Talk:Uninterruptible power supply

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[edit] Surge

Should there be a paragraph about power surges (eg lightning)? None of the 9 levels/types of protection refers to surges. I came here to know more about this, and the topic no even being mentioned in the page is a bit strange. I'll look somewhere else (I have read "Storms and lightnings" here, which is useful), but I just thought a word about power surges would be an improvement.

[edit] UPS for large IT Industry

Sourav: i need to know about the UPS System for large IT industry including the make and model no. Re: "Hey, I think someone..." I agree. This is right from a Powerware brochure. This description needs to be more generic (and accurate). Will look to modify.

Hey, I think someone needs to look into why this reads like a Powerware ad. I'm in IT, and the only place I've heard "the nine power problems" is in their glossy brochures.

Can anyone tell me out there how many generations of UPS there are, and what's their difference? I just came across a GE UPS catalog claiming that GE UPS is second-generation UPS.

I agree. Honestly, it reads like a UPS vendor fear-mongering by stating as many reasons as they could think of in order to sell product. I thought "noise" was a term that meant any undesirable signal, so spikes, switching transients and harmonic distortion to me are all cases of noise. I also don't see any substantial difference between "sag" and "undervoltage." If the only difference is in duration, it would be a lot more helpful to give some sort of benchmark as to how short an undervoltage needs to be to be called a "sag" rather than a "brownout." (They're both brownouts to me.) 129.44.253.96 22:14, 14 October 2006 (UTC)

Next generation or 2nd generation typically just means their latest product. ie, the company's 2nd generation IGBT inverter indicates they have redesign this part of the product. It usually means the methodology is the same but design has been updated. This is more of a sales term than related to the UPS. Djlammi 19:40, 29 August 2007 (UTC)

[edit] Source

I don't believe it is necessary to source that many third world countries suffer a lot of power cuts as that kind of info has been endlessly produced in newspapers, books, etc, e.g. the Honduran newspapers are full of stories of power cuts and the problems of the local electric industry. That this makes UPSes much more popular and commonplace here can be sourced I am sure. It may take time to find a source but should be kept in in the meantime as it is pretty obviously true that when there are lots of power cuts people use UPSes to protect their computers, and they are frequently seen in Central America, part of the Third World. Large generators are also much more common here for the same reason but sourcing statements of fact may not always be straightforward. SqueakBox 14:55, 8 December 2005 (UTC)

Actually it turned out to be VERY simple. The Voltage Stabilisers paragraph here is an excellent source, SqueakBox 14:58, 8 December 2005 (UTC)

yeah i can see their extra utility in a country with crappy power but i also recall them being quite expensive devices, is more popular "per computer" or "per capita" or what? Plugwash 15:10, 8 December 2005 (UTC)

I am about to find out how much they cost here in Honduras as I need to buy one for my computer (having lost a reasonably expensive monitor yesterday as a result of the power cuts, and being drawn to this article to research before going to the shop). Computers are generally the same price here as in the UK (which will mean a little more than in the US) so obviously there are far less computers here though there is a solid minority of people with money in any Third World country, businesses use them a lot and internet cafes are everywhere. So a far higher number of UPSes per computer without a doubt and feasibly per person because they are so much more necessary. Obviously I don't have any figures but I imagine that as with generators there are more of these things per person here than in the First World per person, SqueakBox 15:24, 8 December 2005 (UTC)

I've reworded the statement to avoid the vague word popular. Plugwash 22:53, 8 December 2005 (UTC)damn it didn't contain the word popular it all i was sure it did. Plugwash 22:54, 8 December 2005 (UTC)

[edit] Here's a more honest attempt at categorizing power problems.

If anyone is interested in editing the power problem categories in this UPS entry you are welcome to use the following white paper. The paper bases the categories on IEEE definitions.

http://www.apcmedia.com/salestools/VAVR-5WKLPK_R0_EN.pdf

This white paper may be related to IEEE definitions, but the descriptions of frequency problems are biased. The paper is written by APC, the only manufacturer that has a wide range off UPS NOT capable of correcting frequency variations. The statement "To correct this problem, all generated power sources and other power sources causing the frequency variation should be assessed, then repaired, corrected, or replaced. " is strange: you could apply this statement to all 7 problems and remove the need for a UPS. (Other than that: a good source of information)


[edit] Need your comments...

Tell something about your experience in trouble-shooting 3-Phase UPS. How did you handle it? What is the process?


Generally It is better not get involved in this area without product training, and unless you have drawings and spare PCBs there isn't too much you can do. Remember that some UPS can have live power inside for long periods of time after shutdown.

That said...

Most modern UPS have a large amount of fault codes and even older UPS usually have flashing/lit LEDs to indicate the state of various sections of the unit. They aren't really designed trace faults on PCBs in the field. Most companies have computerised jigs that check the pcbs. The service staff replace the board, it is all about UPS downtime. 5mins to change a PCB is much better than 5 hours repairing it.

Always start with the basics. eg.

If it won't turn on:

is the mains there > Within voltage and frequency limits and is the phase rotation correct.

The display is usually fed by the DC so if that isn't on you have a front end problem.

Power supplies/Rectifier.

A lot depends of the design of the unit and what the fault is.

The main problems are usually Batteries and fans.

Djlammi 02:21, 27 August 2007 (UTC)

[edit] Storms and lightnings

Can UPS prevent the damage caused by nearby lightning hit during the storm (or similar accidents)? This should be answered in the article.--Piotr Konieczny aka Prokonsul Piotrus Talk 21:23, 13 April 2006 (UTC)

A UPS will, to a certain degree, fix the voltage between phases and between phase and neutral. In the case of double-conversion UPS, this voltage will be 100% safe. Due to this, a nearby lighting will NOT affect the voltage coming into the protected equipment. However, most UPS have a through-going neutral. This means the neutral coming in is the same as the neutral coming out. The voltage between that neutral and the phase is 100% safe, but the voltage between neutral and ground cannot be changed by the UPS. Hence: if a lighting hits either neutral or ground, a big voltage may occur between neutral/phase and ground, which could damage equipment. To protect load against this disturbance, an additional isolation transformer would be required. Such a transformer isolates the equipment from the mains and creates a new neutral(usually)connected to ground.

I'd add that Surge suppressors are a useful addition to the Front end of the UPS. This is mainly to protect the UPS itself and mostly done in remote locations.

I have seen them put on the output of a UPS. DON'T DO THIS. The site had an generator changover panel which brakes the earth-neutral connection and the suppressors burnt out. Djlammi 22:51, 26 August 2007 (UTC)

[edit] What devices are supported?

Can I use UPSs for TVs, Microwaves...etc? Or is it strictly just for computer systems?

The answer is, "that depends." I personally chewed up a couple of inverters in UPSes by connecting non-computer loads. In particular, the ones that were the standby type and produced stepped sine wave (instead of pure sine wave) are not engineered to operate anything but computer equipment (or, stuff with switching power supplies). If I'm not mistaken, it has to do with something like impedance mismatch, where certain frequencies will be "absorbed" well, and certain others will be reflected. For example, computer power supplies have significant production of third harmonic frequencies (180Hz). The VCRs I had connected (with transformers in their power supplies) used to buzz noticeably when on inverter power. (I hated to have to program all my favorite weekly shows into them, so I was hoping to preserve their memories on power loss.)

I suspect, however, that the online UPS I purchased this year, which supposedly has a pure sine wave output, could handle non-computer loads.

Being able to operate certain appliances on a UPS sometimes boils down to a capacity problem. For example, many user manuals caution against connecting laser printers to their product. This is because they are high load devices (mine spikes at about 7-8 amps when it is starting up, and levels out at about an amp operating). In particular, lots of devices need "crazy" amounts of current to become operational, but don't take quite so much while operating (electric motors such as air conditioner compressors, and laser printers, are good examples). The microwave oven you mention is like this too, although many devices like that take a lot of current while operating too. Joe 03:21, 15 October 2006 (UTC)

[edit] POV, Reason for UPS

Good article. I have a couple comments.

Article says: In North America in particular, the electrical grid is under increasing strain particularly during heavy demand periods such as summer when air conditioning use is at its highest. In order to prevent blackouts, electrical utilities will, from time to time, use a process called load shedding. This reduces the amount of power being sent to the consumers but sometimes it does eliminate it entirely for an hour or so. This drop in voltage is also sometimes called a voltage sag or a brownout. A UPS will protect equipment from a brownout by correcting the drop in voltage. The single biggest event that brought attention to the need for UPS power backup units was the 2003 North America blackout in the north-eastern US and eastern Canada.

1. The article implies that the primary reason for a UPS is blackouts or brownouts caused by high energy demand, then cites the 2003-Aug-14 blackout as an example. Wording on the blackout should be modified as it may have caused people to think about UPS but it was caused by a failure to trim trees, not by capacity issues.

[1]

2. Wording on the reasons for the UPS also need modification. The UPS is to keep your equipment running during brief interruptions where the equipment would otherwise shut down. For example, if your power goes off for .6 seconds or so, your computer will halt and need to reboot, as will your networking equipment. Your blender, toaster, conveyor belt or welder will not care, generally.

A UPS is not intended to keep equipment operating any longer than it takes to shut it down, for power to be restored, or for a generator to come on line. A generator on the other hand is intended to restore equipment to sustained operation. To get your microwave running again, get a generator. To keep your computer running until the generator starts up, get a UPS.

3. There is a POV problem with the statement "In North America in particular, the electrical grid is under increasing strain". North America clearly has the greatest electricity supply capacity anywhere. The problems with this statement are:

   a. It is not demonstrated that the demand exceeds supply in North America to a greater extent than in other locales
   b. More important to the POV issue, there is a suggestion that the demand in North America is higher that what it <should> be, which is a value judgment and not neutral.

4. UPS commonly use valve regulated lead acid (VRLA) or flooded cell batteries. VRLA are often called "sealed" but this is imprecise. Flooded cells are not mentioned but they are common especially with older or larger units.

Thanks. -- KDTravis

The big blackout may have been directly caused by trees on the line but a cascading blackout is really a symptom of inadequate redundacy PERIOD. Plugwash 14:23, 5 August 2006 (UTC)
Be that as it may (or may not) be, that belongs on the article on that subject, or kindred subjects, not here. The most that would probably be useful would be describing their usefulness during blackouts of any cause or fault. 68.39.174.238 00:03, 22 August 2007 (UTC)
Re: Point 2, this may be true for some uses but is not an absolute. The fact you can buy upses that can have many additional battery modules added indicates that this doesn't hold true in all cases, especially where it is not practical to install a generator. In this type of setup you can have runtimes of many hours, far beyond any "brief" interruption. --Sully 17:22, 5 August 2006 (UTC)

also re point 2: Small UPS are only designed for desks and short time limits, 5mins or so.

Larger UPS, 10kVA and up, generally cant have a shorter run than about 5mins because of battery characteristics. When the battery is under high discharge it is more prone to failure and the cell voltage will drop below that required to run the inverter.

Most battery sizing is between 10-30mins, some hospitals and banks have 2hour cascade (2x 2hrs) plus a generator.Djlammi 20:17, 29 August 2007 (UTC)

[edit] Interaction UPS/computer

In the case of computer protection, how about mentioning:

- that UPS can communicate with a program on the computers they protect (master/slaves roles), in order to maintain a journal, logs, trigger program execution (like email, immediate/clean shutdown,...) ;

- that SNMP-compatible UPS units can be remotely controlled over the network.

--Olivier Debre 09:10, 8 September 2006 (UTC)

UPS can include as options/standard

Voltage-free contacts: mains fault/battery voltage low/ some kind of common alarm or inverter fault. Usually 3-4 standard. Some have mains fail after ten second for AS400. Most offer almost any alarms as an option

Monitoring software: Alarm & status monitoring/shutdown of servers/SMS or paging/history event logs.

Remote panels: remote display or alarm panel with power supplied by UPS connection (so it works in a power cut) some with internal battery.

ambient temp measurement. Battery temp compensation.

modems for service dial in/out for remote locations.

Scala & JBUS - not really sure what this is, some kind of BMS?

One thing I think is very good is fan failure options, but no-one seems to order this as they think it's included.

DC ground fault detection (for leaking batts)

A generator mode - Old UPS used to not charge the batts on generator. With sealed batts this isn't such a problem.(lower charging amps) -A bypass disabled mode is avalible on most units. The frequency of a bad/overloaded generator can throw out some (mainly parallel) UPS.Djlammi 20:54, 29 August 2007 (UTC)

[edit] UPS in the Photograph

I'd love to know where it came from. It looks like it hadn't been touched in years and was dragged out of someone's attic just for the photo. --angrykeyboarder (a/k/a:Scott) 11:25, 7 November 2006 (UTC)

[edit] Delta conversion

I'm sure there's supposed to be something in there, but I can't understand the "delta conversion" section. It's written in a language resembling English, but it's not quite. In other words, it could use some cleanup.

I've added an explanation based on my understanding of APCs literature on the subject. I haven't deleted the old material (of which the first paragraph seemed okay but the others looked like some weird marketing information for some sort of UPS) so someone else can do that. -- Paul Ingemi


Delta is is basically a form of offline UPS. Only afew companies make this type of unit, I've only come across one myself but have heard of others.

Online mean always on the Inverter. Offline means it is not always on the inverter. Djlammi 22:45, 26 August 2007 (UTC)

[edit] Portable Supply

Can a UPS be used to temporarily power appliances where no power supply is available? An example of what I mean would be powering a stereo outside in a street. Liamoliver 23:16, 18 July 2007 (UTC)

Techincally it could. However in practice UPS units are designed for short duration high power so using them for running a small appliances over longer durations would be a waste of money and weight. Plugwash

I have used an offline 500VA unit in this application, specifically to power a drill in a remote location. I would not recommend this use. Most UPS aren't designed to start on battery, or require a "coldstart kit". Some UPS can even be destroyed by connecting the battery without mains. There is also A risk of electric shock and possible damage to equipment as there is no earth-neutral connection. The run time is also short on this type UPS and prolonged discharge damages the battery. This requirement more suits a portable generator, although they are noisy.

Djlammi 23:09, 26 August 2007 (UTC)

[edit] Request for External Link Inclusion

To the Editors and Users of Wikipedia,

Recently I added an external link to the Uninterruptible Power Supply section that I believe was extremely useful and beneficial to the users of this site. The link had remained for several weeks and did indeed appear to be complimentary to the related material since I received numerous referrals from this site. I've also noticed a very high tendency of return visits from users without the Wikipedia referral which leads me to believe that users accepted the material and were most likely bookmarking the page on my site and returning from said bookmark. Also, I have been unable to find any reference material comparable to that provided through the link already in existence on this site which lends credibility to its uniqueness.

As the owner of the site, I must admit that I was unaware that it is considered inappropriate for owners to add links to their own site. I apologize for this. The external link was removed by an admin and the resulting discussion can be viewed here:


http://en.wikipedia.org/wiki/User_talk:Femto#Removal_of_External_Link_in_Uninterruptible_power_supply

Based on this editor's recommendations, I'd like to open a discussion and petition for re-inclusion of the following external link:

http://www.upstrader.com/ups-equipment-glossary.aspx

(originally appearing with the following text: "Glossary of Common UPS Equipment Terms")


If others feel, as I do, that the link in question is in fact beneficial and relevant to the users of this site, I'd like to ask that the link be allowed to remain in the external links section.

Thank you for your time, Ditirro 20:05, 23 May 2007 (UTC)

I'm sorry Ditirro but I'm going to have to disagree. I just don't see the value of linking to the upstrader.com glossary. How does that link improve Wikipedia? Besides, isn't Wikipedia just a glorified glossary? (Requestion 22:36, 23 May 2007 (UTC))
Thank you for your feedback Requestion,
I understand your point, however, I do not see any material that is comparable in any way to that which is offered on my site. That being said, along with the very large number of users that were accessing my site through that link enforces the valuable nature of the content.
I would also disagree with the "glorified glossary" point unless every single topic-related keyword or acronym linked to an article on Wikipedia describing the definition of that word or acronym... which they do not.
If, in a much more simplified example, there was an article on Wikipedia detailing the populations of all the countries of the world but the article only supplied the abbreviation for said countries, do you not think it would be beneficial to have some sort of linked reference giving the names for the abbreviations of the countries?
The only argument I could agree with against that point would be to include the glossary in the article itself or on a separate article solely dealing with countries and their abbreviations, but I believe that would qualify as plagiarism in this case.
To go one step further, you could easily argue that the other external links in that article (and mostly likely a vast majority of other articles) should be removed since they simply detail info which can be found elsewhere, or should be included in the article itself or a related article. If these articles are appropriate I see no reason why my glossary shouldn't be considered appropriate.
Ditirro 22:59, 23 May 2007 (UTC)
The number of wiki-hits you're getting is not a measure of link quality. Also, articles don't have glossaries, see WP:NOT#DICTIONARY. Try using the search box if you need to find something. As a general rule, I don't see the value of linking to any glossary since Wikipedia can cover that fully. In the future, if you're going to reply, it would be nice to ident with "::" for a threaded dialogue. (Requestion 23:26, 23 May 2007 (UTC))
I beg to differ that "the number of hits is not a measure of link quality". If the link clears states what it is and gives the user exactly what is promised, I believe there is no better measure of link quality. The terminology and vocabulary used in the industry can be very specific and confusing to inexperienced users. For example, can Wikipedia tell them what a "Pseudo Sine Wave" or a "Rod-Core Inductor" is? No, it cannot. The glossary can.
Ditirro 01:23, 24 May 2007 (UTC)
You can't use the number of wiki-hits you're getting as a measure of link quality because you have no idea how many clicks the other links are getting. Your logic is just totally wrong unless of course your motivation is to increase traffic to your website. This is starting to sound like a serious WP:COI issue to me. Sorry but your upstrader.com link is not appropriate here. (Requestion 20:28, 24 May 2007 (UTC))
Regardless of my level of interest in this matter, I still feel the content is relevant, helpful, and complimentary to the subject matter of this article. As stated here:
WP:COI
"Merely participating in or having professional expertise in a subject is not, by itself, a conflict of interest."
The fact remains that the link offered a resource to information that is completely 100% unbiased, neutral, and not available within the contents of this site. It is also in line with the definition of what should be linked as defined within this site:
WP:External_links
"Sites that contain neutral and accurate material that cannot be integrated into the Wikipedia article due to copyright issues, amount of detail (such as professional athlete statistics, movie or television credits, interview transcripts, or online textbooks) or other reasons."
I understand if you don't agree with me, however, I am sorry, but I do not feel your arguments are valid. If you care to respond with specific references which contradict my beliefs, I will be happy to listen further to your point of view. Don't get me wrong, I am willing to have my opinion swayed, but so far it hasn't been.
I don't mean for this to develop into an argument over ethics, intentions, or motivations, but in comparison to many of the other external links I've seen, I believe this was one of the more useful ones to the users of this site. Seeing it from a end-user's perspective might help, at least until all of the material that is referenced in the glossary becomes readily available as articles within the contents of this site.
Ditirro 21:00, 24 May 2007 (UTC)
Why are you arguing with me? You asked a question, I gave you my opinion, and I even explained my reasoning. I don't think the upstrader.com link should be added. In fact, if I ever see that upstrader.com link I'm going to delete it. (Requestion 21:45, 24 May 2007 (UTC))
I am sorry if you see this as arguing Requestion, I am merely trying to open a discussion and reach a consensus through polite negotiation.
WP:Consensus
"When there are disagreements, they are resolved through polite discussion and negotiation, in an attempt to develop a consensus."
You state an opinion, I offer a counterpoint while citing specific references obtained directly from this Web site. Its called debate and negotiation. However, you are only able to back up your opinions with more opinions... and threats. I encourage you to elaborate on your opinions, but this is clearly not what I would consider "polite discussion and negotiation". And please correct me if I'm wrong, but I really don't believe threats have any place in this forum. Regardless, you have already severly altered my perceptions and value of your opinions by posing these threats. WP:CIVIL
Ditirro 22:25, 24 May 2007 (UTC)
You're wrong. It wasn't a threat and I really don't care about your "perceptions and value of my opinions". It is my right duty as a Wikipedian to delete WP:SPAM when I see it. (Requestion 22:42, 24 May 2007 (UTC))
Please elaborate and explain to me exactly why the link in question should be considered spam. The only relevant point I could find was:
"Adding a link to the top of an unordered list."
I admit my fault in this respect and apologize for my limited experience with this site at the time of adding the link. I have come a long way since then and now realize the error of my ways.
Also, I have to disagree with you again. This sir, is most definitely a threat:
"In fact, if I ever see that upstrader.com link I'm going to delete it."
Ditirro 22:55, 24 May 2007 (UTC)

The user Ditirro on this site asked me to give my thoughts about the link he is talking about. I am familiar with it since that's the way I stumbled accross his site in the first place. I send the link to this page to uneducated customers many times to familarize then with detailed descriptions of the common UPS terms. I have even told them to specifically look for the upstrader link for help with definitions.

I would have to say that the link is very helpful to users. Dkranz 02:34, 25 May 2007 (UTC) — Dkranz (talk • contribs) has made few or no other edits outside this topic.

Nice input Femto. Thanks for that. Now, do you have anything constructive to add to this discussion? You've also forced me to ask the question: What are the chances that you happen to be masquerading as Mr. "Requestion"?
You obviously have an opinion in this matter since you are the individual who insisted on removing the link that I added. So, I would appreciate it greatly if you would engage in this conversation. You are afterall the one who instigated it.
Ditirro 15:38, 25 May 2007 (UTC)
Second time someone accuses me of being Requestion's sock... I've already made my position clear on my talk. Your link is not appropriate. Femto 16:23, 25 May 2007 (UTC)
That's interesting. Perhaps people are noticing patterns. Perhaps you and Mr. "Requestion" have some sort of relationship or affiliation. If you're not familiar, please see: WP:COI
Now, I'll ask you the same. Please enforce your opinion with credible references. Otherwise your opinion means as much as his/your's.
Thank you, Ditirro 16:29, 25 May 2007 (UTC)
FYI- Femto, I wouldn't admit to this in the future if I were you:
"Second time someone accuses me of being Requestion's sock"
You basically just destroyed your credibility.
Ditirro 16:35, 25 May 2007 (UTC)
Did someone just say "credibility?" I think it might be time to get the parrot. (Requestion 20:20, 25 May 2007 (UTC))
You know nothing of my credibility. Please defend your opinion. Ditirro 20:38, 25 May 2007 (UTC)


The link looks fine to me. Re-include it. Tangurena 17:19, 25 May 2007 (UTC)


Femto, do you believe we are approaching consensus (WP:Consensus) or do you feel the matter needs to be escalated and dispute resolution (WP:Dispute_resolution) is in order?

A few points that I feel are worth mentioning from the consensus article:

"Good editors acknowledge that positions opposed to their own may be reasonable. However, stubborn insistence on an eccentric position, with refusal to consider other viewpoints in good faith, is not justified under Wikipedia's consensus practice."
"Even if an editor's contributions appear to be biased, keep in mind that their edits may have been made in good faith, out of a genuine desire to improve the article. Editors must, in almost all situations, assume good faith and must always remain civil."

Ditirro 19:44, 25 May 2007 (UTC)

Contributions? You have got to be joking. I just checked Ditirro's contribution log and every single edit is to a talk page. Ditirro doesn't even qualify as an editor! I can't find the exact rule but I'm pretty sure that Wikipedia is not a chat line. (Requestion 20:29, 25 May 2007 (UTC))
Everybody has to start somewhere right? The number of contributions I have made has no bearing whatsoever in this matter. Now please contribute constructively to this discussion if you would like to defend your opinion instead of "name-calling".
Thank you, Ditirro 20:35, 25 May 2007 (UTC)
Your number of contributions so far is zero. It's kind of silly of me to have an opinion of your edits when you haven't made any yet. Name calling? I'm confused, what name did I call you? (Requestion 23:25, 25 May 2007 (UTC))

Femto and Requestion, removing all external links from the article does absolutely nothing to resolve this dispute. Please consider other points of view. This behavior is inappropriate and you are acting as a renegade editor. And yes, I have noticed that you have been accused of this before. In fact, I am noticing many patterns with you lately.

And if this is "your" solution, you would also need to remove all of the links listed under the Notes section. This is not the answer, and your behavior is becoming extremely questionable. I must ask- why do you feel your opinion is the only one worth consideration and that your answers are final and uncontestable? Ditirro 20:03, 25 May 2007 (UTC)


Seems that I'm not the only one to experience this little pattern: http://en.wikipedia.org/wiki/User_talk:Cronholm144#Jon_Harrop

"It is obvious looking at Requestion's user page that Femto is not neutral as he often leaps to Requestion's aid."

So, we're basically at a count of 3 - 1 from the opinions expressed so far. You two are clearly and most definitely not unbiased. I believe this qualifies as consensus.

Wikipedia is not your own personal playground guys (if you are indeed two different people). Its a big world out there, learn to share. Ditirro 21:01, 25 May 2007 (UTC)

Let me get this straight, you RUN that website, and accuse US of bias?! Yeah, apparently Requestion and I happen to have each others talkpage on our watchlist, and we frequent the same noticeboards. Obviously: we're socks whose opinions count nothing against yours.
Sure, if you want a few neutral people to look into your "dispute" here (that is, neutral, as in: both sides clearly can agree they're neither low-edit single-purpose socks nor spam-fighting fascists...), feel free to list at Wikipedia:Requests for comment. Femto 22:56, 25 May 2007 (UTC)
Femto, did you just call me a low-edit WP:SPA nor a spam-fighting fascist? I'm not sure which is worse. Should I be insulted? Or did I forget to negate the nor? (Requestion 23:25, 25 May 2007 (UTC))
Nah, I was just referring to those other editors. You can still be a low-edit single-purpose sock AND/or a spam-fighting fascist if you want. :P Femto 23:59, 25 May 2007 (UTC)
OK, the point of this discussion appears to be lost and its just turned into an argument over whose opinion is more important. I am not interested in that debate- its pointless.
I have compiled information which I believe is relevant and useful to the topic of this article and wished to make it available to a wider audience. It is simply supplimentary material too extensive to include in the article, but which contributes to the overall effectiveness of the article. This is one of the main reasons for external links.
Yes, you are correct- I haven't contributed an extensive amount of information to this site to date. I still feel this point is irrelevant; however, I can understand why others have been discouraged and turned away if these "discussions" is what entails "contributing". All I'm asking for is a reason to justify your opinion. I have provided more than enough. Two other neutral users have agreed. I'll list the RfC tomorrow. Ditirro 03:32, 30 May 2007 (UTC)
Your extensive contributions? You have yet to make a non-talk page edit. Please try to understand that Wikipedia does not want a link to your glossary. (Requestion 14:58, 30 May 2007 (UTC))
You are not the sole voice of Wikipedia. I'm attempting to do the RfC now. Ditirro 15:27, 30 May 2007 (UTC)
You seem to be very confrontational. Do you treat your upstrader.com customers like this? (Requestion 16:10, 30 May 2007 (UTC))
Interesting you would bring up such a question. No, I do not. Good luck fishing though! Ditirro 16:31, 30 May 2007 (UTC)
I wouldn't keep bringing up User:Jdh30 (Jon Harrop). He isn't someone you want to attempt to emulate. His promotional spam was deleted from Wikipedia, he received multiple warnings, he was almost blocked, his article was AfD'd by his peers, his website was blacklisted, his user page was CSD'd, and now he has "vanished." I wouldn't recommend any of those things. (Requestion 14:58, 30 May 2007 (UTC))
Fair enough, I just did a quick search and it took literally 2 seconds to find someone who had issues similar to what I seem to be experiencing. The comment looked credible and for the record- I brought it up once. I'm not choosing sides and don't plan on digging through the history to verify the facts- I don't have time for that. I can only take your word against their's. Ditirro 15:27, 30 May 2007 (UTC)
I don't care if you believe me. I'm just trying to give you some good advice. (Requestion 16:10, 30 May 2007 (UTC))
I've gathered that. In any event, thanks for the advice. How about advice concerning posting an RfC? I don't think I'm doing it right. Ditirro 16:31, 30 May 2007 (UTC)
I don't think the addition of an external link is a valid topic for an RfC. (Requestion 16:51, 30 May 2007 (UTC))
I think it is, but thanks again for your advice. Ditirro 16:54, 30 May 2007 (UTC)
Technically, any "dispute" deserves to be commented on by neutral parties, no matter how silly, so here: Wikipedia:Requests for comment/Maths, science, and technology#Technology and engineering. Hope it makes you happy. Femto 18:14, 30 May 2007 (UTC)
Thank you, I appreciate the assistance. Ditirro 18:24, 30 May 2007 (UTC)
The link lacks notability, its addition probably shows a Conflict of interest. I am not an expert on UPS, but in my humble opinion the external link doesn't add a lot to the article. Erik Warmelink 07:15, 31 May 2007 (UTC)
Notability is a criterion for article inclusion and nowhere do I see any indication that it must be met for the inclusion of an external link. Conflict of interest would be a pretty tough one to prove and according to Wikipedia guidelines "good faith" must be assumed. The link adds supplementary and detailed information which is not found within the article itself. If you read through the entire glossary you will find many UPS-industry-related terms and definitions found neither in the article nor the entire Wikipedia web site. Ditirro 14:40, 31 May 2007 (UTC)
I think what Erik Warmelink means is that, literally, the link is not "worthy of notice" in this article. Femto 14:42, 3 June 2007 (UTC)
Well, if this link is worthy of inclusion, thousands of links would be just as worthy, Wikipedia is not a mirror or a repository of links. My interest is having a readable encyclopedia (I guess I am not the only person with that interest), while the owners of those thousands sites have an interest to include a link to their site as long as not all links are included (because in that case the page wouldn't finish loading). Erik Warmelink 16:45, 3 June 2007 (UTC)
Wikipedia also is not a web directory. See WP:NOT#DIRECTORY. (Requestion 21:03, 3 June 2007 (UTC))

[edit] {icture

Can we find a photo of a UPS that's not filthy?


[edit] Double online conversion Overview

I'd like to do an overview of various parts of UPS systems but am not sure how technical I should be. I don't want to modify the main page as I'd like feedback. This is a semi response to the question about fault finding of three phase UPS systems.

The main experience I have is Double online conversion UPS systems from 3kVA to 650kVA single module and afew MVA in parallel configuation. All units are static based. I work with various manufactures and products. As desgn methology varies in companies I list lists the basics parts of the UPS and then below listed some ways they are constructed.


BULIDING BLOCKS

A UPS is made from the following parts:

Rectifier

Battery

Inverter

Static switch/transfer switch

Rectifier

The rectifier converts AC to DC and is rated and the full load of the dc inverter current and the battery recharge current. This is the first part of the "double conversion" process.

Regulated

The DC voltage is kept at a constant level using thyristors (6-pulse, 12-pulse) or for example switching of transistor based components (IGBTs) to regulate the DC. This can also be done with the use of diodes/thyristors used as diodes and then the unregulated voltage converted by boosting or chopping to a regulated level. Most good specs quote input THD 5% or 10% rather than 12pulse or 12pulse with 11% & 13th. Details of current THD and total current at 50% and 100% are good to ask. (I have seen a specification for a "12pulse" UPS on a single phase input 10kVA UPS)


The regulation of the DC voltage is done for a specific reason as this is more expensive. The regulated DC may be used to charge the battery or boost the DC voltage to enable modulation of the Inverter waveform in transformerless UPS systems.

Non-regulated

This design is not common but can be seen on smaller UPS still sold as "online". The DC voltage is approximately 1.414 times the input voltage. As variations occur on the input supply this effects the DC voltage. Generally based on Diode technology but requires some form of pre-charge circuit for the DC. The DC voltage into the inverter is unregulated.

The battery is connected to the DC bus by a diode. The diode only conducts when the input voltage drops below the battery voltage. When the supply voltage drops the battery supplies current into the inverter through the diode. In this design the battery charger is separate from the rectifier. Some frequency converters without batteries also use this design. Some UPS are designed with unregulated rectifers to reduce harmonic distortion on the mains. (ie. the spec looks better)

Battery

The battery is usually connected directly to the DC bus. A circuit breaker/fuses is used for protection both at the UPS and battery. The battery current and voltage are checked to limit the maximum recharging current and voltage.

Some UPS do not have the battery permanently connected to the DC bus (some claim that this reduces life of the battery). A thyristor can be used to connect the battery when needed. The UPS therefore needs a reservoir of power for the inverter during this action.

The Battery supplies the power for the Inverter until end of autonomy. Most modern UPS systems use Sealed lead-acid. Sealed mean that during the normal expected operation the battery does not vent or require topping up. It there is a build up in pressure within the battery a valve on the cell opens to release pressure. In smaller UPS they are mounted on their side.

The battery is configured in "strings" of cells. The UPS is design for a specific number of cells in series to create a DC voltage. A 12Volt battery "Block" contains six cells of 2volts. 192cells is not uncommon on transformer based designs (UK 415Vac), or more or transformerless. Parallel strings can be connected to increase runtime and/or add redundancy. If one cell goes open circuit the string can no longer supply power. Parallel battery string does not automatically mean redundancy as it must be able to supply full rated power.

Transformerless UPS have a positive and negative string (Eg. 61+61) which act as one string with a center point as neutral.

Ah

The Ah (Ampere-Hour)is the sizing of the battery and quoted at a discharge rate. The longer the time taken to draw power from a battery the more energy can be supplied. c10 mainly for europe c20 for the UK. Eg: 100Ah at c20 can supply 5Amps for 20hours. If the same battery is supplied at C10 then it may only be regarded as a 90Ah battery. A 100Ah battery will only be able to supply 100amps for a fraction of an hour.

Charger

The battery charger keeps the batteries charging at approximately 2.25V per 2volt cell. This is different for various types of battery and manufacturer. The charging current on a sealed lead-acid should be 10-15% of the Ah.

A separate battery charger is common in smaller UPS systems. This limits the size of the battery that can be fitted and the runtime of the UPS. It is more efficient but less flexible.

An intergrated charger/rectifier has the advantage of increasing battery recharge current by reducing the load on the inverter.

Inverter

All modern static inverters are IGBT based with pulse width modulation. The IGBT is more fragile than it's predecessor the thyristor but more effient. The inverter switches at high frequency producing a switched DC waveform. Inverter capacitors and the transformer (or a choke on a transformerless) create a low pass filter removing switching noise created by modulation of the IGBTs.


Transformer

In transformer based designs the inductor part of the
filtering is done by the transformer. The transformer 
isolates the DC and AC output. This enable use of one string 
to generate positive and negative halves of the AC waveform. 
Inverter capacitors and the transformer create a low pass 
filter

In transformer based designs the transformer isolates the DC from the AC output. A H-Bridge (single phase inverter)can be used to reverse the Pulse-width_modulation voltage on the input winding of the transformer. This enables use of one string to generate positive and negative halves of the AC waveform with a centre tap. The use of a transformer enables the DC input voltage to the inverter to be designed according to the battery size. (small units may only have a battery of 16, larger may have upto 50). Galvanic isolation operates through the inverter. A rectictier transformer is required for fully galvanic.


Transformerless

The transformerless design requires more batteries to create the AC waveform. The Battery must have a positive string and negative string for each half of the waveform. This is a more effient design. The footprint and weight are reduced. The low frequency transformer noise is replaced by high frequency switching noise from the IGBTs. Transformerless UPS.

Static Switch

The static switch transfers the load between the Inverter and the bypass mains. The static switch is two switches with a commom output. The first input is the inverter and the second is the mains. The Inverter maybe be thyristors or contactors and the bypass is usually thyristors. The bypass is required to be used almost instantly in case of inverter fault so solid state thyristor are required. The use of a contactor on the inverter is to increase effiency compared to a thyristor. Contactors are slightly more prone to failure however a thyristor based version may rely on cooling fans.

Manual Bypass

The manual bypass is used to bypass the UPS for servicing and repair. Most UPS have a manual bypass intergrated. Many customer with larger UPS systems also have an external bypass so that effectively the UPS could be removed without a shutdown. This may be intergrated with a key system to avoid Switching in the wrong sequence(Castell keys).

Bypass Isolation transformer

The main use is to link the neutral into the UPS to the Earth. Neutral is normally linked to earth at the substation. If the UPS neutral can be broken, for example by a generator changeover panel, then it can float from the earth reference. The UPS should not be affected by this however loads on the UPS or surge supressors can be damaged by high earth-neutral voltages. The floating of the earth neutral is mainly dependant on load on the UPS.


Djlammi 23:19, 26 August 2007 (UTC)


While this used to be the dominant type of UPS, they are no longer used for common applications. Power factor correcting equipment found in newer computer systems interacts with static ferro-resonant transformers, causing potentially damaging oscillations, and the transformer itself can create distortions which yield power less acceptable than poor quality line AC.

This sounds like more copy from an APC brochure. It's also untrue.

70.228.163.254 05:27, 28 August 2007 (UTC)

I believe this regards the transformer based inverter statements, please correct me if I'm wrong.

I am aware on Issues, particlurly with 1st gen bladeservers, that the inverter must be downrated because of increased heating. A haven't had any experience with voltage distortion. Air conditioning seems to have a greater affect distorting the waveform on starting the compressors. I have seen similiar issues eg. 6&12pulse rectifier resonanting with PFC on the supply and the distortion is dramatic. What affect does the replacement of the transformer have? I have only see the magnetic component changed to an inductor in transformerless.

My company sells transformerless to 100kVA and most companies sell them now. Transformerless generally also has a reduced footprint compared to the transformer based design.

I tried not to say if one technology was better than the other or push my company products. Selection of a UPS is never one size fits all.

I'm based in the UK and the only APCs i've seen here are under desk types.

Ive just Re-read your statment: ferro-resonant transformers -
I was refering to use of a transformer only to isolate a 
H-Bridge. I did put at the top ONLINE, sorry I will change
the wording to avoid confusion. Thanks for the input,
do any other parts need work? more/less detail?

Djlammi 22:04, 29 August 2007 (UTC)

[edit] Buzz, buzz, buzz

I've been an electrical engineer for over 25 years, and this article makes my eyes glaze over -- too much jargon, buzzwords and stilted phrasing. I pity the reader who doesn't have an engineering background. Some sections need serious rewriting. —QuicksilverT @ 22:25, 12 October 2007 (UTC)

INDEED! 24.6.66.193 (talk) 12:42, 27 February 2008 (UTC)

[edit] Plug UPS back into itself

Perhaps add a trivia section: what happens when you plug a Uninterruptible power supply back into itself? Jidanni 00:39, 13 November 2007 (UTC)

The solution is here. In a nutshell, it's not recommended since it would most likely damage the internal circuitry, as the webpage says. As for adding a trivia section, they are discouraged; maybe WP:TRIVIA can give an explanation. --Bruin_rrss23 (talk) 14:18, 13 November 2007 (UTC)

[edit] SBS

The article says that Standby Power Supply is shortened to "SBS". What does the B in SBS stand for? ZorroIII (talk) 09:52, 23 November 2007 (UTC)

[edit] UPS Designs subsections written with personal opinions

Many of the subsections under UPS Designs discuss the pros and cons, then give the writer's opinion comparing which to buy. For example, "This type of UPS typically costs more than the off-line type, but is worth the additional cost." That line seems more like an editorial than an encyclopedia article. Micaelus (talk) 05:05, 3 January 2008 (UTC)

[edit] Internal UPS not safe?

In the article, the following paragraph states that this type of internal UPS is not safe. Why not? Is there a reference, or more detailed information explaining why?

"The first type often requires extra connection wires between the internal UPS and computer's power supply. Some internal UPS of this group output high voltage (110 V - 220 V) direct current (DC) and some output nine-step table wave AC. Neither design is safe or energy efficient. As of 2006, there are only couple companies still selling this type of internal UPS in Australia, Asia and some part of Europe"

[edit] Sizing

Who can explain the dual sizing that manufacturers sell UPSs by? They offer size in Watts and in VA. Retail customers are expected to select a UPS based primarily on this VA-Watts information. Impossible. A UPS might be sized as 1000 VA and also 670 Watts. This is probably the most important fact that users come to wikipedia to find out - and its not here. —Preceding unsigned comment added by Srcap10 (talk • contribs) 13:53, 10 April 2008 (UTC)

Take a look at the volt amps article and you'll see that this is not a simple question to answer. Most regular people's eyes glaze over when the topic of power factor and apparant power are discussed. I don't see how to approach it in an easy to explain manner, summed up in a paragraph. DMahalko (talk) 09:35, 13 April 2008 (UTC)

[edit] Major rework in progress

I really don't like this article. Way over-technical, too much jargon, and refers to complex topics with no discussion or even linkage. But rather than just complain about it, I'm being bold here and trying to fix it. This is a topic I've researched heavily for my own job, so I think I know what I'm talking about. ;-)

I see a need to split off the UPS types from the application. An Outdoor UPS could be Standby/Interactive or Online, so it doesn't merit being called a type of UPS. But is is an application of one.

The same goes for the discussion of dual-redudant UPS power systems and N+1 UPSen. Probably should be a new section just for these applications. 216.56.12.98 (talk) 19:13, 16 April 2008 (UTC)

Doh, stupid Wikipedia logged me out for taking so long to do my complex edits. I am 216.56.12.98. :-(
DMahalko (talk) 19:24, 16 April 2008 (UTC)
Excellent work! —EncMstr 19:50, 16 April 2008 (UTC)
This article needs simplification for the average person who may not want to read long tedious paragraphs.
I am not an expert at runtimes for some of the more obscure UPS versions, but I'm adding info boxes with the hope that more knowledgable people will correct what I've added.
DMahalko (talk) 05:30, 18 April 2008 (UTC)