dslreports logo
 
    All Forums Hot Topics Gallery
spc

spacer




how-to block ads


Search Topic:
uniqs
793
share rss forum feed


Mike
Premium,Mod
join:2000-09-17
Pittsburgh, PA
kudos:1
Reviews:
·Verizon FiOS

How to select a UPS?

How exactly do you select a UPS? Is it consumption based? Is there an equation against your power supply / monitor?

My power has been flickering for a while and I can only imagine what the computer is going through. I've thought about this for a while.

Here is what I'm running on this one. I just want to clean up the power feed that's all and maybe shutdown when the battery is running low during an outage.

i5 3570k
ASUS P8Z77-V LX
CMPSU-850TXV2 (850 watt)
Zotac GTX 680
WD 2 TB - 64M Cache, 7200rpm, 6.0Gb/s
240 GB Corsair Force Series GT SSD
Misc Creative Fatality sound card
Corsair Hydro Series H60 cooler
Misc fans (120s, 80s).
Random DVD-RW I'll never use

Samsung 2253BW.
--
"If something about the human body disgusts you, complain to the manufacturer" - Lenny Bruce
What this country needs is a good five dollar plasma weapon.

aguen
Premium
join:2003-07-16
Grants Pass, OR
kudos:2
How long do want the BBU to keep your PC/Monitor powered on after an outage? If you also want to maintain an internet connection, you need to add in your router/switch and because you are on Fios, you need to have an additional BBU for the ONT if you want more than 8 min. of internet. Last but not least, what's your budget?

JoelC707
Premium
join:2002-07-09
Lanett, AL
kudos:5
reply to Mike
For a UPS there are two capacities to worry about; one you will see when shopping and one you might not be able to do anything about. First if the capacity of the inverter. This is the capacity to run all your connected loads and is expressed in VA or Watts. The second is the capacity of the battery. This is how long your connected load will last and is expressed in Amp-hours or Ah.

For sizing the inverter, you need to know what you will have connected to it. Don't just go by the size of the power supply as you're probably never going to be more than 300-400W even at full tilt with what you've listed there (just the computer). The monitor could add another 100W or so. Also any other loads like router, switch, modem, etc. will need to be factored in.

Sometimes the networking equipment is best to be connected to a separate UPS either for run time or simply because of placement (they may not actually be near your computer after all). The run time issue is especially important if your phone is routed over your internet connection, you will likely want that to stay running longer than anything else so having a separate UPS is usually the cheapest way to do that.

Now, on to the other capacity, the battery. The battery as I said is something you may not be able to control as you usually can't specify a larger battery without stepping up to a physically larger UPS (which then may or may not have a larger battery anyway). The good news is some of these larger UPS units are designed with provisions for external battery hookups so you can extend run time at will as you decide you need it.

Note, considering many consumer grade UPS units run on standard 12V batteries, it is technically possible to simply hook up larger batteries even if it isn't designed for it (even to the point of using car/marine deep cycle batteries). Will it work? Yes, most likely. Is it recommended? Definitely not, especially depending on the battery type you use as it could vent hydrogen gas into the room. Then you have concerns on the charging circuit and the cooling of the inverter on those extended run times and recharge times. These consumer UPS units simply aren't built to handle multi-hour run times that you could technically make them do.

What you need to do is decide how long you want your connected load to run during an outage. Do you just want to safely shut down the computer at the first sign of an outage or do you want to try and wait out a short outage without having to bail on what you're doing only to have the power come back on shortly after you shut it all down? Cost will be a major factor here too.

Also, cleaning up the power... This is a whole nother ball game. Without drowning you in even more detail, suffice it to say the typical consumer grade UPS will NOT do anything for cleaning up the power. To properly clean up the incoming power you need something called a double-conversion UPS. In essence this type of UPS is ALWAYS running on battery and the AC input is used to recharge the battery only. These types are generally not found in cheaper consumer grade UPS units so if you really want that I would suggest searching ebay or such for a used server grade UPS (but still check it's specs).


Mike
Premium,Mod
join:2000-09-17
Pittsburgh, PA
kudos:1
Reviews:
·Verizon FiOS
reply to aguen
Three minutes. I don't care. Enough time for me to hit save and turn off.

I just want a solid feed going into the machine and something to turn it off safely when it gets low when I'm not around.

When I mean clean up the power, it's more hey the power just went out for 1 second times 15. within a minute.
--
"If something about the human body disgusts you, complain to the manufacturer" - Lenny Bruce
What this country needs is a good five dollar plasma weapon.

JoelC707
Premium
join:2002-07-09
Lanett, AL
kudos:5
OK so basically enough to sustain an outage. Multiple outages back to back (especially within the same minute) means I would either control the shutdown manually or have it set to keep it on battery as long as possible. This is really one of those catch-22 situations. If you have multiple outages you are trying to work through, the takes longer to recharge the battery than it does to drain it. There's really no good solution for something like that other than a large amount of batteries or a generator. Personally, after a few back to back outages I would just shut down the computer and come back later but sometimes you need to finish something so yeah, that's a difficult one.

Most manufacturers have a load/run time calculator on their site (some are more accurate than others, APC seems to err on the really high side in my experience). APC recommends a 1000 VA unit for the basic stats of your computer and claims it would be ~50% loaded. I seriously doubt that unless it were at full tilt and even then that's pushing it.

Based on the specs you provided, I would search in the 500VA or higher range. I wouldn't go lower, but larger wouldn't hurt. Brand really doesn't matter, at the small consumer grade level they all use the same cheap components usually. Many people recommend you stay away from APC, though personally I've never had any major troubles out of them. Really only preventive maintenance issues that would affect any other UPS equally. A typical 500VA UPS should last you around 10-15 minutes or so on battery.


DarkLogix
Texan and Proud
Premium
join:2008-10-23
Baytown, TX
kudos:3
reply to Mike
Well to accurately figure out run time you need to know the actual load.

Sure the power supply "CAN" pull 850, but I'd bet its not pulling 850.

then as you want to keep working you'll likely need to size it to cover your monitor (LCD's aren't to bad, but never put a CRT on a UPS, or a laser printer)

also VA =/= watts
I have a 1500VA backups, but it alerts to overload around 800 or so watts of load.

BTW do you know if the power is dropping out or just sagging?
and what kind of budget do you expect to spend?


Mike
Premium,Mod
join:2000-09-17
Pittsburgh, PA
kudos:1
Reviews:
·Verizon FiOS
Budget is not an issue.

The power can sag or it will fully drop for a second or two and come back. Almost like a kid playing with a light switch.

The entire city of Pittsburgh is basically held together with duct tape and chicken wire. I just need a little safety net.
--
"If something about the human body disgusts you, complain to the manufacturer" - Lenny Bruce
What this country needs is a good five dollar plasma weapon.


DarkLogix
Texan and Proud
Premium
join:2008-10-23
Baytown, TX
kudos:3
a normal consumer UPS will likely do good, though the high end units (ie smart-UPS) have better voltage boost and limit abilities as well as they can recharge faster (downside is cost and that when recharging a Smart-UPS will pull more power)


The WeaseL
Premium
join:2001-12-03
Minnesota
reply to Mike
»www.apc.com/products/resource/in ··· features
--
How lucky am I to have known someone who is so hard to say good-bye to.

JoelC707
Premium
join:2002-07-09
Lanett, AL
kudos:5
I have the slightly older 1300VA version of that one: »www.apc.com/resource/include/tec ··· R1300LCD. If it's anything like the one I have, it's a solid choice.


Mike
Premium,Mod
join:2000-09-17
Pittsburgh, PA
kudos:1
Reviews:
·Verizon FiOS
reply to The WeaseL
»www.amazon.com/APC-BR1500G-BACK- ··· Pro+1500

I still have no idea what my computer actually pulls. I'm guessing this for safety? I read that the surge protector is actually pretty bad in the APCs. Is that basically the only brand?

--
"If something about the human body disgusts you, complain to the manufacturer" - Lenny Bruce
What this country needs is a good five dollar plasma weapon.


DarkLogix
Texan and Proud
Premium
join:2008-10-23
Baytown, TX
kudos:3
I've used APC for quite awhile and other than one place that had the dirtiest power ever (had to use a Smartups there) I've never had a problem.

They're the industry leader.

The limit is if you pull more power than its rated it won't keep you up during an outage, it'd just die instantly or be unable to keep the voltage at 120v.

BTW I have the one you just linked and I plan to get a 2nd, as I'm pulling to much power.


The WeaseL
Premium
join:2001-12-03
Minnesota
reply to Mike
There are other brands (Tripp Lite, Minuteman for instance).

The only way to really know what you are pulling is to measure it with something like a Kill A Watt meter.

From my experience with UPS's, something 750 VA or higher would meet your needs. APC does have a sizing selector that is helpful.

»www.apc.com/tools/ups_selector/i ··· ndex.cfm

Select the PC or Workstation option and fill out the questions.
--
How lucky am I to have known someone who is so hard to say good-bye to.

JoelC707
Premium
join:2002-07-09
Lanett, AL
kudos:5
FWIW, I did that for his stated specs (well as much as I could since their details aren't that up to date). Leaving the default 20% and 10 mins run I got back a 1000 VA Smart-UPS model (yeah, it suggested a Smart-UPS on the PC side of the calculator). Not so sure he needs THAT much but I guess it's better to err on the side of too big than too small. A 500VA would be the smallest I would go and 750 or higher as a better choice.


DarkLogix
Texan and Proud
Premium
join:2008-10-23
Baytown, TX
kudos:3
The main difference from back-ups smart-ups is smat-ups have more powerful charging components and are able to make sine-waves instead of a stepped simulation.

Its mainly a quality thing, as you can get 1500va back-ups.

though after 1500va you would have to go smart-ups.

and if you want long run time go with a smart-ups XL (the xl models can have an add-on battery connected.)

JoelC707
Premium
join:2002-07-09
Lanett, AL
kudos:5
Oh yeah, I agree that a Smart-UPS is better than the Back-UPS model but if there's a comparable one in the required size, why not suggest that? I didn't tell if I was searching for an office PC or server where I might want a Smart-UPS and it isn't like the load was so high I was forced to step up to a Smart-UPS. That's mainly my rant, why suggest something that excessive when there are lesser cheaper models (that I thought I was searching) that will do the job just as well.