Pullbox sizing question

[Smart $]

Code doesn't say how to measure so I go with shortest path method. In the graphic, spacing between entries needs to be 18" for 3" entries and 12" for 2" entries. Actual measure not shown.

 

[infinity]

Sorry about that. Since it was already addressed I thought OP had got that. That would be C in this graphic.

View attachment 13240​

To be honest, at this point I am getting unclear as what type of pull OP has.

I like this graphic better and I found the first graphic confusing because it makes no mention of the required distance between the raceways.

Regarding the OP he would need to also follow the C in this graphic which is the similar to his installation just that the OP's box is rotated 90°.

 

[Carultch]

According to David and Carultch you need to maintain 6X between the conduit entries I don't see that in your graphic.

That's because Mike Holt and Mike Culbreth have looked at this NEC rule numerous times, and never once noticed the word "entries" before they drew this graphic. Not until their video team members asked how you were supposed to anticipate the fitting sizes in advance, when trying to cut the openings in the enclosure.

The word entries makes it so you only need to think about the size of the opening in the enclosure. And not about sizes of hubs or bushings.

 

[jusme123]

If you have two 4" and two 2" conduits entering one side of a pullbox and instead of leaving another side like a straight pull or angle pull, they exit out of the top to go up to floors above, how do you size the dimensions of the box in this regard?

what.size.conductors:jawdrop::jawdrop:

 

[cppoly]

I am attempting a 3D pullbox that I'm describing. Does this help?? Still want to confirm if dimension C is considered an angle pull in pullbox example 1.

If no, would example 2 be considered an angle pull?

 

[david luchini]

I am attempting a 3D pullbox that I'm describing. Does this help?? Still want to confirm if dimension C is considered an angle pull in pullbox example 1.

If no, would example 2 be considered an angle pull?

If I'm reading your sketches correctly, in both cases you are coming in the front and going out the top. You have an angle pull in both cases.

If the back of the box if fixed, then dimension B would be per 314.28(A)(2).
If the bottom of the box is fixed, then dimension C would be per 314.28(A)(2).

If either the back or the bottom of the box is a removable cover, then dim B or dim C (respectively) would be per Table 312.6(A), one wire per terminal.

 

[cppoly]

If I'm reading your sketches correctly, in both cases you are coming in the front and going out the top. You have an angle pull in both cases.

If the back of the box if fixed, then dimension B would be per 314.28(A)(2).
If the bottom of the box is fixed, then dimension C would be per 314.28(A)(2).

If either the back or the bottom of the box is a removable cover, then dim B or dim C (respectively) would be per Table 312.6(A), one wire per terminal.

Thanks

 

[shortcircuit2]

If either the back or the bottom of the box is a removable cover, then dim B or dim C (respectively) would be per Table 312.6(A), one wire per terminal.

In following the removable cover rule that directs us to 312.6(A), one wire per terminal...the rule changes when conductors in the raceways are run in parallel according to the language of section 312.6(A)...

So if I had 4 conductors run in parallel in the raceway opposite a removable cover, I would refer to the column with 4 at the top to find the required measurement?

 

[Carultch]

If I'm reading your sketches correctly, in both cases you are coming in the front and going out the top. You have an angle pull in both cases.

If the back of the box if fixed, then dimension B would be per 314.28(A)(2).
If the bottom of the box is fixed, then dimension C would be per 314.28(A)(2).

If either the back or the bottom of the box is a removable cover, then dim B or dim C (respectively) would be per Table 312.6(A), one wire per terminal.

Is a U-pull considered an angle pull?

 

[Smart $]

In following the removable cover rule that directs us to 312.6(A), one wire per terminal...the rule changes when conductors in the raceways are run in parallel according to the language of section 312.6(A)...

So if I had 4 conductors run in parallel in the raceway opposite a removable cover, I would refer to the column with 4 at the top to find the required measurement?

No. If you arrive at 312.6 by way of 314.28(A)(2) Exception, the stipulation therein instructs you to use "the distance required for one wire per terminal".

 

[Smart $]

Is a U-pull considered an angle pull?

Not in 314.28(A)(2) or the title would not be "Angle or U Pulls, or Splices" and the first sentence would not have a clause containing "where angle or U pulls are made".

Now if you had asked if angle and u-pulls are treated the same, I believe we would have to say yes. Additionally, I believe a u-pull is simply a specific-angle angle pull, i.e. 180° angle pull.

What if we have a curly pull... i.e. 270° or greater? Do we have to maintain the 6 times rule between conduits? Seems there would be no problem as long as we leave the loop, which is the same as not pulling the conductors through tight, right?

 

[shortcircuit2]

No. If you arrive at 312.6 by way of 314.28(A)(2) Exception, the stipulation therein instructs you to use "the distance required for one wire per terminal".

Hmmm...OK So if I have a 4inch conduit entering the back of a jbox opposite a removable cover with 8-350mcm conductors, 4-conductors paralleled, the box need only be 5inches deep? That seems tight.

 

[tkb]

Hmmm...OK So if I have a 4inch conduit entering the back of a jbox opposite a removable cover with 8-350mcm conductors, 4-conductors paralleled, the box need only be 5inches deep? That seems tight.

I never saw a 5" box and with a 4" conduit entering through the side a 6" deep box would work.
You still need 6 times the largest size between the entrance and exit. So with 4" conduits you need 24" between conduits, so a 30" box would be required.