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.
> 3. Preferably is expandable (I'd prefer stackable to rack mount, but > not a big preference) > 4. Isn't insane-loud not at 2kw. batteries don't make any noise. On the other hand, in contrast to what somebody else said, UPS's do make some noise as a result of transformation and cooling/venting fans. The larger it is, the more noise you'll get as a result. In your case, ~2kw is pretty tiny. However, one thing you are going to have to deal with is OSHA/govt/safety requirements for all of those batteries. For that amount of battery power storage, you're likely to need a special room to store it with hazard signs on it. Remember that batteries are highly toxic, are flammable, and do vent toxic and corrosive vapors. The more you have, the more danger. Batteries "do" explode sometimes, and the cleanup is very nasty. If you're going to strike out on your own anyway, deep cycle marine batteries are what you want. They are much heavier and have more lead content than car batteries. Car batteries are usually porous and are not designed for deep discharge cycles whereas deep cycle batteries are. I'd stay away from other battery types. They all have their limitations (including lead-acid, of course). All things considered, under sustained heavy load with deep discharge cycles, lead-acid is the best choice. Flywheels are a nice alternative, but I don't know of any in the tiny 2KW range. > Anyone have anything they like? > > I'm sort of tempted to do http://www.dansdata.com/diyups.htm but if > there is something COTS that is somewhat price-competitive with that > I'd prefer it for safety reasons. > > But in general just general recommendations would also be great, as I > haven't dealt with UPS systems larger that 4u units in the past, and > the ones I did use I wasn't really impressed with (insert horror story > about spending hours and waiting weeks to get replacement batteries > for MGE UPS units here.) > > Happy Hacking, _______________________________________________ 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/
