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. Home / blog / Ultimate Guide to Distribution Boxes (DB Boxes): Types, Components, Applications, and How to Choose the Right One For procurement professionals, electrical contractors, and project managers, choosing the right Distribution Box (DB Box) is a critical decision that directly impacts. What is a Distribution Box? A distribution box, or DB box, is a circuit breaker enclosure. The hub distributes electrical power from a single input source to various circuits throughout a building. For example, you may need flame retardant features. The box should handle surge voltages up to 2kV. Distribution boxes, also called distribution boards, are essential components in both residential and commercial electrical systems.