Junction box sizing software??

[cajun62234]

Does anyone know of software that will size junction boxes/pull boxes?

Thanks in advance.

 

[cajun62234]

Here's my dilemma:
Extending 2 sets of 3#350kcil, 1#1G, 3?"C. via Junction Box (and compression fittings); straight through, no bends.

Handbook NEC 314.28(A)(1) states that 314.28(A)(2) applies if splicing in a straight pull; thus allowing 6x91mm (3?" = 91mm [trade size]) between entry and opposite wall. 6x91mm = 546mm ? 25.4 (mm/inches) = 21.496". This gives me the distance from conduit entry to opposite wall, but where are the requirements for volume allowances of the 6#350kcmil & 2#1 conductors; minimum width & depth of the junction box? Row-spacing of the 3?" conduits?? I know the answer is buried in the NEC somewhere, just can't find it...:-?

 

[e57]

I have never heard of a software for such - but if so enclined I dont think a spread sheet with data imputs to create one would be all that hard to do. Maybe some one alread has????

Maybe if I get seriously board I could make one - but normally a pad of paper is more close at hand when I need to know those things.

 

[BryanMD]

Usually box size is based on the conduit size being used to get the minimum (and then use whatever closest size box is in stock at the SH )

As to the software idea...
How often does a real problem like this come up for you?

Based on your demonstrated ability with the fill criteria and math...
you shouldn't have much difficulty coming up with dimesions.

Do you often build custom dimension boxes in your work?
I used to make them years ago for EC's...

 

[cajun62234]

Yes, you are on-target... I very seldom have to size a junction box (Thank G**!!) but in this situation, I am dealing with an existing situation, limited space and need to be sure that the JB will fit in the allocated space. Amazing that there aren't any good directives for conductors over #4, as there are for #18-#6....I guess I could make it 24"h x 6"d x 12"w....but I'd feel more comfortable knowing that it was sized 'according' to Code, not what I think will suffice

 

[chris kennedy]

I guess I could make it 24"h x 6"d x 12"w....but I'd feel more comfortable knowing that it was sized 'according' to Code, not what I think will suffice

You said 2 sets of conductors in 3?" conduit.

6?3.5=21
21+3.5=24.5

IMO the 24" box is too small.

 

[cajun62234]

Yes... now what about the width & depth...
6 x 91mm = 546mm
+ 91mm = 91mm
= 637mm (? 25.4 = 25.08")
Call: 30"h box.

 

[chris kennedy]

Yes... now what about the width & depth...I can live with a 26"h box...

Width is

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.

21"

The depth is enough to accomodate the conduit entry's. I know you have a space problem, but leave yourself some room to work.

If your tight in one direction only, would a wire way work here?

 

[iwire]

If your tight in one direction only, would a wire way work here?

I am a big fan of a wireway as a pull point. :smile:

 

[roger]

I am a big fan of a wireway as a pull point. :smile:

And I am too. I quit using boxes and condulets (except in some rare occasions) years ago.

Roger

 

[chris kennedy]

I am a big fan of a wireway as a pull point. :smile:

You and me both.

I think I gave some bad advice as to the width. If OP has two 3?" conduits entering one side and leaving the other that distance would be 24?".

314.28(A)(2) Angle or U Pulls, or Splices. Where splices or where angle or U pulls are made, the distance between each raceway entry inside the box and the opposite wall of the box shall not be less than six times the metric designator (trade size) of the largest raceway in a row. This distance shall be increased for additional entries by the amount of the sum of the diameters of all other raceway entries in the same row on the same wall of the box.

 

[cajun62234]

I need to indicate that the existing underground feeder stub-ups (2-3?"C) are approx. 6" c/c and 19" (center) from wall. Unless I can locate a wireway that is approx.: 24"d x 14"w x 30"h, I'll have to provide a JB... I didn't indicate this existing installation, as my primary concern was NEC compliances with width & depth dimensions; as well as volume restrictions relative to the quantity of the 350kcmil & Ground cables.

 

[Mark Marshall]

Electrical Calculation Manager

Electrical Calculation Manager

As far as software, Vision Infosoft has their Electrical Calculation manager. It has a nice pullbox section to it. I've been toying with the demo.