What does the NEC require regarding the placement of pull boxes in a conduit system?

The National Electrical Code (NEC) requires that pull boxes be placed in a conduit system at least every 30 feet. This requirement is established to ensure that there is convenient access to the conductors within the conduit for the purpose of pulling, splicing, or joining them. The every 30 feet guideline helps to prevent damage to the conductors due to excessive pulling tension, which can occur if the distance between pull boxes is too long.

In addition to the distance requirement, the NEC also emphasizes the importance of having pull boxes at locations where changes in direction of the conduit occur, or where there is the need to access the conductors for maintenance and repair. Ensuring proper spacing and placement of pull boxes ultimately contributes to the safety, accessibility, and efficiency of the electrical system.