTS, then you're a complete moron.

 

2. The NEC, in 2011, SPECIFICALLY says that if the coax is already grounded, NO FURTHER PROTECTIVE DEVICES ARE NECESSARY. Furthermore, since that is always TOTALLY IGNORED, over in the 'should I ground it' section, later, in the 'how can I ground it section' there is an exception written that expands on what "already grounded" means, stating that the internal bonding of the shielding to the chassis/grounding conductor in the receiver is sufficient when plugged into a grounded receptacle. Everyone ignores that one too. DirecTV is the only one that seemed to notice. Their solution was to remove the ground prong altogether, and make the tech ground every system. This decision was due to the fact that 98% of installs would be grounded, but 2% would have a problem or old wiring, and knowing the techs are worthless and wouldn't ground that 2%, they fixed it by saying, OK Ground them ALL. 

 

This is why messenger wire EVEN EXISTS! It was back in the old days when you had a receiver with a ground plug, you grounded the dish, through the messenger, to the ground lug on the rear of the receiver. Then idiots took over and now the NEC is desperately trying to fix it, but no one's listening. Well, it's not that no one's listening, it's more like no one wants to be the one to tell Charlie, "Hey, you know all that grounding stuff I said was gospel and made you spend hundreds of millions on all these years? Yea, well..." Can we say, "terminated with no severence"... lol

 

If you ground the coax to the ground rod on the home, YOU ARE CREATING ANOTHER PATH TO GROUND WITH A DIFFERENT POTENTIAL. The code doesn't say another GROUND is bad, it says another PATH to ground is bad. If something happen to the ground on a given circuit which the receiver is plugged into, and there is a neutral fault, the receiver passes the ground fault voltage to ground via the shield. Since the shield is no where near able to handle that, it can start a fire. To the person who said there's no way for neutral voltage to get on the coax, you're an idiot, and it's idiots like you, who have never been in the field, but think you know something that you don't, are why we are in this mess to start with. Just the other day I got a pretty decent tingle by a dish mast. I had not hooked up the ground from the block to the rod yet. I got a multimeter, and I had 65 volts AC between the block and the rod. You may say me getting shocked justifies the grounding, but I argue that the customer DID HAVE, and now HAS REPAIRED a faulty ground connection at the ground lug of the home. Had I hooked up the ground wire, and not been lightly shocked, the customer would still be living there with his two autistic kids, with more than 1/4 of the power in his house leaking out as stray voltage to pop up wherever and kill one of them. Or it would have gotten worse, and simply turning on the microwave while he washed clothes causing the dryer and water heater to be on also, could overload the shielding's current carrying ability and melt.  It is also not the satellite manufacturer's job to reground your whole house in case of a fault. Their job is to make sure that, assuming the house wiring is in order according to code, that their device is safe. The ground prong DOES THAT.

 

The bottom line is, by grounding the system, when it's already connected to the house grounding system, you are creating a secondary path to ground, with a different potential, and IT IS DANGEROUS. It cannot hold the voltage from the home if it's asked to, it further masks REAL electrical problems in the home that need to be addressed, and it's AGAINST NEC CODE. 

 

READ IT!!

 



#63 OFFLINE   bobcamp1

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Posted 09 October 2013 - 11:34 AM

First, you responded to a really old thread.

 

My state is stuck in NEC 2008 NFPA 70, BTW, along with several other states.  Installers are supposed to check the local building codes first, as each town is allowed to make their own tweaks to the NEC, but I'm sure none of the installers do that.

 

I've installed systems for lightning protection on buildings, and the cables used are several orders of magnitude larger than D* uses.  You're right that it won't help at all with a direct lightning strike.  It can help with an indirect or distant lightning strike.

 

When installing a new system, aren't you supposed to connect ground first, then connect the rest of the cables?  Then you wouldn't have been shocked.  I'm glad you're OK.  But the entire point of the cable being there is prevent installers from shock, and it can't do that if it's not connected. Of course, if the building ground is faulty, then it won't do you any good.

 

Anyway, most new D* installations use equipment that don't have a ground plug, but it doesn't matter.  Depending on the local code the dish will probably have to be bonded to ground.  You can use the RF cable shields for this but only if you've also installed a cable shield grounding block.  THE RECEIVER'S CONNECTION TO GROUND (if it is three pronged) DOES NOT COUNT TOWARDS BONDING THE DISH TO GROUND.  The bond to ground must be made near the point of entrance to the building AND must use 10 AWG copper or equivalent.  I doubt an actual 10 AWG copper wire is used to connect the RF shield ground to the receiver's ground plug inside the receiver.  They probably just use the ground plane on the PCB.  Not to mention that the receiver is probably no where near the point of entrance to the building.  

 

All that NEC and UL60950-1 do is protect from a single failure.  If multiple failures occur that put hot or neutral voltage on the dish, or the house is wired incorrectly, well that's just really bad luck.  No code will protect you from that.  You're right in that following the code at that point may make things worse, in which case the installer needs to do the right thing and notify the homeowner.

 

Having two connections to ground might create a ground loop.  If the two connections to ground are proper, there is no potential difference and no danger, but it's certainly not desired from an interference perspective.  What you're not supposed to have is two different grounds at the same house, because they could be at different potentials.  If you do have two grounds (like I do), they have to be bonded together to remove the potential between them.

 

For others, here's a summary of what's required (see mistake #2).  Also keep in mind that the spec. isn't written very well, which is why there are many discussions as to what actually has to be done for compliance:

 

http://ecmweb.com/de...youll-ever-make



#64 OFFLINE   slice1900

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Posted 09 October 2013 - 01:27 PM

If you ground the coax to the ground rod on the home, YOU ARE CREATING ANOTHER PATH TO GROUND WITH A DIFFERENT POTENTIAL

 

 

Errr...shouldn't your electric be grounded to that same ground rod?  Why would there be a differential potential?  If multiple paths to ground are a problem, then anyone who has more than one receiver with a grounded plug has a problem.  I have over a dozen such receivers, which are connected to four separate electrical panels (themselves connected to three separate utility meters)  Hopefully it is all grounded together at the building entrance (building is only 10 years old so that's probably a pretty safe bet)

 

The coax coming from my dish (as well as the dish mast itself) is not grounded outside, but since the coax is grounded inside you're saying that as far as the 2011 NEC there's no need to do anything further? I don't see where it says that being connected to a grounded receiver would eliminate the other grounding requirements, but it is a bit hard to understand with a casual reading so maybe I'm just missing that. I do notice that the 2014 draft has different requirements for antennas over 1m (like a large TV antenna) and antennas under 1m (like a Directv dish)

 

BTW, for anyone who wants to play along at home, here's the 2011 NEC code. Here's the 2014 NEC draft.


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#65 OFFLINE   AntAltMike

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Posted 09 October 2013 - 01:44 PM

Please note that Post #62 is the first post by thasatelliteguy.
 

HOLY COW! How can this many people be COMPLETELY WRONG! 
 
1. Grounding has nothing to do with lightning. If you think for even a second, that a number 10 wire is going to do ANYTHING productive to halt over a BILLION VOLTS, then you're a complete moron.


Actually, the mast ground connection is intended to reduce the liklihood of the antenna being struck by lightning. There are engineers who disagree with the theoretical basis for that requirement.
 

2. The NEC, in 2011, SPECIFICALLY says that if the coax is already grounded, NO FURTHER PROTECTIVE DEVICES ARE NECESSARY. Furthermore, since that is always TOTALLY IGNORED, over in the 'should I ground it' section, later, in the 'how can I ground it section' there is an exception written that expands on what "already grounded" means, stating that the internal bonding of the shielding to the chassis/grounding conductor in the receiver is sufficient when plugged into a grounded receptacle. Everyone ignores that one too.


I am not familiar with any such language in any version of the code. What you have alluded to sounds like someone's characterization of the code.

Beyond that, I see no need to comment on the remainder of that post.

Edited by AntAltMike, 09 October 2013 - 01:46 PM.


#66 OFFLINE   slice1900

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Posted 09 October 2013 - 02:16 PM

Actually, the mast ground connection is intended to reduce the liklihood of the antenna being struck by lightning. There are engineers who disagree with the theoretical basis for that requirement.

 

 

Say what? How would grounding reduce the likelihood of being struck by lightning? I could almost see the argument that it might increase the likelihood by offering a better path to ground than it otherwise would have (if it weren't for the fact it is hard to imagine #10 wire connecting a mast to ground makes much difference to a bolt traveling several miles through air) But I see no way to argue it could reduce the likelihood.

 

I could see it reducing some of the bad effects of a nearby but not direct lightning strike that induces some voltages in the mast. Certainly it would reduce the potential problems if a storm caused a live electrical wire (or a wet tree with a live electrical wire in it) to fall across the dish/antenna.


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#67 OFFLINE   thasatelliteguy

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Posted 09 October 2013 - 03:30 PM

Ok. 2011 - 820.93 states:

 

Coaxial cables entering buildings or attached to buildings shall comply with 820.93 (A) or (B). Where the outer conductive shield of a coaxial cable is grounded, no other protective devices shall be required.

 

2011 - 820.100 Exception: For communication systems using coaxial cable confined within the premises and isolated from outside cable plant, the shield shall be permitted to be grounded by a connection to an equipment grounding conductor as described in 250.118. Connecting to an equipment grounding conductor through a grounded receptacle using a dedicated grounding conductor and permanently connected listed device shall be permitted. Use of a cord and plug for the connection to an equipment grounding conductor shall not be permitted.

 

2011 - 820.103 Unpowered equipment and enclosures or equipment powered by the coaxial cable shall be considered grounded where connected to the cable shield.

 

Another thing I'd like to point out about all this "antenna grounding" garbage. There is NO ANTENNA! At least not for DNet and Hnet. The radio is separated by plastic from the rest of the unit. This means there is no lead in conductor. None. On a different kind of antenna, there is always a lead-in conductor that conducts the RF into the building. On our dishes, there is no such conductor. There is a coax attached to the ODU, which would clearly fall under 820.103, no matter how you ground it. The "dish" then pitches the signal wirelessly to the ODU. There is no electrical connection. We no more need to ground it than we need to ground the customer's lawn gnome. or the stop sign at the corner. 

 

 I doubt an actual 10 AWG copper wire is used to connect the RF shield ground to the receiver's ground plug inside the receiver.

#10 is not required to ground the shield. #14 solid or stranded is the requirement. Ref 820.100 (2) and (3)

 

 If multiple paths to ground are a problem, then anyone who has more than one receiver with a grounded plug has a problem.  I have over a dozen such receivers, which are connected to four separate electrical panels (themselves connected to three separate utility meters)  

 

Your house is very unusual. Not many people have different meter services to their home. My understanding is that each meter service should be bonded to neutral as well as it's own ground rod at the entrance point of the building.  Yes, if there is another ground point, like a ground block, anyone with multiple receivers with ground prongs has multiple paths to ground.

 

But the entire point of the cable being there is prevent installers from shock

Where exactly did you see that? I don't remember anywhere in the code where things are done for the safety of the 'trained person'. There are even many places where grounding protection is waived in areas where 'untrained persons' cannot access the equipment. ie metal receptacle boxes inside the sheetrock. 

 

 

Depending on the local code the dish will probably have to be bonded to ground.  You can use the RF cable shields for this but only if you've also installed a cable shield grounding block.

 

That's a big negative ghostrider... You cannot, according to 810, use the cable's shield to ground the antenna. (Assuming we think we should) If you are going to apply 810, then the dish must be grounded with #10 solid copper, #17 copper clad steel, or #8 aluminum. The shielding of the coax "shall not be required to be more than 14 AWG.", which would make it inadequate for that purpose.

 

 

Say what? How would grounding reduce the likelihood of being struck by lightning? I could almost see the argument that it might increase the likelihood by offering a better path to ground than it otherwise would have (if it weren't for the fact it is hard to imagine #10 wire connecting a mast to ground makes much difference to a bolt traveling several miles through air) But I see no way to argue it could reduce the likelihood.

 

100% Agreed. And I also would rather it be hooked to its own ground rod and electrically separated from my house so as not to destroy every other electrical device I own.



#68 OFFLINE   AntAltMike

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Posted 09 October 2013 - 03:33 PM

Someone should shoot this thread and put it out of its misery.

#69 OFFLINE   thasatelliteguy

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Posted 09 October 2013 - 03:49 PM

I see they even added more wording to the exception to clear up the part about the plug and cord not being allowed in the last sentence. For god's sakes, it even looks like they are saying you can put a ground block behind the receiver and attach it to the back of the receiver. I'll have to read it a couple hundred more times, but that's my first take.



#70 OFFLINE   peds48

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Posted 09 October 2013 - 04:19 PM

 

 


 

Depending on the local code the dish will probably have to be bonded to ground.  You can use the RF cable shields for this but only if you've also installed a cable shield grounding block.

 

So according to this, we still have to ground.  since we have to ground the dish/mast to a ground block and we use a ground block to bond the coax to the ground.  

 

So if I am correct, this is a moot point.....


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#71 OFFLINE   thasatelliteguy

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Posted 09 October 2013 - 07:42 PM

There was NEVER a requirement to ground the dish to a ground block. And I said it looks like you CAN put a ground block behind the receiver. Besides the ground block is covered under 820 and the dish is covered under 810. So grounding the dish to the ground block and then piggy-backing to ground isn't valid most the time anyway because the requirement for 810 is #10 and the requirement for 820 is #14 so it wouldn't be valid unless you use #10 the whole way. 

 

Actually, under the new 2014, it looks like we again, do not have to ground. They loosened a whole bunch of it. We aren't even under 820 anymore anyways. Instead they carved out an exception for dishes under 1 meter and moved us to 840 which used to be fiberoptic only. So there's a whole new section I'll have to explore and conquer b4 going much further. I had ignored it previously since it's preface so specifically designated it for fiber only.



#72 OFFLINE   thasatelliteguy

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Posted 09 October 2013 - 07:43 PM

There was NEVER a requirement to ground the dish to a ground block. And I said it looks like you CAN put a ground block behind the receiver. Besides the ground block is covered under 820 and the dish is covered under 810. So grounding the dish to the ground block and then piggy-backing to ground isn't valid most the time anyway because the requirement for 810 is #10 and the requirement for 820 is #14 so it wouldn't be valid unless you use #10 the whole way. 

 

Actually, under the new 2014, it looks like we again, do not have to ground. They loosened a whole bunch of it. We aren't even under 820 anymore anyways. Instead they carved out an exception for dishes under 1 meter and moved us to 840 which used to be fiberoptic only. So there's a whole new section I'll have to explore and conquer b4 going much further. I had ignored it previously since it's preface so specifically designated it for fiber only.

 

 

Oh, and Texas has no local code. Never has on low voltage. But in 2011 or 2012, they adopted NEC. None of the local govt anywhere around here has local codes regarding low voltage. (Not past building codes anyways)



#73 OFFLINE   thasatelliteguy

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Posted 09 October 2013 - 07:44 PM

There was NEVER a requirement to ground the dish to a ground block. And I said it looks like you CAN put a ground block behind the receiver. Besides the ground block is covered under 820 and the dish is covered under 810. So grounding the dish to the ground block and then piggy-backing to ground isn't valid most the time anyway because the requirement for 810 is #10 and the requirement for 820 is #14 so it wouldn't be valid unless you use #10 the whole way. 

 

Actually, under the new 2014, it looks like we again, do not have to ground. They loosened a whole bunch of it. We aren't even under 820 anymore anyways. Instead they carved out an exception for dishes under 1 meter and moved us to 840 which used to be fiberoptic only. So there's a whole new section I'll have to explore and conquer b4 going much further. I had ignored it previously since it's preface so specifically designated it for fiber only.

 

 

Oh, and Texas has no local code. Never has on low voltage. But in 2011 or 2012, they adopted NEC. None of the local govt anywhere around here has local codes regarding low voltage. (Not past building codes anyways)



#74 OFFLINE   AntAltMike

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Posted 09 October 2013 - 08:13 PM

I have read half a dozen editions of the code but have not scrutinized the 2011 and 2014 editions, as I no longer have enough professional interest in having mastery of them. What follows is from memory, but if you have copies of the codes of this century, they will give you an idea of what you should be looking for.


The code never required grounding of an antenna. It required grounding of the antenna mast. The mast always had to be grounded to the ground electrode system, or in the alternative, it could be grounded to an 8' rod provided that rod was bonded to the ground electrode system with 6 gauge copper.

In I think 2002, they limited the use of cold water pipes for the ground electrode system connection to just their first five feet from where they enter the building.

In either 2005 or 2008, they put an unreasonable limit on how long the mast ground wire could be, such that it would almost never be satisfied by running the so-called messenger-wire to the coax outer conductor ground block, and was absolutely impossible to satisfy in some other circumstances.

The coax outer conductor had to be grounded as near as possible to the point at which it entered the building. The code used to say that it had to be grounded with solid, insulated copper wire approximately equal in current carrying capability to that of the coax outer conductor, but that under no circumstance could a gauge less than 14 be used for that purpose. I'm quite sure that they reduced the coax ground wire size to 12 gauge. This is the first time I've heard 14 gauge, but that might be reasonable. Does it say in the 2014 revision that the outer conductor must be grounded as near as possible to the point where the coax enters the building?

In I think 2005, they they re-introduced the term static discharge unit for the grounding of the coax outer conductor. That term used to be used back in the days of twin lead when you couldn't ground one conductor without cutting the signal level in half and there was a doo-hickey that I have posted pictures of in some other threads, as I found it for sale cheap on eBay. Then, in I think, the 2008 revision, they said a coax outer conductor ground block satisfied the static discharge requirement. FWIW, there is also a doo-dad about the size of a splitter that discharges the center conductor. somewhat.

Edited by AntAltMike, 10 October 2013 - 09:08 AM.


#75 OFFLINE   AntAltMike

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Posted 09 October 2013 - 09:22 PM

...Texas has no local code. Never has on low voltage. But in 2011 or 2012, they adopted NEC. None of the local govt anywhere around here has local codes regarding low voltage. (Not past building codes anyways)


Construction Codes
Current Codes
The City of Fort Worth subscribes to the 2008 National Electric Code and the 2009 International Building Codes. Please find the most recent City of Fort Worth amendments and interpretations below.

http://fortworthtexa...t.aspx?id=31710

It looks to me like, at present, Ft Worth has not amended any 2008 NEC sections above Article 680.25, but they reserve the right to amend them.

Edited by AntAltMike, 09 October 2013 - 09:35 PM.





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