Bonding a Gas Line

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Little Bill

Little Bill

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Tennessee NEC:2017
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I have a house with a meter/main combo. Along with the upstairs panel, there is a subpanel in the basement. The basement is being partially finished is the reason for the sub. I have to bond the gas line and was thinking I could do that in the basement subpanel. I don't want to make another penetration in the basement wall to bond it outside at the HVAC unit so in the basement is the easiest place.

Is bonding in the sub permissible?
 
Not listed as a point of connection in 250.104(B), but the gas line should be sufficiently bonded by the EGC of the appliance circuits that power the gas equipment.


Other Metal Piping. If installed in, or attached to, a building or structure, a metal piping system(s), including gas piping, that is likely to become energized shall be bonded to
any of the following:
(1) Equipment grounding conductor for the circuit that is
likely to energize the piping system
(2) Service equipment enclosure
(3) Grounded conductor at the service
(4) Grounding electrode conductor, if of sufficient size
(5) One or more grounding electrodes used
 
Is this CSST and that's why a separate bond is necessary? Plan old black gas pipe does not need a separate bond as Jumper has stated.
 
infinity said:
Is this CSST and that's why a separate bond is necessary? Plan old black gas pipe does not need a separate bond as Jumper has stated.
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It's just black pipe but every contractor in this area has had a dispute with this inspector over that. None have prevailed so I didn't even try.
 
Little Bill said:
It's just black pipe but every contractor in this area has had a dispute with this inspector over that. None have prevailed so I didn't even try.
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Well if that is the case and the gas line is already bonded by the appliance circuit, then you are not bound by 240.104 and could add a unneeded grounding jumper and land it in a sub panel IMO.
 
Little Bill said:
It's just black pipe but every contractor in this area has had a dispute with this inspector over that. None have prevailed so I didn't even try.
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Is there a higher inspection authority that you could appeal to? County, State, or otherwise? Here the State reserves the right to interpret the NEC requirements, and a call to one of the state inspectors would clear up the question.
 
packersparky said:
Is there a higher inspection authority that you could appeal to? County, State, or otherwise? Here the State reserves the right to interpret the NEC requirements, and a call to one of the state inspectors would clear up the question.
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The State Fire Marshall's office is in charge of the State's electrical inspections. Each (with some exceptions) inspector is a "Deputy Electrical Inspector" working under the Chief Electrical inspector. So I'm sure we could appeal to the "Chief".
 
One way I have seen them justify running the bond conductor instead of just using the EGC in the branch circuit, is they consider any circuit on the premesis, not just the one serving the appliance, as likely to energize the piping.
 
electrofelon said:
One way I have seen them justify running the bond conductor instead of just using the EGC in the branch circuit, is they consider any circuit on the premesis, not just the one serving the appliance, as likely to energize the piping.
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That is nuts. Half or more of the circuits in the house could easily not even be remotely close to the gas pipe or the gas appliances.
 
jumper said:
Not listed as a point of connection in 250.104(B)..

Other Metal Piping. If installed in, or attached to, a building or structure, a metal piping system(s), including gas piping, that is likely to become energized shall be bonded to any of the following:
..(5) One or more grounding electrodes used
Click to expand...

My jurisdiction sees customer side of gas meter as a grounding electrode, part of the Electrode Bonding System, and utility side of gas meter as prohibited from bonding per 250.52(B)(1).

Why can't customer side of gas line, if in basement, be a point of connection?
 
ramsy said:
My jurisdiction sees customer side of gas meter as a grounding electrode, part of the Electrode Bonding System, and utility side of gas meter as prohibited from bonding per 250.52(B)(1).

Why can't customer side of gas line, if in basement, be a point of connection?
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If your AHJ says that section of gas piping is an electrode then I suppose you could.

Strange though, most resi gas installs I have seen, the customer side goes from the meter straight into the house. No 10 feet of underground pipe to qualify as an electrode.

Do they treat it like a water pipe and use that section for rules governing its use as an electrode?
Suppplemental electrodes needed and 250.66 for size of GEC?

Anyways, the dirty secret is that in reality any portion of the gas piping that is bonded and underground is an electrode. The NEC just does not want some goofball trying to use it as the primary or sole electrode.
 
jumper said:
..Do they treat it like a water pipe and use that section for rules governing its use as an electrode?
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You are right. They treat it like a water pipe, as part of the Grounding Electrode System, which must be bonded. Not Electrode-Bonding-System (my error) not substitute electrode.
 
Last edited:
Is the OP’s basement sub-panel within a separate structure that requires it’s own electrode, rather than just a bond to existing GES?
 
In the area i work they allow us to bond the gas line to the water line i.e. when we jumper the water heater we continue it to the gas line.

Sent from my SM-G930T using Tapatalk
 
ramsy said:
You are right. They treat it like a water pipe, as part of the Grounding Electrode System, which must be bonded. Not Electrode-Bonding-System (my error) not substitute electrode.
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What about 250.52(B)?

(B) Not Permitted for Use as Grounding Electrodes.
The following systems and materials shall not be used as
grounding electrodes:
(1) Metal underground gas piping systems
 
How can an inspector see the gas pipe as an electrode when article 250 states

250.52(B) Not Permitted for Use as Grounding Electrodes. The
following systems and materials shall not be used as grounding
electrodes:
(1) Metal underground gas piping systems
(2) Aluminum
(3) The structures and structural reinforcing steel described
in 680.26(B)(1) and (B)(2)
Click to expand...
 
Dennis Alwon said:
How can an inspector see the gas pipe as an electrode when article 250 states
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packersparky said:
What about 250.52(B)?

(B) Not Permitted for Use as Grounding Electrodes.
The following systems and materials shall not be used as
grounding electrodes:
(1) Metal underground gas piping systems
Click to expand...

Ramey did not say he thought it was correct, he just said what his AHJ thinks.

Not his fault that the AHJ is nuts with the interpretation.
 
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