The box should be level, easily accessible, and positioned at the proper height according to local codes. Ensure adequate clearance around the box for maintenance access. Connect the main electrical supply to the main switch or breaker. The internal structure of the distribution box is designed to safely distribute power from the main power source to multiple branch circuits. Circuit breaker wiring configurations involve organizing main switches, busbars. 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.