The primary distribution box refers to the main distribution box, typically located in the distribution room. 4kV), power is distributed to a main distribution panel (primary distribution box). From there, it is routed to individual building distribution boxes (secondary distribution boxes), which subsequently supply power to unit-level distribution boxes. 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. It is specially designed for the special situation of the project construction site and meets the relevant construction power specifications and standards of the. What is the difference between primary, secondary and tertiary distribution boxes? 1. Today, electrical systems are essential for homes and industries.