I think we're all over thinking this. On Jun 23, 2013, at 2:22, Doug Reed <n0nas at amsat.org> wrote: > Hi Brian. > > My take on UPS systems is that they are only useful to ride out a > short outage so the computer can be shut down properly. Without a > really huge battery system you will not ride out a really long outage > anyway. > > In my hobby work, a friend puts a cheap UPS on each radio+computer > system he installs. He used to buy expensive UPSes to get extended > run time. Now he just buys the cheapest one that will give him > maybe 10 minutes backup time to carry over on a short outage. Just be > sure to hook it up for auto-shutdown on the computer. > > If it is critical to keep the system up full time, then you need to > buy and install a generator system with automatic-start and an > automatic-transfer switch that runs on natural gas or maybe propane. > On natural gas you are likely to have a long term supply of fuel for > the generator. But if you are worried about the possibility of NG > being shut off in an emergency, then you may want to buy a > propane-based generator instead. For a long-term emergency backup, > gasoline is least desirable. Diesel is just a little bit better. > In my opinion, propane and NG are the best for long-term stability.... Many > companies go with diesel systems for other reasons.... I think diesel > has too many design challenges in our winter environment. > > For some of the radio sites I know, a 15KW propane-fired generator is > standard and it needs a minimum 500 gallon propane tank to support the > generator at full load and should run for about 3 to 5 days before the > tank needs to be refilled. At lower load it might run for 8 to 10 days > before refilling.... But that is a really serious annual expense. > > Doug. > _______________________________________________ > TCLUG Mailing List - Minneapolis/St. Paul, Minnesota > tclug-list at mn-linux.org > http://mailman.mn-linux.org/mailman/listinfo/tclug-list