Question Recommendations for an uninterruptible power supply?

[MrYossu]

I have a home office, and we sometimes get fuses tripping, which cuts the mains power. Doesn't happen that often, but as my PC is my business, I want to minimise any potential loss.

I was wondering about buying an uninterruptible power supply, so if the fuse goes, the PC will have power for long enough for me to get downstairs and flip the fuse back, or in case of need, power the PC down gracefully.

Spent far too long researching this, and have gone round in circles. Main problem is that I don't trust any reviews I've seen. Amazon reviews are well-known for being prompted by offers of free gift cards, and most review sites are affiliate links, so you've no idea if they praise a product because it's good, or because they get a higher commission than on others.

So, is anyone able to recommend a UPS for me? Here are some details, feel free to ask if I've missed anything...

PC is a custom build, you can see full specs here. Missing from that link is the PSU which is a Semi Modular 550w Gold PSU. I have the PC itself, four monitors and an external drive. However, the main requirement for the UPS is to provide power for the main PC and one monitor, so I can retain access if I need to power down. More power outlets is nice, but not vital.

I am a software dev by profession, no games, etc and live in the UK. Don't know if either of those points make a difference.

Thanks for any help you can give.

 

[slightnitpick]

Just get one that can provide the wattage you need from a major name. Even the major names will probably ship the occasional DOA or dud, but if they've been around for a while or are backed by a major retailer you'll probably be more likely to get a good one that will last for years.

If you don't want to be buying a complete new UPS system every few years make sure to get one with a swappable battery.

I've had an APC BACK-UPS NS 1080 (probably no longer available) for the last 8 years or so and it's been fine. I got a weird error once and replacing the then >5 year old battery worked for that (bought it online from the company for a pretty penny and sent the old one back for recycling with their pre-labeled mailer). We have power outages every once in a while and it has been fine through them.

It has both battery backed outlets and only surge protected outlets. For best battery life during a power loss I'd only plug in one of the monitors into a battery-backed outlet (as you indicate you will do). The outlets work great with power strips too.

Edit to add that it provides sufficient power for my cable modem/router, old 17" monitor, and laptop for a couple of hours of low use. And this is a 1080VA power supply.

 

[bill001g]

Key for modern electronics is you need what is called a pure sine wave UPS.
To get the extremely efficient rating on computer power supplies you need almost perfect power.
Now if you were to buy the simulated sine wave models its hard to say what happens. Some computer power supplies will just turn off if the power is not clean enough. The power supply companies say it might damage the power supply but many people do it and you do not hear reports of power supplies blowing up. Then again you are not running on the batteries very long. If you used a non sine wave generator it might cause more issues.

In any case unless your money is real tight I would look at models that say 1500va. You technically could use a smaller one because your power supply is only 500 watts. Note be careful VA numbers are not the same as watts check the watt rating if you get a smaller one.

There are many brands a lot of people buy cyberpower since it a bit cheaper than say APC.

Note plan to replace the batteries at about 3yrs. They might make 5yrs but unless you actually test by unplugging the UPS from the wall you have no idea how good your batteries are. The UPS will tell you they are fine when they are not.

 

[Paperdoc]

Let me reiterate: VA is NOT Watts. The VA rating of your UPS (that's often how they are specified) should be much larger than your Watts actual load. So the recommendation above for 1500 VA on your system is a good one.

IF you can, look for this info. Many UPS makers do not provide this. Look for specs of how long the unit can support a load of specified Amps (or Watts) load, and hopefully for three or more typical load ranges. Time running at max load (say, 650 W) is important, but time for lower loads may be important because the interruption may NOT happen when you are right there and using it fully.

 

[kanewolf]

I have a home office, and we sometimes get fuses tripping, which cuts the mains power. Doesn't happen that often, but as my PC is my business, I want to minimise any potential loss.

I was wondering about buying an uninterruptible power supply, so if the fuse goes, the PC will have power for long enough for me to get downstairs and flip the fuse back, or in case of need, power the PC down gracefully.

Spent far too long researching this, and have gone round in circles. Main problem is that I don't trust any reviews I've seen. Amazon reviews are well-known for being prompted by offers of free gift cards, and most review sites are affiliate links, so you've no idea if they praise a product because it's good, or because they get a higher commission than on others.

So, is anyone able to recommend a UPS for me? Here are some details, feel free to ask if I've missed anything...

PC is a custom build, you can see full specs here. Missing from that link is the PSU which is a Semi Modular 550w Gold PSU. I have the PC itself, four monitors and an external drive. However, the main requirement for the UPS is to provide power for the main PC and one monitor, so I can retain access if I need to power down. More power outlets is nice, but not vital.

I am a software dev by profession, no games, etc and live in the UK. Don't know if either of those points make a difference.

Thanks for any help you can give.

My first recommendation when discussing UPS purchase is to buy a meter to determine the ACTUAL usage of your PC. The kill-a-watt meter is an excellent method -- https://www.amazon.com/P3-P4400-Electricity-Usage-Monitor/dp/B00009MDBU
After you have ACTUAL data, then you can size your UPS. All the manufacturers provide runtime tables for each model. So if you say you want at-least 15 min protection, then you go to the APC webpage (for example) and look at the different models. You know the ACTUAL wattage used, so you can look in the runtime tables and find one that gives say 20min at that wattage. That way you a guaranteed to get the 15min you desire even after the battery degrades some over time.

 

[MrYossu]

My first recommendation when discussing UPS purchase is to buy a meter to determine the ACTUAL usage of your PC. The kill-a-watt meter is an excellent method -- https://www.amazon.com/P3-P4400-Electricity-Usage-Monitor/dp/B00009MDBU

Thanks for the suggestion, it's a really good idea.

However, as I mentioned, I'm in the UK, and if you look at that product on amazon.co.uk you'll see that the two 1-star reviews are because it doesn't work in the UK.

However, on that same page are suggestions for similar products. Most of these are quite a bit cheaper, which is good as I'm on a limited budget, but have enough poor reviews to make me wonder if the products are cheap because they are poor.

Any thoughts? Thanks again.

 

[MrYossu]

@slightnitpick , @bill001g and @Paperdoc - thanks for the great advice. Not going to jump into anything until I've checked the energy usage as @kanewolf suggested, but your advice is very welcome.

Main problem I have is that there are quite a few UPS around 850Va for around £120, but once the VA increases, the price seems to jump up significantly. Sure it's still way less than replacing the PC or losing data, but I need to be able to afford it!

Thanks again.

 

[kanewolf]

@slightnitpick , @bill001g and @Paperdoc - thanks for the great advice. Not going to jump into anything until I've checked the energy usage as @kanewolf suggested, but your advice is very welcome.

Main problem I have is that there are quite a few UPS around 850Va for around £120, but once the VA increases, the price seems to jump up significantly. Sure it's still way less than replacing the PC or losing data, but I need to be able to afford it!

Thanks again.

I recommend a used commercial UPS that you purchase without batteries to save shipping cost. Then buy new batteries. I use the APC Smart-UPS Online 1500VA units. These are double conversion units that have a constant output.

 

[slightnitpick]

Thanks for the suggestion, it's a really good idea.

However, as I mentioned, I'm in the UK, and if you look at that product on amazon.co.uk you'll see that the two 1-star reviews are because it doesn't work in the UK.

However, on that same page are suggestions for similar products. Most of these are quite a bit cheaper, which is good as I'm on a limited budget, but have enough poor reviews to make me wonder if the products are cheap because they are poor.

Any thoughts? Thanks again.

Edit: I just took a look at the almost cheapest of those alternatives and the drawbacks given in the reviews seem to be ones that won't affect what you're trying to read (well over 1 watt pull). I would say buy it: https://www.amazon.co.uk/Nevsetpo-M...show_all_btm?ie=UTF8&reviewerType=all_reviews


A crude way to estimate your computer's energy usage is to take readings from your energy meter: https://www.which.co.uk/reviews/cut...z#how-to-read-your-electricity-and-gas-meters

You'll want to unplug the three additional monitors, but otherwise leave your computer setup running as normal. Take a reading (especially including the presumably fast-moving ones in red, which should be measuring 100 watt-hour and 10 watt-hour increments) at the start of an hour, and then take a reading at the end of the hour. Turn off your computer and take new readings over the course of an hour. Subtract the energy usage when your computer equipment is off from the energy usage when your computer equipment is on.

Over the course of an hour the maximum this value should be is your power supply maximum output (550 watt-hours), less energy efficiency losses of the PSU, plus the listed energy use for your monitors, modem, speakers, etcetera. It should be much less than this.

To be as accurate as possible, everything else that uses energy in your home should be doing so as steady as possible. So if you use electricity for heating, for example, do this test when local weather stations say that the outside temperature will be pretty steady for a couple of hours. You can do this measurement two or three times over the course of a few days, alternating equipment-on first read, equipment-off second read, and equipment-off first read, equipment-on second read and then average the results. If a couple of days are going to be equivalent temperature-wise, you could do the turned on / turned off test over the course of a few hours over both days (turned on one day, turned off the second day).

It's much easier to buy a measuring device, but this would be cheaper.

Looking at the APC 850VA UPS it has a rated power output of 450 watts. Odds are, even for your setup, this would be an adequate output. But of course I can't guarantee that. And a full 450 watt pull would give only 2 minutes of runtime. (300 watt 6 minutes, 150 watts 20 minutes)

For the cheap

 

[MrYossu]

Edit: I just took a look at the almost cheapest of those alternatives and the drawbacks given in the reviews seem to be ones that won't affect what you're trying to read (well over 1 watt pull). I would say buy it: https://www.amazon.co.uk/Nevsetpo-M...show_all_btm?ie=UTF8&reviewerType=all_reviews

Thanks for the tip, already in my basket.

A crude way to estimate your computer's energy usage is to take readings from your energy meter: https://www.which.co.uk/reviews/cut...z#how-to-read-your-electricity-and-gas-meters

Clever! It would take some fiddling around, as we have 3 freezers, a fridge and various other devices that would draw power at random intervals, but it's a clever way of getting a basic idea.

However, with the monitor you recommended, hopefully I will get a better idea.

Thanks again

 

[kanewolf]

Thanks for the suggestion, it's a really good idea.

However, as I mentioned, I'm in the UK, and if you look at that product on amazon.co.uk you'll see that the two 1-star reviews are because it doesn't work in the UK.

However, on that same page are suggestions for similar products. Most of these are quite a bit cheaper, which is good as I'm on a limited budget, but have enough poor reviews to make me wonder if the products are cheap because they are poor.

Any thoughts? Thanks again.

There are UK versions. I am US based, so it was the link I had saved. If you search Amazon UK with "kill a watt" you will see UK specific devices.

 

[MrYossu]

There are UK versions. I am US based, so it was the link I had saved. If you search Amazon UK with "kill a watt" you will see UK specific devices.

Thanks, but I did search amazon.co.uk for it, and the two 1-star reviews both said that the product being offered does not work in the UK, despite being sold on the UK site.

Anyway, @slightnitpick recommended another which looks good enough for what I need, and considerably cheaper as well.

Thanks again

 

[Paperdoc]

Kanewolf posted a comment above, "These are double conversion units that have a constant output." This refers to a design feature not previously discussed. So IF you have not encountered this before, here's what that means.

The simpler designs of UPS constantly ensure that the battery is charged, and monitor the incoming power. While doing that they simply connect that incoming power to the output so your load is running on power from the supply lines. When failure of that source is detected the monitor circuit switches to drawing power for your load from the batteries via the inverter circuits, but this change-over takes a fraction of a second. SOME devices are sensitive to that momentary sag in power supply and will reset immediately. Most Computer PSU's can keep you going through such a sag, but there is a small risk.

The higher-quality designs always feed the power from the battery via the inverters, and keep the battery charged from the supply lines. There is never a change-over sag when the supply fails. This may not be necessary for you computer, but is is for some sensitive devices.

 

[MrYossu]

Kanewolf posted a comment above <snipped for brevity>

Thanks for that, I didn't know about that feature. As you said, it's possibly not an issue for a regular PC (although I'm not sure how I'd know), but worth keeping an eye out when assessing units.

Thanks again

 

[MrYossu]

OK, so I got a monitor, and have been using it for about 10 days now.

Not sure how to interpret the results, so if anyone can help me it would be great.

I'm assuming that kWh is the main number I need to watch. I generally work for around 6-8 hours a day, and that uses around 1kWh. If I've right, that means that it's using around 143W per hour.

Is that right, and either way, what does it say about the PSU I should get?

Thanks again.

 

[bill001g]

In a way that just shows how much battery you would need if you wanted to run it for 6-8 hours on the UPS. Not really something that you really would be doing.

What would be more important would be the maximum number of watts used during the period. The UPS has to be able to deliver this maximum spike in power so you need to size it for the maximum. If not the UPS will detect you trying to draw too much power and turn off.

It depends on the device. Some show the maximum number others you can just look at it from time to time to try to get a number.

So this is a older thread and I am not sure if you put in details of the 850va unit you were looking at. Be very careful these also have a watts rating and they can vary from 400-500 watts depending the exact model. Also most these are very low end device that do not generate true sine wave output. This may or may not be a problem for your power supply.

 

[MrYossu]

It depends on the device. Some show the maximum number others you can just look at it from time to time to try to get a number.

It does have a max display as well, and it shows that the max was 199W

So this is a older thread and I am not sure if you put in details of the 850va unit you were looking at. Be very careful these also have a watts rating and they can vary from 400-500 watts depending the exact model. Also most these are very low end device that do not generate true sine wave output. This may or may not be a problem for your power supply.

I'm not looking at any specifically, I'm open to advice.

So, given the max shown above, would you have any further comments? I really don' have much idea what I'm doing here, so any pointers would be useful.

Thanks again

 

[kanewolf]

OK, so I got a monitor, and have been using it for about 10 days now.

Not sure how to interpret the results, so if anyone can help me it would be great.

I'm assuming that kWh is the main number I need to watch. I generally work for around 6-8 hours a day, and that uses around 1kWh. If I've right, that means that it's using around 143W per hour.

Is that right, and either way, what does it say about the PSU I should get?

Thanks again.

If you got the meter you linked to above then the main display on the meter shows the wattage in real time. You need to find the max number of instantaneous watts.

 

[slightnitpick]

This one from Cyberpower would allow a 270 watt draw for 7 minutes, and outputs a pure sine wave: https://www.cyberpower.com/uk/en/product/sku/cp900epfclcd-uk

The SMART-UPS line from APC also output pure sine waves.

I think pure sine is more expensive than a regular UPS, so to save money it might be worthwhile buying a sub-1000VA UPS without pure sine from a local electronics store, plug your computer into it, make sure you have no programs running, and just disconnect the UPS from the main line to see if your computer keeps running fine or shutsdown/reboots. If it shutsdown/reboots, return the UPS to the store and buy a pure sine one.

Other commenters, please let us know whether this is a safe or dangerous test for a computer.

 

[MrYossu]

If you got the meter you linked to above then the main display on the meter shows the wattage in real time. You need to find the max number of instantaneous watts.

It has a button that alters the display to show other things, including the max wattage, which is where I got those numbers from

 

[MrYossu]

This one from Cyberpower would allow a 270 watt draw for 7 minutes, and outputs a pure sine wave: https://www.cyberpower.com/uk/en/product/sku/cp900epfclcd-uk

Please can you explain how you got the 270W for 7 minutes, as that bit is confusing me. Was it in the link (in which case I missed it), or did you calculate it?

Thanks

 

[slightnitpick]

Please can you explain how you got the 270W for 7 minutes, as that bit is confusing me. Was it in the link (in which case I missed it), or did you calculate it?

Thanks

It's right there in the description:
Watts 540
Half Load Runtime ( min ) 7

One half of a 540 watt load is 270 watts.
It costs a bit over 200 pounds from the retailers I looked at when clicking the "where to buy" button. Though unfortunately those retailers were also saying that it is currently out of stock.

 

[Paperdoc]

That way of specifying the ability of the UPS to keep your system running is reasonable. There are too many makers who will tell you only the max Watts rating, and not how long that lasts. Telling you how long it WILL keep your system running at half max load is good info. The very best makers sometimes will tell you run time for each of several load levels.

 

[General_Cool]

https://tripplite.eaton.com/700va-3...s-avr-120v-50-60-hz-lcd-usb-tower~OMNI700LCDT

Eaton is generally considered to be the best brand of UPS without going into multiple thousand dollar industrial units. This model here supports up to 10 minutes of runtime at half load and 3 minutes at full load, which should be more than enough to save everything. Runs off of your wall outlet too (115V) so no special power connectors needed.

 

[Paperdoc]

That link by General_Cool shows a good unit with proper info on its ability. One small point to consider. At 200 W (your claimed max) this unit can keep you running for 7.5 min. That certainly is enough time for an orderly shut-down IF you are then when power fails. Are you confident you or someone competent WILL be present when power fails?