Dual input PDUs are built with two separate circuits that provide primary and secondary power respectively to electrical equipment within a rack enclosure. It takes electricity from the main source and safely sends it to different circuits in a home, office, or industrial setup. Without it, managing power would be messy, unsafe, and inefficient. In this guide, we'll explain what a power. A distribution boxes is an essential device that manages the safe and efficient flow of electrical power throughout different areas of a building or facility. RackLink Dual Supply PDUs do not have ATS (Automatic Transfer.