Need help choosing a UPS (plus general UPS tips)

[nstgc]

Firstly this is NOT for my external HDD enclosure, but for my computer. However the mentioning of a UPS in that thread did make me think of what it. I don't have an oscilloscope to check my power, but from experience, I do believe that the power in my house is pretty bad (lots of dead and/or whiny PSUs and other electronics). Instead of just getting a line conditioner I figured I may as well get a full UPS. Looking around it also seems as if it would be a good idea to get one that emulates a sine wave (as opposed to one that produces stepped waves). The only one that I could find in my price range that did this was the CyberPower CP1350PFCLCD. From what I've seen in reviews it does a nice job of emulating a sine-wave and unlike the APC SmartUPSs won't break the bank (those things run between $300 and $500). I don't need a UPS that will power my computer for longer than it takes to shut down the power. I want to make sure, however that if I'm in the middle of something that maxes out my system, it will not overload (or whatever) the UPS and that I will have a few minutes to shut everything off. Also it would be nice if I'm not by my computer to have time to go from whever I am to my compute and then turn it of (so add another 2 minutes).

Questions:

• Is there any need for an AVR since the one I choose seems to have one built in (in addition to a battery backup)?
• Can anyone suggest anything better?
• Does anyone know the voltage deviation for the CyberPower pure-sine UPSs? For APC's its something like +/- 3V from where they pulse the voltage at high frequencies then run it through a capacitor.
• HOw much harder are these emulated sine-waves on electronics?
• Anything else that could help me?

http://us.ncix.com/products/?sku=58081&vpn=CP1350PFCLCD&manufacture=CyberPower

[krumm]

The emulated sine-waves should not cause any problems.  The psu in the computer turns it into a flat line anyway.  I just know the basic ac-dc conversions but it goes through some diodes to make the sine-wave into a bouncy wave with capacitors to level it out.  The important part is that it is consistent which the UPS does.  Someone else might know more but, I think the important part is to get one with the power to handle the load your giving it, and last a satisfactory amount of time.

I like APC but, its just brand loyalty I don't know if there is better I've just never had a problem with one.

[kitamesume]

some UPS manages emulated sine-waves through force smoothing stepped-sine or pulsed-DC, just like how PSUs manage a steady voltage output.

im using a powercom UPS, they were sold as refurbished for quite cheap so dad bought a few dozens of them, it's a stepped-sine and i'm not sure about their quality but it does it's job on backing up the power for a few minutes and it seems like it can hold about 400watts without making itself overheat.

Edit: oh and it's not made for compact-florescent bulbs, i blew a flourecent bulb after a few hours when tried to power them during a power-outage, tho i think its the stepped-sine that caused the bulb to blew it's circuitry.

[nstgc]

I've been reading that the steped sine waves can interfere with active PFC. Also, I don't want to put more strain on my components then I have to. While I'm [edit]not[/edit] worried about a steped wave damaging my computer, I am worried that it may damage my monitor, speakers, or external HDD enclosure (I'm not getting rid of the thing damn it!).

[datora]

.
I've used APC a lot over the last 25  years, probably 30 or maybe even 35 units, quite a number of different models.  They've never failed me.  Batteries do wear out and need replacement, so that's a normal maintenance cost to plan for.  More on that below: make sure what you buy has a user-replaceable battery.

I don't go for the crazy feature-rich models.  Just good basic.

Currently I have three of these:

 - APC BE750G 750 VA 450 Watts

and three of the similar model, but in 550 VoltAmp.  I would like to have something more like these:

 - APC BX1300G 1300 VA 780 Watts

However, that's getting pretty expensive for my budget, and really has more capacity and more features than I need.


I didn't buy mine at newegg; shipping charges for something this heavy can get pretty steep, so if you can find them locally it's usually cheaper after taxes & gas money.  I waited for mine to go on sale at local office supply stores, which usually happens about three or four times per year.  In August it will almost certainly happen again for the Fall/Back-to-School season, but probably at least once before then.  Picked up my 750 VA units for $59.99 each and my 550 VA units for $39.99 each at Staples; Office Depot and Best Buy were running very similar sales at approximately the same times.  SuperLucky for me: in a state without sales tax, even, so maybe four or five dollars in gas money for all of them.

The batteries in them can be replaced, which I really like about most APC products.  Others (CyberPower) often manufacture such that when the battery goes ... which it will about every 3-5 years if nothing else goes wrong ... the entire unit needs to be tossed.  Uhm, recycled.  Please recycle these: they are large chunks of toxic materials, much like car batteries.

In the past, I search out farm supply warehouses where they have large stocks of equipment for rural/remote ,,,well, farmsteads.  There are batteries available for various uses (trucks/tractors, electric fences, etc.) and you can often find replacements cheap, like $20 or $25.  In some cases you can even upgrade, so your 750 VA model might suddenly become an 850VA or 900 VA model if you can find a compatible battery.  It's been ten years since I last did that, so I don't know the possibilities and exact market value these days.


Anyway.  The 750 model will run a fairly robust computer + monitor for 3-5 minutes on full load.  Plenty of time to walk through the house and shut it down gracefully.  It's rare that a system is running balls-out at full load, so 10-12 or even 15 minutes is more likely.  Usually when I walk out of the room, I turn my monitors off, so even better.  "Fairly robust" in this case is an AMD Deneb x4 core 965 CPU @ 3.8 GHz, a 630 watt PSU, Zotac nvidea 460 GPU @ 850 MHz, a 750 WD Caviar Black system drive and 3x Samsung F4 Spinpoint 2 GB drives.  The main router for my home network also runs off this UPS: Linksys E-3000.  Two monitors, one an older HP 19" 3:4 LCD and a newer Dell 22" widescreen.  The HP 19" is on battery backup since it's the "main" screen with all the Windows control icons, task bar, etc.  The Dell is on surge protection only, so it goes out with the power while the battery allows me to view the HP monitor long enough shut down.

I use the 550 models on older, low power systems.  For example, I run an old Dell GX 260 w/ a 1.8 GHz CPU and 180 watt PSU as my torrenting box.  The monitor .. an ancient 17" ViewSonic CRT ... is off about 95% of the time, it's running an old 20 GB hard drive as it's system drive, and I have a USB external case w/ a 750 GB WD Caviar Black loaded with torrents.  That system ran nearly 20 minutes before I shut it down gracefully in the last blackout.  Meaning, I was outside the house, realized the power was out, walked to the room with this system and powered on the monitor to complete a shutdown nearly 20 min after power went out.  Notice the USB external drive also on this UPS, as is an 8-port ASUS green switch.

When I recharge my cell phone or my Droid, I also temporarily plug into the surge protection.  My speakers also are surge protection only.  No need to waste battery on those.


The 750 model has battery & surge protection for CAT 5e 10/100 data cable.  So, I run a gigabit ethernet  internally in my house w/ CAT6e cables, but that final direct connection between my router and my ISP gets necked down to 100 Mbit/sec ... which vastly exceeds my connection to the outside world, so no loss.  I'll get pretty excited when APC makes a filtered & protected gigabit pass-through on their equipment ... it'll make the routing of my wires a lot easier.

The 550 units don't handle ethernet, but they do handle phone lines ... and so one of them protects the phone line-in to my fax/printer and a different one protects the phone line-in to the landline in a different room.

Both these models ... and most APC models ... have a USB (PC) to ethernet (UPS) cable that allows your Windows system to shut itself down through power management settings.  In the past I've used this feature under linux, too.  There is no need to install/use any software with APC: Windows has it natively and linux has many freeware packages available that are well-tested and compatible.


One advantage of having so many units is that I move them between systems every few months and try to distribute the total load on them so it's as low as possible.  This extends their life expectancy; I usually get five years out of each unit and have gone longer.  Also, when one goes out, I have enough surplus capacity to shop around for a replacement for a few weeks or a month and some and buy at a decent price instead of getting gouged for an emergency must-replace-it-NOW situation.


I also have surge protectors plugged directly into my house current.  I run most other electronics off these, such as printers.  My APC units are plugged into these surge protectors so that they will survive if there is somehow a direct lightening strike.

Neweg doesn't have my model currently, although I bought them through newegg.  Waited for specials and grabbed them for $39.99 each, free shipping.  The ones I have are about identical to these in specification, but with some minor differences:

 - http://www.newegg.com/Product/Product.aspx?Item=N82E16842111080

Mine are metal case, black, have coax protection, phoneline protection, and ethernet cable protection.  They look more like this model, but with 12 foot cord & 8 outlets, and far more Joules of protection:

 - http://www.newegg.com/Product/Product.aspx?Item=N82E16812120528

When I shop for surge protectors, I look for about 4000 or better Joules protection and extremely fast clamping speeds, like 1-5 nanoseconds ... if they bother to list it.  These Tripp-lites with 3840 Joules were a nice compromise for the price; I'd be fairly happy with anything over 3200 Joules protection ... but, lower than that you could get leak-through if there's a direct lightening strike right on or nearby your building.

The line-conditioning capacitors and other components kind of have to be there if you're "wasting" money on a real surge protector.  Otherwise, you might as well just get a power strip with a circuit breaker and take your chances for $8 or $10.

[ EDIT: to fix a couple typos. ]
 

[nstgc]

Datora, you mention you have a 630W PSU, but you don't say anything else about it. From what I've read on Newegg reviews, some PSU have problems with the stepped sine wave used in other UPSs. Can you tell me more about your PSU, as well as your thoughts about this. UPSs that produce a nice smooth sine wave cost quite a bit from APC and so I'm concerned about the relatively low price of the CyberPower units' quality.

By the way, one of the reasons I chose the UPS listed in my opening post is that it seems to have a built in surge protector which presumably means I don't need another (although its only 1kJ). Also, I made sure that it would have replaceable batteries.

Here is one thread I read on the matter: http://www.tomshardware.com/forum/252532-28-purest-sine-wave-output

[edit] here's some more information:

http://www.techenclave.com/topic/431055-of-psu-ups-pfc-and-sine-wave/

[kitamesume]

if the PSU has a PFC it'll correct the input voltage by itself, its not much of a strain since they're designed to correct the input voltage for as long as they live.

PFC filters current-surges/fluctuations/voltage-spikes/etc. and they also even out the on/off surge induced by a PC, just think about it, turning on a 1,000watt PC should induce a flicker on the lights like when turning on a water pump, but it doesn't, right?

Edit: oh but active-PFC works kind of different, so it might be not so good with active-PFCs.

[datora]

.
[ ninja'd by kitamesume ... ]

I can't speak specifically to your other questions.  I'm just not that literate on the topic.  I described my experiences.  This whole thing about sine wave interference isn't something that's come up for me before.

The setup I generally described above I've been using for nearly 20 years, and it's never caused me a problem.  All my systems ran smoothly, including my stereo gear, which has always been in the semi-pro range since the mid-1980s.  Every electronic component I've lost has been when it wasn't protected, and my systems have been through dozens of power outages and hundreds of other minor burps & farts in the supply.

That said, I can't list my other PSUs (a couple are Dell branded, that I know), and I've used a fair number of CoolerMasters over the years.

This one (turns out its 620 watts) is in my home-build from last year:

 - Antec NEO ECO 620C 620W Continuous Power ATX12V v2.3 / EPS12V 80 PLUS Certified Active PFC


The APC units I described above work with this flawlessly.  Also, the APC units I described above have built-in surge suppression ... so, the other Tripp-Lite surge suppressors are certainly not necessary.  It's a case that I happen to have robust surge suppressors, and it does not hurt to run the APCs off of them.

What you should never do, though, is to plug a surge suppressor (or power strip) into your battery UPS.  The electronics of the power strip or suppressor can degrade the clean current you get out of the UPS ... as well as set you up to overload your UPS and vastly shorten its life expectancy.

[nstgc]

I think I need to contact Corsair (who makes my PSU) and ask them directly since I'm just getting conflicting information without any real explination. I understand that PFC consists of lots of filtering. It makes sense, from what I know about a modern PSU, that it wouldn't matter. At the same time people are saying that there is something about active PFC that causes problems, that many companies are strongly urging and sometimes even requiring sine-wave UPSs, and people saying that their old UPS doesn't work with their new PSU. One person in a thread I read had the same UPS that Datora recommended, but when he (or she) bought a new PSU with an active PFC the PSU turned off when fed the stepped wave. But then Datora (who posted before I could post this) says that the PSU being used with the BE750 has active PFC

...AHHH!!! What the fuck!?

Definitely need to contact Corsair or just stop giving a shit and buy something. I also probably should contact APC.

[edit] Also HP since I'm worried about my monitor which if I were to replace it, it would be with a LP2475 which would cost me quite a bit.

[halfelite]

For home use I run the cyberpower 1500AVR, I run 3 of them http://www.newegg.com/Product/Product.aspx?Item=N82E16842102048  been using one of them for more then 2 years before it became the green model, Also not sure if you run linux at all but you would need to make sure NUT has support for whatever model you go with if you do.  My only complaint about APC models is there batteries tend to not last as long for me. Not sure if its something with my setup or just how they are.

[Pentium100]

UPS output waveform:

• Square - only the cheapest devices have it, as it is the simplest to make. Can be used only with switching power supplies. Inductive loads (transformers, AC motors) will most likely burn, especially the motors, they don't even start spinning.
• Modified square/modified sine - this one's better, inductive loads still buzz like hell though, but at least they work somewhat.
• True sine - perfect, just like the waveform in the outlet. Also most expensive.

UPS output power:
Don't forget it's rated in VA and at a specific power factor (usually 0.7) so you will most likely get less power than is written in the specs. The UPS can supply its maximum apparent power or maximum real power, whichever your load reaches first (load with low power factor will max out the apparent power, a bunch of incandescent light bulbs will max out the real power).

UPS run time:
It depends on the power to the load, converter efficiency and battery capacity. Usually more powerful UPSs have bigger batteries and will power a fixed load longer, but be very careful about that. Some UPSs allow you to connect external battery packs or you can just connect bigger batteries to any UPS, though then they won't fit inside the unit and there may be problems with charging.

UPS batteries:
Try to choose a UPS that uses few big batteries instead of lots of small batteries, because lots of small batteries cost more for the same amount of energy.

UPS topology:

• Off-line - power from the mains is filtered and connected to a battery charger and the load. When outside power fails, inverter discharges the battery and provides the power. Cheapest, but has no voltage regulation in "pass" mode and longest power interruption (time between external power failure and inverter starting up). Have a good PC power supply if you plan to use this type of UPS.
• Line-Interactive - power from mains is filtered, inverter is run "in reverse" to charge the batteries. Usually the transformer has one additional winding that can be connected in series with the primary to step up or down the voltage by about 10% (the AVR function). More expensive but provides some voltage regulation and can sometimes safely step the voltage up or down without the need to switch to battery power. Also the interruption time is shorter.
• On-line (double conversion) UPS - similar to off-line, but here the charger and inverter runs all the time, the power is provided from the battery and the battery is constantly charged as long as there is external power. Expensive, but provides "perfect" protection against line noise, under/over voltage, distortion. Less efficient than other topologies when there is external power due to the double conversion.
  
• On-line (delta conversion) UPS - a modification to the double conversion UPS. Here the external voltage is converted to intermediate voltage (usually higher) then an inverter converts that to the required output voltage. Battery is charged separately and in case of external power failure, a DC-DC converter converts battery voltage to that intermediate voltage. Intermediate stage has big capacitors to make up for the time that the DC-DC converter needs to start up. Most expensive, but more efficient in "pass" mode. However, it is less efficient when running on the battery, because the voltage gets converted twice, so the run time is lower.

Batteries:
Buy good batteries, the cheap ones do not last very long so they become more expensive in the long run. Especially if the room is hot in the summer. Also, buy a UPS that can use generic batteries (has no special chips or whatever to prevent you from using generic batteries), because the UPS manufacturers really inflate the price and you will get the same batteries, just branded differently.

PC PSU PFC:
If PFC gives you trouble, it is quite easy to bypass it as it usually is a separate circuit. PFC does not provide anything for the home user, just reduces the efficiency of the power supply. The majority of home users do not pay for reactive power (factories pay for it and they need to correct the power factor).


My advice is to look for a used UPS, there isn't a lot that can go wrong in a UPS (other than the batteries, but they are consumables), but it will be better for the same price (though it may not look as good as a new one. I mostly use two UPSs (both line-interactive) - APC SmartUPS 2200, made in 1998 and APC SmartUPS 700, made in 2002. Both work great and can communicate with a computer using a serial cable (with special pin assignment), but I bought special add-in cards that provide access using SNMP and HTTP protocols.

[nstgc]

I think I'll do that (buy a used UPS from APC).

[Proin Drakenzol]

I've found APC to be incredibly reliable. Even those that were exposed to weather while underway only ever had the battery go bad (which is normal, as was mentioned) and that was after it was there for... well, longer than anyone had been on board so at least 4 years.

[Pentium100]

Also, UPS batteries that can no loner work in a UPS can be most of the time used for lighting or something like that. Also, if a UPS has multiple batteries, then only one of them can be bad (but you still have to replace all of them, mixing old and new batteries is a bad idea), others can be used in an extended outage to power a laptop or something like that.

When the batteries in one of my UPSs become bad, I replace them and then test them individually, those that are truly bad (no current at all) get sold for recycling, batteries with a shorted cell (10V instead of 12) can still be used for lights, but will become bad soon (as I do not have a 10V charger) and those with increased internal resistance (voltage drops a lot when under load) can still be used for small loads or loads that do not need precise voltage (lights, audio etc).

[AnimeJanai]

If you have a Sam's Club in your area, just go buy the APC UPS there.   The 1250 VA load rating models are the biggest ones and they are $159 USD or so.  That may seem pricey until you find out how much higher they are at other stores.  The bigger units feature automatic voltage correction (up to a point) without causing the battery to be used.  In such a case, the input voltage can drop below 112 VAC and the unit will simply draw more power from the wall outlet and use that to raise the output voltage back up to a more normal level. 

In a separate thread, I mentioned what happened when I connected a high-end APC surge/noise suppressor strip to the output of the UPS.  The suppressor strip vibrated like crazy because the inductors were vibrating like crazy from the simulated sine wave output.   While the APC unit puts out a good simulation, it is by no means the same as a pure sine wave.  And of course, you expect all the best highest end surge suppressor units to try to detect and filter out the sharp edges of the square waves as "noise".   So, if you need multiple outlets a distance away from the UPS, use an outlet strip that is not a surge suppressor. 

Because APC keeps on improving their UPS models, I usually just buy a new one instead of getting replacement batteries.  UPS batteries last 3 to 5 year from my experience so far.  The oldest APC units seemed to overcharge the cells, so I suspect that was the real culprit in the units with short battery lifespan (older APC UPS).   The newer units also have LCD displays on them and also allow use as a standalone power supply when power goes out.  The LCD display is useful since it can display things like how many watts all your devices are using (doesn't have to be on battery power).  Of course, APC could take that wattmeter feature away with newer units; I haven't bought one for 3 years now since the batteries in them all seem to be going strong yet.  APC has since changed their big units into tall thin plastic cases rather than the long horizontal brick metal or plastic cases my big units have.   My oldest APC big units have dual massive batteries and my plastic brick ones have smaller batteries but the same advertised run time.  The latest tall thin ones have smaller batteries yet.  So either they are going the "Cyberpower" route and inflating claims in order to obtain a better profit/cost ratio on their products, or....  When Cyberpower (chinese company) first came out with UPS units, they received terrible reviews in the situations where the review included an evaluation of the insides of the units.  Advertisements and "paid" reviews had great positive claims of course.  After that, I had great problems accepting Cyberpower as being any more legit than those tiny 3 inch by 7 inch plastic box speakers claiming to have 480 watt peak power that were also made in china. 

[Pentium100]

While the APC unit puts out a good simulation, it is by no means the same as a pure sine wave.

Actually, the big APC Smart-UPS devices create quite good sine wave. AC motors work perfectly (without any buzzing) and an UPS plugged into the output of another UPS works normally. If you plug a UPS into the output of a cheap UPS, then both units will go on battery at the same time, because the UPS will detect the square wave as "unacceptabele". However, I have not used an oscilloscope to see how the waveform looks like or measured the THD, so I cannot say for certain, but for all connected devices it is as good as the mains.

Of course, APC could take that wattmeter feature away with newer units; I haven't bought one for 3 years now since the batteries in them all seem to be going strong yet.

No need to replace the whole UPS when the battery dies - just replace the battery, the majority of UPSs use standard lead-acid batteries and quite a few manufacturers make them. No need to buy from APC or other UPS manufacturer.

My oldest APC big units have dual massive batteries and my plastic brick ones have smaller batteries but the same advertised run time.

My biggest UPS (2200VA) has four 12V/18Ah batteries.  Maybe the newer models are more efficient. Or maybe they are over-discharging the batteries and damaging them.

[nstgc]

When the batteries in one of my UPSs become bad, I replace them and then test them individually, those that are truly bad (no current at all) get sold for recycling, batteries with a shorted cell (10V instead of 12) can still be used for lights, but will become bad soon (as I do not have a 10V charger) and those with increased internal resistance (voltage drops a lot when under load) can still be used for small loads or loads that do not need precise voltage (lights, audio etc).

There are places that buy old UPS batteries...nice. Any good ones online, because I'm not sure any one locally would do that.

@ Janai: I didn't want to take any chances so I baught a SUA1500 which produces a "pure" sine wave (PWM + capacitor). Its pricy and I don't have whatever bad ass job you seem to have so I'm buying batteries.

While the APC unit puts out a good simulation, it is by no means the same as a pure sine wave.

Actually, the big APC Smart-UPS devices create quite good sine wave. AC motors work perfectly (without any buzzing) and an UPS plugged into the output of another UPS works normally. If you plug a UPS into the output of a cheap UPS, then both units will go on battery at the same time, because the UPS will detect the square wave as "unacceptabele". However, I have not used an oscilloscope to see how the waveform looks like or measured the THD, so I cannot say for certain, but for all connected devices it is as good as the mains.

I still see no reason for me to plug a surge suppressor into the out put of a UPS. Shouldn't it be fine if I have it on the input (which is how its currently set up)?

[Pentium100]

There are places that buy old UPS batteries...nice. Any good ones online, because I'm not sure any one locally would do that.

Shipping a heavy battery will cost more than you will get for the lead. Like with paper, those places don't pay a lot, but still, it's better than just give it away for free.

I still see no reason for me to plug a surge suppressor into the out put of a UPS. Shouldn't it be fine if I have it on the input (which is how its currently set up)?

I agree, it is pointless to plug a surge suppressor into the output of a UPS. Well, unless it is the only unused "extension cord" you have, then you could save some money by using it as it will not be worse than using a regular extension cord.

[AnimeJanai]

I still see no reason for me to plug a surge suppressor into the out put of a UPS. Shouldn't it be fine if I have it on the input (which is how its currently set up)?

Reread carefully.  That is not what was said by either datora or myself.

Do not do that.  As datora said, and I also said (after having a bad experience), it is bad.  There is no problem to put the surge suppressor in front of the UPS (between the UPS and the wall socket).  But you should NOT put the surge suppressor on the battery-powered outputs of the UPS.

[nstgc]

Right. THe UPS is plugged into the SP which is plugged into the wall.

[edit]

I just saw this:

Plugging your UPS into a surge protector: In order for your UPS to get the best power available, you should plug your UPS directly into the wall receptacle. Plugging your UPS into a surge protector may cause the UPS to go to battery often when it normally should remain online. This is because other, more powerful equipment may draw necessary voltage away from the UPS which it requires to remain online.