Help with junction box size

[paulie01]

I have a run of 24-2" EMT conduits to be installed running vetically on a colunm through a floor

and entering a junctuin box at the ceiling on the floor below then all running horizontally the

same direction on that ceiling. Need help in sizing the junction box.

 

[augie47]

Assuming your conductors are #4 or larger, 314.28(A)(2) will be your guide.
Are all the conduits in the same row ? If not how many per row ?

 

[paulie01]

There will be 6 2" pipes mounted on strut to the column, stacked 4 deep.

 

[augie47]

Of course, spacing of the conduits will play a major role, but, if I calculate correctly, 314.28 would call for 6 X 2 or 12" +
5 x 2 or 10" (other conduits in the same row). So, as far as minimum a 22" x 22" box as deep as your spacing allows.
Note, however, 314.28 also requires that conduits containing the same conductors be 6 X apart.

 

[augie47]

one of us is wrong

 

[Dennis Alwon]

I will be honest and say I do not understand if these are straight pulls or angle pulls. Could you describe it differently.

 

[Dennis Alwon]

It sounds like 48 conduits entering on one side of a box.

 

[chris kennedy]

Could you describe it differently.

And whats in these conduits?

 

[Dennis Alwon]

I would have to go with Gus if that is the case

 

[paulie01]

Angle pull.

 

[Dennis Alwon]

Angle pull.

Sorry I meant angle or U pull. Sounds like a U pull in which case Gus is correct.

 

[infinity]

It sounds like 48 conduits entering on one side of a box.

Sounds to me like 24 entering the bottom. The question is are they leaving via the top (opposite of entry) or the side of the box?

 

[Dennis Alwon]

Here is Upull

Here is an angle pull

 

[Dennis Alwon]

Sounds to me like 24 entering the bottom. The question is are they leaving via the top (opposite of entry) or the side of the box?

Sounds like 48 entering the bottom to me.

 

[paulie01]

24 - 2" conduits through the floor entering top of junction box, 6 conduits across 4 deep.

24 - 2" conduits out side of junction box, 6 conduits across 4 high.

 

[iwire]

Sounds to me like 24 entering the bottom.

I agree

The question is are they leaving via the top (opposite of entry) or the side of the box?

I agree again and along with the basic angle pull requirements this will also have to be considered.

Part of 314.28(A)(2)

The distance between raceway entries enclosing the
same conductor shall not be less than six times the metric
designator (trade size) of the larger raceway.

 

[Dennis Alwon]

24 - 2" conduits through the floor entering top of junction box, 6 conduits across 4 deep.

24 - 2" conduits out side of junction box, 6 conduits across 4 high.

That's angle pull and it complicates things since they are not the same configuration.

 

[paulie01]

No same configuration.

 

[Dennis Alwon]

Then I would say 30x34

Calculate 22x18 but I think you need to add 12" to keep the pipes apart.

 

[infinity]

Part of 314.28(A)(2)

Can comply with this by using opposite conduits (crossing the conductors in the box) and making the box smaller as opposed to try to get the two closest conduits 6X apart?