Note that the rack doesn't accept DC input, like lots of (e.g., NEBS certified) telco equipment. There's a bus bar, but it's enclosed within the rack itself.

Note that the rack doesn't accept DC input, like lots of (e.g., NEBS certified) telco equipment. There's a bus bar, but it's enclosed within the rack itself. The rack takes single- or three-phase AC inputs to power the rectifiers, which are then attached to the internal bus bar.