bonding of gas line (Grounding A Gas Line)

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  #1  
Old 01-27-05, 11:25 AM
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bonding of gas line (Grounding A Gas Line)

Is it required or if not required good practice to bond the natural gas piping in a home to ground. If so how should this be done and with what size conductor for a 150 amp service.
 
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  #2  
Old 01-27-05, 12:20 PM
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This is more of a local code thing. Some areas require it, some prohibit it. Most do not require it. Your gas piping is effectively grounded through any electricly fed appliance (furnace) through the circuit grounding conductor.

If your area requires it you would use a #6 copper conductor.

The NYS Residential Code book (NYSRBC) says gas piping SHALL NOT be used as a grounding electrode. This book is mostly based on the International Residential Code (IRC).
 
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Old 01-27-05, 12:44 PM
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Hello: sean_sarah

The immediate answer to your question is a NO!

Many, if not all, natural gas utility companies primarily and most likely all propane supplies do not want ANY electrical line grounded to their facilities, equipment and/or supply lines ever.

Several reasons why: (Not Inclusive Of All Reasons)
1)
Static electricity causes electrolysis to the under ground steel and/or iron pipes. Electrolysis causes corrosion to the pipes. Corrosion creates leaks. Leaks are dangerous. All leaks must be fixed as soon as possible, if unable to fix the leak immediately.
2)
A Public Utility Commissions Requirement in this state. Your state may or may not have such a requirement or a like requirement. Surely some type in one form or another is very possible.
3)
Some states have codes which do not allow any electrical line of any type or voltage amount, etc to be grounded to any gas line of a type of fuel source.
4)
Some states require natural gas lines to be only PCV types. PCV is a poly chloride vinyl plastic piping material approved for use with natural gas. Because the material is plastic, the material does not corrode and will not insulate against grounding of electical current of any type. Plastic is a non electrical conductive material.

As a result, grounding any electrical line to a plastic (PCV) gas supply line does not ground the line. Grounding to any plastic gas supply line only gives the false sense of grounding. Grounding to a plastic gas line does nothing.

CAUTIONARY NOTES:
Do not ground any electrical line or electrical circuit to any gas line without asking the approval of the gas supply utility. All facilities, lines and equipment supplied to provide gas of any type, belongs to the supplier of the gas and not to the end user.

State and/or local codes or both are very likely to apply to grounding an electrical line or electrical circuit. Best to inquire from either or both agencies what those rules and/or codes are before doing the work.

Failure to adhere and comply to rules and codes is a violation. Also a safety hazard to personal and property safety.

For your own personal safety, to protect the electrical circuits, the structure and not void any home owners insurance policy, hire a licensed electrical professional to do the work.

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  #4  
Old 01-27-05, 01:52 PM
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A gas line may _not_ be used as a grounding electrode, grounding electrode conductor, or equipment grounding conductor. This means that you can't use the pipe to ground your electrical system, but must have proper ground rods, etc.

A metal gas line _must_ be bonded to the electrical system ground to provide protection in the case that the gas pipe becomes energized by a fault in the wiring. Per the NEC, this bond is made using a suitable equipment grounding conductor sized for the circuit which is likely to energize the metallic piping system, the same rule which applies to _any_ metallic system which might become energized. As Speedy suggests, this bonding often happens as a result of the circuits feeding the appliance connected to the gas pipes.

I believe that this rule is a good one to follow, but you will have to check with your local AHJ (inspector): Bond the pipe using an equipment grounding conductor sized for the largest circuit that the pipe encounters.

However there is a bit of controversy on this subject, since it appears that the gas industry suggests that the piping must be bonded to the grounding electrode system for its own protection. See the following article for the discussion: http://www.ecmweb.com/mag/electric_code_forum_9/

Best Regards,
Jon
 
  #5  
Old 01-27-05, 05:37 PM
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A little confused

It seems (at least to me) that the responses are potentially contradictory. The consensus thus far seems to be that the gas line cannot be used as the egc which I understand.
This summer I had a service upgrade in conjunction with a major remodel. I hired the service upgrade out but did the remaining electrical work associated with the remodel. The electrician used a copper rod (only 1) as the egc and then tied the ground to the entry point of the water supply and then provided a jumper around the meter. He did not bond the gas line and it was not bonded previously. The inspector did not go down into the crawl space where the water line was bonded so I don't think his approving the upgrade is evidence that the gas line should or should not have been bonded.

My question is related to the gas piping on the house side of the gas meter. All of that piping is metal (black pipe).

Speedy indicates that this is a local gas company issue.
Sharp says no, but I'm unclear as to whether he is referring to the gas company side of the meter or house side. He also raises the issue of electrolysis due to the dissimilar metals.
Winnie implies that bonding the gas lines is a must

I live in Rochester NY. Any other opinions?
 
  #6  
Old 01-27-05, 06:05 PM
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I want to clarify your terminology a bit. When you say "EGC" it appears you mean "grounding electrode". The EGC is something else, and while it is true that the gas pipe cannot be used as an EGC, that doesn't seem to be what this thread is about. Of course, the gas pipe cannot be used as the grounding electrode either. I think the only question is whether or not the gas line should be bonded.

I suggest you call your gas company and ask what is proper in your area.
 
  #7  
Old 01-27-05, 06:28 PM
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seems ambiguous

John,
I will take your advice and contact my gas company. It is a little disconcerting that NEC/gas companies don't have a clear direction here. I acknowledge the potential for competing levels of safety concerns, ie potential corrosion vs ground fault issues, but it seems as though there should be a general consensus as to which potential danger poses the greatest risk.
Scott.
 
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Old 01-27-05, 06:49 PM
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Like most areas of life, there is little consensus. Why does Chicago require conduit but Kansas City does not? Why does California require efficient lighting in kitchens but most of the rest of the country does not? Why does the U.S. allow 15-amp receptacles on 20-amp circuits but Canada does not? Why do some people drive Fords and others drive Chevys?

Keeps things interesting.
 
  #9  
Old 01-27-05, 07:01 PM
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cynic

John,
I don't know the definitive answer to youe rhetorical questions but the cynic in me says money is involved (ie lobyists/unions etc). The question as to whether or not to bond a gas pipe or not seems more pure, in that safety seems to be the predominant if not sole consideration.
Scott
 
  #10  
Old 01-28-05, 12:30 PM
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I read the question to ask "does the gas line need to be grounded", not "can I use the gas line *as* a ground".

My *opinion* is that the gas line _cannot_ (and should not) be used a ground, but that it should be grounded.

In my old house, the line was defacto grounded, as the gas line was buried.
New house, the line AND the tank will be buried, as soon as I get around to buying a tank..
 
  #11  
Old 01-28-05, 07:38 PM
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I just finished upgrading the wiring in two houses here in Toronto and the inspector did look at both to ensure that a bonding strap was connected to the gas line off the furnace to the cold water pipe.
 
  #12  
Old 01-30-05, 10:38 PM
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I'll just chime in as well... Up here in Ontario, it is mandatory to bond the gas line to the service grounding electrode(s) using a #6 conductor. [Rule 10-406(4)] Alternately, one is NOT allowed to use a gas line as a grounding point for other conductors.

If it is not required in a person's area, I still think it is a good idea should they have any gas pipe runs that are outside/aboveground or that run outside the house and then back in again. Sure there is a bond at the furnace (or other gas appliance) but that may or may not be sufficient depending on the circumstance. I was cleaning up the wiring in a house not too long ago and I added a gas line bond to the ground electrode for good measure, and when doing it I found a current on it. Turns out at a point where the gas line ran outside and then back in again the cable tv/telephone folks had decided they wanted to use the gas pipe as a ground since it ran a foot away from the cable/telephone demarc. Needless to say I was not impressed.

Regards,

Savant
 
  #13  
Old 12-05-09, 08:11 PM
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Having read these replies, I remain in confusion as to how one goes about grounding the gas line. I had gas lines run from my outside gas line around to my fireplaces. the line is metal, and exposed. By Virginia code, apparently the gas line must be grounded. I need to know what I must do to ground it.

I was told by the code inspector that I would have to have an electrician come out, apply #6 copper wire to the gas line and connect it to my electrical box.??...that doesn't seem safe or feasible as the electrical box is, naturally, in my basement and the basement is all finished. So cutting holes in the wall might be necessary to access the electric box. Also, when I called an electrician, he was completely unaware of this code and didn't seem to have much of an idea of what he was going to have to do to ground the gas line.

Can anyone give me an idea of how I should ground the gas line? Should I find a 5' copper rod and drive it into the ground and connect it by #6 wire to my gas line? The cable people used my water spicket to connect their ground wire. Why would that not work with the gas line as well??

Thank you!!
 
  #14  
Old 12-05-09, 11:31 PM
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Should I find a 5' copper rod and drive it into the ground and connect it by #6 wire to my gas line?
No do not do that it would be incorrect and a possible hazard to safety of humans.

His ruling that it must be grounded is likely a local requirement in conjunction with the local gas authority. However as far as the NEC is concerned you do not have to bond it unless it is likely to be energized. So maybe the inspector thinks it is likely to be energized. But regardless he has required it to be grounded so you must comply. There are a few places you can run the #6 copper he wants to 'ground' the gas piping... besides the electrical panel. You can connect to the metal water pipe that is grounded back to the electrical panel or you can connect the #6 to any point on the grounding electrode system. There are two things you will need to do to comply. 1.) You cannot inadvertently turn the gas pipe into a grounding electrode. This is prohibited by NEC 250.52(B)(1). To keep from doing this a dielectric union must be installed in the gas pipe between where it enters the ground and where you connect your #6 bond wire to the gas pipe. This ' non-conductive' union may already exist where the gas pipe interfaces with your home (enters the home). 2.) You can bond the gas pipe to the cold water pipe within 5 feet after it leaves the ground and enters your home... if.. the water line is being used as an grounding electrode. If it is you should see a copper wire clamped to the water line and running back to your service panel. So just bond the pipe close to that with your #6 using the correct listed clamp.. Or you can find the ground rod outside or other outside electode or the conductor running to it from the electrical panel and connect the #6 to either... again using the correct clamp.

Why your codes inspector is wanting you to ground the gas pipes with a #6 because you ran this new gas line is rather puzzling. If it isn't likely to be energized where it connects to some electrical equipment he is flat wrong in requesting grounding of the pipes in this manner as far as code is concerned... You might want to have him take a peek at NEC 250.104(B) and ask him where the area is that he feels is likely to be energized. If he can show you that the gas line is terminating in some electrically connected component serving that fireplace then he is correct in asking for the ground or bonding to ground of the pipe. However... this is usually already taken care of by the equipment grounding conductor serving the electrical equipment that the gas pipe supplies. This will satisfy the grounding requirement as far as the NEC is concerned.

But since the inspector has requested you to ground with a #6 to the service panel you will have to see if one of the areas I mentioned earlier is acceptable to the inspector...it should be fine if he knows his apples... But you will have to make sure that the gas line is not turned into a grounding electrode by making sure there is a dielectric union installed like I explained earlier.

Hope this answers your question.
 

Last edited by Bruto; 12-06-09 at 12:47 AM.
  #15  
Old 12-06-09, 05:35 AM
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The 2006 edition of the VA. Uniform Statewide Building Code added an amendment to say that if you use CSST piping, then it needs to be bonded anywhere in the grounding electrode system with a #6 at the point where it enters the house.

If your fireplace has a blower, then the EGC of that circuit is adequate, if not, then the gas line has to be bonded anywhere in the grounding electrode system using an approved means. A cold water clamp on the pipe before the point of entrance to the house and a #6 to any convenient point.

This is an excerpt to where/how the bonding takes place for CSST:
a. To the bonding lug of the main electrical panel of the structure provided the main electrical service has an approved grounding electrode system.
b. To the existing grounding electrode conductor using a UL listed split bolt connector.
c. To the existing grounding electrode with its own UL listed bonding clamp.

This is an excerpt if it's not CSST:
2. Bonding of all other metallic gas piping systems: All metallic gas piping systems are required to be bonded to the main electrical service grounding system in the methods provided above with the following exception:
a. Any gas piping system which is connected to an appliance that is electrically connected to the main electrical service grounding system is considered effectively bonded and needs no additional bond.
 
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