house ground to water pipe

Dale

In rare cases one neighbor has a fault to gound and the person next door get zapped. Another good reason for the 2 ground rods outside. However depending on soil type and moisture lever the water system may still be the better ground meaning that current sometimes prefers it. In some areas the water Must be insulated to keep current off it so corrosion of the water system is lessened. If you have a shared well system, up to 10 houses on one well it is MUCH more common for this to happen, since you have a high voltage source at the well.

Jay_17

Is this still ok?

I am in the midst of doing a renovation, I noted that the house ground is connected to the incomeing (city) water pipe. Is this still considered acceptable code wise? and if so is it really a legitimate ground?
Not really a heating question, but I figured someone might have some insight.
BTW, I am in CT
JS

Al Letellier

ground rod

Not sure about in CT but here in Maine it's done all the time, assuming copper or galv. service pipe. A rod in the ground is also required. Check with a local electrician for the code requirements in your area. It's under their jurisdiction.

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EBEBRATT-Ed

Yes. The water pipe is used as a grounding electrode. To bring it up to the current code have an electrician put a jumper around the wter meter. This insures the interior metal piping is grounded even if you have a plastic water meter. Also the current code would require an additional ground rod(s) to supliment the water pipe. This is also due to the increased use of plastic.

If the installation met code when it was installed it is still ok code wise you are not required to change it but may do so to increase safety. If the electrical service is changed then the grounding must be brought up to the new code.

ED

Maine Ken

I love the ground clamp on the copper pipe...then the copper transitions to plastic as it leaves the basement!!! See it all the time on new homes.

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Quick

Water Ground


I thought the jumper across the water meter was so the ground would still exist if the meter was ever removed, not because the meter might have plastic in it.

Also, as long as the clamp is on copper then even if the pipe going outside later turns to plastic wouldn't there still be a "ground" as the water in the pipe would be the conductor anyway. As long as the pipes are filled with water, the water (not the pipe) will conduct the electricity right?

Donald_2

Has anyone ever seen stray current coming back IN from the street via a water pipe ground? I had a current meter on a water line the other day showing 2-4 amps coming back into the house from the outside (disconnected the meter, etc. to make sure it wasn't originating in the building)

Has anyone ever seen that before? Where could it be coming from? Problem in neighbor's panel backfeeding the water ground? Any ideas?

jim lockard

No Don

But then again I never looked for one either. Don the point of bonding the interior water system is to maintain the same potenial thru out the home. The water service bond connects to the netural bar in the panel along with the ground rod conductor and the netural / grounded conductor for the power company. Best Wishes J.Lockard

Rollie Peck

Grounding

I've heard of stray currents showing up especially near electical sub stations and high voltage transmission lines.
We had quite a controversy going here in Wisconsin a few years ago with stray currents shocking cows through their stantions and reducing milk output.
Just out of curiosity, what did you connect the other lead of your current meter to?

Rollie Peck, homeowner

jerry scharf_3

IMO, necessary but not sufficient

Jay,

Current code would call for an additional ground. The idea is that as some point, the pipe may change and you still need ground. It is necesessary so that all the piping in the house is at earth ground potential. The fact that it provides additional grounding is a good thing.

Grounds can either be in the form of a copper rod driven into the ground (technically you may need more than one depending on your soil) or a UFER ground (20' piece of rebar attached to the main rebar in the foundation footing.) Connections on these must be approved for grounding and some places are not accepting thermowelded attachement any more (concern with brittleness of the ground wire just past the weld breaking.) They each have their benefit, with the slight edge IMO going to the UFER ground.

Don't forget to use heavy guage copper for the wiring. It makes no sense to me to use 10G ground wire, though it may be legal in some cases. When there is a lightning strike nearby, you really don't want your wire to fail to keep the same ground potential. I always use bare 6G for panel and ground attachments. same for any larger length of pipe.

Sometimes there are silly ground strapping requests, and those I do to the neareast 12G ground.

jerry

Constantin

Oh sure...

... a site dedicated to Bill Wattenburg makes for some interesting reading with regard to blue water, stray currents, and the like. The best part allegedly was that the water utility tried to deny that they were responsible until the engineer proved them wrong.

I would avoid making a home dependent on external pipe. Rather, I'd build and tie a home grounding system into the home (i.e. make it large enough to handle local conditions (conductivity of the soil and all that), then tie the home system to the pipe. In this case, the pipe becomes supplemental.

Naturally, any stray current coming in or going out should be addressed to avoid galvanic corrosion of the pipes. One way to detect it would be to have a dielectric fitting and a jumper that runs through a very small fuse. No significant current should ever flow through the fuse, so a blown fuse would indicate some current.

If you're pouring a new foundation, an even better building ground is the UFER grounding system, which basically guarantees a good ground to earth without the need for lots of rods. However, you have to think of it before you pour, which, unfortunately, I didn't.

Gordy

Stray Current

I have a friend that works for COM ED. They routinely check guy wires on wooden poles for stray current, and deteriorated plastic sleeves. There is an acceptable limit of stray current. Thats why there is plastic sleeves on the lower portion of the guy wires. You know how kids like to swing on the guy wires. So would there maybe have been a guy wire for a pole by the incomming water line Donald?

Gordy

Rookie_3

I have a friend who is an electrician and he is totally against grounding swimming pools (mandatory in MA) because he says people under estimate the risk of stray current.
Right or wrong it sure gives you something to think about!!
ROOKIE

Gordy

Bonding to water pipe

Hmmm, being bonded to my water main..... I wonder how a direct hit by lightning would effect my radiant ceiling with all copper tube. Could be some intense resistance heating for a second. Plaster on the floor maybe.

Jay_17

Thanks!

Thanks for the responses, the meter boxes were installed in 1968, still has screw in fuses.. as far as I know there is no other ground. There is a strap around the meter though, and the pipe is metal out to the main. I am going to have new meter boxes installed etc, and I was planning to add some independant grounding at that time, for my own peace of mind. I will probably keep the pipe ground too, as long as it is still allowed and seems prudent.
I figured you guys would have some experience with this stuff.
Jay

stonehouse_2

Ground currents...

Getting current on a ground line is fairly common. Current, like steam, is essentially the movement from high to low.

The utility is supposed to ground the neutral side of their transformer to ground, and that is supposed to be repeated in the main breaker box as well.

Current flow in your end of the grounding probably would be the result of an electrical resistance condition at your ground. With ohms law we can calculate that a 2 amp flow in your ground at 220 volt would be around 110 ohms. Easy to be if your clamps are loose, corroded or the soil is very dry.

The current flow would be caused by inductive currents within your wires (basically your wires behave like a transformer; current flowing through a conductor generates a magnetic field. A magnetic field cutting across a wire will generate an electrical current).

If the utilites ground is also bad, that could cause all sorts of weird problems for your electronic equipment.

You can't (essentially) over ground your system. However it is important that all your interior grounding (as opposed to your "grounded" conductor, which is the white (neutral wire) all comes to a common point at the main breaker panel and then is carried by a single heavy condutor to your grounding sytem...

Hope that helps...

JackFre

Secondary ground but not a primary

Doesn't or at least shouldn't replace the ground rod, IMHO. Does it work? Yes! Is it good practice? Personally, I don't think so, other than as a secondary.