"Sectioned" EGC - 310.10(H)(5)

[George Stolz]

What is a "sectioned" EGC as referenced in 2011 310.10(H)(5)?

310.10(H)(5) Equipment Grounding Conductors. Where parallel equipment grounding conductors are used, they shall be sized in accordance with 250.122. Sectioned equipment grounding conductors smaller than 1/0 AWG shall be permitted in multiconductor cables in accordance with 310.104, provided the combined circular mil area of the sectioned equipment grounding conductors in each cable complies with 250.122.

 

[infinity]

Funny I would have assumed that the ROP for the 2011 NEC would provide some insight but I cannot find 310.10(H)(5) in the ROP.

 

[jim dungar]

Because they refer to multi-conductor cables, I believe a 'sectionalized EGC' is one that has been divided into several parts so that it can be laid into the gaps created by the phase conductors when the cable is formed.

 

[infinity]

Because they refer to multi-conductor cables, I believe a 'sectionalized EGC' is one that has been divided into several parts so that it can be laid into the gaps created by the phase conductors when the cable is formed.

I think that i remember exactly what you've described. It allows smaller conductors to fit into the interstices of the larger conductors and when terminated together it will be equivalent to the size of one normal EGC in the cable.

 

[George Stolz]

Funny I would have assumed that the ROP for the 2011 NEC would provide some insight but I cannot find 310.10(H)(5) in the ROP.

Good call - it was a proposal to the 2008.

310.4 moved to 310.10 in the 2011.

6-7 Log #1674 NEC-P06 Final Action: Accept in Principle in Part
(310.4)
____________________________________________________________
TCC Action: It was the action of the Technical Correlating Committee that
this Proposal be referred to Code-Making Panel 5 for Comment.
Submitter: Paul E. Guidry, Fluor Enterprises, Inc.
Recommendation: Add text to read as follows:
310.4, Exception No. 5: Equipment grounding conductors in sizes smaller than
1/0 AWG shall be permitted to be run in parallel to supply motor loads from
variable frequency drives where listed multiconductor cable is utilized.
Substantiation: It is a common practice and a common VFD manufacturer?s
recommendation to parallel three equipment grounding conductors where
multiconductor power supply cables are utilized with a variable frequency
drive. Many times these equipment grounding conductors are of sizes less than
1/0 AWG. Even though 110.3(A)(1) and 110.3(B) allows listed cable such as
this to be used in this manner, there seems to be a conflict with NEC 310.4.
Adding the exception above would clarify that this practice is acceptable.
Note: Supporting material is available for review at NFPA Headquarters.
Panel Meeting Action: Accept in Principle in Part
Insert as a new paragraph to 310.13 after the fine print note and change the
proposed text to read as follows:
Equipment grounding conductors shall be permitted to be sectioned within a
listed multi-conductor cable provided the combined circular mil area complies
with 250.122.
Panel Statement: The panel agrees that the equipment grounding conductor in
listed multi-conductor cable shall be permitted to be sectioned. The use of a
sectioned EGC is not limited to variable frequency drives and therefore this has
been moved to conductor construction.
Number Eligible to Vote: 11
Ballot Results: Affirmative: 11

 

[George Stolz]

So... does this jive with what you guys are talking about?

:dunce: <-- Me

 

[jim dungar]

So... does this jive with what you guys are talking about?

:dunce: <-- Me

Yes.

 

[George Stolz]

So it's talking about SEU?

 

[iwire]

So it's talking about SEU?

Maybe, but I don't think so.

I think they are talking about cables like this http://www.okonite.com/Product_Catalog/section4/sec4-pdf/4-1.pdf Check out arrow "C" it points to one of three EGCs in the cable.

 

[infinity]

Maybe, but I don't think so.

I think they are talking about cables like this http://www.okonite.com/Product_Catalog/section4/sec4-pdf/4-1.pdf Check out arrow "C" it points to one of three EGCs in the cable.

In Bob's photo that's exactly what they're referring to when they say sectioned EGC's. IMO maybe they could have used a better word than sectioned.

 

[George Stolz]

Ah! Never seen that cable before, got it.

Thanks!