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.