Grounding wire from panel to gas pipe???

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More explaination...
EC&M
Beyond the 2005 NEC Changes: Art. 250 Grounding and Bonding By Steven Owen, National Code Seminars http://ecmweb.com/mag/electric_beyond_nec_changes/index.html [see link for article]
Code Quandaries By Mike Holt, NEC Consultant http://ecmweb.com/mag/electric_stumped_code_25/index.html
[excerpt - see above link for full article] Changes to 250.50 were made to clarify that, where any of the following electrodes "are present" they must be bonded together to create the grounding electrode system.
Underground metal water pipe [250.52(A)(1)]
Metal frame of the building or structure [250.52(A)(2)]
Concrete-encased foundation or footer steel [250.52(A)(3)]
Ground ring [250.52(A)(4)]
Ground rod [250.52(A)(5)]
Grounding plate [250.52(A)(6)]
The intent of the change to 250.50 (wording changed from "if available" to "are present") and the addition of the exception was meant to require the use of concrete-encased foundation or footer steel as part of the building or structure grounding electrode system in new construction (if they are present), since they are considered "present" before they pour concrete.
Randy
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Randy wrote:

Particularly clear info on Ufer ground in new construction. Thanks

To me this wording is clearer than "concrete encased electrode", which to me implies that connection to the steel has been made available. Nothing else in the list is named as an "electrode".

IMHO the code should make this even more explicit. Good requirement though.

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Doug Miller wrote:

Your fact is not consistent with what you said: “The electrical system has its own, *separate* grounding electrode. Metal water piping is bonded to the electrical system grounding electrodes to ensure that the metal water piping cannot become live, *not* to provide a ground for the electrical system.”
I do not see how "*not* to provide a ground for the electrical system" can be read other than the water pipe is not to be a grounding electrode and the system grounding is provided by the system's "own, *separate* grounding electrode."
bud--
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It's real simple: the water pipe is bonded to the other grounding electrodes, not to provide a ground for the electrical system -- that's what the *other* electrodes are there for, remember? -- but to ensure that the metal water piping is always at the same potential as the electrical system's ground and therefore cannot become live no matter *what* might go wrong electrically.
I'm sorry that you're having such a hard time grasping this... but you really need to spend a little more time educating yourself before you post again.
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Regards,
Doug Miller (alphageek at milmac dot com)
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Doug Miller wrote:

"250.50 Grounding Electrode System. If available on the premises at each building or structure served, each item in 250.52(A)(1) through (A)(6) shall be bonded together to form the grounding electrode system. 250.52 Grounding Electrodes. (A) Electrodes Permitted for Grounding. (1) Metal Underground Water Pipe. A metal underground water pipe in direct contact with the earth for 3.0 m (10 ft) or more (including any metal well casing effectively bonded to the pipe) and electrically continuous (or made electrically continuous by bonding around insulating joints or insulating pipe) to the points of connection of the grounding electrode conductor and the bonding conductors. Interior metal water piping located more than 1.52 m (5 ft) from the point of entrance to the building shall not be used as a part of the grounding electrode system or as a conductor to interconnect electrodes that are part of the grounding electrode system." Copyright 2002 National Fire Protection Association
Now who is it that needs to educate themselves?
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Tom Horne

"This alternating current stuff is just a fad. It is much too dangerous
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snipped-for-privacy@mindspring.com wrote:

I hope you're not contending that metal underground water piping is permitted to be the *sole* grounding electrode...

Geez, *another* one with reading comprehension problems. I have never disputed that metal underground water piping is required to be part of the grounding electrode system.
The whole argument is over *why*.
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Doug Miller (alphageek at milmac dot com)
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Doug Miller wrote:

Is your position on why so as to keep it at the same potential as the other electrodes? Yes or no no dodging.
My position on why is that it is the best electrode available on premises served by large underground metallic water systems. In a building with no internal metallic plumbing supplied by a utility that requires copper laterals; many do; why do we still need to connect the Grounding Electrode Conductor to that piping. How is it to become energized in the absence of interior metallic piping? Why does the code require that the portion of the GEC that is the connection to the underground metal water piping be sized according to the table rather than limited in size like the one to the Concrete Encased Electrode, Ground Ring, Driven Rods, and so forth. It is because it is a superior electrode to any of those others. How many Grounding Electrode Systems have you measured for impedance to ground? How many have you installed? I cannot answer such questions my self because I lost track decades ago. In areas served by metallic public water systems I've never found an electrode with a lower impedance to ground than the metallic water service lateral from the metal water mains. That includes the ground rings and genuine Ufers installed at radio stations and the deep driven rod arrays installed at telegraphic fire alarm receiving stations.
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Tom Horne

Well we aren\'t no thin blue heroes and yet we aren\'t no blackguards to.
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I guess you haven't been following the thread too closely, because I've stated that quite explicitly a number of times -- even quoted a portion of the NEC Handbook that says exactly that.
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Doug Miller (alphageek at milmac dot com)
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I think he is likely trolling.
or maybe he is a member of w_'s grounding cult.
bud--
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Bud-- wrote:

Thanks Bud. I try to remember not to wrestle with pigs. You just get filthy dirty and the pig enjoys it.
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Tom Horne

"This alternating current stuff is just a fad. It is much too dangerous
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snipped-for-privacy@milmac.com (Doug Miller) wrote:

And this really is an important thing!
My mother in law's dishwasher developed a short to the incoming water pipe. Most of her water piping is PVC, but some of the outside parts are metal, and NOT bonded to ground.
We discovered this one day when she went to water the lawn while the dishwasher was running. She reached for the faucet, and ZAP! Fortunately, it was not lethal.
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Click Fraud wrote:

Did you find out HOW the dishwasher shorted to the inlet pipe? Seems a bit hard to fathom unless whoever installed the wiring to the dishwaher didn't ground it properly.
A plastic bodied water inlet solenoid valve might have insulated the inlet pipe from the rest of the dishwasher, but how did a switched hot lead contact the pipe? Maybe the solenoid valve's coil developed a short to it's case, which was electrically connected to the piping, but not to the rest of the machine.
My curious mind wants to know...
Jeff
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Jeffry Wisnia
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Brad wrote:

Wrong, wrong...
Someone already mentioned the words "cathodic protection" with respect to gas pipes.
What that means is that the gas company has connected a low voltage source between a metal anode buried in the earth and the gas main and the pipes leading off it to each user. The purpose is to make the pipes slightly more electrically negative than ground so that they don't get eaten away by galvanic corrosion.
The same sort of active protection is sometimes used at boat marinas and on buried metal structures like guy wire anchors. The systems are also known by the names "active cathodic protection" or "impressed current protection".
There's a dielectric (insulated) coupling somewhere near the gas meter to insulate the gas pipe in your house from the buried main and feeder so that you don't "short out" that deliberately applied protection voltage, because the gas pipe in your home probably gets electrically grounded through some gas appliance it's connected to.
The use of plastic buried gas piping has eliiminated the need for those kinds of corrosion protection systems on new work.

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Jeffry Wisnia
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According to your explanation, then I would think that the gas pipe SHOULD be grounded. For you say that the in-house pipe is insulated from the underground piping and hence NEITHER grounded nor "cathodic protected".
Of course the pipe may end up being indirectly grounded through an appliance ground, but that seems like all the more reason for installing a solid, secure, permanent ground connection to the panel ground. After all, what if the appliance is miswired and the appliance ground is energized resulting in the pipe being energized (yet insulated from earth ground), resulting in shock just like with a water pipe...
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blueman wrote:

I agree with you on that providing as you say, the grounding is done on the house side of any insulated coupling.
I was responding the the "buried thus same potential" statement, and should have made mention of the what you just did, that an "extra" ground between the panel ground and the in-house gas piping can't hurt, and may even be required by code.
Jeff
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Jeffry Wisnia
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Well, I called our local gas company (Keyspan) and after a few handoffs, I was told that they do NOT recommend grounding the gas pipe. In fact, they say that if they see such a bridging on a service call, they typically remove it.
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While both pipes are buried and may be made of metal, only the water line should be used as a ground unless it is fed by a plastic pipe. The gas line should NEVER be used as a ground, although it should be grounded to the building ground, because gas supply lines can also be made of plastic, and even if it is metallic it will have an insulating fitting at the meter to prevent interference with cathodic corrosion protection of the underground lines.
If you have a furnace or a powered water heater and grounded wiring, the connection through this equipment will also ground the gas lines. However, I believe NEC requires a separate cross connection to ensure proper grounding.

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Yes, but my question remains whether to attach the gas pipe to panel ground not for the purpose of grounding the panel but for the converse purpose of ensuring that the metal pipe inside the house never gets energized.
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The correct term is "Bonded". The current code as written requires that all interior metal piping be bonded together. This can be accomplished by using #6 copper wire and approved clamps. It is common in New Jersey to bond the hot and cold water pipes together at the water heater location. It would be very easy to continue the bonding wire to the gas pipe at the water heater. Some jurisdictions do not require that the gas pipe also be bonded. Some gas companies do not want their pipes bonded. The electrical inspector would have noticed this and would have failed the job if it wasn't done correctly.
Did the electrician also install at least one (Preferably two) ground rod?
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The electrician installed one exterior copper rod sunk in the ground and attached directly to the 200A main breaker (which is exterior to the house in a box with the meter) and then a second copper wire running from where the water source enters the house (old galvanized 1" metal pipe) to the grounding strip within the 200A Subpanel.
Service Entrance 200A Main Breaker 200A Subpanel 100A Subpanel Neurtral----->[----------]---------->[-----------]--------->[-----------] [ | ] [ ] [ ] Earth grnd -->[--------- ]---------->[-----------]--------->[-----------] | Water pipe -----|
Note that all other subpanels feed off of the 200A Subpanel. Note I have also shown where the neutral and grounds are bonded at the main breaker.
Does this make sense and is it legal?
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