On Fri, 8 Aug 1997, Nathan Stratton wrote: |On Fri, 8 Aug 1997, Matthew White wrote: | |> |> I can't speak for BBN planet, but the power was out in Cambridge for a 2 |> hours. |> Anybody that can survive 2 hours running huge amounts of equipment must |> have their own power grid. :) |> |> Our little UPSes didn't survive... | |Well you don't want to design your power system so that your UPS will keep |you through the outage. When you get to 250 KVA systems like we use for |our POPs it is hard to get more then 30 min of uptime. All you want your |UPS to do is keep you up until the generator gets you up to speed. Incorrect. Stop using AC equipment in your pops. Use DC equipment and get a _good_ DC Powerplant. Every carrier Class4/5 switchroom usually has 10-20,0000 AMP/hours of standby power. 1 DSC or Nortel switch sucks _quite_ a bit more power than even the largest of superpops. Every carrier has _at least_ 4hours of battery plant (most have 8-12). Relying on generators is a _bad_ idea. Its not hard to have 4-12hours of standby battery plant. Lucent/Lorain/Peco2 all make rather nice rectifiers, and C&D/Lucent/GDB all make some nice vented batteries. By going DC you also don't get hit with the inefficiencies of AC --> DC --> AC --> DC. You can bet that MCI/Sprint don't have a piece of AC equipment in their facilities and most likely are laughing their asses off right now. Jonah