Choose the right box based on environment (indoor/outdoor), load capacity, and durability. Check for proper IP/NEMA ratings and material quality. It takes the incoming power and safely distributes it to different circuits throughout your building. What Is a Distribution Box? A distribution box, also known as an electrical distribution board, is a critical component in electrical systems. As the construction unit responsible for electrical equipment installation, it is essential to carry out the finalization, procurement, and installation of distribution boxes in accordance with.