The distribution box (cabinet) is suitable for temporary power supply at the construction site and should meet the requirements of "three-level power distribution, two-level leakage protection, one machine one switch, one leakage one box" for power distribution and. The distribution box (cabinet) is suitable for temporary power supply at the construction site and should meet the requirements of "three-level power distribution, two-level leakage protection, one machine one switch, one leakage one box" for power distribution and. A distribution box is a low-voltage electrical enclosure that receives incoming power and distributes it safely to multiple outgoing circuits through protective and switching devices such as MCBs, RCDs, RCBOs, fuses, isolators, busbars, neutral bars, earth bars, and surge protective devices. The main distribution. MAXGE SGDB3 series distribution box is a professional three‑phase and single‑phase power distribution equipment designed in strict accordance with EN/IEC 61439‑3 standard, with stable structure and strong applicability, widely used in indoor and outdoor power distribution of commercial buildings. In this guide, we'll break down everything you need to know to install a distribution box correctly and confidently. Choose the right box based on environment (indoor/outdoor), load capacity, and durability. Check for proper IP/NEMA ratings and material quality. Ensure safe placement: install in. Proper hierarchical design of the distribution system and selection of circuit breakers are fundamental to achieving selective protection and ensuring power supply reliability. Low-voltage switchgear and controlgear assemblies - Part 3: Distribution boards intended to be operated by ordinary persons (DBO) NOTE The voltage limits for DC applications are under consideration.