Check for proper IP/NEMA ratings and material quality. Ensure safe placement: install in dry, accessible areas with good ventilation and at appropriate height (typically ~1. In this guide, we'll break down everything you need to know to install a distribution box correctly and confidently. General requirements - Electrical continuity of. We'll decode NEC Article 312 requirements, compare NEMA vs IP ratings, analyze busbar sizing calculations, and provide specification decision matrices for different applications. 💡 Specification Insight: NEC 312. Article 314 applies to: These. The IEC (International Electrotechnical Commission) and BS 7671 (British Standard for Electrical Installations) both provide essential requirements for electrical installations, including those for fuse boards like garage unit, consumer unit and distribution board.