What is the purpose of the required depth for pull boxes in electrical installations?

The required depth for pull boxes in electrical installations is primarily to accommodate the number of conductors and ensure adequate bending space. This is crucial because when cables are pulled through conduits or boxes, they must be able to bend without being damaged. The National Electrical Code (NEC) outlines specific requirements for pull box sizes to ensure that conductors can be installed safely and efficiently, minimizing stress on the cables and allowing for proper handling during installation and maintenance.

When the pull box has the appropriate depth, it allows enough room for the conductors to enter and exit without sharp bends, which can cause wear and potentially lead to failure. Additionally, a correctly sized pull box supports the installation of cables of various sizes and types, making it a key factor in maintaining the integrity of the electrical system over time.