Provide adhesive marking labels on the outside cover of all junction, pull, outlet and connection boxes that identify voltage and all contained circuits. Provide labels for all Wiring Devices indicating the circuit and panel serving the device. Also called a distribution board, panel board, breaker panel, or electric panel, it is the central hub in an electrical system that divides incoming power into various subsidiary circuits. Each. Check electrical parameters: First understand the basic electrical parameters of Distribution box so that you can have a general understanding of the capacity and performance of the distribution box.