Conduit Body Fill

[infinity]

From 2014 NEC 314.16(C)(1)

"The maximum number of conductors permitted shall be the maximum number permitted by Table 1 of Chapter 9 for the conduit or tubing to which it is attached."

That wouldn't directly apply to conduit bodies where the conductors are #4 and larger. When the conductors are #4 and larger then the 6X and 8X pull box rules would apply.

 

[lauraj]

That wouldn't directly apply to conduit bodies where the conductors are #4 and larger. When the conductors are #4 and larger then the 6X and 8X pull box rules would apply.

I've never seen a 2" C-condulet that is 16" long in its opening. I think 314.28(A)(3) applies more often to conduit bodies, last paragraph. "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."

How I read that, for #4 and larger, we can still use the conduit fill based off of raceway size unless stamped otherwise.

 

[infinity]

I've never seen a 2" C-condulet that is 16" long in its opening. I think 314.28(A)(3) applies more often to conduit bodies, last paragraph. "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."

How I read that, for #4 and larger, we can still use the conduit fill based off of raceway size unless stamped otherwise.

If the conductors are #4 or larger then the opening in the conduit body needs to be 6X the trade size for angle pulls or 8X the trade size for straight pulls. If it is smaller than those dimensions then you may use the size and the number of conductors stamped on the inside. Standard C conduit bodies are typically much smaller than the 8X dimension required.

 

[infinity]

It's a violation but I would guess that most of us here could easily splice 8-#12's in a conduit body without any problems.

Maybe not in a 1/2" SLB.

2 inch no problem

I was referring to the 3/4" LB mentioned in the OP but left that out of my post. 12-#12's in a 3/4" no problem.

 

[victor.cherkashi]

I was referring to the 3/4" LB mentioned in the OP but left that out of my post. 12-#12's in a 3/4" no problem.

I cant see pictures. Is someone else also has problem?

Sent from my Nexus 5 using Tapatalk

 

[don_resqcapt19]

I've never seen a 2" C-condulet that is 16" long in its opening. I think 314.28(A)(3) applies more often to conduit bodies, last paragraph. "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."

How I read that, for #4 and larger, we can still use the conduit fill based off of raceway size unless stamped otherwise.

Almost all of the conduit bodies 1" and larger are so marked.

The biggest problem with the stamping is that I have never seen it marked for one size of 3 conductors and there is nothing in the code that actually permits the use of the other size combinations that are listed in the manufacturer's documents.

 

[jusme123]

Almost all of the conduit bodies 1" and larger are so marked.

The biggest problem with the stamping is that I have never seen it marked for one size of 3 conductors and there is nothing in the code that actually permits the use of the other size combinations that are listed in the manufacturer's documents.

troublemaker :slaphead:

 

[don_resqcapt19]

troublemaker :slaphead:

This all got a bit more confusing with the change in the 2014 code that was made to accommodate a different type of fitting where the conductor fill is based on the raceway fill.

In this type of fitting the bending radius of the conductors is not less than the minimum permitted bending radius for conduit of the same trade size and there are no restrictions on wire fill other than the conduit fill rules. The text shown in blue below applies to this type of fitting.

314.28(A)(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.

The text in bold applies to standard conduit bodies where conductors sized #4 and larger are used. The code very clearly requires the marking to be on the conduit body and gives no permission to do any type of calculation or to used the manufacturer's published list of other combinations that could be used in that conduit body.

This rule is very often violated. Many code users have no idea that the box sizing for conductors #4 and larger also applies to conduit bodies. They look right over the words in the section title.

314.28 Pull and Junction Boxes and Conduit Bodies

 

[kwired]

This all got a bit more confusing with the change in the 2014 code that was made to accommodate a different type of fitting where the conductor fill is based on the raceway fill.

In this type of fitting the bending radius of the conductors is not less than the minimum permitted bending radius for conduit of the same trade size and there are no restrictions on wire fill other than the conduit fill rules. The text shown in blue below applies to this type of fitting.

The text in bold applies to standard conduit bodies where conductors sized #4 and larger are used. The code very clearly requires the marking to be on the conduit body and gives no permission to do any type of calculation or to used the manufacturer's published list of other combinations that could be used in that conduit body.

This rule is very often violated. Many code users have no idea that the box sizing for conductors #4 and larger also applies to conduit bodies. They look right over the words in the section title.

Instead of looking over the words I think many assume if you can pull it through say a 2 inch raceway then a 2 inch LB will also be fine within the run.

This is violated a lot and even gets by many inspectors a lot.

 

[don_resqcapt19]

Instead of looking over the words I think many assume if you can pull it through say a 2 inch raceway then a 2 inch LB will also be fine within the run.

This is violated a lot and even gets by many inspectors a lot.

But when you have to use a sledge hammer and 2x4 to get the wires into the LB, you should understand that there is a problem

 

[kwired]

But when you have to use a sledge hammer and 2x4 to get the wires into the LB, you should understand that there is a problem

When you have been doing that for years you think that is normal though.