On Wed, Nov 17, 2010 at 10:35 PM, Singer Wang <[email protected]> wrote: > > > On Wed, Nov 17, 2010 at 7:59 PM, Doug Hughes <[email protected]> wrote: >> >> I'll reemphasize some earlier points and make some of my own. >> >> On 11/17/2010 11:37 AM, Daniel Clark wrote: >> > Looking for a UPS system that: >> > >> > 1. Runs off of US 115V / 20A >> That isn't much power. Remember, you can only use 16A of a 20A circuit, >> that limits the size of your UPS and your load to about 1.8KW. That's >> not a heckuva a lot. I'd definitely recommend at least going to 220V (or >> 208V, depending upon your building electric power plant) >> > 2. Can handle frequent extended power outages while continuing to >> > provide power to computers and HVAC systems (so amp spikes will be >> > common) >> add batteries for run time. Just remember, the more batteries you have >> and the closer you get it to specifications, the longer it's going to >> take to charge that baby. >> I'd give at least a 20% leeway on the input side. >> > Acutally more about 1.2KW if you think the best case. He's estimating a 16 > hour charge cycle followed by a 8 hour discharge cycle. So during the 16 > hour charge cycle, the 115V/20A must charge the battery as well as provide > for the HVAC and the computer. Since there's a 2-1 ratio of charge vs > discharge time, out of your 1.8KW you have to give at least 0.6KW to > charging the battery (all best case).
BTW found something that may work great (or at least as well as possible given site limitations) - http://www.bdbatteries.com/upskits.php?id=293 An important point is that you can set the current it uses to any arbitrary value between 0 and 20 amps, amongst other niftyness. Haven't been able to find any 3rd party discussion of the system however... If I end up going with it I'll be sure to report experiences here. Thanks for the above info as well, very very useful. Cheers, -- \|/ Daniel JB Clark | Activist; Owner FREEDOM -+-> INCLUDED ~ http://freedomincluded.com /|\ Free Software respecting hardware _______________________________________________ Tech mailing list [email protected] https://lists.lopsa.org/cgi-bin/mailman/listinfo/tech This list provided by the League of Professional System Administrators http://lopsa.org/
