# Subtle 314.28(A)(2) change?



## HARRY304E (Sep 15, 2010)

chicken steve said:


> My '11 highlights _'or conduit body'_ twice in 314.28(a)(2).
> 
> Has the old LB raceway/ jb debate suffered a substantial change here?
> 
> ...


Yes they mean with the cover on.


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## Pete m. (Nov 19, 2011)

Conduit bodies (LL, LR, LB, C) are all now to be sized the same as we would a box with respect to 314.28.

The distance between a conduit entry and an opposite removable cover is based on the permitted bending radius in 312.

The change seems subtle at first but it has caused headaches for some contractors especially after they have the conduit ran.

Pete


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## chicken steve (Mar 22, 2011)

Thank you Pete, yet i'm still stymied....:001_huh:

the Ex refers to T312.6(A)

so perhaps applying a field example would help.....?

say we have 3---250kcmil in a 3" raceway & pass through a 3" LB

The _'wires per terminal'_ part confuses me, because there no terminals would exist in an LB, unless said LB was being used as a JB 

Am I missing the obvious.....?:blink:

~CS~


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## Pete m. (Nov 19, 2011)

314.28(A)(2) _Exception: Where a raceway or cable entry is in the wall of 
a box or conduit body opposite a removable cover, the distance from that wall to the cover* shall be permitted to comply with the distance required for one wire per terminal in Table 312.6(A).*_

So in your example, using 250 kcmil, Table 312.6(A) requires 4 1/2 inches from the conduit entry to the removable cover.

I don't have a 3" LB handy but I would assume that to receive a listing from an NRTL the LB (or any conduit body for that matter) would need to meet the minimum dimension from 312.6(A) based upon the largest conductors that could be contained in the conduit body.

If you have one in your shop, and feel so inclined, check to see what the distance is from the conduit entry to the cover. I'm actually curious because, honestly, I've never checked this on an inspection or installation.

Pete


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## chicken steve (Mar 22, 2011)

I'm on it, asap.....~CS~


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## don_resqcapt19 (Jul 18, 2010)

Pete m. said:


> Conduit bodies (LL, LR, LB, C) are all now to be sized the same as we would a box with respect to 314.28. ...
> Pete


That is not anything new...it was in the 99 (370-28) code and probably older codes too, but the 99 is the oldest I have on the computer and I don't want to go dig the older books out.


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## chicken steve (Mar 22, 2011)

don_resqcapt19 said:


> That is not anything new...it was in the 99 (370-28) code and probably older codes too, but the 99 is the oldest I have on the computer and I don't want to go dig the older books out.


which references T373-6(a) ('99) in the same manner as 314.28 references T312.6(A) ('11)

interestingly enough, the '99 370.28 refers to _'boxes and conduit bodies'_, while the '11 change highlights _'or conduit body'_

this is old news , so just what has changed in the '11? :001_huh:

............and why am i out in the barn measuring these? (2" best i could do)

















~CS~


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## don_resqcapt19 (Jul 18, 2010)

The charging statement in 370-28 and 314.28 use the wording "boxes and conduit bodies". That wording applies to the complete section. The words "or conduit bodies" were added to 314.28(A)(1) & (A)(2) by the panel action on proposal 9-83 without out any substantiation or panel comment. It did not change anything because the charging statement in 314.28 included conduit bodies for the complete section.

As far as the conduit bodies in the pictures, if they are being used with conductors #4 and larger, then the distance between the conduit entries has to be 6 times the trade size of the conduit. That is in addition to being require to have a depth that is required by 314.28(A)(2) Exception.


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## chicken steve (Mar 22, 2011)

don_resqcapt19 said:


> > The charging statement in 370-28 and 314.28 use the wording "boxes and conduit bodies". That wording applies to the complete section. The words "or conduit bodies" were added to 314.28(A)(1) & (A)(2) by the panel action on proposal 9-83 without out any substantiation or panel comment. It did not change anything because the charging statement in 314.28 included conduit bodies for the complete section.
> 
> 
> So this is simply a clarification by their technical correlation commity ?
> ...


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## Dennis Alwon (May 9, 2009)

It is interesting that the NEC has made it very difficult to comply with standard equipment. Now most LB's are marked - for instance a 2" lb I believe is marked for 3/ 4/0 conductors. I think this would be allowed


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## chicken steve (Mar 22, 2011)

Dennis Alwon said:


> It is interesting that the NEC has made it very difficult to comply with standard equipment. Now most LB's are marked - for instance a 2" lb I believe is marked for 3/ 4/0 conductors. I think this would be allowed


_EGGZACTLY!_

While I do appreciate you're ability to describe the crux of the issue in such a short concise manner , please allow me to peck that point apart here Denny>

from the manufacturer's spec page we're given the impression said 2" LB is good for just what you've stated, 3-4/0's 

In fact it's _stamped_ inside the LB's in my barn...



> LB-200* 2* 31
> ⁄4 35
> ⁄8 95
> ⁄8 23
> ...


Yet according to the code loop , which is no NEW loop, we can't by code requirements install anything larger than a #1

*HOW then, can this be listed for the sizes the manufacturer describes ?*



> Third Party Certification:
> UL Listed *E-18095*
> Suitable for wet locations when used
> with gasketed covers.
> ...


~C S~


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## chicken steve (Mar 22, 2011)

etta, can anyone here provide a ref to _any_ of these listings?

~CS~


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## hardworkingstiff (Jan 22, 2007)

chicken steve said:


> *HOW then, can this be listed for the sizes the manufacturer describes ?*
> 
> 
> 
> ~C S~


Money talking?


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## chicken steve (Mar 22, 2011)

That's even more _cutting _that Denny's response Lou.....:whistling2:

Especially given i may need to buy the answer
~CS~


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## don_resqcapt19 (Jul 18, 2010)

chicken steve said:


> don_resqcapt19 said:
> 
> 
> > So this is simply a clarification by their technical correlation commity ?
> ...


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## don_resqcapt19 (Jul 18, 2010)

The real issue with the markings on the conduit bodies, is the fact that they almost always say 3 conductors of x size. There is no code provision that permits you to do a field calculation and use 4 conductors of a smaller size. There is also no provision to let you use the other combination of sizes that are shown in the manufactures instructions. A reasonable AHJ would permit the sizes in the instructions but the code does not say that.

A good place for 2017 proposal.


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## chicken steve (Mar 22, 2011)

I'm not understanding this then Don

~CS~


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## don_resqcapt19 (Jul 18, 2010)

chicken steve said:


> I'm not understanding this then Don
> 
> ~CS~


What part of it?


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## hardworkingstiff (Jan 22, 2007)

don_resqcapt19 said:


> A reasonable AHJ would permit the sizes in the instructions but the code does not say that.


 Luckily, I've just had to deal with reasonable inspectors.


> A good place for 2017 proposal.


 Agreed.


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## chicken steve (Mar 22, 2011)

I'm under the impression the EX allows for the T312.6A 1 wire per terminal column for _'conduit bodies'_ , or whatever may have a removeable cover 


If so, said table is addressing the _dimensional_ qualities of what falls under the EX.

Thus my reference to the 2" lb's being good for _up to_ wire size #1

That said, i can either go out to my shop to find the very same lb's _marked_ 3-4/0's , as in the manufacturers links 


The only manufacturer i have found addressing this code loop is Appleton , which in fact has the older code loop ref's you've posted as well


As for all my 2" lb's marked 3-4/0's , _(or whatever they may be marked) _what do i do? Am i held to their markings & manufacturer's links to wire size(s) , or am i held to T312.6A ?

I can't get this image of a 12" deep 2" LB outta my head....

~CS~


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## don_resqcapt19 (Jul 18, 2010)

There are two "6 times the trade size of the conduit" rules in 314.28(A)(2). You have to comply with both if you are using conductors #4 and larger. The exception only covers the first one...the one that says the side of the enclosure opposite the conduit entry must be 6 times the conduit size away. The second rule in not affected by the exception. That part of the rule requires that the distance between the conduit entries be 6 times the conduit size away from each other, so yes the 2" LB would have to be about 16" long over all to have the conduit entries 12" apart as required by the rule. There are fittings that are that size, but they are very expensive. Often the EC will use a section of wireway to create an LB for these types of installations.

The markings on the conduit bodies are per the rule in 314.28(A)(3). Without that marking conduit bodies cannot be used for conductors #4 and larger unless the conduit entries are 6 x apart for 90° fittings or 8 x apart for "C" fittings.

The code rule for boxes or conduit bodies having "smaller dimensions" [meaning smaller than what is required by 314.28(A)(1) or (A)] says the maximum size and number of conductors that are permitted, "shall be permanently marked with the maximum number and maximum size of conductors permitted". There is no provision to use more conductors of a smaller size. For example your LB that is marked for "3-4/0's" can't be used with four #4s per the code rule. It is very likely that the instructions for that conduit body would permit its use with the four #4s, but there is no provision in the code to permit you to use those instructions.


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## hardworkingstiff (Jan 22, 2007)

don_resqcapt19 said:


> It is very likely that the instructions for that conduit body would permit its use with the four #4s, but there is no provision in the code to permit you to use those instructions.


I would think you could use 110.3(B).

But, I'm pretty sure you are aware of that section, so why can't it be used to install more of a smaller wire size (according to manufacturer's instructions)?


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## Pete m. (Nov 19, 2011)

hardworkingstiff said:


> I would think you could use 110.3(B).
> 
> But, I'm pretty sure you are aware of that section, so why can't it be used to install more of a smaller wire size (according to manufacturer's instructions)?


An NRTL listing doesn't "trump" NEC requirements as far as I know.

Pete


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## hardworkingstiff (Jan 22, 2007)

Pete m. said:


> An NRTL listing doesn't "trump" NEC requirements as far as I know.
> 
> Pete


So you are saying you can't use 110.3(B) in conjunction with 314.28(A)(3) to install 4-#4's in an LB marked for 3-#3/0's?

I've seen a manufacturer instructions (as I'm sure you have) on how to calculate how many of a smaller conductor can be used in that LB.


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## chicken steve (Mar 22, 2011)

don_resqcapt19 said:


> > There are *two* "6 times the trade size of the conduit" rules in 314.28(A)(2). You have to comply with both if you are using conductors #4 and larger. The exception only covers the first one...the one that says the side of the enclosure opposite the conduit entry must be 6 times the conduit size away. The second rule in not affected by the exception. That part of the rule requires that the distance between the conduit entries be 6 times the conduit size away from each other, so yes the 2" LB would have to be about 16" long over all to have the conduit entries 12" apart as required by the rule. There are fittings that are that size, but they are very expensive. Often the EC will use a section of wireway to create an LB for these types of installations.
> 
> 
> That is what i missed Don, thank you
> ...


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## don_resqcapt19 (Jul 18, 2010)

hardworkingstiff said:


> I would think you could use 110.3(B).
> 
> But, I'm pretty sure you are aware of that section, so why can't it be used to install more of a smaller wire size (according to manufacturer's instructions)?


It is my opinion that 110.3(B) cannot make a code rule less stringent...it may make one more stringent. Letting you use a combination that is not marked on the conduit body would be making the code rule less stringent. 

Like I said in an earlier post, this needs a proposal for the 2017 code to permit the use of the combinations listed in the manufacturer's instructions.


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## hardworkingstiff (Jan 22, 2007)

don_resqcapt19 said:


> It is my opinion that 110.3(B) cannot make a code rule less stringent...it may make one more stringent. Letting you use a combination that is not marked on the conduit body would be making the code rule less stringent.


So if you were an AHJ inspector, you would turn down 4-#4's in an LB marked for 3-3/0 maximum?


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## hardworkingstiff (Jan 22, 2007)

chicken steve said:


> now i've a shop full of lb's that _aren't_ , either by listing or code, good for anything i previously thought they were good for
> 
> ~CS~


Were you getting by with them before? In other words, the AHJ let it slide?


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## hardworkingstiff (Jan 22, 2007)

don_resqcapt19 said:


> It is my opinion that 110.3(B) cannot make a code rule less stringent...it may make one more stringent. Letting you use a combination that is not marked on the conduit body would be making the code rule less stringent.


 I don't see it that way. 110.3(B) is not making a code less stringent, it's allowing for the calculations according to the manufacturer's instructions on how to properly size the number of smaller conductors allowed in the conduit body.


> Like I said in an earlier post, this needs a proposal for the 2017 code to permit the use of the combinations listed in the manufacturer's instructions.


It would remove any debate on the issue. I'm glad the state of NC doesn't subscribe to your interpretation.


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## don_resqcapt19 (Jul 18, 2010)

hardworkingstiff said:


> So if you were an AHJ inspector, you would turn down 4-#4's in an LB marked for 3-3/0 maximum?


It depends on if I have reached my quote of red tags for the month


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## don_resqcapt19 (Jul 18, 2010)

hardworkingstiff said:


> I don't see it that way. 110.3(B) is not making a code less stringent, it's allowing for the calculations according to the manufacturer's instructions on how to properly size the number of smaller conductors allowed in the conduit body.
> It would remove any debate on the issue. I'm glad the state of NC doesn't subscribe to your interpretation.


I think the code is clear and the wording does not allow for the use of the published information. The code needs to be fixed.


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## hardworkingstiff (Jan 22, 2007)

Have you ever wondered how the manufacturer came up with there max conductor rating?

I'm not sure, but I wonder if in order to comply with 314.28, they got approval to use the 3-#3/0's max because you can fit them into a 1-1/2" conduit and 1.5*6=9 which might fit there dimensions? If that indeed is correct, then there is no reason to not allow the calculations the manufacturer has come up with for different conductor sizes.

I still say 110 allows it.


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## chicken steve (Mar 22, 2011)

hardworkingstiff said:


> Were you getting by with them before? In other words, the AHJ let it slide?


The AHJ's here are all experienced men Lou, it's just that their dept is so seriously undermanned they often can't enforce much of what i'll simply call _'the finer points'_

It sometimes makes me mad, that my state spends more tax dollars on the needs of cows....

~CS~


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## redwoodk (Jun 14, 2013)

*T&B says it is simple.*

"Analysis of Change: 
This section was revised to eliminate the specific conductor marking requirements for listed conduit bodies of smaller dimensions having a radius of the curve to the centerline not less than as indicated in Table 2, Chapter 9. This is the same minimum radius of curve required for field bends in IMC, RMC and EMT found in Sections 342.24, 344.24 and 358.24 respectively. Therefore, these are suitable for installations of combinations of conductors of the maximum conduit or tubing wire fill (of conduit or tubing being used) 
permitted by Table 1 in Chapter 9.
These designs greatly simplify wire fill calculations for conduit bodies for both design and inspection and do not require conductor size markings. The 2011 NEC text in Section 314.28 (A) (3) was restrictive for these designs as it technically did not permit installation of the full Table 1, Chapter 9 wire fill 
for the conduit or tubing being used. 
These conduit body designs effectively negate the concern for wire jamming 
addressed in Informational Note No. 2 to Tables in Chapter 9."
http://tnblnx3.tnb.com/emAlbum/albums//us_resource/gm7304hr_2014NECCodeChanges.pdf


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## don_resqcapt19 (Jul 18, 2010)

redwoodk said:


> "Analysis of Change:
> This section was revised to eliminate the specific conductor marking requirements for listed conduit bodies of smaller dimensions having a radius of the curve to the centerline not less than as indicated in Table 2, Chapter 9. This is the same minimum radius of curve required for field bends in IMC, RMC and EMT found in Sections 342.24, 344.24 and 358.24 respectively. Therefore, these are suitable for installations of combinations of conductors of the maximum conduit or tubing wire fill (of conduit or tubing being used)
> permitted by Table 1 in Chapter 9.
> These designs greatly simplify wire fill calculations for conduit bodies for both design and inspection and do not require conductor size markings. The 2011 NEC text in Section 314.28 (A) (3) was restrictive for these designs as it technically did not permit installation of the full Table 1, Chapter 9 wire fill
> ...


That change does not apply to standard conduit bodies. It only applies to this type of conduit body.


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