Bonding gas pipe to new residential service

[tom baker]

Re: Bonding gas pipe to new residential service

Water pipes may be used as a grounding electrode if they are in contact with the soil for 10 ft. Typically the connection to a water pipe is a bonding connection per 250.104 to allow a low impedance path to the service for a fault current return in the event the pipe is energized.

Grounding to gas piping is not allowed by the NEC, the gas meter has had dielectric unions for many years, as the metal gas piping has cathodic protection, the additional metal on the customer side complicates the cathodic proteciton. Also most new gas service lines are now plastic, as well as many of the gas mains are plastic.

 

[pierre]

Re: Bonding gas pipe to new residential service

Bennie

If you are saying the problem of living 'a lot of history' is you would have a lot of writing, I suggest you start now. If it is because you have been around a long time - God bless you!
You can start by bits and pieces right here in this forum. Lots of fun for us to read.

Pierre

 

[bennie]

Re: Bonding gas pipe to new residential service

Pierre: My respect, thanks. I have had a unique career, some activities were planned, many just happened.

I worked a few years on Federal projects, many were classified at the time. Most have now been declassified.

I worked on the Nuclear Weapon Test Program from 1958 to 1963. I recently received a phone call from George Peterson, chief designer of the nuclear device detonated in the yucca test. He is now 78 years old. We are trying to get a reunion among the few of us left.

So I have wired the fuse, fire, and destruct system on the H-Bombs, in the Marshall Islands. A few years later I got to wire a pig farm in Roseburg, Oregon.

I have so many sea stories,(mostly true) I forget which ones.

 

[brian john]

Re: Bonding gas pipe to new residential service

The problem is, I have lived a lot of the history

Bennie the problem is not having lived a lot of history, getting the chance to live through history, is good. Hopefully you still have a lot more history to go, beats the alternative.

 

[bennie]

Re: Bonding gas pipe to new residential service

Brian: Thanks, I need all the help I can get.

I am slowly improving, and making plans to visit the Test Site in the Marshall Islands. I have applied for a renewal of my passport.

I am practicing and learning how to edit and make CDs from my digital video camera.

 

[ronaldrc]

Re: Bonding gas pipe to new residential service

Makes no sense if you think about it if the gas being in the pipe is not a factor which doesn't need to be a concern and I agree. Then why shouldn't it be just as important to bond to a metal gas pipe just like we are required to bond to the water pipe?

As far as the gas companies not wanting this maybe some plumbing companies might have or maybe feel the same.

 

[karl riley]

Re: Bonding gas pipe to new residential service

If a water worker separates a water pipe when the service neutral is open, he may get a fatal shock.

If a gas worker separates a pipe (used as a grounding electrode) he may get a fatal shock and in addition get blown up.

Yes, the gas was a factor in the Code change.

Karl

 

[ronaldrc]

Re: Bonding gas pipe to new residential service

Karl were not talking about using it as a grounding electrode were bonding it to keep it from being a shock hazard. If both pipe are capable of carrying the neutral current separating just one of the two wouldn't arc anyway.

Chances of that ever happening would be very slim.

Ronald

 

[bennie]

Re: Bonding gas pipe to new residential service

Electrolysis was a big issue. Bonding to prevent energizing, is the same as using the gas pipe for an electrode when the dielectric union is jumpered.

The gas pipe ceased as an electrode, by default, when the gas people started installing the dielectric union.

 

[ronaldrc]

Re: Bonding gas pipe to new residential service

Bennie I don't think its SOP. to use either pipe as the grounding electrode anymore is it? Since most have went to plastic.I have driven two 8 foot grd rods where it was plastic on new installions.


Our inspector here last jobs I had inspected made us bond to the water pipe as a supplement if its long enough and bond to the gas for shock hazard.We have to ground anything that is metal and might have a hot wire touch it and energize it.

I liked the idea that someone said if its likely for the gas line to become energized then bond it that makes good sense.If the gas line is several feet from any electrical wires and very unlikely to become energized if it were up to me I wouldn't bond it.

Ronald

 

[bennie]

Re: Bonding gas pipe to new residential service

Ronald: I think the gas pipe gets bonded by the appliances it serves. Furnaces have a fan motor. gas dryers have motors, there is a lot of bonding going on.(another good song title)

 

[ronaldrc]

Re: Bonding gas pipe to new residential service

I agree Bennie but some inspectors require these items being bonded separately anyway.

Its hard to argue the point when one see a piece of old duct in the basement and they say you ought to run a # 10 wire and bond it just to be sure can't never tell it might not be in use anymore. And you can see 3 or 4 pieces of 12/2 nm runing above it.

This is really another subject I think I've got us side ways again sorry.

Ronald

 

[bennie]

Re: Bonding gas pipe to new residential service

Ronald: I don't like the term "likely to be energized"

I favor impressing means to prevent energizing, such as isolating and insulating.

Likely to be energized is an admission of poor quality of performance. :roll:

 

[ronaldrc]

Re: Bonding gas pipe to new residential service

I couldn't agree more Bennie. But Bob brought up the point about getting blowed up besides being fataly shocked to death by a gas line being used as a neutral from a loose neutral.

And you're right again the gas line if being used on a HVAC unit has a equipment ground and this would make it be used as the neutral reguardless and the bonding of this line would really be just a supplement. Whole lot of bonding going on.

I guess we need to complicate this issue a little more and just add some more Ifs.

You need to bond

If its likely to become energized.

If you know the eguipment it feeds doesn't have
an equipment ground.

If it has been unhooked.

Ain't grounding fun?

Ronald:

[ July 13, 2003, 12:03 PM: Message edited by: ronaldrc ]

 

[eprice]

Re: Bonding gas pipe to new residential service

Interesting discussion.

The point has been made that gas piping connected to appliances with power are already bonded by the EGCs of the circuits supplying power to those appliances. This raises the following questions in my mind: Those flexible connectors used to connnect the gas piping to the appliance look a lot like flexible raceway to me. 250.118 requires some of the flexible raceways to be listed in order to be used as an EGC. I doubt any of the flexible gas connectors have been tested or listed for bonding. Are all flexible gas connectors created equal when it comes to their ability to bond the gas piping to the appliance? Just how well do they bond the gas piping to the appliances? In the case of a fault to the gas piping at a point other than an appliance, if a flexible gas connector were to be relied upon to carry the fault current, how quickly would it burn through releasing gas accompanied by a quickly spreading fire or a loud bang? Do we really want our primary path for fault current to go through a gas appliance?

[ July 15, 2003, 12:00 PM: Message edited by: eprice ]

 

[don_resqcapt19]

Re: Bonding gas pipe to new residential service

wocolt,

I am not as old as Bennie but I cannot remember ever being able to use the 'Gas Line' as a Grounding electrode, and just to be sure I just called one of our inspectors, and he cant
EVER remember it either.

Look at 250-83(a) in the '87 code.
Don

 

[bennie]

Re: Bonding gas pipe to new residential service

Don: In the 30's in Oklahoma, many homes had gas service many years before water. The house I lived in until I was nine, had gas only no water or electricity. Of course no ground electrode either. We did have the magneto crank telephones, 6 customers per line.

The gas was used mainly for lights. The nearby oil fields supplied the gas.

Rural houses needed power, for well pumps, before there was running water. When the power was installed the gas line was the ground electrode.

I just noticed this is a repeat of the previous post. I'll leave it anyway

[ July 24, 2003, 11:35 PM: Message edited by: bennie ]

 

[ronaldrc]

Re: Bonding gas pipe to new residential service

Don and Bennie I don't know if anyone used it as a grounding electrode but heres proof it could have been and probably was.If the conditions where right.

 

[bennie]

Re: Bonding gas pipe to new residential service

Ronald: Remember that electricity replaced the gas light, this meant that gas piping was available at square one. Yes, it has been used in the past. Gas piping eliminated itself when the gas companies broke continuity to the dirt. The hazard of gas being present was not in the equation. It was irrelevant for the exclusion.

[ July 29, 2003, 09:58 AM: Message edited by: bennie ]

 

[wocolt]

Re: Bonding gas pipe to new residential service

Ok it is in the code. I couldnt find it because we have never used the Gas Pipe as a Grounging Electrode.

From Ronald Coleman
Don and Bennie I don't know if anyone used it as a grounding electrode but heres proof it could have been and probably was.If the conditions where right.

"As I said it is in the code, but if read carefully I believe it was there to satisfy somebody. They have on alternate code cycles removed it and then put it back in and most recently we were suppose to Bond it."

But my point is this. In Part H of the 87 code under 250-83(a)
Metal Underground Gas Piping System.

1. First proviso: An electrically continuous metal underground gas piping system.

2. Second proviso:Uninterruppted with insulating sections and joints.

3. Third Proviso: Without an outer NON-conductive coating.

4. And now the good part you need permission from the serving Utility and the AHJ has to say it is OK.

And I would assume to one of those it would have to be in writing.

Just the language of this section says, better Screams< We do not want you to use the Gas Pipe as a grounding electrode.

First how does anyone verify, and to whom is it verified , that the thing is electrically continuous. And for that matter from what to what is the gas pipe to be verified.distance from where to where is it 10 feet, there is no distance given for this

Second With out digging up the gas line how is it verified that there is no NON-conductive material on the pipe and at what point does that start to count the whole length ? or insulated joints
Now for the best part of getting permission from the utility, and the AHJ.
I cannot imagine any inspector taking responsibilty for this one, Or the utility.
Yes it is in there but it is NOT in there.

Ok now shoot me.
WmColt