Area controversy around sizing of GEC for ground rod

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wbalsam1 said:
So then, back to my original post that started this thread:

It was just a pedestal service, no building, foundation or water main involved. Just a pair of ground rods 5/8" X 8'. The contractor installed #4 cu to the rods and when the inspector showed, he failed him and demanded that the contractor install something in the neighborhood of 1/0 cu to the rods.

Smart$ are you agreeing with this inspector?
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Dennis Alwon said:
I believe he is, but only in what he says the code states. In reality I think he knows it is not the intent.
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To a degree, yes... as Dennis wrote (Thanks).

However, it is highly dependent on how the conductors were run to the rods. If the rods were driven ≥6' from each other, there would have been no question that no larger than a #6 could have been run to each rod from the MBJ location. Any feed-through single conductor or jumpered two-piece routing and conductor sizing is subject to literal interpretation vs. intent.
 
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Smart $ said:
To a degree, yes... as Dennis wrote (Thanks).

However, it is highly dependent on how the conductors were run to the rods. If the rods were driven ≥6' from each other, there would have been no question that no larger than a #6 could have been run to each rod from the MBJ location. Any feed-through single conductor or jumpered two-piece routing and the GEC sizing is subject to literal interpretation vs. intent.
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If you ran "two" conductors does that meet 250.56?
 
LarryFine said:
It looks like he's saying the wire from the main to the first rod can be #6, but the jumper from the first rod to the second must be larger.

"Not on my watch." :cool:
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I didn't think that was what he was saying but I have forgotten half of who said what...;)
 
Ground rod loop

Ground rod loop

Typically, electricians around my area have their GEC originate in the service equipment, travel to the first ground rod, pass through the ground rod clamp on their way to the second ground rod, pass through this ground rod connector and return to the service equipment. They call it a "continuous ground rod loop". It's very common here. The only thing is, the POCO will not accept #6 cu and instead requires not less than #4 cu.
But it is very, very uncommon to see a conductor larger than #4 cu connected to one or more ground rods.
 
Smart $ said:
Ohh! I see you are referring to the 2011 NEC...

...but I don't see you point relative to the issue (an other-than-sole connection of a GEC to an electrode). The only one(s) I can think of is bonding to the water pipe or structural steel electrode to establish an SDS GES (these are more common acronyms :))... but I was referring to an other-than-sole GEC connection from the same system. And the gist of the matter is that bonding jumper connections count when considering the "sole connection" condition.
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My point is I think it is "pointless" to require a conductor larger than 6 AWG from the first rod electrode to another rod electrode. Given the fact that if you choose via [250.53(A)(2)(1) as your supplemental option that at that point the 25 ohms is not an issue with the NEC. While we all can agree that [250.66(A)] allows the installation of a 6 AWG to the GE, which in this case is a rod type. The reference in [250.53(C)] to [250.66] doe lend you to using the table since the sole connection statement in [250.66(A)] will limit you to not use that allowance. However, I don't think (my personal opinion ) that this is what it is trying to say....again agree to disagree if you wish.

I revert back to the IRC on this as a higher supporting document under most jurisdictions to give you the following:

E3608.3 Rod, pipe and plate electrode requirements. Where practicable, rod, pipe and plate electrodes shall be embedded below permanent moisture level. Such electrodes shall be free from nonconductive coatings such as paint or enamel. Where more than one such electrode is used, each electrode of one grounding system shall be not less than 6 feet (1829 mm) from any other electrode of another grounding system. Two or more grounding electrodes that are effectively bonded together shall be considered as a single grounding electrode system. That portion of a bonding jumper that is the sole connection to a rod, pipe or plate electrode shall not be required to be larger than 6 AWG copper or 4 AWG aluminum wire.

TABLE E3603.1 SERVICE CONDUCTOR AND GROUNDING ELECTRODE CONDUCTOR SIZING
Which will call for a 4 AWG CU to a 200A Service....just for an example and will also reference (d) below as to the sizing of the GEC.

d. Where the sole grounding electrode system is a ground rod or pipe as covered in Section E3608.2, the grounding electrode conductor shall not be required to be larger than 6 AWG copper or 4 AWG aluminum. Where the sole grounding electrode system is the footing steel as covered in Section E3608.1.2, the grounding electrode conductor shall not be required to be larger than 4 AWG copper conductor.

E3608.2 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 Sections E3610.2, and E3610.3, shall be sized in accordance with Section E3603.4, and shall be connected in the manner specified in Section E3611.1.

So in my view ( if I am like...fighting in court or something...lol ) I would argue the "sole grounding electrode system" as stated above and the verbiage that says when the two rods are tied together they are considered a single grounding electrode system [250.53(B)]...then Mr. Judge I think I am meeting the intent ...so that is one way of using code logic to present it.

Anyway....you get my point....sometimes as inspectors we have use common sense and push through the mud.

P.S. Yes, I am using the 2011 NEC....;)
 
LarryFine said:
It looks like he's saying the wire from the main to the first rod can be #6, but the jumper from the first rod to the second must be larger.

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I'm saying by strict literal interpretation of the Code wording, ignoring what is believed or otherwise appears to be the CMP's intent, the grounding conductors as pictured in the original Mike Holt illustration must be sized per Table 250.66. ...And I stress most emphatically this is not my personal view.
 
wbalsam1 said:
Typically, electricians around my area have their GEC originate in the service equipment, travel to the first ground rod, pass through the ground rod clamp on their way to the second ground rod, pass through this ground rod connector and return to the service equipment. They call it a "continuous ground rod loop". It's very common here. The only thing is, the POCO will not accept #6 cu and instead requires not less than #4 cu.
But it is very, very uncommon to see a conductor larger than #4 cu connected to one or more ground rods.
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While I would say such an looped unspliced GEC would qualify under 250.66(A) quite literally... it is still open to the AHJ interpretting the portion between rods as a bonding jumper and/or the portion between service and each rod as not being the sole connection to each electrode.
 
radiopet said:
IF we are dealing with the connection to a sole electrode which happens to be a rod then 6 AWG is all that is required. The fact you can't meet the requirements of the 25 ohms or less and an additional electrode is added makes no difference since connecting these two electrodes together creates a single electrode in my view. Also I hardly think lighting could care less. I have no worries if someone runs a 6 AWG to one rod and then loops to an additional rod...why would anyone be concerned over something that happens every day of the week.
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iwire said:
250.56 clearly shows that is not true.
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Well here is what they had to say when asked this question

Thank you for your email concerning the National Electrical Code? (NEC?).

The following reply is based upon the provisions of the NEC 2011.

The key to understanding this is in the text of the NEC. The largest required size for a grounding electrode conductor (250.66) or a bonding jumper (250.53(C) and 250.66) as the sole connection to or between two rod electrodes is provided in 250.66(A), that is a 6 AWG copper wire. The provision does not prohibit the use of Table 250.66 for sizing a grounding electrode conductor or bonding jumper when run to a rod electrode.
 
jwelectric said:




Well here is what they had to say when asked this question

Thank you for your email concerning the National Electrical Code? (NEC?).

The following reply is based upon the provisions of the NEC 2011.

The key to understanding this is in the text of the NEC. The largest required size for a grounding electrode conductor (250.66) or a bonding jumper (250.53(C) and 250.66) as the sole connection to or between two rod electrodes is provided in 250.66(A), that is a 6 AWG copper wire. The provision does not prohibit the use of Table 250.66 for sizing a grounding electrode conductor or bonding jumper when run to a rod electrode.
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Thanxs.
 
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Thank You

Thank You

jwelectric said:
Well here is what they had to say when asked this question

Thank you for your email concerning the National Electrical Code? (NEC?).

The following reply is based upon the provisions of the NEC 2011.

The key to understanding this is in the text of the NEC. The largest required size for a grounding electrode conductor (250.66) or a bonding jumper (250.53(C) and 250.66) as the sole connection to or between two rod electrodes is provided in 250.66(A), that is a 6 AWG copper wire. The provision does not prohibit the use of Table 250.66 for sizing a grounding electrode conductor or bonding jumper when run to a rod electrode.
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Thanks very much. It's as I originally suspected and interpreted. :cool:
 
jwelectric said:
Well here is what they had to say when asked this question

Thank you for your email concerning the National Electrical Code? (NEC?).

The following reply is based upon the provisions of the NEC 2011.

The key to understanding this is in the text of the NEC. The largest required size for a grounding electrode conductor (250.66) or a bonding jumper (250.53(C) and 250.66) as the sole connection to or between two rod electrodes is provided in 250.66(A), that is a 6 AWG copper wire. The provision does not prohibit the use of Table 250.66 for sizing a grounding electrode conductor or bonding jumper when run to a rod electrode.
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You forgot to add the footer to the email, I think it bears notice.

IMPORTANT NOTICE: This correspondence is NOT a Formal Interpretation issued pursuant to NFPA Regulations. Any opinion expressed is the personal opinion of the author and does not necessarily represent the official position of the NFPA or its Technical Committees. In addition, this correspondence is neither intended, nor should be relied upon, to provide professional consultation or services.
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In essence, they are stating outright that the above email is just another opinion. I haven't been following the discussion, but it appears from Paul's quote that part of his argument was that a pair of electrodes became "one electrode" and that was pertinent to his argument. IMO, the NFPA employee's response contradicts that. He or she described them as a pair of electrodes with a bonding jumper in between.
 
George Stolz said:
part of his argument was that a pair of electrodes became "one electrode" and that was pertinent to his argument.
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Which is my argument as well, if one rod can not be used as an electrode if it doesn't meet the 25 ohm requirement then it is not an electrode until the second rod is added, at this time a single electrode has been created.

Roger
 
Area controversy around sizing of GEC for ground rod

Area controversy around sizing of GEC for ground rod

infinity said:
Will it's just my opinion but I don't see how decades of installations are suddenly incorrect based on a new interpretation of old code language. Certainly this section has been read millions of times yet no one, including Mike Holt has come to some of the conclusions made in this thread. IMO that would indicate that there is something incorrect in that new interpretation.

I would center on the words sole connection and how they relate to the requirement. IMO they mean that when using plate, rod or pipe eletrodes the GEC need not be larger than #6 Cu. If you were to continue on to another electrode, say a water pipe then you would not have a sole connection to the rod, pipe or plate electrode since the GEC continues to a different electrode.
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Of all the responses that I read, I agree with this one the most.
 
Well I haven’t read all this thread and I am not going to. From what I can gather from this one page is the discussion is revolving around what that is defined in 250.50 the system.

It doesn’t matter how many of the eight items outlined in 250.52 there are the second that a second one is added it becomes a system.

The grounding electrode conductor will ALWAYS have one end in the service equipment. Any conductor that connects one of the eight items together is a bonding jumper.

Steel of a building, concrete encased, rings, and other buried metal are the only items that can be a standalone electrode. Metal water pipe, pipes, rods, plates will ALWAYS be part of an electrode system.

Yes there is a difference in an electrode and an electrode system. The system will have more than one electrode.
 
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