Here, you can see the wiring diagram of the 230V single-phase distribution box wiring diagram. It has the highest capacity than other MCBs used in the DB. Wiring Direction: Wiring between the main circuit breaker and each branch circuit breaker in the box generally. A distribution box, also known as a distribution board, electrical panel, or breaker box, is an enclosure that houses electrical components responsible for distributing electricity throughout a building. It is responsible for distributing electricity from the main power source to various circuits throughout the building. It has three categories: residential, commercial and industrial electrical distribution boxes, all of which play important roles in their respective electrical.