so should we be ignoring the VA rating?
Of course not because, sadly, that is all many UPS report in their specs. But it is important to note that, sadly, there is no industry standard designating what PF value will be used when advertising the VA or wattage rating of UPS. So marketing weenies can use what they want, and typically that means the value that makes their product shine the most.
To accurately calculate power factor, you need a
power quality analyzer or power analyzer that measures both working power (kW) and apparent power (kVA). These are tools we all have in our tool box, right?
The answer to that is obviously, "no". So we have to come up with some value that will work. If no PF value is stated, I always use .65. Is that arbitrary? Yes. But it results in a conservative, thus the most "safe" value. And I'm okay with that.
So if a UPS is rated at 1000VA with no PF stipulated, and using the formula of VA x PF = W, I get 1000 x .65 = 650W. So as long as I keep my connected components from demanding more than 650W, I should be fine.
***
Let me add something else here for those who like to add inverters into the mix as silly (I'm being nice there) excuses to misinform users they "need" pure sinewave UPS. Again, I say nonsense. Or rather, total ignorant, naïve nonsense.
In addition to all the evidence presented above from PSU and UPS makers, consider the following facts (facts, as in truth, not fiction)
1. There are entire cities, maybe countries, that supply power from generators to homes through inverters. Are those APFC PSUs failing, going up in smoke, failing to support their computers and other electronics like refrigerators, AC units, heaters, TVs, etc.? Nope!
2. Many homes (especially in Tornado Alley where I live, as well as other areas subject to tornados, hurricanes, cyclones and other severe weather) use and depend on backup generators and inverters during power outages. Are those APFC PSUs going up in smoke, or failing to support their computers and other electronics? Nope!
3. Many of us have cars and trucks with 120VAC outlets supplied by inverters. Are those APFC PSUs failing, going up in smoke, failing to support our connected devices? Nope.
4. There are millions and millions of travel trailers, RVs, and motor homes (some with full timers living inside) using generators and inverters. Are those APFC PSUs, appliances, and all sorts of other devices failing or going up in smoke? Nope.
5. There are millions and millions of recreational/pleasure and commercial boats, luxury yachts, cargo ships, even "ships of war" at sea that use generators and inverters to supply power - not just to the crew, but also very sensitive navigational, weapons, and communications systems. Are those APFC PSUs failing, going up in smoke, or failing to support their connected equipment? Nope.
Note all those example are for full time power supply. Full time, as in 24/7/365!!!!! Yet here, we are talking about typical home and small office UPSs that rarely ever kick over to full battery and instead supply mains waveforms more than 99.9% of the time.
So
get real people. NOBODY here "
needs" a pure sinewave UPS. Again, if they can find one in their budget that fits their power demands, fine. I am NOT against pure sinewave UPS. But PLEASE!!!! Stop spreading FUD and total ignorant, naïve nonsense! Stop advising users "need" pure sinewave for their computers. That is totally wrong and BAD, inaccurate advice.
