On Fri, 8 Aug 1997, Rodney Joffe wrote: |> 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. |> |Not quite as simple Jonah.... CO equipment is designed for 48v for many |reasons. It's also designed to deal with concrete floors, inefficient |HVAC, dust, etc. | |Unfortunately, a modern megapop consists of a lot of interesting |equipment that doesn't come in 48v DC versions. Alpha 8400s, Large SGIs, |and server like things (yeah, I know, there are companies who make |retrofit kits for some of them, but they're not standard). Use invertors off your -48VDC plant for your AC equipment. An AC UPS: AC feed from electric co --> rectifier --> DC batteries --> inverters I have yet to see an AC UPS with a longer runtime than 2hours (100KW+) with full battery options installed. Exide/Liebert make excellent UPS systems, but they are _not_ meant for extended runtime. Instead they are meant for a graceful shutdown of all systems when extended power outages occur. Jonah