OT: UPS for FreeBSD

[Paul Pathiakis]

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.