UPS: Uninterruptible Power Supply Guide
As none of the major forums have a comprehensive Uninterruptible Power Supply (UPS) Guide, we here at EOCF shall again lead the way, as we did in 2004 with our "Power Supply Guide for Today's & Tomorrow's Computers".
Input from all of the many knowledgeable EOCF members will be required in order to make "our" UPS Guide the definitive Uninterruptible Power Supply Guide, just as we have made our Power Supply Guide for "Today's & Tomorrow's Computers" the definitive PSU Guide.
Start Date: 4-10-09 & of course this shall never be completed, Dave. Updated 4-25-09.
(1) Calculate your wattage, using the Outer Vision eXtreme PSU Calculator . Just use the wattage given, everything offsets very nicely.
(2) Select UPS Type, either "Simulated Sine Wave" for controlled shutdown only or
"True Sine Wave" for long term operation under battery power.
"Simulated Sine Wave" with AVR for Controlled Shutdown Only:
Similar UPS's are available from several Name Brand sources linked below.
Buying Refurbished UPS's with New Battery & Warranty Can Save You 50% to 70%!
This UPS Guide will focus solely on Uninterruptible Power Supplies designed & priced for the PC & Workstation markets. We will not get in to the extreme requirements of mission-critical Electronic Draft Capture (EDC) transaction processing centers, NASA or the DOD. Will will use KISS, Keep It Simple Silly, & concentrate on what 95%+ of EOCF members & guest might like to use in their home, Home/Office & Small Business systems, with emphasis on OC'ing & gaming systems.
What is an Uninterruptible Power Supply? An UPS is a battery back-up power system that is placed between the wall outlet & your computer system & provides power for your system when power from the wall is unavailable or unusable.
Why do I/we need/want a UPS: There are several reasons that once you understand UPS's, you will never want to be without one ever again. These include:
Power Outages: When the power goes out, without a UPS your system crashes, period! This frags the OS/apps & games. You lose data & often results in BDOS upon reboot. Of course in addition to having to reinstall everything, you may need a new HDD or more to install it on! A surge protector will not help.
Brown Outs: Brown outs occur when the incoming AC voltage drops 15% or more, this causes your PSU to pull more amperage to make up for the lack of voltage, thereby creating overheating for the PSU & unstable voltages for your system. This will lead to poor performance, system crashes & early failure. A surge protector will not help.
Over Voltage: The opposite of brown outs, where the incoming voltage is too high causing similar problems for your system. A surge protector will not help.
Dirty Voltage: The incoming AC voltage is unstable, contains sever transient spikes & is not presenting a proper sign wave. This is a primary cause of ELF (Early Life Failure) or if less sever kill more slowly over time. Also there is no way to get stable, high OC'es with dirty voltage. A surge protector will not help.
Surge Protection: A good UPS will sacrifice itself to save your system in case of lightening or surges from other sources. With lightening there are no guarantees, but you are far better off with a UPS, than without one! A surge protector will help.
System Life, System Stability & OC'ing: With voltage going up, down, on, off, having large transient spikes & all manner of other noise, how do you expect your system to "Live Long & Prosper"? The highest "Bench Shot" OC'es are obtained using UPS's! The highest "24/7" OC'es are obtained using UPS's! A surge protector will not help. Systems using UPS's are proven "on average" to last longer & perform better! You want a UPS! But which one?
Automatic Voltage Regulation (AVR): When the AC input voltage is too low or too high, AVR steps in and raises or lowers the voltage accordingly, to get it back in spec & it does this without using the back-up battery.
Cheap UPS's lacking AVR must go to battery every time the AC input voltage is too high or too low. This constant, but usually minor draining, greatly lowers the battery run-time should the power fail & will also shorten the life of your battery, requiring more frequent battery replacements.
Not all AVR's are created equal! Some units allow the VAC output to go as low as 75VAC & this is just too low for safe & efficient long-term operation of a ATX/EPS PSU! Better PSU's will run forever on 100VAC & for quite awhile on 89VAC, but going below about 87VAC for long-term operation is just asking for trouble.
For our purposes we want AVR, so we will automatically reject all of the extreme lowend UPS's that do not have AVR or have poorly or loosely regulated AVR.
So, AVR is now a Requirement for Recommendation!
Types of UPS by Wave Output:
Sticking with our KISS principle & making this a buyers guide, not a tech discussion or debate, let's look at what is important to our target users.
Stepped Wave AKA Modified/Simulated Sine Wave AKA PWM Sine Wave: Starting out as a true "Square Wave", which is by definition "pulsed DC" & will not work with AC appliances & would damage most AC appliances including your computer's PSU, the wave form is modified to become a "dirty" AC wave form. This dirty AC "stepped wave" or a "modified sine wave" is NOT intended for long term operation of any AC devices, other than perhaps light bulbs, but is intended to provide sufficient power to allow for an orderly, controlled & thus non-damaging, non-data losing shut-down.
Running a stepped wave/modified sine wave for a long period of time will damage the Active PFC circuitry of your PSU & cause your PSU to overheat, shortening the life of your PSU & possibly harming the system itself.
So, stepped wave/modified sine wave is acceptable for short term use, to allow enough time for a controlled shutdown.
True or Pure Sine Wave Output: Now we are heading in to the higher end of the UPS spectrum. These UPS's output a perfect or near perfect sine wave just like the generators at a hydro-electric plant & can run your system FOREVER, without damaging anything.
If you live in an area with frequent &/or prolonged power outages, then you also need the ability to add extra external batteries to increase your run-time.
If you need the ability to run on battery for more than just a few minutes, then you MUST use a True/Pure Sine Wave UPS.
Wattage & V/A: For consumer units powering modern computers who's PSU have Active PFC we do not even consider V/A (Volt/Amps). Now if you were powering 100+ systems in a business park, things would be different.
We are only concerned with WATTAGE! The wattage rating of your UPS must equal or exceed the actual wattage used by your system, including, monitor(s), modems, routers & everything that you intend to run on battery power during a power outage.
Although APC & others provide UPS Calculators, none are as up to date & as useful as the Outer Vision eXtreme PSU Calculator, use it to determine the minimum UPS wattage rating required to power your system. The results are conservative, reaching an excellent balance, go with its results as a minimum starting point. Higher wattage UPS's provide longer run time, however so do attaching external battery packs, which is often the more cost effective route.
If you have an inexpensive, portable generator, do NOT plan on running your UPS or computer off of it, unless it specifies True/Pure Sine Wave output. Using a cheap generator will quickly kill both your UPS & your computer!
Types & Topologies: This is a highly technical discussion & we will address these issues later, for now we are primarily looking at "Line Interactive Stand By UPS's" and "Dual Conversion On-Line UPS's".
"Line Interactive Stand By UPS's" are on constant standby, always ready to use their AVR to lower high voltage or boost low voltage & take over completely in the event of a power outage. Their "switching time" is so fast, that no system powered by a good PSU will ever notice any interruption. They also provide some power conditioning and noise suppression, in addition to keeping the system on regardless of the VAC input or lack there of.
"Dual Conversion On-Line UPS's" are always on & convert the incoming VAC to DC, charge the batteries, then convert the DC back to VAC, thus they always provide complete power conditioning, absolute voltage regulation, total noise suppression & "0" "switching time" in the event of a power outage. Although designed for "mission critical" operations, especially in "N+1" configurations, they are also the ONLY choice in locations with truly "dirty" VAC. PM me if you think you need a Dual Conversion UPS.
Please see "Additional Information & Resources" for additional discussions & information.
Brands: Listed below in alphabetical order are the most common consumer brands available in North America. APC UPS's are by far the most common & are used as examples in this UPS Guide because, (1) I am personally familiar with APC UPS's having used several hundred over the past 15 or so years, (2) they are very reliable in that out of several hundred only a dozen or so were DOA or suffered Early Life Failure (ELF), (3) their extensive lines include all classes from cheap non-AVR (not recommended) units to $100K+ major data center "mission critical" power management systems.
Tripp Lite UPS's are very difficult to "Recommend" as the quality varies greatly even within their higher-end lines, so no "series" other than their "top of the line, All SmartOnline" series can be recommended & the specific models that are recommended are based on the publishes specs & general reputation, not on personal experience or professional test/reviews. If you want to "play it safe" stick to the "Recommended" APC & Leviton UPS's. I will personally "vouch" for these APC's & Leviton's.
There are many private & "In house" brands & we will probably never know their levels of quality, so none can be recommended.
As is the case with almost all PSU's, most UPS's are subcontracted to Asian, primarily Chinese companies for manufacture. This does not make them "re-branded" anythings, as products are built to the specs & standards of the contracting companies.
Reviews: I have yet to find any websites doing professional UPS reviews, this is exactly the same situation we faced back in 2004, when I started the PSU Guide & hopefully this will soon change! Please post any sites you find doing UPS test & reviews.
برای مشاهده این لینک/عکس می بایست عضو شوید !برای عضویت اینجا کلیک کنید ]
Battery Selection & Replacement: Obviously replacement batteries are usually available from the name brand vendors listed above, however you can often save 50% & get a better battery else where.
Sources:
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APC's extensive website has virtually everything anyone would want to learn about UPS's, their technology & uses. It makes for both excellent research & interesting reading. If you sign-up for their various publications, you also get truly scholarly white papers as well.
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Additional Information & Resources:
برای مشاهده این لینک/عکس می بایست عضو شوید !برای عضویت اینجا کلیک کنید ]
This very informative site was linked & I believe created by "toneus", a brand new EOCF member, who was kind enough to link it in his very first post! See post # 6 for details.
Dave
Last Update: 4-25-09
Last edited by davidhammock200 : 04-26-09 at 13:58.
