NEC 314.71 - Straight and Angle MV Pull

[bdm5066]

I am sizing a manhole for pulling medium voltage cable (shielded in this case).

314.71(A) provides requirements for straight pulls -> 48* largest cable diameter

314.71(B) provides requirements for angle pulls. -> 36* largest cable diameter + the sum of all other cable diameters

What I'm struggling with is how to calculate the manhole size for an application with both straight and angle pulls. If 10 conduits worth of cable are angled and 5 are straight, can I do the following

36*largest cable diameter + sum of all other cable diameters in the 10 conduits

or do I need to do the following:

36*largest cable diameter + sum of all other cable diameter in the 15 conduits

In my application, both of the above calculations result in larger manhole sizes than the straight pull formula.

 

[don_resqcapt19]

It would be my opinion that you do the calculations separately for the straight and angle pulls and take the larger of the two sizes. I would use 10 conduits for the angle pulls and 5 for the straight pulls.

Also make sure the manhole entry will be large enough that you can feed a "U" loop of conductor through it without having to bend the conductor in a radius that is less than permitted.