Sub-distribution power boxes, sometimes known as secondary electrical panels or subpanels, distribute power from the main panel to specific areas within an industrial facility. These boxes are especially useful in large settings where separate power management is required for. The Secondary Distribution Box (SDB) receives power from Main Power Distribution box via an extender cable and provides a central power distribution to feed normal branch circuits to the electric floor modules through snap-on extender cables. A feeder usually begins with a feeder breaker at the distribution substation. Many feeders leave substation in a concrete ducts and are routed to a nearby pole. At this. This ultimate guide explains what a distribution box does, its internal components, common types, real-world applications, and how to select the right DB Box for your project.