What is required for the installation of underground boxes according to NEC guidelines?

The requirement for accessibility without excavation is critical for underground boxes as stated in the NEC guidelines. This ensures that these installations can be easily accessed for maintenance, repairs, or inspections without the need for digging up the ground, which can be time-consuming and costly. Accessibility is essential for safety and functionality, allowing quick fixes and evaluations, ultimately promoting efficient electrical management.

While some of the other options may seem relevant in particular contexts, they do not address the key requirement set forth by the NEC for underground boxes. Insulation of wiring, for instance, is important but does not specifically pertain to the accessibility aspect, and sealing against water is necessary for protection but not solely sufficient for ease of access. Color coding of wires, while beneficial for organization and identification, is not a requirement relevant to the installation process concerning accessibility.