That's logical reasoning... but the wording of the Code does not support said reasoning. Placing a resistance requirement on the first rod does not change the fact that it is an electrode. 250.52(A)(5) "defines" a Code-recognized rod electrode, while 250.53(G) describes its installation, and neither say anything about two being considered one where two are installed to comply with 250.56. As I said, nowhere in Article 250 does it say two installed electrodes can be considered one. Reasoning otherwise by implicit deduction is your perogative... but that don't make it code.
Area controversy around sizing of GEC for ground rod
- Thread starter wbalsam1
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jxofaltrds
Inspector Mike®
- Location
- Mike P. Columbus Ohio
- Occupation
- ESI, PI, RBO
"prerogative" a pet peeve of mine. pre- not per-
Paul Harvey was the only one that I have ever heard pronounce it correctly.
Paul Harvey was the only one that I have ever heard pronounce it correctly.
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
Do you all really think the NEC gets this technical in the wording of the NEC. Golly if we have half the people here seeing something one way and the others see it differently then , IMO, there is a problem. I think we are over thinking this, But it is an education to say the least. Why is English so hard- I wonder if other languages are this difficult to convey what they what to say.
But it is an education to say the least. Why is English so hard- I wonder if other languages are this difficult to convey what they what to say.
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
Simply: there's no earthly (pun intended) reason for a jumper between two rods to be any larger than the GEC between the service and the rods.
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
I don't think that was ever the issue. At least I didn't think so.
I agree... but the wording doesn't permit a #6 GEC (if Table size is larger) to the first rod if the second rod is jumpered (i.e. two connections at the first rod). So a Table sized GEc would be required to the first, and a Table-sized jumper would not be larger than the GEC between service and rod. It's that sole connection part of 250.66(A) which screws it up.
mivey
Senior Member
I think it hit the nail on the head. Although I see no reason for the bonding jumper in the first pic to be bigger as the code wording seems to indicate.
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mivey
Senior Member
mivey
Senior Member
Oh yeah. But I have really enjoyed reading it. It makes you realize how such a simple thing can turn out to not be so simple. A great lesson in technical writing.I think we are over thinking this,
- Location
- Massachusetts
There in no such thing as a multiple-rod 'single' electrode.
mivey
Senior Member
Since we are going to be all technical and what-not
:Not to mention electrodes with rods that are joined together for a longer length.
But I get what you are saying. Put the rods in series and they are called one electrode, parallel them with sufficient spacing and they are called a system.
radiopet
Senior Member
- Location
- Spotsylvania, VA
Yes...but I always forget when you post here you have to SPELL IT OUT a little more than usual...
radiopet
Senior Member
- Location
- Spotsylvania, VA
radiopet
Senior Member
- Location
- Spotsylvania, VA
Determining something is code versus determining something is common sense are two different things. Clearly why if is an interpretation and a ruling by local AHJ.
radiopet
Senior Member
- Location
- Spotsylvania, VA
i think that clearly adding the additional electrode to the first ground rod does not make a multiple rod electrode but it does complete a grounding electrode system in this case. The problem is that I can see where it gets screwy in that clearly the sole connection to the first electrode (the first rod ) is not required to be larger than the 6 AWG. The problem starts when it says size the bonding jumper per 250.66 and the table gets used and so it becomes a situation where the bonding jumper from rod 1 to rod 2 is no longer a GEC . In this case I can see where someone can argue that the bonding jumper run to the second electrode cant use 250.66(A) and could lead to a larger bonding jumper.
However, I don't think this is the intent as I am quite sure lightning could careless but alas I am not engineer.
radiopet
Senior Member
- Location
- Spotsylvania, VA
Roger,
For fun I sent for an informal opinion from the NFPA to see if they are on the same page. I know, it's informal and its not the CMP but hey....I always like to see. I agree in that #6 AWG should be all that is required but like iwire has stated and how it has been debated here......many opinions vary.
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
In my opinion, the jumper is "the sole connection" to the second rod, and the #6 limit applies.
Added:
Wouldn't one need many opinions for them to vary? :grin:
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radiopet
Senior Member
- Location
- Spotsylvania, VA
lol....well considering we have varied opinions here I guess it would apply. interesting enough i like many tend to give our opinion to what the intent actually was only to post what the code actually says ...and then it gets all mixed up..
BTW...how are things going in Richmond....doing ok?
I agree it is a sole connection... but the rule?250.66(A)?only applies to that portion of a GEC... not electrode bonding jumpers.
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