Conductor damage during installation is one consequence of under sizing junction and pull boxes. This damage is often not apparent until post-installation cable testing. Then, after the boxes are replaced, the defective conductors are repl. Conductor damage during installation is one consequence of under sizing junction and pull boxes. This damage is often not apparent until post-installation cable testing. Then, after the boxes are replaced, the defective conductors are replaced. This is an inefficient and expensive way to do an electrical installation. So, while the NEC box size req. A pull box contains a 2-in. and a 3-in. raceway on the left side, a 3-in. raceway on the top, and a 2-in. raceway on the right side. The 2-in. raceways are a straight pull and the 3-in. raceways are an angle pull. Remember: Draw the junction box, raceways and where the conductors are run. Horizontal dimensionThese rules are based on the characteristics of standard electrical conductors and thus apply only to raceway systems for electrical conductors. Many types of cables, such as fiber-optic for example, have a much higher minimum bend radius than electrical conductors of the same diameter. You don't size the boxes for these as if you were installing e.