NG Bonding Question.

[WCEI]

Is there a code mandated location for the bonding connection to a NG gas piping supply to a residential occupancy?

 

[augie47]

From the NEC
An actual bond jumper may not be needed if the equipment supplied has an equipment ground
{250.104(B)} (In that Section you will find a list of points to connect a bond jumper if one is used)

CSST gas piping does have separate bonding requirements from the mechanical codes and does specify termination points.

 

[infinity]

If it's black gas pipe no additional bonding is required.

 

[WCEI]

If it's black gas pipe no additional bonding is required.

Then the assumption is that it is bonded through the branch circuit through the appliance(s)?

And yes, black iron piping, no CSST.

 

[electrofelon]

If it's black gas pipe no additional bonding is required.

While I agree, I am CONSTANTLY fighting with inspectors on this. There seem to be two ways they weasel into requiring a separate bonding jumper. First is the phrase "EGC for the circuit likely to energize the piping." While it might seem the gas utilizing appliance is the only circuit likely to energize, the term "likely to energize" is not defined so they will say any number of other circuits can energize the piping. Second, even if they give in that the gas utilizing appliance is the only thing likely to energize, they will say the EGC with the supply is not necessarily bonded to the gas piping so you need a separate jumper.

It just a tough situation as everyone is already nuts about grounding and bonding, and then you ad the word "gas" into the mix and all critical thinking evaporates.

 

[WCEI]

While I agree, I am CONSTANTLY fighting with inspectors on this. There seem to be two ways they weasel into requiring a separate bonding jumper. First is the phrase "EGC for the circuit likely to energize the piping." While it might seem the gas utilizing appliance is the only circuit likely to energize, the term "likely to energize" is not defined so they will say any number of other circuits can energize the piping. Second, even if they give in that the gas utilizing appliance is the only thing likely to energize, they will say the EGC with the supply is not necessarily bonded to the gas piping so you need a separate jumper.

It just a tough situation as everyone is already nuts about grounding and bonding, and then you ad the word "gas" into the mix and all critical thinking evaporates.

That’s what led me to ask the question. It’s like throwing darts trying to figure out which inspector requires what.

So, relenting to the probable requirement to install a separate bonding conductor, my contention is to make the connection after the meter. With the assumption that occasionally the meter may be removed for non payment in some extreme situations. And I try to make this termination before the piping enters the structure or crawlspace so that it is readily visible to the inspector.

Followup question, (just like at a Presidential news conference), I assume sizeing
the conductor according to Table 250.122?

 

[LarryFine]

I will make the bonding connection to the solid piping closest to the electrical connection.

 

[electrofelon]

Second, even if they give in that the gas utilizing appliance is the only thing likely to energize, they will say the EGC with the supply is not necessarily bonded to the gas piping so you need a separate jumper.

I just wanted to elaborate on the above point a bit. I Actually dont think this is unreasonable. Just because the supply EGC lands on a ground screw in the terminal box, How do we know that is electrically connected to the gas piping? There could be a dielectric union or non-metallic fitting somewhere in there. Now I am not saying we would need a separate bonding jumper from the service, just that a bonding jumper from the supply EGC in the connection box to the gas piping may be prudent.

 

[LarryFine]

Just because the supply EGC lands on a ground screw in the terminal box, How do we know that is electrically connected to the gas piping? There could be a dielectric union or non-metallic fitting somewhere in there.

I would counter with saying that, if there is no electrical connection/pathway between the grounded appliance and the gas piping, then the appliance is not likely to energize the piping.

 

[electrofelon]

I would counter with saying that, if there is no electrical connection/pathway between the grounded appliance and the gas piping, then the appliance is not likely to energize the piping.

Yeah, I think I would agree with that. I guess the counter argument could be that perhaps there is a connection, but not a "solid" connection adequate for fault clearing. The NEC says (essentially) "bonded to the EGC", which is kinda vague and isnt specific about what is and is not acceptable.

 

[WCEI]

I would counter with saying that, if there is no electrical connection/pathway between the grounded appliance and the gas piping, then the appliance is not likely to energize the piping.

But, “likely to become energized” up stream of the appliance would still require bonding. And typically, there is a conductor, branch circuit or otherwise, in the vicinity of gas piping that could be construed to possibly energize the piping system. No argument if there is absolutely nothing that could energize the piping system. But that is a rare occurrence.

 

[infinity]

Even the circuit feeding a gas appliance is not likely to energize the pipe. The wording here is terrible.

 

[don_resqcapt19]

Even the circuit feeding a gas appliance is not likely to energize the pipe. The wording here is terrible.

It is the same wording for a number of bonding requirements. This has been buried in the NEC Style manual or the NFPA glossary of terms for a long time, but was placed into Article 100 in the 2023 code.

Energized, Likely to Become. (Likely to Become Energized)
Conductive material that could become energized because of the failure of electrical insulation or electrical spacing. (CMP-5)

 

[Dennis Alwon]

That’s what led me to ask the question. It’s like throwing darts trying to figure out which inspector requires what.

So, relenting to the probable requirement to install a separate bonding conductor, my contention is to make the connection after the meter. With the assumption that occasionally the meter may be removed for non payment in some extreme situations. And I try to make this termination before the piping enters the structure or crawlspace so that it is readily visible to the inspector.

Followup question, (just like at a Presidential news conference), I assume sizeing
the conductor according to Table 250.122?

If you bond before the meter you better leave town as the gas company will have a fit. Also look at this section of the code. The gas meters usually use an insulated fitting to keep from connecting to the underground piping.

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)

 

[electrofelon]

Even the circuit feeding a gas appliance is not likely to energize the pipe. The wording here is terrible.

It is the same wording for a number of bonding requirements. This has been buried in the NEC Style manual or the NFPA glossary of terms for a long time, but was placed into Article 100 in the 2023 code.

They should just delete the gas pipe bonding section. I don't see the gas piping as likely to become energized. If there is an insulation failure in the gas appliance, it's EGC will take care of it. Just get rid of that whole damn stupid section.

 

[WCEI]

If you bond before the meter you better leave town as the gas company will have a fit. Also look at this section of the code. The gas meters usually use an insulated fitting to keep from connecting to the underground piping.

I had not really looked at it this way; as it would be the same as trying to use the underground gas pipe as a grounding electrode.

 

[infinity]

They should just delete the gas pipe bonding section. I don't see the gas piping as likely to become energized. If there is an insulation failure in the gas appliance, it's EGC will take care of it. Just get rid of that whole damn stupid section.

I agree and the use of the word likely is just incorrect. They should say that if it could become energized then there is no argument. Likely means that it probably will happen and truth is it most likely won't.

 

[Steve16]

From the IRC:

G2411.1 (310.1) Pipe and Tubing Other Than CSST​

Each above-ground portion of a gas piping system other than corrugated stainless steel tubing (CSST) that is likely to become energized shall be electrically continuous and bonded to an effective ground-fault current path. Gas piping other than CSST shall be considered to be bonded where it is connected to an appliance that is connected to the equipment grounding conductor of the circuit that supplies that appliance.

 

[WCEI]

From the IRC:

G2411.1 (310.1) Pipe and Tubing Other Than CSST​

Each above-ground portion of a gas piping system other than corrugated stainless steel tubing (CSST) that is likely to become energized shall be electrically continuous and bonded to an effective ground-fault current path. Gas piping other than CSST shall be considered to be bonded where it is connected to an appliance that is connected to the equipment grounding conductor of the circuit that supplies that appliance.

Thank you sir. Is that wording in the NEC anywhere?

 

[Steve16]

Thank you sir. Is that wording in the NEC anywhere?

No but depending on your state, the IBC typically takes precedent over all over codes including the NEC. Residentially my code path typically goes IBC -> IRC -> NEC

So are we bonding it because it's gas piping in residential or are we bonding it because it's connected to electrical equipment?

I would point to the CSST bonding requirements that we get from the IRC also. I dont recall seeing any bonding requirements in the NEC for CSST.

So of course it would still come down to the AHJs interpretation