314.28 Conduit Bodies

[augie47]

There was recently a post that discussed a Code change that addressed conduit body fill but I can't find it in a search. I believe it concerned a 2107 change. Anyone have a link?

 

[dkidd]

There was recently a post that discussed a Code change that addressed conduit body fill but I can't find it in a search. I believe it concerned a 2107 change. Anyone have a link?

To a time machine?

 

[augie47]

not nice to kid old people about dyslexia

220, 221 what ever it takes.... 2017, 2107 whichever

 

[dkidd]

not nice to kid old people about dyslexia

220, 221 what ever it takes.... 2017, 2107 whichever

No kid jokes.

http://ecmweb.com/nec/2017-national-electrical-code-changes?page=10

See underlined revision

(3) Smaller Dimensions.
Listed boxes or listed conduit bodies of dimensions less than those required in 314.28(A)(1) and (A)(2) shall be permitted for installations of
combinations of conductors that are less than the maximum conduit or tubing fill (of conduits or tubing being used) permitted by Table 1 of
Chapter 9.
Listed conduit bodies of dimensions less than those required in 314.28(A)(2), and having a radius of the curve to the centerline not less than that
indicated in Table 2 of Chapter 9 for one-shot and full-shoe benders, shall be permitted for installations of combinations of conductors permitted
by Table 1 of Chapter 9. These conduit bodies shall be marked to show they have been specifically evaluated in accordance with this provision.
Where the permitted combinations of conductors for which the box or conduit body has been listed are less than the maximum conduit or tubing
fill permitted by Table 1 of Chapter 9, the box or conduit body shall be permanently marked with the maximum number and maximum size of
conductors permitted. For other conductor sizes and combinations, the total cross-sectional area of the fill shall not exceed the cross-section
area of the conductors specified in the marking, based on the type of conductor identified as part of the product listing.

Informational Note: Unless otherwise specified, the applicable product standards evaluate the fill markings covered here based on
conductors with Type XHHW insulation.

 

[Smart $]

No kid jokes.

http://ecmweb.com/nec/2017-national-electrical-code-changes?page=10

See underlined revision

(3) Smaller Dimensions.
Listed boxes or listed conduit bodies of dimensions less than those required in 314.28(A)(1) and (A)(2) shall be permitted for installations of
combinations of conductors that are less than the maximum conduit or tubing fill (of conduits or tubing being used) permitted by Table 1 of
Chapter 9.
Listed conduit bodies of dimensions less than those required in 314.28(A)(2), and having a radius of the curve to the centerline not less than that
indicated in Table 2 of Chapter 9 for one-shot and full-shoe benders, shall be permitted for installations of combinations of conductors permitted
by Table 1 of Chapter 9. These conduit bodies shall be marked to show they have been specifically evaluated in accordance with this provision.
Where the permitted combinations of conductors for which the box or conduit body has been listed are less than the maximum conduit or tubing
fill permitted by Table 1 of Chapter 9, the box or conduit body shall be permanently marked with the maximum number and maximum size of
conductors permitted. For other conductor sizes and combinations, the total cross-sectional area of the fill shall not exceed the cross-section
area of the conductors specified in the marking, based on the type of conductor identified as part of the product listing.

Informational Note: Unless otherwise specified, the applicable product standards evaluate the fill markings covered here based on
conductors with Type XHHW insulation.

Your paste of the section text has line breaks every other line... making for hard reading. Easier to read as a quote. :angel:

 

[infinity]

There was recently a post that discussed a Code change that addressed conduit body fill but I can't find it in a search. I believe it concerned a 2107 change. Anyone have a link?

Basically take the combination of conductors stamped on the inside of the conduit body, add up their fill and use that number for other different combinations of conductors. This one has been a long time coming.

 

[Carultch]

Basically take the combination of conductors stamped on the inside of the conduit body, add up their fill and use that number for other different combinations of conductors. This one has been a long time coming.

Sure has. And I'm sure many people simply did that anyway. The case of 3 equal sized conductors, as is usually stamped on conduit bodies, is rare in sizes larger than #6.

I think what would make even more sense, is if L-bodies & C-bodies were designed to accept any 3+ conductor combination that the corresponding conduit can accept at 40% fill. Such that you wouldn't even need to think about a different sizing algorithm for the conduit body, and just match it to the conduit you are using anyway.

 

[augie47]

Sure has. And I'm sure many people simply did that anyway. The case of 3 equal sized conductors, as is usually stamped on conduit bodies, is rare in sizes larger than #6.

I think what would make even more sense, is if L-bodies & C-bodies were designed to accept any 3+ conductor combination that the corresponding conduit can accept at 40% fill. Such that you wouldn't even need to think about a different sizing algorithm for the conduit body, and just match it to the conduit you are using anyway.

If I'm not mistaken, the mogul type such as Appleton's NEC-LB series will accept the same conductors as the conduit but they require you to open your wallet a lot more.