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).
_______________________________________________ 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/
