Antenna Grounding

[Bigmack630]

Hello All,
Looking for some straight answers or hopefully somthing that will persuade myself on which way to go. I have looked and search on here many times and am unsure if what I have found really answers my question so here goes.

I am looking to put a discone antenna on the roof of my house I live in a small town so I have city water, from what i have read multiple time is that grounding the antenna, and the coax, should all be bonded together (1) with atleast one grounding rod outside and (2) then bonded to the main electrical pannel in the house. My question is; Can i bond it all together using the water main which is used as the ground for the electrical main instead of running ground wire all the way to the electrical box and bonding directly in the box?

Thank You for your feedback in advance

BigMack

 

[N8RUS]

If your electric panel is grounded to your water main in the house---it is not properly grounded. Remove the ground wire from the water main and ground it to a ground rod outside your house along with the coax and antenna. The purpose of the ground rod is to keep the voltage of a lightening strike from entering the house. Never ground to the water pipe, period.

 

[talkpair]

Remove the ground wire from the water main

i wouldn't do that if i were you.

 

[N_Jay]

If your electric panel is grounded to your water main in the house---it is not properly grounded. Remove the ground wire from the water main and ground it to a ground rod outside your house along with the coax and antenna. The purpose of the ground rod is to keep the voltage of a lightening strike from entering the house. Never ground to the water pipe, period.

You don't "GROUND" to a water pipe, but you do BOND to the water pipe!

DO NOT DISCONNECT the 'ground/bond' wire to the water pipe.

Go to your local home center and buy a book on home and farm wiring.

It will give you a lot of CORRECT information.

 

[Bigmack630]

So maybe i was wrong with it grounded to the water pipe then. I am betting it is probably run back to the power pole in the back yard. So either which way i need to ground it DIRECTLY to the box in the house i can not short cut it thru the water main coming in the house?

 

[n5ims]

Just remember that for proper lightning protection, don't take shortcuts. Do it right! Taking the easy way out now may allow lightning to take the easy way out later and burn down your house.

 

[TVT]

An antenna ground should be to direct to a ground rod in the ground. No shortcuts in that area. You will be much happier that way. You will have alot less interference from other electrical devices in and around your house.

 

[prcguy]

Why would this be best? Would this be dangerous in any way? Is this to NEC code? Does it provide better lightning protection?
prcguy

An antenna ground should be to direct to a ground rod in the ground. No shortcuts in that area. You will be much happier that way. You will have alot less interference from other electrical devices in and around your house.

 

[Alliance01TX]

Antenna Grounding - Opinions

One Point of View and Opinion follows....

Most serious Radio folks will say one of the best methods for grounding, reducing static discharge, noise and reducing impacts via lightning strikes is simple: Direct & proper grounding via Ground Rod(s) and use of arrestors or like equipment used in most Ham Radio and Professional antenna installations.

ARRL has several good Engineering Reference books on Antenna's and has grounding discussions. In some folks opinion, the NEC is really only for House Power (110 VAC) and the related basic (Neutral) grounding systems. Not for Radio (RF) systems per se., although many of the concepts are somewhat the same, the NEC does not really account for nor does it really address impacts of lightning, static, noise as related to RF matters and RF grounding. NEC would likely also say (if so inclined) that placing a metal pole type object on the roof of your house would be perhaps an unsafe act for any number of reasons....

The NEC is mostly around proper wiring and Safety measures and is a great source for same. Just not RF Systems.

On to the key issues.....if you have no other option but to mount an antenna on your house and thus create you own lightning rod, then most would recommend you run a separate ground wire ( size of the wire depends on distance) from the antenna - ground connect point, direct as possible to a dedicated 8' copper ground rod (in the ground) that is at least a couple feet away from your house foundation and not attached to any other metal objects whatsoever. And you want a clean 'bond' via the proper (same metal material) clamping the copper wire to the copper ground 8' rod....and yes a 4' will work, just 8' is what is most used in RF installations and add's an extra measure of grounding opportunity, especially in dry areas where often a ground-grid is required to reduce the ground resistance as low as reasonably possible to at of below say <20 ohms. Lower is better.

As one of the other post retorts, do not let the RF Systems grounding get inside (direct) to your house if you can prevent same....And do-not disconnect any existing House wiring or grounding. Separate grounding is a low-cost solution vs a radio and other gear taking a hit in a non/poorly grounded set up...

The use of BOTH a direct grounding system (antenna-to-ground rod) coupled with an GAS type arrestor inline in the coax at the outside of the house (to a Ground Rod), near entry point to the house will likely provide the best grounding solution, outside of a grid or over-complex solution for a simple receive-only application. You can research this via several Ham Radio on-line store providing these type devices.

If you have other options to mount an antenna other than the roof, that is a better solution, but the same grounding still applies...just less of a change of you creating a lightning rod on the roof.

Hope this gives you more ideas to ponder and these opinions are simply to assist in the thought process and although we can not prevent lightning hits or other damages, we can reduce the likelihood of the impacts if proper grounding is applied correctly.

 

[prcguy]

Lots of bad bad info here as usual.
If you add a ground rod to an antenna you must bond it to the house electrical ground, period. Its NEC code for safety and if not bonded adequately the huge difference in potential between the equipment connected to the ground rod and the rest of the house will usually destroy every appliance in the house during a lightning strike. A difference in potential on the neutral line is probably the biggest cause of damage from lightning.

The cable companies, satellite dish companies and TV antenna installers are required to bond the antennas and cable to the house ground and this is what partially determines the location of your satellite dish, it must be within about 25-30ft of wire length to a major house electrical ground point.

This is not a good forum for critical safety or lightning grounding answers, there is too much at stake from bad bad info. Seek out an expert unless the people giving you advise will take all responsibility for damages you will get from their advice. Even basic grounding for RF ventures into the NEC relm when you talk about ground rods that are not bonded to the electrical system.

If you feel you must give specific advise on a subject like this, ask yourself if you want to be financially responsible for the outcome then post accordingly.

I work in a building that by now has over 100 8ft ground rods installed and probably 1000ft or more of buried 500MCM (1" diameter") ground wire. I've helped build many mountaintop repeater sites that have survived direct hits with no damage and I'm a certified SBCA installer and SBCA instructor and still I will refer anyone to the NEC rather than give specific info and take responsibility on how protect from lightning strikes.
prcguy

 

[N_Jay]

One Point of View and Opinion follows....

. . . . . .
As one of the other post retorts, do not let the RF Systems grounding get inside (direct) to your house if you can prevent same....And do-not disconnect any existing House wiring or grounding. Separate grounding is a low-cost solution vs a radio and other gear taking a hit in a non/poorly grounded set up...

. . . . . ..

All ground systems must be bonded together.

Don't try to build a separate ground system.

 

[N8RUS]

By now Bigmack630, I can imagine your totally confused after reading info from "experts and wannabes". I will not claim to be an expert in the field.You do what you feel is the safest for you. I will stand by my opinion--do not allow voltage from a lightening strike enter your home via a ground wire to the water main. I gotta believe this is common sense to you. Some of the info given is correct and some of it doesn't make any sense. I can only base my judgment as a ham radio operator and +35 years in the fire service. Best of luck to you, 1002.

 

[N_Jay]

1002, Do you have ONE authoritative source that agrees with your opinion?

Some references that agree with PRC and me:
2002 NEC Grounding Communications Systems
Grounding antenna mast and antenna discharge unit
How to ground a TV antenna mast? - DoItYourself.com Community Forums

So maybe before you start proclaiming who are the "experts and wannabes", please be sure you are not the one giving out bad information.

 

[N8RUS]

Yes, I do-------------my 1st post dated 3-22-10. 6:29pm Good day !

 

[N_Jay]

Yes, I do-------------my 1st post dated 3-22-10. 6:29pm Good day !

:evil::lol::evil: So let me understand, because, I would not want to accidentally misinterpret what you are saying/implying.

Now correct me if I am wrong.
You are defining yourself as the "expert" without need for any verification, yet you disagree with several others here (and several other authoritative sources) and yet you are so sure that you have taken the attitude that others are "wannabees"?

Does that cover it?:roll:

 

[N8RUS]

You"re easy.

 

[datainmotion]

So, while I have run a common ground line from my two antenna mounts on the chimney straight down to an 8 ft ground rod and have installed a gas discharge lightning module on each coax run, I have not bonded the ground rod to the water line.

Since the water line comes in over 25ft. away from the aforementioned ground rod, would it be acceptable to ground to the closest cold water line (inside the crawlspace adjacent to the ground rod outside) rather running a ground wire the 25+ ft. to where the line makes entry to the house?

 

[N_Jay]

No,
While it is permissible to use the incoming copper water line as an earth ground, (I believe this must be with 6 feet of entering the house),
it is not permissible to use the copper water piping system as a ground conductor.

 

[N_Jay]

Deleted

 

[fourthhorseman]

If your electric panel is grounded to your water main in the house---it is not properly grounded.

False,
Depends on the cities code..here in philly i had my serv panel gndnd to the water pipe,,very common,,
allmost the standard...

allthough it was propperly done,meaning jumped the meter,ecct,,i still sledgehammerd a 8ft copper rod into the ground outside n secured it in with about 2 in of quikcrete..leaving about 1.5in exposed..