APC BackUPS are modified sine wave and there is no issue with them and your garden variety Dell or HP desktop, but of course you are taking your chances with anything high quality on them.
APC SmartUPSes are pure sine wave. They are more expensive. APC makes all of this very clear in their documentation. Select BackUPS and you get trash cheap UPS select SmartUPS and you get the real deal. The BioMed folks were blowing smoke up your ass, APC doesn't substitute one UPS for the other, the BioMed people were just skimming more $ off the top. As to why they sell modified sine wave in the first place, the reason is that most UPS buyers are dumb as a box of rocks and just want The Cheapest Thing and many of them are so dumb they can't even change a battery, I've had customers in the past that when a UPS stated beeping they would toss it and buy a new one from Office Depot. The UPS market got flooded with crappy UPSes it was not that long ago that ALL CyberPower UPSes were modified sine not true sine. APC was getting undercut so they responded to the flooding by crap UPSes with their own crap UPSes at the same price point Ted -----Original Message----- From: PLUG <plug-boun...@lists.pdxlinux.org> On Behalf Of Chuck Hast Sent: Saturday, December 30, 2023 3:30 PM To: Portland Linux/Unix Group <plug@lists.pdxlinux.org> Subject: Re: [PLUG] UPS shopping I am not sure you would have to check on each manufacturer, the best ones are on line double conversion the power goes through the UPS, it is rectified, the battery floats on it and the DC feeds an inverter so that the load never sees mains power. The rest of them are some form of standby/offline UPS which switches to the battery backed inverter if there is a failure or sag of some sort on the power line. The better ones will have line filtering to clean up the trash that is sometimes called utility power, again your mileage may vary Google is you friend on this one. Most of the better "pure sine wave" units do quite well, Triplite was used heavily on the glass container inspection machines I worked on, some plants had their own gen stations and the power was "up and down" line wiese (voltage and frequency) those never seemed to go offline they just did their job. In the hospital labs we have been using Cyber Power, these UPS also appear to do the job, everywhere we have put equipment behind them we have had no more issues with DOA PSU's and logic modules. There is APC which is all over the place, my issue with them was mainly that was the go to by the BioMed folks and APC kept on selling them modified sine wave vice pure sine wave and we would continue to have issues. Why APC would sell them modified sine wave when we had told them that they needed pure sine wave I do not not but kind of left a bad note in my mind about APC. I have a lab that put in APC pure sine wave and they have had no issues with power since. So I think that as long as you do a bit of due diligence you are probably in good shape. On Sat, Dec 30, 2023 at 1:39 PM Dick Steffens <d...@dicksteffens.com> wrote: > On 12/30/23 09:30, Chuck Hast wrote: > > Google 24v inverter there are boat loads of them for 24v PV systems. > > Ranging from 300W on up. > > > https://www.amazon.com/24-volt-pure-sine-wave-inverter/s?k=24+volt+pur > e+sine+wave+inverter > > If you are planning on running computers and whatnot get a sine wave > > inverter, many switched PSU's do not like modified sine wave (weasel > > words actually modified SQUARE WAVE) they will put up with it but > > shortens life. The prices have dropped considerably on them, same > > for the pure sine wave UPS. > > How well do those units deal with poor quality power from an emergency > generator? I have a Champi8on 100296 dual fuel generator. When I'm > running it, my UPS boxes won't run. They reject the power from the > generator. I'm guessing it's because it's not 60 HZ, but something > close enough that it's good for all the rest of the appliances, but > not the UPS boxes. > > -- > Regards, > > Dick Steffens >
