Do I really need pure sine wave?

[dedekind]

Hi guys, I'm looking for an UPS to protect my system from power outages, etc. Don't need to keep the computer on too much time, I just want to protect the hardware.

My PSU is a PPC Silencer 760W. In the official webpage, no Active PFC is listed, though on 99% of the reviews that I've read, they do list it as .99 Active PFC. I don't know how to check it myself and I would think it's a bit complicated, so to be on the safe side I guess I should assume that it has ineed Active PFC.

So the question is: do I really need a pure sine wave UPS? The cheapest one I can find is around $200
http://www.newegg.com/Product/Product.aspx?Item=N82E16842102133&nm_mc=KNC-GoogleAdwords&cm_mmc=KNC-GoogleAdwords-_-pla-_-NA-_-NA

and that seems a bit too much. I don't want to buy it unless it's really the best choice for my PSU (apart from the PSU, I only connect a monitor which uses something like 10-30 W). It also seems a bit too fancy IMO, I don't want any LED indicators or anything, as I said, just want the hardware to be protected!

Any recommendations on this are welcome!

EDIT: I also forgot to ask the following. Do I need an UPS that delivers at least 770-800W? I have no idea how UPS work. If there is no problem with the power coming from the wall, then the amount of watts that get to the PSU should not be limited by the number specified in the UPS, right? I mean, this number should only be relevant when in battery mode. In that case I don't think I would need that much power.. or do I?

 

[ko888]

For a power supply unit to be able to get 80 PLUS level certification it must have Active PFC. Since the PC Power & Cooling Silencer 760W has 80 PLUS SILVER certification then it definitely has Active PFC.

Another way of determining if the PSU has Active PFC is too look for the absence of the little red AC input voltage selector switch. The absence of that little switch indicates that it has automatic input voltage detection and selection and Active PFC. There should also be a label next to the PSU's AC power input jack that specifies the acceptable AC input voltage range (e.g. 100-240VAC).

Some PSUs with Active PFC will not work properly with a UPS that outputs a simulated sine wave when operating on battery power. The UPS will usually fail to switch over to battery operation or it will make a bunch of audible squeals then report an overload or error condition and shut itself down. There's no way of telling if your specific power supply will cause this type of behavior unless you know of someone who has the same power supply as you and has tested it with a simulated sine wave UPS. There are the rare PSU test reviews that will actually test the PSU with a simulated sine wave UPS.

A pure sine wave UPS eliminates the guessing.

Sizing of the UPS will depend on the desired battery run time you want which is based on the PC's power draw from the AC wall outlet while the PC is under load plus any other devices you need to power like the monitor. I highly doubt that your system is drawing the full 760 Watts from the power supply because it wouldn't last very long if it is.

You can get one of these P3 International P4400 Kill A Watt Electricity Usage Monitor for $14.98 to get an accurate reading of your actual power draw from the power grid so that you can get a better determination of the UPS size required.

http://www.amazon.com/P3-International-P4400-Electricity-Monitor/dp/B00009MDBU

 

[dedekind]

Thanks! But anyway, if battery mode would fail, the hardware would still be "protected" from spikes and brownouts? (I can also just get a surge protector but it doesn't protect from brownouts AFAIK).

 

[Kursun]

I have PC Power & Cooling Silencer 750 Quad on my PC.
I also have 3 UPS, all APC rated from 400 to 800 VA models. I have used the PC with each UPS, some of which output simulated sine wave and I had no problems. I don’t think modern switched mode power supplies really care about wave form of the line supply. As far as I know PSUs directly rectify the line voltage at the input end. Then they produce their own high frequency oscillations which are fed to a high frequency transformer. Since the line voltage is rectified to DC right at its line supply input PSUs shouldn’t be overly critical about line supply waveform.

Your power supply may be rated for 760VA but you don’t have to buy an UPS rated for that capacity. What your PC and peripherals actually draws during full load is more important.

BTW do note that UPSs consume electricity all the time (about 15W), even when your PC is off.

 

[ko888]

Thanks! But anyway, if battery mode would fail, the hardware would still be "protected" from spikes and brownouts? (I can also just get a surge protector but it doesn't protect from brownouts AFAIK).

You will have to check the feature set of the UPS to determine if it has that functionality included.

You're describing the functions of a power conditioner/line conditioner/power line conditioner that doesn't have a battery backup function but just has the protection functions like the voltage regulation you're looking for when voltage sags/brownouts happen.

I'm currently using a Corsair Professional Series HX750W PSU, that has Active PFC, on an APC Back-UPS XS 1300 that outputs a stepped approximation to a sine wave and it functions just fine.

The only way to find out, if it's going to work for you, is to test your PSU with the UPS.

 

[ko888]

Here's an example where it doesn't work.

From X-bit lab's review of the Seasonic M12-II 620 Bronze (SS-620GM)

Compatibility with UPSes

Like the S12-II 520, this PSU refused to work normally with my UPS. It was stable at loads up to 350 watts when powered by the mains but did not work after switching to the batteries.

Thus, I can suppose that the high-wattage S12-II and M12-II series models have a different active PFC design than the low-wattage models and cannot work normally with UPSes that have non-sinusoid output voltage. The S12-II 430, having a somewhat different interior design than the S12-II 520 and M12-II 620, had no problems working with my UPS.

Seasonic doesn't even guarantee a PSU will be compatible with simulated sine wave UPS'.

It all comes down to the Active PFC circuit design's interaction with the UPS.

The PC Power & Cooling Silencer 760W is made by Seasonic for PC Power & Cooling. I would hazard a guess and say that you probably won't have any problem using it with a simulated sine wave UPS.

 

[Chainzsaw]

Hello,

I also have the PPC & C 760W PSU. I also have a cyberpower UPS - forgot what model but its something like an 850W version.

I can test it out for you once I get home.

It will be a few hours though if you can wait that long.

 

[dedekind]

Hi Chainszsaw, great. Do you usually use it with the PPC? Do you know if it's simulated or pure sine wave?

 

[Chainzsaw]

AFAIK the cyberpower one I got was not a simulated sine wave UPS. I will test it out when I get home.

 

[Chainzsaw]

Hi Chainszsaw, great. Do you usually use it with the PPC? Do you know if it's simulated or pure sine wave?

Well I kind of feel like an idiot for not testing out my CyberPower UPS (since i've had it for a few weeks) until now....anyways - good news. I did a test and it worked flawlessly.

For my scientific test, I opened up Crysis and loaded a level with some action (last boss if anyone cares). Played a little bit - then disconnected my UPS. My UPS started beeping - then I continued to play some Crysis for about 3 minutes. The battery still showed full most of the time. I closed crysis, re-plugged in my UPS and all was good.

I don't recommend other people trying what I just did, but I know the risks involved so i'm ok with that.

This is my exact UPS:

http://www.newegg.ca/Product/Product.aspx?Item=N82E16842102070

According to this it's a simulated sine wave:

http://www.cyberpowersystems.com/products/ups-systems/intelligent-lcd-ups/cp1350avrlcd.html

 

[ko888]

That's good to hear.

Too bad there isn't some central repository of PSU and UPS combo compatibility information available that can be searched.

 

[Chainzsaw]

That's good to hear.

Too bad there isn't some central repository of PSU and UPS combo compatibility information available that can be searched.

Word.

That would be pretty...unique information in a good way.

 

[dedekind]

Thanks a lot! Actually I ended up buying this one:
http://www.microcenter.com/single_product_results.phtml?product_id=0353891

It says it works well with Active PFC, and the price was good, so.. I took it. Don't need to last long in full load so 510 watts seemed enough for me.

 

[dedekind]

Best answer selected by dedekind.

 

[Chainzsaw]

Thanks a lot! Actually I ended up buying this one:
http://www.microcenter.com/single_product_results.phtml?product_id=0353891

It says it works well with Active PFC, and the price was good, so.. I took it. Don't need to last long in full load so 510 watts seemed enough for me.

Nice. I hope it all works out for you!

Have fun.