To size a pull box for a straight pull, what is the minimum distance to the opposite wall relative to the trade size of the largest raceway?

The minimum distance to the opposite wall of a pull box for a straight pull is determined based on the trade size of the largest raceway. For a straight pull, the National Electrical Code (NEC) specifies that the clearance should be at least 4 times the trade size of the largest raceway. This allows for sufficient space to manipulate and install conductors without risk of damage or difficulty during future maintenance.

Choosing 4 times the trade size ensures that there is enough room for the bends in the conductors as they exit the raceway, thus maintaining compliance with safety standards and facilitating ease of use. This standard is critical for preventing damage to wires and ensuring that they do not become kinked or stressed in the pull box, which could lead to insulation failure or other electrical issues.

Understanding this sizing requirement is crucial for electrical professionals when planning installations, as it impacts both safety and functionality of the electrical system.