The primary distribution box refers to the main distribution box, typically located in the distribution room. They also include metering systems, ensuring. The outgoing line from the low-voltage end of the transformer is 0. 4kV to the distribution cabinet (primary distribution cabinet), then the outgoing line is led to the distribution box (secondary distribution box) in each building, and finally the outgoing line is led to the distribution cabinet. The simplest primary distribution system consists of independent feeders with each customer connected to a single feeder. Since there are no feeder interconnections, a fault will interrupt all downstream customers until it is repaired. A distribution box, also known as a distribution board, panel board, breaker panel, or electric panel, ensures that electrical power is distributed throughout the facility.