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Author Topic: Water Pipe Must Be Connected to Ground Rod?  (Read 15077 times)
KB6DAY
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« on: April 03, 2010, 07:29:07 PM »

Despite reading many online forums and my ARRL handbook I am still not totally clear on this...so I will dare wade into the grounding debate.

I am putting in a new HF antenna (20 meter dipole). I am running the coax off the roof and trying to figure out the "proper" ground...both RF and Safety (compliant). Keep in mind that I live in an are of very little lighting but I still want to be up to code. I already ordered an ICE impulse suppressor so I will be using that.

The house electrical is grounded to the cold water pipe. Do I:

1)Use that cold water pipe?

2)Put a eight foot copper pipe in the ground and use that?

3)If I use the ground rod do I have to bond that rod to the water pipe/house ground? If so, how long can the run of wire between the ground rod and water pipe be? I would have to be over 40ft in my case if the ground rod had to be by the point of entry.

Thanks for anybody that can help clarify this.
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K9KJM
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« Reply #1 on: April 03, 2010, 11:51:03 PM »

Any grounding that you do needs to go to its own ground rod first.
(Heavy copperclad steel rods 5/8" X 8 feet long sell for about 10 bucks at most home supply type stores)  Then that ground rod needs to be bonded with your power ground.

In a lightning protection system, The actual "device" (lightning arrestor, Coax switch etc) Is about the LEAST important item. Much more important is proper bonding and grounding.

Tips about grounding on a low budget:
http://www.scribd.com/doc/14868226/lightning-protectiontaming-thors-thunderon-a-budget
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KB9CRY
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« Reply #2 on: April 05, 2010, 09:18:47 AM »

I am putting in a new HF antenna (20 meter dipole). I am running the coax off the roof and trying to figure out the "proper" ground...both RF and Safety (compliant).

"No need for an RF ground since the dipole is a balanced antenna."


The house electrical is grounded to the cold water pipe. Do I:

1)Use that cold water pipe?

"No bond to the electrical ground wire."

2)Put a eight foot copper pipe in the ground and use that?

"Yes, I would."

3)If I use the ground rod do I have to bond that rod to the water pipe/house ground? If so, how long can the run of wire between the ground rod and water pipe be? I would have to be over 40ft in my case if the ground rod had to be by the point of entry.

"That would be fine, use only an outdoor path and avoid any sharp bends.  You'll be fine."
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AB4D
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« Reply #3 on: April 08, 2010, 04:51:12 AM »

All grounds (station/house/etc) should be tied together.  You must keep all your grounds at the same potential.  Even though you have "very little" lightining in your area, it only takes one bolt of lightining to destroy your equipment.

The reason for tying all your grounds together is so your station and electrical service grounds will be at the same potential, you don't want your station ground being more effective than your service entrance ground.

If lightining were to hit the power lines a few blocks from your home that energy needs to dissapate, and as we know, electricity looks for the path of least resistance.  If your station ground is more effective than your service entrance ground, and you don't have them tied together, the energy is going to want to disspate through your station instead of the service panel ground.

If you do not or can not tie all your grounds together, IMO you are probably better off having no ground at all.

73
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KB6DAY
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« Reply #4 on: April 09, 2010, 05:28:18 PM »

OK, thanks for the replies. I have my antenna and supplies...just need some time off to work on it, hopefully soon. I will ground to the 8ft copper pipe and bond that to the water pipe/main electrical ground. Is the 40ft between the copper pipe and water pipe too long? Just wondering if that 40ft length of 6 guage wire creates a problem?
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K9KJM
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« Reply #5 on: April 09, 2010, 08:27:54 PM »

That will be fine. Like CRY said, Avoid any sharp bends.
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AA4PB
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« Reply #6 on: April 10, 2010, 06:53:12 AM »

The NEC (National Electric Code) requires that your ground system be "bonded" via at least a #6 wire to the electrical system ground. It also requires conductive water pipes to be "bonded" to the electrical system ground. There is no maximum length specification. The goal is to ensure that all grounds are at the same potential in case "you" get connected between two of them.

It is NOT necessary for your ground to be tied directly to the water pipe. You can connect it to the ground wire leaving the electrical service panel if that is shorter or easier. Actually, that is probably better because you are not depending on the ground between the water pipe and the electric panel for your connection.


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AI8O
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« Reply #7 on: April 13, 2010, 07:02:55 PM »

Are you sure that the cold water pipe that you connect to is indeed metal going all the way into the ground?
Just because you have copper or iron pipe inside your house walls does not meant that metal pipe continues underground.
My house was built in 1983. It has copper pipe in the walls above ground level, but where the water service comes up thru the slab and connects to the house you can see that the exterior service " Pipe" is really a 2 1/2 inch O.D. black plastic hose.
Verify! Dont assume that your inground water pipe is metal, just because where someone connected to it above ground is metal.
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W6RMK
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« Reply #8 on: April 28, 2010, 10:17:11 PM »

The code says Water pipes can't be used for ground in new construction (for precisely the reason mentioned above.. they're often plastic, or corroded, or don't make good contact). In new construction for, oh, at least 10 and probably 20 years, the preferred ground is the "concrete encased grounding electrode" or Ufer ground: 20 feet of wire embedded in the foundation, footing, or slab. The pipe *might* be bonded to the building's ground system for other reasons (corrosion reduction).

But.. worrying about code compliance is not necessarily what you want to do.  You're not going to find a amateur market " listed antenna discharge unit" which is what the code requires. Nor are you likely to run your coax inside a conduit, or use only suitably sized copperweld for antenna wires.

The impedance of some ground wire that is dozens of feet long makes it almost not worth having.

Work on the "common reference point" for the radio gear.  Make sure all the equipment in the shack is connected to the same electrical circuit. Put a decent RF choke (5-6 turns on a 2.4" #31 toroid core) on the coax to keep RF the outside of the coax. Disconnect when lightning is near.  Buy a good insurance policy.
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AA4PB
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« Reply #9 on: April 29, 2010, 05:52:20 AM »

The National Electric Code (NEC) **REQUIRES** that your antenna grounding system be bonded to the electrical service grounding system. It is not a suggestion nor a recommendation in most juristictions - it is a requirement. It also requires that metal water pipes be bonded to the electrical system ground.

That does not mean that you are using the water pipe for a ground. You still have a ground rod for the electrical system and another ground rod for your antenna system ground. The requirement is to bond all of the grounding systems and the metal water pipes together so that they are ensured to all be at the same potential. You don't want people in the house getting "zapped" because they touch two different grounds.
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W0DLM
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« Reply #10 on: May 05, 2010, 11:25:11 AM »

Quote from: AB4D
If you do not or can not tie all your grounds together, IMO you are probably better off having no ground at all.
I think this might be my situation and am just wondering if no ground at all is truly a reasonable alternative.

My problem is that I'm not sure where my electrical system is grounded.  The service panel is out in the garage, on the far wall, not easy to get to.  The plumbing throughout the house (at least, everything I've seen so far) is pvc.  I have no idea how I would connect an antenna to my electrical service ground, nor how to connect the radio inside the house to any ground other than the electrical sockets.

So should I just forget about grounds, hook everything up, and see how it works?
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KB1LKR
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« Reply #11 on: May 21, 2010, 02:39:02 PM »

see my comment in http://www.eham.net/ehamforum/smf/index.php/topic,68269.0.html on electrical service grounding practice/requirements past vs. present (at least in the N.E. US). At one time grounding via the cold water service where it entered the structure, apparently later the code changed to require a driven grounding rod.
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K1CJS
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« Reply #12 on: June 06, 2010, 06:20:07 AM »

The ICE supressor should be bonded to its own ground rod on the outside.  Then, bond THAT to the cold water pipe or the electrical service ground for personal safety sake.

The reason for the change in grounding procedures is the use today of plastic or pvc pipe for water service coming into the house.  When the water service was metallic pipe, the grounding would be OK, but as the water utility redo the water mains, they usually replace the metallic feed pipes to the houses with plastic--which eliminates the grounding.  Of course, construction in the last thirty years or so already has plastic piping coming into the house.
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AA4PB
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« Reply #13 on: June 06, 2010, 01:59:36 PM »

I think some are confusing "using the water pipe for a ground" and "bonding the water pipe to the electrical system ground". You can no longer use the water pipe for a ground because there may be plastic outside the house and it wouldn't be much of a ground. You still are required to bond copper plumbing to the electrical system ground. It makes no difference if there is plastic outside the house. The bonding is to ensure that the conductive water pipe inside the house is never at a different voltage than the electrical system ground. The same applies to bonding your amateur radio grounds to the electrical service ground.

Think about the person in the kitchen who has one hand on a grounded appliance like the microwave and the other hand on the water faucet. It wouldn't be good if there was a voltage difference between the two.

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AB4D
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« Reply #14 on: June 06, 2010, 05:09:47 PM »

Quote from: AB4D
If you do not or can not tie all your grounds together, IMO you are probably better off having no ground at all.
I think this might be my situation and am just wondering if no ground at all is truly a reasonable alternative.

My problem is that I'm not sure where my electrical system is grounded.  The service panel is out in the garage, on the far wall, not easy to get to.  The plumbing throughout the house (at least, everything I've seen so far) is pvc.  I have no idea how I would connect an antenna to my electrical service ground, nor how to connect the radio inside the house to any ground other than the electrical sockets.

So should I just forget about grounds, hook everything up, and see how it works?

I know a lot of guys who for years have run no grounding whatsoever,  because as rationaled to me, they have either lost gear during storms, or they have ground loops/RFI when they ground their stations.

Just hook it up and see how it works, as noted by CRY, if you are running a balanced antenna like a dipole or yagi, grounding should have no affect on the performance of your signal. 
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