You're correct to be cautious and consider both possibilities. Here's the breakdown to help you decide which section of 314.71 applies: Understanding the Code Intent

The goal of 314.71 is to provide adequate space for cable bending radius and ease of installation/maintenance. Straight pulls require less space than angle/U pulls because the cables don't need to bend significantly within the box.

Your Scenario

You have two sets of cables passing straight through from West to East. These are the continuous "straight pulls." However, the set branching off to the North introduces an angle. The splice itself further complicates the situation.

Why 314.71(B) (Angle or U Pulls) is more applicable

Although some cables are pulling straight, you need to consider the worst-case scenario and the cable that changes direction. The north bound set of cables that's spliced from the westbound/eastbound cables is where you should follow section B of 314.71. A straight pull only has a set length the cables need to be pulled across, whereas an angled pull or u-pull requires the cables to turn to the next conduit run.

Here's how to apply 314.71(B)


Determine the largest dimension

Identify the largest conduit entry point, this could be in the conduit run going west/east or the conduit run going north. In this case, you will be using the dimension of the conduit run going north.2.

Multiply by 6

the dimension from step 1 will be multiplied by 6 for a minimum length measurement for the distance from one wall to the opposite wall.

Important Considerations



Cable Bending Radius

Always double-check that the calculated pull box size accommodates the minimum bending radius of the MV cables you're using. The cable manufacturer will specify this. The pull box dimensions must allow for this bend radius without stressing the cable insulation.

Splice Dimensions

Splices add bulk. Make sure the pull box is deep enough to accommodate the splice without excessively crowding the cables. Factor in the size of the splice kits you plan to use.

Working Space

Remember that the pull box must also comply with relevant working space requirements for electricians to safely install and maintain the cables and splices.*

AHJ Approval

If there's any doubt, discuss your design with the local Authority Having Jurisdiction (AHJ) before proceeding. They have the final say in code interpretation and can provide valuable guidance.

In summary, while you have straight pulls through the box, the presence of the angle pull/splice requires you to size the pull box based on 314.71(B). This will ensure sufficient space for cable bending, splicing, and future maintenance. Flag for review