NEC Requirements for Outdoor Distribution Boxes: Complete specification guide for outdoor electrical distribution boxes covering NEC Article 312 requirements, NEMA ratings, sizing calculations, and selection criteria for commercial and residential applications. Getting the selection wrong means more than inconvenience—it can mean shutdowns, damaged machinery, or worse. 💡 Specification Insight: NEC 312. 2 requires outdoor distribution boxes to have rain-tight enclosures when installed in. These specialized units are engineered cabinets designed to safely divide main generator or grid electrical feeds. They house vital active protective components, including main circuit breakers, industrial-grade sockets, and emergency stop mechanisms. From powering heavy machinery to supporting lighting and tools, temporary power boxes must operate in harsh outdoor conditions while ensuring electrical safety and flexibility. The scope of this specification covers Weather / Vermin proof LT distribution boxes (LTD) with controllers, MCCB, MCB, Bus bars, Contactors, CT's, Energy Meter, LT gas filled fixed capacitor, DC Battery and Charger as per relevant Standards and Specifications, and shall be suitably wired for the. The first requirement for outdoor temporary power is environmental protection. An IP65 electrical cabinet is commonly understood as dust-tight and protected against water jets, making it suitable.