Please let me know if the UPS that I want to buy is good or not for my PC.

[unwind-protect]

It is 650VA USB / DIN : I'm not sure that it is enough for me. The UPS on ebay is 800W ; 800W is better than 650VA ?

It's complicated. The ebay seller probably doesn't know that he listed 800VA, not watts.

I think it is questionable whether the Ebay unit really has stronger current capabilities, despite the numbers listed. It is like with PC PSUs. A high-quality 600 watt PSU can have more power than a low-quality 800 watt one.

 

[Dr. Dro]

Important to keep in mind VA (volt-amps) =! W (watts). The formula to calculate your required capacity in volt-amps is to divide the amount of watts by power factor, for example, 750 VA will translate to 525 W at a 70% power factor, thus making a 750 VA unit adequate if your power consumption requirements don't exceed 450 to 500 W. To convert amps to VA, you multiply amps by voltage, for example, 10 amperes multiplied by 115 volts would translate to 1150 VA - again, assuming a purely resistive load with a power factor of 100%. Power factor equation is W divided by VA, and a safety margin of 20-25% is recommended.

What is Power Factor? | How to Calculate Power Factor Formula | Fluke

What is power factor and why is it important? Learn how to calculate the power factor formula, each component of the equation, and why it matters.

www.fluke.com

 

[ziomario]

and as the Dr and others said, its a good idea to go with pure sine wave out units, especially if you dont plan on shutting down the pc right away if the power is gone.
might be ok with blackouts, but if you have lots of brownouts (power goes out and comes right back), you waste more time on booting/shutdown, instead of just using the computer.

From time to time I have 2 blackouts. Power goes out and comes back two times in a few milliseconds. I'm scared that this behavior will damage my PC. Anyway,usually the power comes back to be stable in 3/4 minutes. What's the best UPS to buy in this specific case ? Pure sin wave or approximated sin ? Without the UPS when the power goes out,I turn off the button of the power supply,to avoid more than one blackout close together. Is this a wrong decision ?

It's complicated. The ebay seller probably doesn't know that he listed 800VA, not watts.

I think it is questionable whether the Ebay unit really has stronger current capabilities, despite the numbers listed. It is like with PC PSUs. A high-quality 600 watt PSU can have more power than a low-quality 800 watt one.

So. the 650VA USB / DIN is enough good for me ?

 

[Dr. Dro]

From time to time I have 2 brownouts. Power goes out and comes back two times in a few milliseconds. I'm scared that this behavior will damage my PC. Anyway,usually the power comes back to be stable in 3/4 minutes. What's the best UPS to buy in this specific case ? Pure sin wave or approximated sin ? Without the UPS when the power goes out,I turn off the button of the power supply,to avoid more than one brownout. Is this a wrong decision ?

A brownout is what occurs when the grid's voltage is reduced below nominal range - this causes an incandescent lamp's red light to weaken and look brown
A blackout is what occurs when the power goes out completely (i.e. no light)

If you have an issue with intermittent power, you may want to ask your electric company to come check if there's anything wrong with the power delivery from the street instead of buying an UPS. If that is fine, then you should have an electrician verify your installation, see if anything is overloaded. These interruptions may coincide with any home appliances you may have that contain an AC motor (for example, your fridge or washer) resuming its functionality. When your fridge's compressor powers on, there will be an inrush current that causes the symptoms you've described - if your installation is inadequate, you will see this interruption manifest. Ideally, such devices should not be on the same circuit as your computer or other home appliances if it can be helped.

If you have too many things plugged in the same outlet, don't do that either. It's not good for the installation or your stuff. An UPS is only going to be a band-aid fix for intermittent supply issues.

 

[ziomario]

A brownout is what occurs when the grid's voltage is reduced below nominal range - this causes an incandescent lamp's red light to weaken and look brown
A blackout is what occurs when the power goes out completely (i.e. no light)I

I have fixed brownout with blackout,thanks.

If you have an issue with intermittent power, you may want to ask your electric company to come check if there's anything wrong with the power delivery from the street instead of buying an UPS.

That's the real problem. No one cares about the problem. It is there since 6 months. I have developed my own idea about the reason why they don't fix it : the company don't want to spend money for a failure that happens 2 times in a month and it lasts 3 minutes. They leave the situation as is. And we can't push it to fix it,because the shortage is too low and it does not happens more often. Everytime it happens,on the website of the company I see that they are fixing the problem,but I don't think they do because after some time,it happens again. It could be that all they do is reconnect the power without fixing the problem. There is not a problem with my building,but with a small piece of district where I live. When the electricity goes out, the street lights and those illuminating a campsite go out.

 

[unwind-protect]

So. the 650VA USB / DIN is enough good for me ?

I estimate yes based on a 9900k and a 2080ti. And you probably don't keep full load on CPU and GPU when power fails, no?

Unless you run unattended compute jobs.

If you want to be sure you would have to get a power meter.

 

[ziomario]

I can't buy on Amazon. I prefer Ebay,because I can pay in 3 installments. So,the same product on Ebay should be this one :

Eaton Ellipse ECO 650 DIN gruppo di continuità (UPS) Standby (Offline) 0,65 kVA 3553340620621 | eBay

Le migliori offerte per Eaton Ellipse ECO 650 DIN gruppo di continuità (UPS) Standby (Offline) 0,65 kVA sono su eBay ✓ Confronta prezzi e caratteristiche di prodotti nuovi e usati ✓ Molti articoli con consegna gratis!

www.ebay.it

 

[unwind-protect]

I can't buy on Amazon. I prefer Ebay,because I can pay in 3 installments. So,the same product on Ebay should be this one :

Eaton Ellipse ECO 650 DIN gruppo di continuità (UPS) Standby (Offline) 0,65 kVA 3553340620621 | eBay

Le migliori offerte per Eaton Ellipse ECO 650 DIN gruppo di continuità (UPS) Standby (Offline) 0,65 kVA sono su eBay ✓ Confronta prezzi e caratteristiche di prodotti nuovi e usati ✓ Molti articoli con consegna gratis!

www.ebay.it

I have a lot more confidence in that unit than the first one.

 

[Shrek]

From time to time I have 2 blackouts. Power goes out and comes back two times in a few milliseconds. I'm scared that this behavior will damage my PC.

If you are only concerned about the PC and don't mind the power dropping, get a good surge protector; cheaper than a UPS and no batteries to change.

 

[ziomario]

If you are only concerned about the PC and don't mind the power dropping, get a good surge protector; cheaper than a UPS and no batteries to change.

View attachment 368247

Nice idea. Yeah,I don't care so much if I lose some work. I'm worried about the damages that more blackouts happened in few milliseconds can break the electronics of my PC. Can you share the Ebay link of the surge protector that I see on the picture ? thanks.

Is this good ?

Ci scusiamo per l'interruzione.

 

[Shrek]

That is for 110V, you are at 220V; that is why I pictured a 220V unit.

Do I Need a Surge Protector? - A1 Computer Repair
claims "Over 50% of equipment failures can be attributed to power surge/failure."

 

[ziomario]

What I would like to know is if several very close blackouts could damage the circuits of my PC. That is, how likely is it that this will happen ?

 

[Dr. Dro]

What I would like to know is if several very close blackouts could damage the circuits of my PC. That is, how likely is it that this will happen ?

If you notice power grid instability, it is advisable to turn the power supply off. I do not think anything will happen but better safe than sorry.

 

[Caring1]

It's not the blackouts that cause problems, but the power surge when power is reconnected again.

 

[Waldorf]

@ziomario
even if your not worried about losing data, power issues can lead to corrupted or bricked drives, especially with non-hdd based drives.

even without power losses, i still recommend using a ups once the pc is worth some money.
any decent ups will clean up the incoming power, and the pure sine out all come with avr, so power fluctations will get corrected without switching to battery power.
alll will help the psu life etc.

so in short, i always use a ups, if possible with pure sine out, as newer psus will not like running on battery power from a stepped wave, and will also come with the avr feature.

just make sure to setup the unit for the widest voltage range possible, and shutdown of pc if it drops below 80 battery capacity (if ur not there to do it), as lead batteries dont like to be discharged, and will last longer that way..

 

[Bill_Bright]

No sane person is saying you "need" a pure sine UPS.

LOL Then there seems to be quite a few insane people around here.

And @Tahagomizer - I have to assume you didn't bother to read the links I provided for EVGA or Seasonic, or Dr Dro's link to Eaton - all of which clearly said modified waveforms are fine with their PSUs and PCs. I have to assume that or else you must believe you know more than their engineers who you must believe are inept! Otherwise, why would you repeat the same old marketing hype spewed by the marketing weenies of pure sinewave UPS? You can see by the link in my sig I have a bit of experience here and I have no reason to believe I know better than those experts.

Here lies the problem

No. That is not the problem. The problem is those marketing weenies and opponents of stepped approximation UPS use images like that to illustrate their point, suggesting all UPS output approximated sinewaves that look like that. That is total nonsense.

A much more accurate representation is a modified/stepped/approximated sinewave waveform that looks like this:

Most units take about half wave to switch, so you can go from long zero state to another long zero state, which is too much for many power supplies

Not even. Most units? Nonsense. This is exactly the type of marketing "hype" and "misinformation" being spewed by the marketing weenies of pure sinewave UPS makers.

Half wave? Long zero state to long zero state? Come on people! Snap back to reality, okay?

Yes, @Tahagomizer is right, technically - in theory for the most basic (near "squarewave" output) "battery backup" UPS - the type that might be used on a building Exit sign and emergency lighting to illuminate the way out of a dark building after a power outage. But NO ONE is suggesting the use of a basic battery backup UPS on a computer. Come on, people!!! That type of ridiculous argument is why I get riled up over this.

It is, always has been, and will continue to be a "good UPS with AVR". So to suggest "many power supplies" can't deal with such long state events is simply WRONG!!!! Or at the very least, extremely deceptive and totally unrealistic marketing hype!

How many half-waves are there in 1 second? There are 100 for 50Hz mains and 120 for 60Hz. So when someone says "long state" to "long state", that means 0.01 second or 10ms @ 50Hz, and 0.0083 seconds or 8.3ms @ 60Hz respectively.

To suggest that 1/100th of 1 second is so long it can disrupt many ATX Form Factor power supplies is total nonsense. Why? Because 1/100th of 1 second is not even reality! As seen in the more realistic image of a stepped approximated waveform, the reality is the "long state" is much MUCH shorter than a half wave. It is closer to 1ms or even less!!!

Nobody is talking about a $5 counterfeit 烂Deer PSU from some backwoods factory in China that uses underaged, force labor to build their supplies with components from its sister factory upriver.

We are talking about ATX Form Factor compliant PSUs. PSUs that are required to "hold up" power in the event input power drops below ATX defined thresholds for a minimum of 17ms at 80% load, 12ms at 100% load.

Worse condition is 12ms. That is way WAY more than enough to handle that ≤ 1ms "long" state.

In other words, even 1/2 way decent, budget ATX PSUs are designed to maintain output with a stepped approximated waveform from a good UPS.

Here's another dose of reality. Who here recommends cheap, budget PSUs? Not me. Never. I always recommend quality supplies from reputable companies.

Same goes with UPS. I always recommend a "good" UPS with AVR (automatic voltage regulation) - pure or stepped.

So to make the argument using cheap PSUs and UPS, and attempting to apply that across the board, is deceptive at best, and plays right into the hands of the marketing weenies, "hook, line and sinker".

but if you have lots of brownouts (power goes out and comes right back)

Sorry, but that is not a brownout. A brownout is a "low" voltage event, often called a long duration "sag". If your mains is normally 120VAC, an example of a brownout would be if your mains voltage drops to 100VAC and sits there for a few seconds or even longer. If the voltage quickly drops to 100V but instantly returns to a normal 120V, that would be a "dip". Dips typically cannot be seen (as flickers) by the human eye, but can still be disruptive to sensitive, unprotected electronics.

When the power goes "out", it drops to 0V. If it immediately comes right back, it might be called a "flicker", though that is not really a proper technical term. A power "blink" is the more accurate term.

 

[Shrek]

Is as good as a sine wave (in my opinion); do your units do this?


Your image file is titled
"Synthesis-of-a-step-wise-approximated-50-Hz-sine-wave-using-a-10-V-Josephson-junction-765747116"

A Josephson junction refers to super-conductivity

 

[ziomario]

My question released Krakens

 

[Shrek]

Karens

 

[eidairaman1]

You need a total pc wattage, that includes your monitor, and once you have wattage you use a Wattage to VA calculation to find the minimum ups required to give you ample time to save work and shut down

Karens

Kevins too

 

[Waldorf]

temporary used a 800VA and i had no trouble feeding 5800X + 2080S (both under water and oced) and the 50in tv as well, just not much runtime.

so 800-1000VA should be fine.

 

[ziomario]

temporary used a 800VA and i had no trouble feeding 5800X + 2080S (both under water and oced) and the 50in tv as well, just not much runtime.

so 800-1000VA should be fine.

for sure,but the costs are higher as you can see :

Ci scusiamo per l'interruzione.

Anyway,that's what I want. Unfortunately,no money,no party.

 

[Waldorf]

this here
pure sine wave

or if you dont worry about running it on battery much 1500 VA
new

 

[ziomario]

this here
pure sine wave

ohhhh pure sine wave...so you are on the "pure sine wave" part of the barricade. Ok. Anyway,it is used. I never buy used stuff. More if it should protect my PC. Come on bro. Give me the link of a new "pure sine wave / 800VA " UPS. And,put also the link of a new "modified sine wave / 800VA " UPS. If the first one is out of my budget,I could grab the second one,that sounds still good for protecting a "normal" PC.

The second one is 500VA ? I think it is not enough for me. I prefer 800VA.

 

[Waldorf]

buyer protection is pretty good on bay, and seller has 100% rating, and not much that can go wrong besides the battery, and they are common, and would still allow you to claim "not as promised".
maybe have the seller do the unit self test thru the sw, and send you a pic with battery capacity.

i dont see the little difference in price between stepped and pure as the reason to not get one, and pure sine out have usually features the stepped dont always have, like avr/display.
and while not proof, i had quality psu with aPFC that died from running on battery and some ppl i helped as well, but no issues over the same time frame using pure sine out (+5y), so i rather spend 20-50 more instead of a chance of having to get a new psu (earlier).
we spend a lot more on other parts, so why not on a part thats crucial for clean power.

i only did a quick Search since im on the phone, so maybe try yourself, either just with pure sine out and power, or look for cyberpower units and just filter "new".

cp900 new
sine out
has everthing and cheaper than the eaton.

if you dont care about pure sine
1500VA