Is the equipment capable of dual power supplies? I am currently working on a project involving upgrading some Cisco switches in an office building. The new switches will have an AC and a DC supply. During normal operation, both supplies share the load. If the AC fails, the DC fed supply will carry the switch, and vice versa. The DC source is a battery backed system, similar to a UPS without the double conversion. Initially, the IT group wanted to install a UPS on each switch. After some investigation, we found this solution to be preferable to UPSs and their associated maintenance.