Panel ground to gas line ?

[Sam Morris]

I inspected a new home today and the 1st thing wrong was the AFCI outlets for the bedrooms didn't trip when i tested them with my new Ideal arc faulty tester and the 2nd was the the panel had a bonding/grounding wire that connected to the gas supply line, is there a new code that allows this?? Is the ground rod or footer ground used in this case because of the apex supply line. I had never seen this before . Thank you for your insight.. Sam

[Jim Luttrall]

Not a new code or rule, ALL metal piping systems that are likely to become energized are required to be BONDED to the Grounding Electrode System. Gas pipe may NOT be used AS the Grounding Electrode but must be bonded to the system.
As the oft repeated mantra goes, the only approved AFCI test is the test button on the AFCI itself. There are no standards from which to build a universal AFCI testing device.

[A.D. Miller]

NEC 250.104(B) Other Metal Piping. Where 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 the service equipment enclosure, the grounded conductor at the service, the grounding electrode conductor where of sufficient size, or the one or more grounding electrodes used. The bonding jumper(s) shall be sized in accordance with 250.122, using the rating of the circuit that is likely to energize the piping system(s). The equipment grounding conductor for the circuit that is likely to energize the piping shall be permitted to serve as the bonding means. The points of attachment of the bonding jumper(s) shall be accessible.

FPN: Bonding all piping and metal air ducts within the premises will provide additional safety.
Unlike the metal piping systems covered in 250.104(A), this requirement applies only to metal piping systems that are likely to become energized. What this means is that where metal piping systems and electrical circuits interface through mechanical and electrical connections within equipment, a failure of electrical insulation can result in the connected piping system(s) becoming energized. Gas appliances are a common example of metal gas piping and electrical circuits being connected to a common piece of equipment, and in this case the 250.104(B) requirements apply. The required bonding of these other piping systems can occur at the same locations specified in 250.104(A), or an additional provision within this paragraph permits the equipment grounding conductor of the circuit that is likely to energize the piping as the means for bonding the piping. Typically, the use of an additional bonding jumper is not necessary to comply with this requirement, because the equipment grounding connection to the non–current-carrying metal parts of the appliance also provides a bonding connection to the metal piping attached to the appliance. This is a bonding requirement, and the other piping is not being used as an electrode. Therefore, this requirement does not conflict with 250.52(B)(1), which prohibits the use of metal underground gas piping as a grounding electrode for electrical services or other sources of supply. To prevent the underground gas piping from inadvertently becoming a grounding electrode there must be electrical isolation between the portion that is required to be bonded from the underground segment of metal gas piping. This may be inherent at the interface between the gas supplier's equipment and the premises gas piping.

[Speedy Petey]

At least in my area, it is extremely rare to see an external gas pipe bond. In fact, in over 20 years I have NEVER installed one and have never been asked to.

Here is one of the main reasons:

The bonding jumper(s) shall be sized in accordance with 250.122, using the rating of the circuit that is likely to energize the piping system(s). The equipment grounding conductor for the circuit that is likely to energize the piping shall be permitted to serve as the bonding means.

[Jim Luttrall]

At least in my area, it is extremely rare to see an external gas pipe bond. In fact, in over 20 years I have NEVER installed one and have never been asked to.

Here is one of the main reasons:
The photo shows a commonly required bonding if there is CSST piping.

[Jerry Peck]

I inspected a new home today and the 1st thing wrong was the AFCI outlets for the bedrooms didn't trip when i tested them with my new Ideal arc faulty tester

That's because that is not an AFCI "tester" and THE ONLY WAY TO TEST AFCI breakers is at the "Test" button on the AFCI breaker.

NEVER write up a AFCI which *does not trip* when you use a *not-AFCI tester*. Those testers *MAY*, but *probably not*, trip an AFCI breaker.

Repeating here ... THE ONLY ... yes, the ONLY ... AFCI tester for AFCI breakers are the "Test" buttons on those AFCI breakers.


and the 2nd was the the panel had a bonding/grounding wire that connected to the gas supply line, is there a new code that allows this??

Yes, but it is called a "bond" wire, not a "ground" wire.


Is the ground rod or footer ground used in this case

The gas pipe, any gas pipe, is not a grounding electrode, so the gas pipe is not allowed be used as such, which means that the footing steel and any other grounding electrodes are required to be used.

[ken horak]

Just as a side note to Jerry's and Jim's reply:
The only approved method of testing AFCI cicrciut breaker4s is the test button on the circuit breaker itself. The same goes for GFCI circuit breakers also. The only approved method is the test button on the circuit breaker.