GEC vs Bonding Jumpers

[Seven-Delta-FortyOne]

Yes I know this has been beat to death, so I apologize in advance.

My reading is the GEC, which must be a continuous conductor, is from the panel, (in my case) to “a” point on the GES.

So for example, I can come out of my meter main combo, to the first ground rod. This is the GEC.

From there, I can run a separate conductor to the gas line, water line, and second ground rod, as those are bonding jumpers, and connect those to the first ground rod, and those are allowed to be separate conductors to each.

My situation is, I want to use armored ground cable, which can’t be run continuous through the clamps made for them, so they will have to be individual conductors.

 

[roger]

You are correct, although the largest GE would be the first to hit and the gas line would not be part of the GES

 

[don_resqcapt19]

Yes I know this has been beat to death, so I apologize in advance.

My reading is the GEC, which must be a continuous conductor, is from the panel, (in my case) to “a” point on the GES.

So for example, I can come out of my meter main combo, to the first ground rod. This is the GEC.

From there, I can run a separate conductor to the gas line, water line, and second ground rod, as those are bonding jumpers, and connect those to the first ground rod, and those are allowed to be separate conductors to each.

My situation is, I want to use armored ground cable, which can’t be run continuous through the clamps made for them, so they will have to be individual conductors.

Why would you run a grounding electrode conductor to a gas line? That implies that you are using the gas line as a grounding electrode and that is not permitted.


You only need one GEC and you can attach grounding electrode bonding jumpers to that GEC to connect additional grounding electrodes, or to connect to multiple service panels. The only issue is that the actual GEC must be at least as large as what would be required for the other grounding electrodes that you are connecting via jumpers.

 

[Seven-Delta-FortyOne]

I’m only bonding the gas line and water lines.

I type like I talk, which is borderline unintelligible.

 

[kwired]

I’m only bonding the gas line and water lines.

I type like I talk, which is borderline unintelligible.

If the water line is metallic for at least ten feet in the ground it is an electrode.

If you are only bonding interior metallic piping and the supply is not a qualifying electrode, I believe your bonding jumper to the water piping still needs to be same size as a GEC. If bonding some isolated section of piping and not an entire metallic water piping system pretty sure it only needs to be sized per the EGC of the largest circuit that may possibly be able to energize it.

 

[Seven-Delta-FortyOne]

Yep.

I will try to reexplain.

These are panel change out situations. I do not know the situation with the water line. It’s existing, usually galvanized or copper stubbed up to a hose bib and then into the house. Most of these more than likely have been replaced with either PVC or PB to the meter at some point in the past.

The gas line needs to be bonded. More than likely, it is somewhere. But unless I can show it, inspector is going to want to see a new one.

Most of these I don’t have access to the interior. Some I barely even meet the HO.

So, I come out of the meter/main, which is standard in my area, with a #4 (for 200 amp upgraded panel) to the first ground rod, continue to the second, continue to the gas line just past the meter, and then on to the water stub up.

My understanding is, only from the panel to the first ground rod must be continuous. Then, I can continue to the second rod, the gas line, and the water. This is how I usually do it, and it passes inspection.

But, should I run the bonding jumper from the gas and water lines to the first ground rod, or does it have to land directly in the panel? I don’t think it does.

And the section between the first and second ground rods is not required to be continuous

 

[kwired]

The gas line needs to be bonded. More than likely, it is somewhere. But unless I can show it, inspector is going to want to see a new one.

Some AHJ's haven't a clue on this or just want to assert their authority. NEC says the equipment grounding conductor of the circuit likely to energize the gas line is sufficient. Often that might be a 14 or 12 AWG that is powering the gas appliance that is likely to energize the gas piping. No additional bonding jumpers are needed

 

[LarryFine]

From there, I can run a separate conductor to the . . . water line . . .

Except that the water line required size may make the GEC to the rod unnecessarily larger.

 

[jaggedben]

The NEC isn't that strict on the arrangment of the GES. I think the main point here is that only the GEC needs to be continuous. Bonding jumpers do not.

Thus the following...
Run full size GEC (sized to 250.66) to nearest electrode.
Clamp separate bonding jumpers between that electrode and other electrodes (sized to other electrode if only purpose is to connect to that one electrode).
...is always fine no matter which electrode is nearer or first.

Alternatively, running separate GECs to each electrode is allowed, but each GEC must be continuous.

 

[Seven-Delta-FortyOne]

Some AHJ's haven't a clue on this or just want to assert their authority. NEC says the equipment grounding conductor of the circuit likely to energize the gas line is sufficient. Often that might be a 14 or 12 AWG that is powering the gas appliance that is likely to energize the gas piping. No additional bonding jumpers are needed

Agreed. But, I can see from the inspectors perspective, while that is allowed, you’re now depending on the homeowner having a gas appliance installed in order to have the gas line bonded.

Around here, there are a lot of homes with both gas and electric supplied to the WH, stove, furnace, dryer, etc, but the HO might opt for electric appliances, and that leaves the gas system unbonded.

 

[jaggedben]

You can't assume that gas appliances have an electrical hookup with a EGC. Most gas tank type water heaters don't have one. If that's the only gas appliance in the house then the gas won't be bonded. Same with older pilot light stoves and heaters.

 

[LarryFine]

There are two different kinds of gas-piping bonding; simple bonding like water pipe and CSST bypassing.

 

[wwhitney]

Alternatively, running separate GECs to each electrode is allowed, but each GEC must be continuous.

I'd say it would suffice to run a (full-size) GEC to one electrode from say the service disconnect neutral bar, and then run bonding jumpers to the other electrodes from the service disconnect enclosure. Obviously it would be OK to terminate those bonding jumpers to the GEC within the service disconnect enclosure. Given that, it is not reasonable to say that if you instead terminate those bonding jumpers to the neutral bar, they are now GECs and must be continuous.

Cheers, Wayne

 

[jaggedben]

I'd say it would suffice to run a (full-size) GEC to one electrode from say the service disconnect neutral bar, and then run bonding jumpers to the other electrodes from the service disconnect enclosure. Obviously it would be OK to terminate those bonding jumpers to the GEC within the service disconnect enclosure. Given that, it is not reasonable to say that if you instead terminate those bonding jumpers to the neutral bar, they are now GECs and must be continuous.

Maybe not reasonable, but I think if you are invoking the permission to run individual GECs then that's what the code calls them. That said, the code is pretty vague on defining bonding jumpers as far as I recall.

 

[wwhitney]

Maybe not reasonable, but I think if you are invoking the permission to run individual GECs then that's what the code calls them.

What permission to run individual GECs? All I see is 250.50's requirement that all the grounding electrodes be bonded together, along with some requirements for a GEC and how it is installed.

Cheers, Wayne

 

[jaggedben]

250.64(F)(2)

 

[wwhitney]

250.64(F)(2)

OK, but that's a "shall be permitted" statement, so it is an allowance, not a requirement. Also, (2) is one of 3 choices provided in (F), the parent text says to comply with any one of them.

Let's look at 250.64(F)(1) which says that the GEC may be run to "any convenient grounding electrode" as long as "the other electrode(s), if any, is connected by bonding jumpers that are installed in accordance with 250.53(C)."

Looking 250.53(C), and the sections it references, I see nothing that specifies the topology of the bonding jumpers. I can conclude that you can run them in any topology that causes all of the grounding electrodes to be interconnected.

Cheers, Wayne

 

[jaggedben]

The only thing that's really unreasonable here is that GECs are required to be continuous and GES bonding jumpers are not. That makes no sense. (I'd vote to relax the requirements for GECs, not vice versa.)

I think the flaws with your interpretation are, first, that if a GEC lands on the neutral and thus meets the definition of a GEC, it's a GEC and don't get to claim it's a binding jumper. Secondly, but less clearly, 250.70 talks about connecting bonding jumpers to electrodes, not to GECs or each other.

But I don't really care that much. If you get a chance to argue this one with an AHJ, let me know how it goes.

 

[Seven-Delta-FortyOne]

This is how I usually do mine. I rarely have access inside, so water and gas bonding gets done outside.

I run the GEC to one ground rod, and bonding jumpers from that GE, to any other GE, and to the water and gas lines.

This is on panel changeouts, as almost all new construction the GEC goes to the CEE, and the gas and water line bonding gets landed on the grounded neutral/ground bar in the panel.

 

[LarryFine]

I run the GEC to one ground rod, and bonding jumpers from that GE, to any other GE, and to the water and gas lines.

Don't you then need a larger-than-#6 GEC to the rod on 200a-and-up services?

This is on panel changeouts, as almost all new construction the GEC goes to the CEE, and the gas and water line bonding gets landed on the grounded neutral/ground bar in the panel.

I agree with the tendency to consider all of them to be GECs in that instance.