You can find distribution boxes made from various distribution box materials such as steel, aluminum, PVC, polycarbonate, high-density polyethylene, and thermoset plastics like SMC. Each distribution box material has its own special strengths. For example, you may need flame. 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. Since there are no feeder interconnections, a fault will interrupt all downstream customers until it is repaired. This configuration is called a radial system and is common for. A primary distribution substation is the connection point of a distribution system to a trans-mission or a sub-transmission network.