But there is no icing on the cake in the 2011 NEC. 310.4 or that exact statement does not exist anywhere in the 2011 NEC.
I am not contesting the premise. I'm just pointing out wording or lack thereof which makes us doubt the implementation.
Equipment grounding conductors in parallel
- Thread starter Steelhead
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I agree. With the exception of a sectioned EGC in a cable (smaller conductors together making one large conductor) the EGC is full sized according to the OCPD anyway so the point is moot.
Sorry, my 2011 book apparently has legs since it keeps walking off, but it looks like its right in the begining of the paragraph you posted earlier: 310.10(H)(5):
(5) Equipment Grounding Conductors. Where parallel
equipment grounding conductors are used, they shall be sized
in accordance with 250.122....
('08 NEC)
There is no problem with the wording. Look up 'Equipment Grounding Conductor' in the index (back of NEC), now under that look up 'parallel'. Carefully read the sections it list, which are 310.4(C) and 310.4(E). It eventually leads you to 250.122(F) .
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And the rest of that requirement says the part about sectioned EGC less than 1/0AWG permitted in cable.
Anyway, that is not exactly the same as...
Regardless, 250.122 is a minimum size requirement. The minimum size per 250.122 can be overridden by any other requirement (but I'm not saying there actually is another requirement) which says it has to be larger. Take for example sizing a feeder conductor. You have to meet minimum sizing requirements of 110.14(C), 215.2(A)(1), which has two independent requirements, and indirectly 240.4(B). The largest of the minimum sizes is the actual minimum size. There are similar requirements for the minimum size of a feeder's neutral conductor.
And I remind readers I am only pointing out the the wording or lack thereof which makes us doubt implementation... not that I disagree with the assessment.
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As I said, 310.4 doesn't exist in the 2011 NEC, in which we are stuck with only 250.122(F).
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I think part of the problem is that the word parallel is used in differing contexts. I see nothing in 250.122(A) that says that we can use two or more smaller EGC's in parallel to make a larger one, that section references T250.122 which are for single EGC's. As Smart stated there is a time when the EGC's can be paralleled and that when they're sectioned by a manufacturer in a cable.
So although EGC's connected on both ends are by definition parallel conductors they're not being used in the same way as phase or neutral conductors where smaller conductors are connected at both ends to make a larger conductor.
So although EGC's connected on both ends are by definition parallel conductors they're not being used in the same way as phase or neutral conductors where smaller conductors are connected at both ends to make a larger conductor.
And I quoted that earlier. Here it is again...
Note that allowing sectioned EGC's to be smaller than 1/0AWG in the same section implies that paralled EGC's are not otherwise permitted to be smaller than 1/0AWG.310.10(H) said:
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I know you quoted that section but I was clarifying for others. When you say 310.4 is gone it sounds like you are saying it doesn't exist anymore
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With the exception of the sectioned cable where does it say that you can parallel two smaller EGC's to make a larger one?
Nowhere. But why say sectioned EGC's shall be permitted to be smaller than 1/0AWG. Wouldn't it suffice without the "smaller than 1/0AWG" clause???
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They changed 310.10(H)(2) to include the equipment grounding conductor but I think it was there in 2008 also. I think they forgot to add it in 310.10(H)(1)
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I see what you're saying and that you're hung up on the fact that they chose to include those words in the requirement but the reality it doesn't matter because you cannot parallel two smaller EGC to make a larger one.
So at the end of the day does that smaller than 1/0AWG really mean anything?
petersonra
Senior Member
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this prohibits sectioned EGCs >=1/0 in cables. I have no idea why. if you need a sectioned ground in a cable, they all have to be < 1/0. you can have (2)#1 but not (2) 1/0 as sections of EGCs in cables.
Nope!!! And I'm not hung up on it. As I said, just pointing out wording...
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I agree with you that it makes little sense.
I took a quick look at the 2011 ROP but found no direct evidence as to why this was put into the code wording. It all came together under a simple but lengthy editorial change to act in concert with the NEC manual of style. Maybe the CMP didn't even read it. :roll:
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Do you not think it was accidentally omitted in 310.10(H)(1) because almost the same wording was used in 310.10(H)(2) and there they used the equipment grounding conductor. Actually it looks like it was purposely omitted
When it comes to the wording of the NEC, I shy away from making any assumptions
Likely so, but it can be construed to mean otherwise. For example, thinking 1/0 and larger EGC's are permitted.
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