Main Switch: This switch controls all electricity coming into the box. Busbar: A metal strip spreads power to each circuit. A distribution box uses MCBs, RCDs, and busbars to protect circuits, prevent shocks, and ensure safe power distribution in homes and buildings. But what exactly is a power distribution box, and why does it matter so much in our daily lives? The DB panel board controls how. A distribution box is a key part of electrical systems in buildings. Inside, you'll find parts like circuit breakers and fuses that protect the system from problems like overloads and short circuits.