A distribution box divides one incoming electrical supply into multiple outgoing circuits. Typical components include a main switch, busbars, circuit breakers, neutral and earth bars, terminals and an enclosure. In this comprehensive guide, we will explore. The main parts are the Miniature Circuit Breaker (MCB), Residual Current Device (RCD), busbars, and the main switch. Learn about the main parts in a distribution box. It is a vital part and central hub of any electrical system. Whether it's a home, office, or factory.