In this video, I'll show you the complete wiring diagram of a home distribution board (DB). You'll learn how to connect the main circuit breaker (MCB), residual current device (RCD), and individual circuit breakers for lighting, sockets, and appliances. #dbbox. A well-chosen distribution box ensures the safety and efficiency of your household electrical system. Distribution board is a safe system designed for house or building that included protective devices, isolator switches, circuit breaker and fuses to connect safely the cables and wires to the sub circuits and final sub circuits including their associated Live (Phase) Neutral and Earth conductors. Today, electrical systems are essential for homes and industries.