----- Original Message ----- > From: "Michael Loftis" <[email protected]> > > On Fri, Dec 3, 2010 at 10:33 PM, Jay Ashworth <[email protected]> wrote: > > And in fact, much carrier class equipment can be had with -48V > > power, there are ATX and similar power supplies for PCs that are -48, and I > > *think* I've seen commercial small UPSs (<3kVa) that give with -48 > > as well... using 48V battery strings, obviously. > > Take a look at the Solar/Renewable energy systems, Xantrex (Schneider > actually) makes the XW series inverter/chargers which use 48V battery > strings and can be paralleled up to a rated total of about > 1...@120/240. This is done by paralleling 3x 6kW inverter/chargers. > They've an integrated transfer switch, load shaving/sharing (IE if > you've got say 6kW of generator, but 12kW of Inverter, the system > capacity is up to 12kW, with battery assist). > > And that's just one option, Magnasine makes parallel inverter/charger > and inverter systems up to around 12kW, also using 48VDC (or 24VDC) > strings. > > Both of these are sinewave inverters. > > There's also a telco oriented 48V inverter rack system thats escaping > my mind at the moment. It can be setup with A/B 48V strings, and you > plug in inverter modules up to IIRC around 8kW. Not parallel capable > between racks AFAIK.
I phrased my comment poorly, which mislead you. I was suggesting a UPS which took 208VAC on on the charge side, and charged 48VDC batteries with it, providing -48 to a rack full of equipment which took that. People actually call those "48VDC UPSs", though in fact they're just Little Teeny Battery Plants. :-) Cheers, -- jra
