The main parts are the Miniature Circuit Breaker (MCB), Residual Current Device (RCD), busbars, and the main switch. Safe habits and checking the box often help stop electrical accidents. These are MCBs, RCDs, busbars, and the. For procurement professionals, electrical contractors, and project managers, choosing the right Distribution Box (DB Box) is a critical decision that directly impacts system safety, reliability, and long-term operating costs. In this comprehensive guide, we will explore. Inside a distribution box are components like circuit breakers, earth leakage units, doorbells, and timers. The building's electrical power enters through the main feeding cable, which connects to the distribution board.