Rich Freeman wrote: > On Sat, Sep 2, 2017 at 5:06 PM, Walter Dnes <waltd...@waltdnes.org> wrote: >> On Thu, Aug 31, 2017 at 09:19:00AM -0700, Ian Zimmerman wrote >>> On 2017-08-31 08:47, Walter Dnes wrote: >>> >>>> 1) To protect my gear against power surges/spikes/drops >>>> 2) To protect against the rare occurence when power goes off for 1 >>>> or 2 seconds >>> I do the same. Or at least I did until last week, when the UPS died >>> after more than a decade of perfect service. (Here, the outages are >>> longer than 2 seconds; it's not often, but is very annoying when it >>> happens, with the UPS square wave beeps.) >> I just had a second look at your message. Did you say your UPS puts >> out ***SQUARE WAVES***? That is very bad for consumer grade electrical >> stuff. >> > He said the beeps were square waves. That is roughly what mine sound > like, though mine is a sine-wave UPS. > > A lot of stuff can handle square wave power output, though PFC power > supplies don't like it as I understand things. I think most of the > cheaper UPSs on the market still put out fairly raw inverter output. >
I can tell you one thing that doesn't like square wave or the modified square waves some UPSs put out. The air pump for a fish tank. The ones I had and tried to run off a UPS when we had a large power failure would not run off the UPS. Generator, fine. UPS, not happening. I was told that if one hooks up a 120v>120v transformer, it will work. I never tested that but according to the person that told me that, it changes the wave enough that it is more like a sine wave, since transformers don't recreate square to well. It makes sense that it would work. Also, some AC motors won't run off of it either. They have a name for the type of motor but can't recall what it is. I think the compressors in a fridge/freezer will run off that tho. Then again, may vary by model. Our little small fans, won't run but they do get hot pretty quick. o_O Since power outages are not so often nowadays, I depend on the surge protection in my UPS more than I do the backup power. Both of my UPSs have a LOT of MOVs in them. I put new batteries in my old UPS last month. Third set of batteries in that thing. It's pretty old but works well. Odd how some things work and some don't. Dale :-) :-)