Date: Fri, 28 Nov 2014 17:04:26 -0500 From: Paul Pathiakis <pathiaki2@yahoo.com> To: freebsd-questions@freebsd.org Subject: Re: OT: UPS for FreeBSD Message-ID: <5478F16A.80605@yahoo.com> In-Reply-To: <20141128204722.561f948e@archlinux> References: <CAHieY7QGp2ELF-R91eu=vSrPsimVmVNJQ4kfucQ56PR7EEZmig@mail.gmail.com> <m57qdq$did$1@ger.gmane.org> <54777AB1.9010800@bluerosetech.com> <m581p1$65m$1@ger.gmane.org> <54779629.302@bluerosetech.com> <alpine.BSF.2.11.1411271433320.60866@wonkity.com> <5478BD4F.7020306@yahoo.com> <5478BEE6.30308@bluerosetech.com> <5478CC08.9090307@yahoo.com> <20141128204722.561f948e@archlinux>
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I guess I'm just that old. ;-) I used to see a lot of issues with the power coming in. You could never tell if it was the initial power unless you got it at the junction of where it connected into the building. About 50% of the time, it was horrible due to terrible, old infrastructure. (I'm in New England and some of it is STILL that way except I'll get an Electrical guy to run the power through an oscilloscope (so, yes, I still see them occasionally.) and prove to me it's clean coming in.) After that, right after the main junction of where you will be drawing power for your UPS - mainly, I deal with floor mounted units. (The large building breaker(s)), is the next place to test. The worst place of the 'unclean' power I've ever seen was a renovated gun barrel machining factory. Get this, the main junction breaker, was a piece of bimetallic chunk of metal 1500 kVA circuit designed to melt upon overload. *shiver*) And, yes, switching UPS are a bane. The early ones had a seriously loud audible 'click' upon switch over. I was educated by an Electrical Engineer (I'm CompSci) about 'simulated' sine wave. Good ones can even look like a real sine wave not square or stepped but they still are not. However, 'truth in advertising' won't allow them to put 'double conversion sine wave' on it without it being true. He told me that was the key and everyone tries every type of wording but will fall short of that phrase. Words like 'simulated' 'sine wave' 'sine wave conversion' (this last one is the attempt to just have a single conversion, usually the second which is less expensive) etc are just marketing games. After this thread, I had to revisit locations to make sure I wasn't spouting crap or misinforming. I started to have a doubt. I found this which seems to be pretty solid. I believe it someone mentioned UltraUPS. http://www.controlledpwr.com/whitepapers/uutopla1.pdf "miles of power lines to your building" aren't the issues nowadays, the power switching supplies inside our buildings pollute the mains. Regards, Ralf PS: 99,999999999999% when I needed to repair broken gear in the last years, I needed to repair a f...ine switching power supply. Anyhow, everyone have a good day/night and weekend, P.
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