This box segregates switches from other components to avoid negative interferences. It can be mounted onto the 19" profiles exactly where required. Opening for up to 22 modules (18 mm). Key components include circuit breakers, fuses, bus bars, and internal wiring for safety and. Distribution boxes, often called breaker boxes or fuse boxes, are basically the central hub where electricity from your main supply gets divided into different circuits. But what exactly is a power distribution box, and why is it so essential in our daily lives? The DB panel board controls the flow of electricity.