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04/21/2007 Entry: "New UPS(s)"

I've had several small UPS units behind my standards and my servers for several years, but the batteries were becoming questionable and I wanted to consolidate things a bit.

So, I acquired two APC SmartNet line interactive UPS units (model SU1200RMLXNet to be exact). They each have three external rack-mount battery packs, so there are a total of 28 12 volt, 17 amp-hour gel-cells in each.

Unit #1, which runs my two main T&F racks with GPS, WWVB and Loran receivers; several OCXOs; counters, synthesizers, and other gadgets; and several computers (mainly low-power single board timeservers), has a standby power load of about 40% of capacity; if I turn all the synths and counters on, that rises to nearly 80% (the HP 5370B and 5369A are by far the biggest power hogs).

After running the calibrate command on #1, which runs the batteries down to about 25% to measure their true capacity, the UPS shows that at 39.5% capacity it has a run-time of 1105 minutes (18 hours, 25 minutes). Its fully-charged battery voltage is 54.55 volts.