Ground rod jumper?

[nizak]

I have a driven ground rod with a single #6 Cu conductor to it from the service disconnect.

Inspector is requiring a second ground rod be added to the system.

He said it needs to be continuous #6 from the disconnect to the second rod.

I said that the second rod only needs a bonding jumper between it and the first one. It can be attached with an acorn clamp and go the second rod.

I believe I’m correct.
Am I?

Thanks

 

[infinity]

You are correct the inspector is wrong. The GEC ends at the first rod and a bonding jumper connects the two rods together

 

[nizak]

You are correct the inspector is wrong. The GEC ends at the first rod and a bonding jumper connects the two rods together View attachment 2574828

Thanks. I will send him this diagram you provided
so he can address it properly going forward.

 

[Joe.B]

Thanks. I will send him this diagram you provided
so he can address it properly going forward.

Skip the diagrams, just send him the code section:

250.54 Auxiliary Grounding Electrodes. One or more
grounding electrodes shall be permitted to be connected to the
equipment grounding conductors specified in 250.118 and
shall not be required to comply with the electrode bonding
requirements of 250.50 or 250.53(C) or the resistance requirements
of 250.53(A)(2) Exception, but the earth shall not be
used as an effective ground-fault current path as specified in
250.4(A)(5) and 250.4(B)(4).

 

[infinity]

Skip the diagrams, just send him the code section:

250.54 Auxiliary Grounding Electrodes. One or more
grounding electrodes shall be permitted to be connected to the
equipment grounding conductors specified in 250.118 and
shall not be required to comply with the electrode bonding
requirements of 250.50 or 250.53(C) or the resistance requirements
of 250.53(A)(2) Exception, but the earth shall not be
used as an effective ground-fault current path as specified in
250.4(A)(5) and 250.4(B)(4).

That is the incorrect code section. This is a supplemental ground rod not an auxiliary electrode.

 

[Joe.B]

That is the incorrect code section. This is a supplemental ground rod not an auxiliary electrode.

Apologies, you're correct. I didn't take the time, just went straight to that... but the point still stands, it's in the code.

 

[JohnE]

And the picture cites the code article. I'd send the inspector the picture along with the code article.

 

[infinity]

Apologies, you're correct. I didn't take the time, just went straight to that... but the point still stands, it's in the code.

Yup it is in there 250.53.

 

[Joe.B]

And the picture cites the code article.

Yeah, but I didn't bother to verify the code sections because the picture says 2005.

250.53 (C) Bonding Jumper. The bonding jumper(s) used to connect
the grounding electrodes together to form the grounding
electrode system shall be installed in accordance with
250.64(A), (B), and (E), shall be sized in accordance with 250.66,
and shall be connected in the manner specified in 250.70. Rebar
shall not be used as a conductor to interconnect the electrodes of
wounding electrode systems.

 

[LarryFine]

The only reason we run the wire unbroken between rods is to save the cost of an acorn clamp.

 

[roger]

Here's another image showing the jumper.

 

[102 Inspector]

Can someone explain the difference between an auxiliary electrode and a supplemental electrode. When would the distinction be made?

 

[Little Bill]

Can someone explain the difference between an auxiliary electrode and a supplemental electrode. When would the distinction be made?

I believe an auxiliary electrode is just one that is added, but not required.
A supplemental electrode is required, such as when using metal water pipe, only one rod without proving 25 ohm resistance, etc.

 

[infinity]

Can someone explain the difference between an auxiliary electrode and a supplemental electrode. When would the distinction be made?

Sure, an auxiliary electrode is not part of the GES. They're often used for a piece of machinery when required by the machine manufacturer. Take a look at the code section in post #4.

Supplemental electrodes are electrodes that are required to supplement another electrode like a water pipe. Back a few code cycles ago auxiliary electrodes were called supplementary electrodes which was very confusing.

 

[102 Inspector]

I think I understand the difference. If job specs call for 6 ground rods, the second one is supplemental, but the remaining would be considered auxiliary. I also understand the machinery application. Thanks for the clarification.

 

[infinity]

I think I understand the difference. If job specs call for 6 ground rods, the second one is supplemental, but the remaining would be considered auxiliary. I also understand the machinery application. Thanks for the clarification.

Unfortunately it's not that simple. One code section requires all electrodes that are present to be included as part of the GES so in your 6 ground rod scenario they all would be required to be part of the GES unless one or more of those 6 rods were auxiliary electrodes. The auxiliary electrodes could be omitted from connection to the GES.

 

[Joe.B]

Take a look at the code section in post #4.

It was useful after all

 

[jaggedben]

IMO you can declare any electrode as auxiliary if it doesn't contribute to meeting the NEC requirements for the GES. For the sake of argument, I'd say if you have two rods you can declare the UFER to be an auxiliary. That said, such a thing goes against the idea of auxiliary electrodes.

The following video is out of date (the section in 690 that Mike criticizes has thankfully been removed from the code since 2017) but starting around 7:30 gives a good explanation for why auxiliary electrodes are allowed in the NEC but are generally not a good idea.

 

[infinity]

I'd say if you have two rods you can declare the UFER to be an auxiliary.

IMO you cannot simply call an electrode an auxiliary electrode and it becomes one, it would need to physically wired as one to be one as per 250.54. Maybe that's what you're saying?

 

[tom baker]

When I taught electrical classes many wanted to if it’s one wire and two clamps or two wires and three clamps.
But in defense of the AHJ, the NEC was not clear on this rule and the CMP fixed that