KDC carries a redundant N+1 PSU array.
From the site, I found a nifty feature: dual AC inlet.
http://www.istar.com.tw/cd/owa/siw_t..._id=8820995333
It was designed for facilities with a power generator: plug your main power line (with UPS) to one input, and the emergency circuit line to the other inlet. The result is that during a power failure, the UPS covers the black out, and is relieved by the generator, whenever it kicks in.
Kinda neat...