# Thread: Is this ground correct?

1. ## Is this ground correct?

I was just wondering if this is normal. It's my house so it's not a big deal, unless it is a big deal. Anyhow, I've always been wondering...Thanks

Last edited by Marc M; 01-18-2010 at 09:04 PM.

2. ## Re: Is this ground correct?

This would not be a ground on the gas line, it would be a bond.

There should be another larger size conductor bonding the hot and cold water lines together. This does not look large enough even for a 100 amp service. Is there another grounding conductor on another part of the water lines?

3. ## Re: Is this ground correct?

there is, thanks

4. ## Re: Is this ground correct?

Originally Posted by Marc M
I was just wondering if this is normal. It's my house so it's not a big deal, unless it is a big deal. Anyhow, I've always been wondering...Thanks
Like Jim said, this appears to be bonding. I would also expect to see the cold to be directly connected to the grounded terminal block in the service equipment panel or at the ufer/ground rod. That clamp and wire is probably located at the water service main. However, the wire that you have looks a bit small. I generally see a #6 copper wire used for bonding. However, I have never understood the method to determine the size of the Grounding Electrode Conductor. Some of the NEC text seems to require the bonding to correspond to the potential current it might carry and other text seems to accept #6 as a minimum, even if the service is 200 amps. Maybe someone with more knowledge will chime in.

5. ## Re: Is this ground correct?

Can't tell from the photos, but they might be too small.

The minimum size required for the bonding jumper is a #8 AWG for services with a #2 AWG or smaller SE conductor, basically 125 amp and smaller services.

For a 1 or 1/0, the minimum size of the bonding jumper goes to #6, basically 150 to 175 am services.

For 2/0 or 3/0, the minimum size of the bonding jumper goes to #4, basically 200 to 225 amp services.

For 3/0 to 350 kcmil, the minimum size of the bonding jumper goes to a #2, basically 225 to 350 amp services.

Talking about copper all the way through - SE conductors and bonding jumpers for WATER PIPING.

The bonding jumper for GAS PIPING is sized differently. Bonding for the gas line is based on "the rating of the circuit that is likely to energize the piping system(s)."

Typically, that would be the largest rated circuit, and could even be the SE conductor rating.

A 60 amp circuit would require a #10 bonding jumper.

A 100 amp circuit would require a #8 bonding jumper.

A 200 amp circuit would require a #6 bonding jumper.

A 300 amp circuit would require a #4 bonding jumper.

6. ## Re: Is this ground correct?

JP,

Perfect. But, where do you get that in the NEC? I keep going around in circles looking for the required size of the grounding electrode conductor and the bonding jumper sizes. The bonding requirements refers me to the GEC table, which refers me to the SEC table. I probably am not carrying the numbers over correctly, but they seem to require larger conductors than you have posted.

Are the grounding electrode conductors and the bonding jumpers required to be the same size?

Oh, by the way, happy Thanksgiving.

7. ## Re: Is this ground correct?

Originally Posted by Gunnar Alquist
But, where do you get that in the NEC?
250.104(A) Metal Water Piping, which refers, in 250.104(A)(1), to Table 250.66 for sizing.

250104(B) Other Metal Piping, which refers to Table 250.122 via 250.122 for sizing.

I was typing my previous post while you were typing your, it just took me longer to put all that stuff in there.

Have a Happy Thanksgiving also.

My wife had her gall bladder removed yesterday, so we're just hanging around not doing anything tomorrow, may not even have any turkey, depends on how she feels. Has her doctor said, "It'll feel like you have 3 stab wounds." - yeah, that about sizes it up.

One good thing we found out about the doctor before the surgery was that the incidence of 'complications' during gall bladder surgery is only 1 in 3000. I asked him how many he had already done, and he said about 3200 or so. Then I asked if he had any with complications, and he said one.

I said "GREAT! That means that you've already got your one complication out of the way and there is nothing to worry about.", my wife did not think it was as funny as we did.

8. ## Re: Is this ground correct?

Gas piping bonding has been greatly debated due to the fact it states "likely to become energized".

Most inspectors will accept the appliance with the largest load as "likely to become energized" which means if the only appliance connected to a gas line is a small boiler running off of a 15A circuit with 14/2 then the equipment grounding conductor of the 14/2 is acceptable as bonding for the entire gas system at its point of connection to the appliance.

I do not agree with that and my interpretation is that any part of the system can possible come into contact therefore I want to see bonding IAW the service entrance conductors.

Now for a spin:

If you use Gastite CSST then they require a 6awg copper bonding jumper in addition to any other bonding that you may have from the appliance. This is a manufacturer requirement. They want the bonding to be to the manifold which should be made from rigid black pipe.

So this is a subjective area depending on the AHJ's interpretation of "likely to become energized".

As an AHJ I choose to require bonding per the service entrance conductor sizing.

Jerry, what is your view on this one?

9. ## Re: Is this ground correct?

Originally Posted by Jeff Remas
Gas piping bonding has been greatly debated due to the fact it states "likely to become energized".
This is what the 2008 NEC says (and no changes from 2005): (underlining is mine)
- (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.

I do not agree with that and my interpretation is that any part of the system can possible come into contact therefore I want to see bonding IAW the service entrance conductors.
If any voltage is supplied to the structure or building, then 'it is possible' that such voltage, by way of its circuit, 'could energize' the "other metal piping system", including "gas piping".

Now, does "it is possible" equate to "is likely to"?

The only answer I can give is this example, which is hard for the other side to dispute and argue against:

"It is possible" for lightning to strike a building. However, "is it likely" that lightning will strike a building? No, if it were "likely" then many more buildings would be struck than actually are struck.

With that being said, the electrical systems in those buildings are "required" to be protected against that "possible" occurrence as though it "were likely" to happen.

Thus, with the same safety standard in mind, is it not "possible" for the gas piping to become energized by the voltage of the service to the building, and, thus, under the same conditions and reasoning as with lightning, is it not "likely" that the protective bonding could be carry the current produced by that voltage energizing the piping, and should not the bonding conductor be sized for that occurrence?

If the answer is "No.", then explain why that same answer to the same question is "Yes." when it comes to the "possibility" of a lightning strike.

Both are just as "possible", those both are, using the same definition, just as "likely".

Thus, use the service size as the circuit rating for sizing the bonding conductor.

Also notice where the bonding jumper is required to go to in the above code reference - I have also underlined that part.

10. ## Re: Is this ground correct?

Jerry said: "Thus, use the service size as the circuit rating for sizing the bonding conductor."

I share that opinion but will let you know that was not the opinion shared at our IAEI chapter meeting. Most inspectors are considering the appliance installed in the gas system as acceptable bonding.

I however, do not because of my opinion of "likely to become energized"

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