Choose the right box based on environment (indoor/outdoor), load capacity, and durability. Check for proper IP/NEMA ratings and material quality. In this guide, we'll break down everything you need to know to install a distribution box correctly and confidently. Neither the main distribution board nor the distribution boards shall be directly connected to any other equipment; otherwise, the. The installation requirements and specifications of Distribution box involve many aspects, including site selection, fixing method, wiring specifications and safety protection.