AVS Forum banner
Status
Not open for further replies.
1 - 18 of 18 Posts

·
Registered
Joined
·
695 Posts
Discussion Starter · #1 ·
I'm not the most mechanically inclined person, but in order to save the cost of professional installation, I think it's a fairly straightforward process to mount an antenna to my house. It's the grounding requirements that I need help with. Here's the situation and perhaps someone can provide a clear, 6th grade-level answer that I can use http://www.avsforum.com/ubb/smile.gif


The antenna will be wall mounted to the highest peak of my house.


The ideal location to mount the antenna is on the opposite side of the house from where the electrical panel is located, as well as the opposite side of where my home theater is located.


For the antenna line itself, I intend to run the line down the side of the house, and then up underneath the bottom-most vinyl siding panel around to where I will connect it via a diplexer to my satellite line to run into the house.


The electrical panel is grounded to the main water line, which is inside the house and in the basement.


Questions:

Will the diplexer serve as a grounding block?

On the side of the house where I will mount the antenna, there is the gas meter and my air conditioner. Can I ground the antenna to the a/c power box?


What and where do I need to ground? I've read so many things about bonding, grounding blocks, surge arrestors, etc. Once upon a time it was just a 10# wire running to a stake in the ground. I want to make sure I get this done right. Any assistance will be most greatly appreciated!
 

·
Registered
Joined
·
1,797 Posts
The most up-to-date version of the NEC (National Electrical Code) requires that new residences' power panel be grounded via an 8' grounding stake. Since this is not your situation, I'm guessing your house is older. The best suggestion I can give you is to use RG6 coax with an integral ground wire for your antenna lead, and run it all the way to your power panel and ground it there.


You can, as an alternative, drive an 8' copper-clad grounding rod into the ground underneath your antenna, and ground it there. Assumming you do not ground the coax shield there, this should provide good lightlning protection and not introduce ground loops.


The reason an antenna is required to be grounded by the NEC is lightning (fire) protection, not to make the antenna work properly. For this reason, the NEC requires the use of a ground wire seperate from the co-ax shield, so no, your diplexor is not a good solution for grounding.


Hope this helps.


------------------
BOYCOTT DVI/HDCP & JVC!
 

·
Registered
Joined
·
695 Posts
Discussion Starter · #3 ·
Ok, so I can ground the antenna to a ground stake. Do I still need a grounding block where the coax enters the house? (running all the way to the service panel would be problematic).


And does the mast need to be grounded separately from the antenna?
 

·
Registered
Joined
·
136 Posts
All you need is to ground the mast then get a seperate grounding block which any Radio schack or Home depot sells.

This is for the coax leading to the house. You must ground this seperately.


------------------

PeterDz
 

·
Registered
Joined
·
695 Posts
Discussion Starter · #5 ·
So there's no problem with grounding the antenna and the grounding block with different ground rods? They will be on different sides of the house.


I also have two satellite dishes already grounded with a ground rod. The ground rod is reasonably close to where the coax enters the house. Should I try to ground the grounding block to the same ground rod as the dishes, or would that be a bad thing?
 

·
Registered
LG 55" C9 OLED, Yamaha RX-A660, Monoprice 5.1.2 Speakers, WMC HTPC, TiVo Bolt, X1
Joined
·
45,617 Posts
I'm not an expert by any means, but I think all grounding must be bonded together at some point. This is NEC code, which is the law of the land.


A good overview drawing of a grounding system can be found in the instruction manual of any TV, VCR or sat dish.


There have been a few in-depth discussions about grounding recently, try a search for a lot more info.


------------------

"better living thru modern expensive electronics"

tm
 

·
Registered
Joined
·
363 Posts
If the antenna is bonded to a seperate ground rod, that ground rod must be bonded to the building power grounding electrode system with a bonding jumper not smaller than No. 6 copper. If these separate grounds are not bonded together, a very large difference in ground potential can develop across, and equalize through, your TV tuner, satellite receiver, etc. Check your local codes. More information about grounding: http://forums.nfpa.org:8081/necfaq/necsrch.htm (search for "dish") http://www.cinergy.com/surge/ttip08.htm
http://www.psihq.com/iread/strpgrnd.htm
http://www.powerclinic.com/tex01.htm
http://www.powerclinic.com/images/te1fig1.gif
http://www.polyphaser.com/ppc_technical.asp
http://www.qsl.net/n1lo/tower.htm
 

·
Registered
Joined
·
695 Posts
Discussion Starter · #8 ·
In order to bond the grounds together, then, do I need to run ground wire directly from the service panel (I have no idea what or where the ground electrode system is, my ground wire terminates at my water meter in the basement) or can I connect it to any electrical system, like my air conditioning power box, which is on the same side of the house? I notice that the phone system box is grounded to the outside of the electric meter (not on the inside of the house where the front of the service panel is).


Who would I call at the city/township level to find out about local grounding requirements? There's got to be a way to do this legally and safely without drilling multiple holes in my house (which I'm trying to avoid) and running yards of wire all over the yard.
 

·
Registered
Joined
·
1,797 Posts
I think there's been some confusion here. There is a difference between grounding the antenna mast and the antenna lead's shield. Yes, it would be very wise to have the grounding blocks (the antenna lead shield) tied to the same ground to prevent a ground-loop current. However, you need not ground the antenna mast to the building power ground.


Since the mast should be isolated from the antenna's leads (both shield and conductor), a ground loop cannot develop. Moreover, the NEC has separate specifications for grounding of masts and antenna leads.


------------------
BOYCOTT DVI/HDCP & JVC!
 

·
Registered
Joined
·
695 Posts
Discussion Starter · #10 ·
Ok, let me see if I've got this straight:


Option #1:

I can ground the mast directly to the ground with a #10 ground wire and a ground stake from Home Depot.


The grounding block from the antenna lead needs to also be grounded to a ground stake, which then should be bonded to the house ground.


Am I close now? If I'm going to ground the antenna lead to the house ground, should I also then bond the satellite dishes at the same time? (they are currently just grounded to a ground stake)


Option #2: (sounds less complicated)

With regard to the A/C and water spickets, here's some more info that might make it easier:

The A/C box is located just under where I want to install the antenna (and right next to the gas meter). Could I just connect the ground wire to the screw that clamps in the power line? I also have a hose bib a little further down, but still in the same vicinity. Should I ground to that instead?


Where the line goes into the house (on the other side of the house), there is no water pipe. The main service panel is further around the house and would require additional wiring. That's where the problem is.


SOOO... If I grounded the mast to the hose bib, and then grounded the antenna leads to a single ground stake, would that work? I'm looking for the easier (and still legal) way to do this.


[This message has been edited by Randy Boecker (edited 05-21-2001).]


[This message has been edited by Randy Boecker (edited 05-21-2001).]
 

·
Registered
Joined
·
363 Posts
Randy, I don't claim to be an expert on this subject but I tried to point you in the right direction by posting links to factual information from reliable sources and suggesting that you check your local codes. This is from the National Electrical Code:


The grounding conductor shall be connected to the nearest accessible location as follows:

a. The building or structure grounding electrode system

as covered in 250.50

b. The grounded interior metal water piping systems

c. The power service accessible means external to the

building, as covered in 250.92(B)

d. The metallic power service raceway

e. The service equipment enclosure, or

f. The grounding electrode conductor or the grounding

electrode conductor metal enclosures;


Bonding of Electrodes. A bonding jumper not smaller than 6 AWG copper or equivalent shall be connected between the radio and television equipment grounding electrode and the power grounding electrode system at the building or structure served where separate electrodes are used.


It is my understanding that these grounding requirements apply to the the mast and discharge unit. I'm sure everyone posted their suggestions with the best intentions, but some of these suggestions may conflict with the NEC or your local codes.


[This message has been edited by Signal (edited 05-21-2001).]
 

·
Registered
Joined
·
1,797 Posts
If you're looking to conform to code with your existing installation, you can't ground anything to a cold water pipe. That used to be allowed, but isn't anymore.


OK, so never mind code, what's needed to prevent ground loops in your electronic equipment, and provide some degree of lightning protection? Here's my suggestion:


Ground your antenna mast to a grounding stake. Ground the grounding block for your antenna lead to the existing house ground, in this case the cold water pipes. Ideally, you want the antenna grounding block as close as possible to the existing building electrical ground and satellite lead ground.


By the way - only your satellite dish should be grounded through a stake, not both the dish and the satellite lead (coax) ground. Since you have a seperate building ground (cold water pipes), all of your antenna (satellite and OTA) leads should be connected to the building ground; grounding of other metallic objects (antenna mast, satellite dish) can be done through separate stakes.


------------------
BOYCOTT DVI/HDCP & JVC!
 

·
Registered
Joined
·
695 Posts
Discussion Starter · #13 ·
Thanks for all of the information, folks.


Signal, I checked a lot of the references you provided that I got from a previous post. Personally, I think much of that is written for electricians, which is why I posted here to ask for a simplified, more detailed method to ground.


My problem continues to be this:

I can ground the antenna mast itself to a ground stake. Not a problem.


However, there are no water pipes or anything else connected to the house ground anywhere near where the line goes into the house. In order to connect that antenna lead to the house ground, I'm going to need to run wire along the foundation around the house to the electrical box, somethine I was hoping to avoid.


And another quick question, since it was brought up. My dishes themselves are gounded to a ground stake, which is connected to the switch (grounding block) that combines both satellite leads into one. It's mounted up near the satellite dishes, but still reasonably close to where the line enters the house (around the corner). Sounds like this isn't legal? Since the dishes are connected to the switch, the switch should be grounded to the house ground? Also, I'm going to combine the satellite lead and antenna lead into a single line via a diplexer on the outside of the house. Since the dish leads are already grounded via the switch, should I just ground the tv antenna lead before it hits the diplexer?
 

·
Registered
Joined
·
476 Posts
I have to wonder about the NEC rules in the practical world.


First, almost all antennas of any type are connected directly to the metal mast that supports them, either directly or indirectly (for instance, through a rotor). So, you have an electrical connection from the mast to the shield of the coax anyway. These two grounds (the coax shield and the mast) are not insulated or separated, but are joined. I haven't seen an installation different than this anywhere - in practice.


Second, running a lengthy ground lead from one side of the house to the other results in a relatively high resistance/impedance path anyway. Won't the electricity (lightning, in this case) take the easiest path to ground, which might in any event be through the tuner?


Third, aren't these precautions mainly to deal with a direct or near-direct lightning strike? In that event, isn't it likely that your equipment is toast no matter what you do? Maybe a surge protector would help - maybe not.


Just some thoughts from the practical world.


Les
 

·
Registered
Joined
·
730 Posts
I have a single big wire that I use to couple my terrestrial antenna mast, a Dish 300, a dish 500, and a SW21 sat switch on the roof to the ground stake at the electrical panel. I didn't have a single wire that was long enough, so I coupled 2 wires with a couple of wire clamps. (The same as the ones I used for the guy wires of my antenna mast.)


Does that sound NEC kosher?
 

·
Registered
Joined
·
363 Posts
Randy, it's my understanding that all grounding electrodes (ground rods) for your antenna and dish must be bonded to the power grounding electrode (the water pipe in your case) with a bonding jumper not smaller than 6 AWG copper or equivalent. The grounding electrode conductor from the service equipment (panel) and the bonding jumpers from the ground rods must be connected to the water pipe within the first five feet of where the pipe enters the building. A jumper must be installed around the water meter.
http://www.mikeholt.com/Newsletters/satellite.htm


Splicing the grounding electrode conductor: see 250-64(c)at
http://www.mgi-hcn.com/archive/topic...fNEC120500.htm


Interesting reading:
http://powerquality.copper.org/mtwashington.htm
http://powerquality.copper.org/nebraska.htm
http://powerquality.copper.org/homepage.htm



[This message has been edited by Signal (edited 05-22-2001).]
 

·
Registered
Joined
·
1,797 Posts
Grounding rods do not all have to be bonded to the building power ground, however, all leads entering the dwelling ARE supposed to be bonded to the building ground.


As far as protection from a lightning strike, the grounding only protects your building from fire, not your electronics. To protect your electronics, you've got to use a good surge protector, and sometimes even that won't help.


As to the antenna shield being connected to the mast anyway, you're right, at least in some instances. The Rat Shack Yagiss and Channel Master Yagis both have contact between the antenna shield and the mast. In my case, it's not true, as I have a plastic channel master that isn't connected. I stand corrected.


Randy: All of this discussion is centered around preventing ground loops (which is a weak current going through your equipment due to the different potential of two different grounds). While a ground loop can sometimes cause a problem in CE (rolling video bars, noise in audio, etc...), it's not likely to blow up your stuff, especially if you have everything connected through a good surge suppressor (and I mean everything, including all coax leads and phone lines). Frankly, I'd just ground your antenna with a stake and be done with it!


------------------
BOYCOTT DVI/HDCP & JVC!
 

·
Registered
Joined
·
695 Posts
Discussion Starter · #18 ·
Thanks to all for the responses. Obviously, code should be followed, but from the information I've seen, some of this seems to be somewhat ridiculously complicated. For a new structure, it's great. For existing dwellings, it's just not practical in all cases. Based on the information I've seen here, here's what I'm going to do:


Ground the antenna mast to a ground stake (Question: Does the ground wire need to be perfectly straight, direct to the ground? I'd prefer to run it a little vertically down the angle of the roof to the side molding where I can tuck it in behind the siding so it's not so visible. If it needs to be straight, I can get some standoffs for sure. We're not talking right angles here, but it would be roughly two 45 degree turns in the ground wire)


I'm going to go ahead and use a ground stake and grounding block near where the antenna/satellite lead goes into the house. It won't be right next to the opening, but I understand about 5 feet is ok.


My father-in-law is an electrician. Unfortunately, he lives in Las Vegas and we don't expect another visit from him until mid-August. When he gets here, I'll ask him to review what I've got set up and we can make modifications at that time.


The antenna is going to be up maybe a foot higher than the metal furnace cap/chimney. I'm putting up a 50' tower here. I'm not saying lightning can't strike anywhere, but the odds are pretty low. As long as the antenna is grounded to the ground, I think that would provide adequate protection. And if lightning were to hit my house/antenna, I think my electronics would be the least of my worries.


Thanks to everyone for all of the help. I was worried about mounting the antenna, but have been amazed that most complicated part of the installation would be the grounding part. Paying for professional installation wouldn't make me feel any better, either. When I had my DSS dish professionally installed a couple of years ago, the guy grounded the dish itself to the ground and that's it.


From what I'm reading, regardless of code, it seems to me the most important aspect of this whole thing is making sure the mast is grounded to the ground, either by stake or directly to the house ground. I would think more damage would occur if I grounded it to the hose bib on that side of the house, since then the current would have to travel through the house to get to the main water line and ground. With a stake, it should head directly for the ground, outside of the house.
 
1 - 18 of 18 Posts
Status
Not open for further replies.
Top