Is 80+ PSU really not working with stepped sine wave UPS?

[PCForStreaming]

 

I just heard this new information that someone says:
" If the PSU AC Input is in the range of 110v~240v or 200v~240v it's okay to use stepped sine wave, but if the PSU AC Input is 220v~240v then it must be paired with true sine wave UPS."
How much true is this information true?

I heard someone say some PSU with active PFC doesn't work with stepped sine wave UPS but some other models with active PFC works for them. Why there's no list showing which PSU work with stepped sine wave and which PSU doesn't?

[mahyar]

well yes its about model some of them even work high enough dc voltage and some only work with perfect sine wave

[mariushm]

There's no rule about it, like the text says, but some power supply models are indeed more sensitive / picky about AC input, and won't like simulated sine wave.

The ac input that's not pure sine wave can put extra load on the active pfc circuit, making it work harder - if the psu saves pennies using cheaper components (for example with lower peak current rating) then the circuit may not be able to work well enough to make it possible for the psu to output it's full advertised wattage for example

 

[PCForStreaming]

Well then it's bewildered me why people don't make a list of which model compatible and which one aren't. Because the difference in price between stepped sine wave UPS and true sine wave UPS is a lot!

 

Mine is Seasonic s12iii 80+, I wonder if anyone is using it with stepped sine wave and how's the result.

[Likwid]

There are standars and when your part doesn't work with those standarts then that's not your problem

[Likwid]

Quote

"I just spoke with both Silverstone and APC. Silverstone is going to get back to me on this question, but APC was pretty clear -- they strongly felt that PFC power supplies should use true sine wave UPSs. They told me that the reason for this was because PFC power supplies require a much faster changeover time when the battery kicks in, and that due to the design of stepped sine wave UPSs, they were not always fast enough to satisfy the power supply. This could lead to the PSU shutting down when the battery tried to kick in. The guy I spoke with said that the stepped sine wave wouldn't "damage" the PSU, but that it simply might not work, and that if it DID work, it might not "always" work. Apparently it depends on the specific power supply."

tgfyhre    https://www.sevenforums.com/hardware-devices/373699-ups-advice-stepped-sine-wave-pure.html  

[mariushm]

Seasonic makes good power supplies, and that model is decent. I'd say 90% sure you're gonna be fine.

 

Nobody's gonna make a list because there's various kinds of simulated sine wave, from super crappy (almost square wave) to almost sine wave... you'd have to test each psu with multiple upses and you'd also have to test with multiple load levels... for example a 550w psu may work fine with a simulated sine wave ups when components inside consume less than 250 watts, but may shut off above 250 watts.

 

Also note that usually your pc is connected to AC and UPS only turns on and produces that crappy AC when there's something bad with AC input ... so you're basically worrying about 5-10 minutes of running from battery every few weeks/months (depending on how good your power grid is)

[PCForStreaming]

42 minutes ago, mariushm said:

Seasonic makes good power supplies, and that model is decent. I'd say 90% sure you're gonna be fine.

 

Nobody's gonna make a list because there's various kinds of simulated sine wave, from super crappy (almost square wave) to almost sine wave... you'd have to test each psu with multiple upses and you'd also have to test with multiple load levels... for example a 550w psu may work fine with a simulated sine wave ups when components inside consume less than 250 watts, but may shut off above 250 watts.

 

Also note that usually your pc is connected to AC and UPS only turns on and produces that crappy AC when there's something bad with AC input ... so you're basically worrying about 5-10 minutes of running from battery every few weeks/months (depending on how good your power grid is)

Ah I see, can you elaborate what do you mean by power grid?

Yes basically with stepped sine wave I will only use the battery 1~4 times every month just to get that 5~15 minutes to turn the computer off.
I was just worried if it happened during heavy load and for some reason it turn my computer off immediately during the switch. Will it be possible to damage the other components like PSU or the other?
I also heard about this could create a humming sounds on the PSU during using the battery and it could damage the PSU. Not sure how accurate this is.

[mariushm]

power grid ... mains power, what comes in your wall sockets in your house etc

 

psus can whine and make noise when running on simulated sine wave, because the power factor correction circuit contains inductor (coils of wire wrapped on a ferrite core) which can vibrate and/or resonate when not working in the usual way (usual being with pure sine wave input).  It doesn't mean the psu gets damaged and it's usually not a big deal, just annoying to hear that whine.

 

It's really unlikely for anything else to be damaged IF the power supply fails due to working with simulated sine wave input ... the secondary (low voltage) side is typically isolated from the ac voltage side, if something fails on ac side usually won't damage the other side, unless it's a really bad design psu.

 

[PCForStreaming]

47 minutes ago, mariushm said:

power grid ... mains power, what comes in your wall sockets in your house etc

 

psus can whine and make noise when running on simulated sine wave, because the power factor correction circuit contains inductor (coils of wire wrapped on a ferrite core) which can vibrate and/or resonate when not working in the usual way (usual being with pure sine wave input).  It doesn't mean the psu gets damaged and it's usually not a big deal, just annoying to hear that whine.

 

It's really unlikely for anything else to be damaged IF the power supply fails due to working with simulated sine wave input ... the secondary (low voltage) side is typically isolated from the ac voltage side, if something fails on ac side usually won't damage the other side, unless it's a really bad design psu.

Thank you ^^
This sounds convincing for me to go with stepped sine wave. Because it saves a lot of money in here. the true sine wave I think cost double the cost. I'll try to contact the PSU technical support in this case Seasonic and see what they say about it. If I do hear from them I will update it here.
Oh and the mains electricity or the power grid here is 220V, does it means something or something that I need to consider?
 

And I also try to contact a seller for used or second hand UPS, they say that they can modify the UPS and change the battery to automotive battery that will make the UPS to be able to support for hours. I'm not sure how safe this is but I won't think of risking the PC for this although it does sounds great if it can really work without having risk.

And also How safe it is to buy second hand UPS, are they still as nearly as good as new after we replace the battery with a new one?

[mariushm]

1 hour ago, PCForStreaming said:

And I also try to contact a seller for used or second hand UPS, they say that they can modify the UPS and change the battery to automotive battery that will make the UPS to be able to support for hours. I'm not sure how safe this is but I won't think of risking the PC for this although it does sounds great if it can really work without having risk.

No, you shouldn't do that. I mean he probably can do it, but it doesn't mean it's a good idea.

For at least two reasons

 

Car / truck batteries are different than the batteries used in UPSes, they're "optimized" for different things.

Car batteries are high burst discharged, they're optimized to pump out a lot of current for brief moments of time when you start the engine... but they suck a giving a near constant amount of energy for long periods of time (5-10+ minutes for example). In your car, the alternator's powering most of the electronics, not the battery.

 

UPS batteries are optimized for continuous discharge, for not leaking energy and they're typically sealed and some varieties (crystal lead acid battery) can be discharged without being damaged (regular lead acid batteries will be damaged if discharged to somewhere less than 10.8v

 

You can order your own SLA batteries for UPS and replace the internal ones with your own, here's some examples: https://www.digikey.com/products/en/battery-products/batteries-rechargeable-secondary/91?k=&pkeyword=&sv=0&sf=0&FV=412|426222%2C-8|91&quantity=&ColumnSort=-33&page=1&stock=1&pageSize=25

 

A 290$ 65Wh battery will keep a pc that consumes 80w for around 9-10 hours.

 

The other problem is that a lot of cheap UPSes have battery charging circuitry that's undersized, basically designed with components just good enough to work for around 20-30 hours at a time, knowing that fully discharged batteries inside will charge in around 15-20 hours, and that most of the time batteries will not be fully discharged so they'll take less than that period of time and then the circuit can take a break and cool down.... basically while the ups is guaranteed for 2-3 years or more, they design that circuit hoping it will only run once a week or once every few weeks.

 

If you put much bigger batteries, the charging circuitry will be running for much longer time, and the heat generated by that circuit will start to affect the components of that circuit (capacitors, transformers etc) and could even damage the plastic case of the ups with the heat.

[PCForStreaming]

8 minutes ago, mariushm said:

No, you shouldn't do that. I mean he probably can do it, but it doesn't mean it's a good idea.

For at least two reasons

 

Car / truck batteries are different than the batteries used in UPSes, they're "optimized" for different things.

Car batteries are high burst discharged, they're optimized to pump out a lot of current for brief moments of time when you start the engine... but they suck a giving a near constant amount of energy for long periods of time (5-10+ minutes for example). In your car, the alternator's powering most of the electronics, not the battery.

 

UPS batteries are optimized for continuous discharge, for not leaking energy and they're typically sealed and some varieties (crystal lead acid battery) can be discharged without being damaged (regular lead acid batteries will be damaged if discharged to somewhere less than 10.8v

 

You can order your own SLA batteries for UPS and replace the internal ones with your own, here's some examples: https://www.digikey.com/products/en/battery-products/batteries-rechargeable-secondary/91?k=&pkeyword=&sv=0&sf=0&FV=412|426222%2C-8|91&quantity=&ColumnSort=-33&page=1&stock=1&pageSize=25

 

A 290$ 65Wh battery will keep a pc that consumes 80w for around 9-10 hours.

 

The other problem is that a lot of cheap UPSes have battery charging circuitry that's undersized, basically designed with components just good enough to work for around 20-30 hours at a time, knowing that fully discharged batteries inside will charge in around 15-20 hours, and that most of the time batteries will not be fully discharged so they'll take less than that period of time and then the circuit can take a break and cool down.... basically while the ups is guaranteed for 2-3 years or more, they design that circuit hoping it will only run once a week or once every few weeks.

 

If you put much bigger batteries, the charging circuitry will be running for much longer time, and the heat generated by that circuit will start to affect the components of that circuit (capacitors, transformers etc) and could even damage the plastic case of the ups with the heat.

Thank you, I will just go with the standard battery, 10~15 minutes is what I need to safely saving and turning off the computer. Thank you for the awesome reply!

Ah and the mains electricity or the power grid here is 220V, does it means something or something that I need to consider?

All in all do you think UPS APC 1100VA will be good enough for my PSU? I saw the second hand price is good enough it's no longer have the original battery but I heard from the seller I can get SMT power battery 12v 7ah for a bit more price (I guess SMT is the brand of the battery). Overall I think it's a good price which I can afford for now.

[mariushm]

1 hour ago, PCForStreaming said:

Thank you, I will just go with the standard battery, 10~15 minutes is what I need to safely saving and turning off the computer. Thank you for the awesome reply!

Ah and the mains electricity or the power grid here is 220V, does it means something or something that I need to consider?

All in all do you think UPS APC 1100VA will be good enough for my PSU? I saw the second hand price is good enough it's no longer have the original battery but I heard from the seller I can get SMT power battery 12v 7ah for a bit more price (I guess SMT is the brand of the battery). Overall I think it's a good price which I can afford for now.

1100 VA sounds good.

The VA rating should be at least 1.5x -2x the power consumption of your pc. So for example, if your computer consumes around 300 watts when you're gaming, it would be best to look at 650VA or higher.

A higher VA rating won't necessarily mean longer running time on batteries, you'll still be limited by the Ah value of the battery ... in your case the seller recommends a 7Ah battery which is pretty standard almost lowest size (I think it's common capacity because same size battery is used on scooters and motorbikes, but like I said, a bit different chemistry compared to the ones for motorbikes and scooters)

Should keep your system running for 10 minutes or so, if you're not in a game.

 

No, doesn't matter if you're on 220v, as long as the UPS is also design to work with 220v - and your mains is probably not 220v anyways, in Europe it's standardized to 230v +/- 5-10% ... so any computer power supply should work with 210..250v, something like that. If your psu is universal input, it will work with as little as 100v.

A UPS for 230v countries, will stabilize the voltage a bit depending on input .. ex if your input voltage goes to something like 200v it may boost your ac to 230v-ish... depends on how cheap the ups is, if it has this feature.

If the voltage goes below 200v (or whatever value it has set), it will switch to internal batteries.

Same goes for too high voltage.

 

[PCForStreaming]

 

2 hours ago, mariushm said:

1100 VA sounds good.

The VA rating should be at least 1.5x -2x the power consumption of your pc. So for example, if your computer consumes around 300 watts when you're gaming, it would be best to look at 650VA or higher.

A higher VA rating won't necessarily mean longer running time on batteries, you'll still be limited by the Ah value of the battery ... in your case the seller recommends a 7Ah battery which is pretty standard almost lowest size (I think it's common capacity because same size battery is used on scooters and motorbikes, but like I said, a bit different chemistry compared to the ones for motorbikes and scooters)

Should keep your system running for 10 minutes or so, if you're not in a game.

 

No, doesn't matter if you're on 220v, as long as the UPS is also design to work with 220v - and your mains is probably not 220v anyways, in Europe it's standardized to 230v +/- 5-10% ... so any computer power supply should work with 210..250v, something like that. If your psu is universal input, it will work with as little as 100v.

A UPS for 230v countries, will stabilize the voltage a bit depending on input .. ex if your input voltage goes to something like 200v it may boost your ac to 230v-ish... depends on how cheap the ups is, if it has this feature.

If the voltage goes below 200v (or whatever value it has set), it will switch to internal batteries.

Same goes for too high voltage.

 

Thank you so much for the thorough explanation it's been really helpful ^^
I will ask the Seasonic technical support if I could, share it here if I got any respond and make my decision.

So considering if I bought the used UPS or second hand UPS, how could I easily check the quality of the UPS whether it's still good or not, or know if it's the same as the original item (the parts haven't been replaced with something else)?
And how long a UPS can usually last?

[Guest]

It's not new information.. Its very old.

 

I haven't seen an APFC PSU trip on a square wave UPS in over a decade. 

 

I'm pretty sure 99% of the PSUs made today will work flawlessly on a square wave input. 

[PCForStreaming]

I got an email back from Seasonic and here is their reply:

 

"Hello,

Thank you for contacting Seasonic.

In order to answer your questions:

1. All our retail PSU, S12III included, are APFC products.
2. Compatibility with an UPS is mainly due to the UPS itself, not the PSU. As long as UPS can provide power power to the PSU in case of power outage, then it will work. In 2020, any good average UPS will do this even with an APFC PSU and a Simulated Sinewave.

Regarding the last part of your email, It's difficult to know behavior of a PSU and an UPS if not tested together. we do not test for compatibility UPS and PSU. We only make some recommendations to go for high-end Simulated Sinewave or Pure Sinewave from a known manufacturer (APC, CyberPower etc...). The best is to contact UPS manufacturers to get feedback on their product. Like previously said, in 2020, any average UPS Should work with an APFC PSU.

Thank you."

 

So well yeah it does seems that nowadays you can pair Active PFC (APFC) Power supply with any decent simulated sine wave PSU and shall not worry about all the issues that were lying around. This is a great news for me since I really can go for an affordable simulated sine wave UPS ^^