Most mission-critical network devices feature redundant power supplies (each with its own power cord) that can connect to separate power sources. Network managers need to guard against plugging the devices into a single PDU with a single power cord, which would eliminate failsafe redundancy. PDUs with two separate power circuits support the important fail-safe redundancy of devices with multiple power cords. Depending on the desired level of power protection, the two power sources can be two UPS systems, two generator-supported utility wall outlets or one UPS system and one generator-supported utility wall outlet.