I looked at the recommneded spacing for conduits and see that the recommended spacing between (2) 2.5" conduits is 4" So seeing that I had 4" between the centers of conduits and assuming the radius of each 2.5" conduit is 1.5" then this would give 7" of total lenght from end to end of (2) conduits. If I arranged these conduits in a 2x2 arrangement then I would have a 1/2" space around the edge of the box? Do you not think this would work?
So in this case would the 6x times rule refer to and dictate the height of the box? So in other words with (4) 2.5" conduits the height of the box would be 2.5x6 + 2.5 + 2.5 +2.5 = 22.5 with the next standard box size being 24"? Am I correct in saying that we do not need to consider the 6x rule for the 8"between the equipment cable entrance and the side of the box at the wall since the box will be considered a wireway?
Thanks
A 2 x 2 arrangement of 2-1/2" conduits will be tight but it is feasible.
The calculation is a by row calculation.
So you would have 2-1/2" x 6 + 2-1/2" would be 17-1/2" and would require a minimum of 18" wireway.
There is also a minimum of 2-1/2" x 6 = 15" between where the conduit enters the top to where it exits out the side.
I don't think you would be able to maintain this dimension by using the minimum size wireway of 18"
You will need to use a minimum size of 24” to maintain the spacing between in and out.
(You use pipe size and not hole size for calculations, I am showing the hole size for 2-1/2" conduit.)
Obviously the longer the wireway, the easier it will be to pull and install the wires without damage.
When you order your wireway make sure you order it and the end plates without knockouts.
Drawn with Google Sketchup a free 3D drawing program, check it out.