Once inside the box, the incoming power is connected to bus bars, which are metal strips that conduct electricity. Depending on the system design, the electricity is regulated to usable voltage levels, such as. A power distribution box is a key part of any electrical system. It takes electricity from the main source and safely sends it to different circuits in a home, office, or industrial setup. It contains safety mechanisms like circuit breakers, neutral and ground bars, and wiring. 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.