On 4/15/2011 10:48, John R Pierce wrote: > On 04/15/11 4:38 AM, Howard Fleming wrote: >> I have used several Best Ferrups UPSs over the years, other than one >> that toasted it's transformer, have never had any trouble out of them >> (just replace the battery every 3 to 4 years....). >> >> They are picky about their input power, do not run not connect them to >> an auto regulating transformer (not the proper term?), or on the output >> of other UPSs, it can cause interesting problems... > > I don't think they make any FerrUPS anymore. Those were based on a > massive ferroresonant transformer which, yes, is very sensitive to the > input frequency. Specifically, they don't like generator power, unless > it has extremely well regulated frequency output (such as a DC generator > with a digital sinusoidal converter) Eaton has the Ferrups line now (still available as far as I know). I have actually run into the input frequency problem in the past with the Ferrups. I was working at a gas company that for political reasons generated their own power inhouse. Had one Ferrups UPS (of 10?) that was complaining about it (kept going online/offline/online.... There is a parameter in the settings that can be adjusted to allow a greater input freq range on the UPS (59.5 - 60.5 hz is the default range, from what I remember). In this case that took care of the problem. I have 3 1.4kw units at home, no trouble to date running them off of my backup generator (Campbell 5k unit). They are also 18 years old at this point and still going... :o). Running 3 of my CentOS servers at home in fact.