Database of UPS inverter output waveforms

[Behemot]

Hi and welcome

The most important question is, what's the NAS of your choice? If it is some simple single/two disk station with 12V brick, the best choice would be to get DC UPS directly. The availabiltiy is still kinda limited, but there are at least some units on the market in most countries and you can get others directly from China. Cause inverting the power from 12/24 V DC (nominal - batetry voltage) to 230 (120) V AC and back to 12 V DC is very inefficient and robs you of runtime.

If it is some larger unit (or) with embedded power supply, still most NASes draw up to about 100 W thus the PSUs ion these are simple and do not have active power corection (usually boost type). These units gladly accept anything you throw at them as after retification is gets smoothed right away by the bulk capacitor. So actually I would really recommend sine-wave output UPS just in case you have some professional/enterprise NAS (or actual server being used as NAS) with many drives and some high-quality high-efficiency (thus digitally controlled) power supply.

[fneuf]

Thanks for your reply. It's a 4 bay Synology powered by this 100W 12V brick from EDAC:


And as I interpret your answer, the cheapest one would be the best choice? As to say in those consumer-grade UPSes there are no real differences (would that be on building, efficiency, etc) able to justify price differences?

What DC UPS model would you recommend?

[Behemot]

What country are you from? On czech market there are some Mean Well units, I also found some units from a Switzerland company. And than the chinese ones, I bought only small (12W) ones but they make a plastic brick with SLA capable of delivering couple hundred watts.

The connector on the brick of yours looks like Kycon KPPX-4P, I carry those

[fneuf]

I'm based in France, the exact spec of this PSU is "PGB EA11011D-120" mine brick has an tripole IEC 14 connector. And yes, the connector to the NAS very closely looks like your Kycon reference.

[Behemot]

That's not far from Switzerland Nextys has some range of industrial DC UPS. It's not very cheap though.

The DCU20 would work with your HW, it is basically a pass-through UPS with external PSU (you can use the original or some 120W one so there is also some headroom for charging) and externally-connected SLA accumulators.

[strawbale]

Hello Behemot,

Another new member and, like fneuf, based in France - UPS sort of newbie.

My UPS (APC BR800FR, the one where you found the "interesting waveform", died last August, probably of old age (2010) and poor construction.

Having recently bought a new computer (Mac mini 2018 model) and living in the French countryside with overhead power and phone lines, with lots of trees around.
Although subjectively the situation has improved in the last 5-10 years, I would still like to protect the following with an UPS:
2x Mac mini (max 150W & 115W), 2x monitor (24" & 19"), couple of external HDs (mostly off), router, phone charger, printer, battery charger.
Some of them would only need surge protection, I guess (like printer).

Having read that some computer with Active PFC PSUs may have problems with an UPS that doesn't deliver a nice sine wave signal and assuming my new Mac mini has such a modern/efficient aPFC PSU (as it's conform EnergyStar 7.0), what kind of UPS should I be looking at, given my budget (max 200-250€) if at all possible?

Reading in your tests that APC SMT models with a good sine are the SMT750i (and up): 310€

The Eaton SC750i you tested had only 'half sine' waves, no? That one is about 200€ (and the smaller SC500i about 150€)
The Eaton 5P1550i you tested seem OK, it's smallest version (5P650i) is about 240€. I don't know if the smaller versions than the SC and 5P models that you tested have the same/similar wave outputs, or that they are worse - like the APC SMT 420 & 620 are worse than the SMT750 and above.

I also looked at the Cyber Power CPxxxPFCLCD series, based on good user experiences, although I don't know how good its output is. Their representative in France is Nitram (they add their sticker onto it, basically), but their better UPSs are difficult to find.

Any advice and suggestions much appreciated!

[Behemot]

My UPS (APC BR800FR, the one where you found the "interesting waveform", died last August, probably of old age (2010) and poor construction.!

Bad capacitors, the SMD ones, most of the times

If that printer is ink printer, than you can also hook it to UPS, other types (thermo, laser) use very high power (though for short period each time) for the heating element so that would require at least 2000VA unit.

I am not familiar with the smaller SMT units, only know about SC420 and SC620 which are modified sine-wave, though support Smart protocol and do measure the important values for calculating runtime and report them. But APS is making many types of different plastic ones lately to combat with that Must Power (and other) cheap chinese junk so if you can find such model, feel free to post a link

I did not have such Eaton unit again, the thing is I measure the phase against ground, though it could be that these units put one half of the sine wave (the positive) to phase conductor and the other half (the negative) to neutral, which would be highly strange but I can imagine it could work. Eaton units are usually cheaper as they have smaller accumulators thus shorter runtime, that's good to consider.

Don't have much knowledge about the other, though generally if they state sine wave, it should have such output. The cheaper models either state nothing or some BS like "approximation to a sine wave", "modified sine wave" etc. which means some kind of square wave most of the time

Another option is to get second-hand unit and refurbish it yourself, if you can solder. There are shitloads of such units from companies which replace them after given service life (3-5 years) and as most ppl can't fefurbish them reliably, these units are dirty cheap (as they do sometimes go bad, at least much more often than brand new units and since there is no warranty…).

[strawbale]

Thanks a lot for your elaborate response!

What's your position on the necessity of a sine wave UPS for modern computer (and other?) PSUs, that have Active PFC (Power Factor Correction)?
As aPFC PSUs are not new, I think, maybe at least 5 years old for some PC PSUs, and most people buy cheap-is UPSs, which are unlikely to produce (pure/good) sine wave, it's surprising that you read very little about problems with such new aPFC PSUs in combination with (some kind of) square wave UPSs, no?

Are such cheap-ish UPSs always bad for (the longevity of) a computer's PSUs?

PS: these are some of the sine wave models for sale in France:
http://www.onduleurs.fr/shop_by_tech.ph ... =1&sort=7a

[Behemot]

Later PSUs usually handle it OK. I always recommend to test such unit running from accumulator(s) under different levels of load and user scenarios to test whether the PSU operates normally (no too strange noises, not shutting down or restarting). If not, return and try different model.

I'd also myself prefer some models which do not have long periods in wave with minimal or no voltage, such are ordinary square wave or some of the basic stepped-aproximations to a sine wave. So that would be some variants of itteration aproximation to a sine wave, such as the Smart SC series has https://www.hardwareinsights.com/databa ... art-UPS-SC That shop wrongly lists SC series as sine wave, none of the SC units I have ever tested had clean sine wave, always this itteration aproximation. Also the Back-UPS Pro (what is, I think, direct predecessor of Smart SC, which only got better CPU and full Smart set of features) and Back-UPS CS have similar wave. The Smart SC, though also not as robust as the Smart itself, does report fairly accurate values so you can usually rely on it to shut down/hibernate your computer not sooner than after the accumulator charge does indeed drop to some low level. Many others also from different brands only just guess the runtime according to voltage, which could produce unwanted surprises with older and worn-out accumulators

I'd avoid getting Back-UPS RS again, even the current variant sold again under "Back-UPS Pro" line with display seems to be much more problematic than other series, look for "F02" and similar errors, there's quite many affected users.

About CyberPower, who knows. The cheapest plastic series seem to be similar crap as all the others, check BadCaps, there is a few threads about repairing some of them. Some people claim to have good experience with them, I've mostly seen only bad, though that's mostly as people come to service them I guess. (Although, other ones also come to just check and replace accumulators.)

[strawbale]

Thanks a lot, again.

I'll forget about CyberPower, as their representative in France (Nitram: https://www.nitram.fr) just put a Nitram sticker/logo on the CyberPower UPSs and than increase the price with 50%, as they primarily sell through regional distributeurs, who then supply (physical) shops. The 'normal' CyberPower PSUs available in France through the internet will therefore come from somewhere else, which will complicated warranty issues.

So that leaves me with APC and Eaton, as these two brands are widely available, and for which replacement batteries are easy to find too - all stepped sine wave:

550-650VA / 330-400W (130-155€):
http://www.onduleurs.fr/product_info.ph ... 550GI.html
http://www.onduleurs.fr/product_info.ph ... 650FR.html

850-900VA / 510-540W (190-230€):
http://www.onduleurs.fr/product_info.ph ... 850FR.html
http://www.onduleurs.fr/product_info.ph ... 0G-FR.html

and the smart(er) but still not pure sine wave SC620 (620VA / 390W) for 240€:
http://www.onduleurs.fr/product_info.ph ... C620I.html