gas pipe bond

[hurricaneflyer]

If gas pipe bonding is to be sized according to the size of the circuit that might energize it, could a grossly oversized gas pipe bonding conductor cause the pipe to become part of the grounding electrode system reguardless of any good intensions? If the grounding electrode conductor and the gas pipe bond are the same size, and are terminated at the same place in the service panel then a buried gas pipe would carry the same or more current than the grounding electrode in case of fault or lighting strike?

If gas goes to three appliances, the size of the bonding conductor would be based on the size of the largest appliance circuit, based on the idea that it is not likely more than one of the appliances will cause a fault at the same time? In other words dont total up all the appliances that could energize the gas pipe?

In this instance I cant just use the appliance ground, it is new construction and the inspector wants the bond installed at rough in.

It seems obvious I am not understanding something.

 

[al hildenbrand]

could a grossly oversized gas pipe bonding conductor cause the pipe to become part of the grounding electrode system regardless of any good intensions?

There are two things that prevent a conductive gas pipe from being part of the GES:

1. The underground gas pipe can't be a grounding electrode by Code. See 250.52(B)(1).
2. The gas utility installs a dielectric coupling(s) at their connection to the premises gas piping to electrically isolate their pipe.

The pipe inside the structure, however, must be bonded by 250.104(B).

The interesting thing about the "good intentions" you mention and #1 that I mention is that neither mean anything to the simple physics that "current takes all available paths in the circuit."

The current can't see a path in the utility gas pipe because of the dielectric coupling.

However, if a conductive gas line is installed from the home to a detached garage and it isn't electrically isolated, that customer owned underground gas line will be a path.

But even though it is a path for the return current from the main bonding jumper to go to the PoCo transformer, we fall back on 250.52(B)(1), and say that this thing that "looks like" a GE is not a GE.

Maybe others here will know if there is gas code that describes isolating the customer owned underground gas line going to, say, a garage.

 

[barbeer]

In Fl we have the Florida Building Code, based on the International codes for the most part. The way i interpret 310 of the 2004 Florida fuel gas code, it says " bonding will be required for all upstream piping and this will be achieved by the appliances electric connection(grounded of course)". I know that others will know more than me on this subject and look forward to more knowledge.

 

[al hildenbrand]

Oh yeah,

I forgot about the "grossly oversized gas pipe bonding conductor" part of your question.

The whole focus of the bonding, 250.104(B), is to provide a minimum size of conductor. Nothing limits the oversized conductor to a maximum.

The bonding jumper has to be, at least, low enough in impedance to permit a fault current (that is coming from the pipe and going to the main bonding jumper on its way to the PoCo transformer) large enough to trip the overcurrent protective device on the branch circuit supply to the fault at the pipe. A larger bond than "just large enough" only slightly improves performance.

 

[hurricaneflyer]

Thanks, I did not know the utility installed an insulator.
What about the minimum size? Base it on the one largest appliance (circuit) that the gas pipe is connected to?

 

[infinity]

Thanks, I did not know the utility installed an insulator.
What about the minimum size? Base it on the one largest appliance (circuit) that the gas pipe is connected to?

If it's already connected to an appliance the EGC for that appliance has bonded the pipe.

 

[celtic]

......... it says " bonding will be required for all upstream piping and this will be achieved by the appliances electric connection(grounded of course)".

If it's already connected to an appliance the EGC for that appliance has bonded the pipe.

Just for arguments sake....
What if....
The only appliance that uses a gas connection is the HWH. The heat is electric as is the cooking.

 

[hurricaneflyer]

Thanks Trevor,
The inspector wanted us to run a #6 from the pipe to any of the panels for rough in. No appliances yet.

 

[infinity]

Just for arguments sake....
What if....
The only appliance that uses a gas connection is the HWH. The heat is electric as is the cooking.

If there is no electrical connection at all is it likely to become energized?

 

[al hildenbrand]

Ahh.

What a pretty question. . .suspended. . .hanging in mid-air. . .

Add that the clothes dryer is also electrically heated.

 

[celtic]

If there is no electrical connection at all is it likely to become energized?

Fair enough.

 

[don_resqcapt19]

Trevor,

If there is no electrical connection at all is it likely to become energized?

Even where the gas line is connected to equipment with electrical power, is the gas line likely to become energized? The old code wording was "may become energized" and I would agree that any conductive object "may become energized", but very few are "likely to become energized".

Likely 1 : having a high probability of occurring or being true : very probable

likely adjective
describes something that will probably happen or is expected:

Don

 

[mark henderson]

It seems obvious I am not understanding something.

Well If this is something new in your area then it might be because the plumbers are using CSST tubing. CSST manufactures sent out 12,500 letters to building officials all over the nation, stating that the manufacture recommends a separate bond run from the main electric service to the gas service and sized according to the electric service.
I started a thread on this a while back.

Mark

 

[JohnJ0906]

The CSST manufacurer must have bought copper futures!:roll:

 

[mark henderson]

What happened briefly they had a class action law suit. Wont get into details but someone figured if the gas pipe had been bonded at the main when the lighting struck they might not of had a problem. HUMMM
Don't know if I agree with this. What happens if you loose your grounding electrode? What becomes a ground? With out looking up the code# now It does state DO NOT USE THE GAS PIPE AS A GROUNDING ELECTRODE.
Okay its 250.52b1

Mark

 

[goatsniffer]

Where can i find your thread on this. I am trying to determine sizing for ground for GASTITE. Thanks

 

[al hildenbrand]

Where can i find your thread on this. I am trying to determine sizing for ground for GASTITE. Thanks

When you say "this", what are you thinking about?:-?

 

[A/A Fuel GTX]

There must be some kind of problem with GASTITE flexible gas piping as the AHJ in my area is requiring a separate bonding jumper for installations using this particular brand of pipe. Just wondering if anyone else is in this situation also?

 

[Dennis Alwon]

I don't know about your area but our gas company almost killed me when I installed a ground wire to their gas line. That was years ago. They would not turn the gas on until it was disconnected. The inspector said I needed it, the gas utility said no way. The gas company won and I have never bonded a gas pipe since except through the appliances , furnace, etc.

 

[jameshot]

bonding the gas and cold water piping is usually done /allowed at the water heater with 2 clamps and a piece of no 6 copper and meets all the requirements.