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Running a Home-Office Through a UPS 141

Posted by Cliff
from the something-an-electrician-should-do dept.
mwagner_00 asks: "After spending lots of money and time, I now have an office in my home. My wife and I both have computers (mine is a high powered gaming rig), and I also have a workbench where I work on other people's PCs. I have a web/email server as well. I would like to protect the investment by running the room's power through a UPS. I have a APC 3000NET that my workplace was going to throw out. The only thing it needs is a good set of batteries. Has anyone tried something like this before? Basically I want to find the breaker for the room, and after the breaker, run the power through the UPS and back out to the room. Is the UPS that I have sufficient to run a whole small office?"
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Running a Home-Office Through a UPS

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  • My recommendation (Score:5, Insightful)

    by RingDev (879105) on Wednesday September 21, 2005 @10:38PM (#13618971) Homepage Journal
    A surge strip and extention cord for the work bench. If you are going to try to patch into the house wiring you're going to want a certified electritian, and depending on housing codes in your area, you may need a certificate from the building inspector.

    Much easier to mount the UPS under the work bench and to run an extention cord/surge strip to the other PCs. You don't want to have anything running off the protector you don't need. Things like speakers, printers, PDA chargers, etc.

    -Rick
    • by Myself (57572)
      Don't even think about doing this without talking to your city's electrical inspector. She will, of course, laugh you out of her office.

      The UPS is an appliance, not a fixture. It has to be separable from the building wiring by a plug. It doesn't carry the appropriate ratings and classifications for being wired-in. Use the appropriate output cords and power strips.

      That being said, you might want to do some research into generator transfer switches, and the idea that some of the house's loads would be on a se
      • Just go PV (Score:3, Interesting)

        by RingDev (879105)
        If you really want to isolate the system look into installing a photovalitile roof system. Not only can you keep your whole house up and running during power outages, you can reduce your monthly power bill. ;) And those system, while still a challange to get OKed by the building inspector, can get federal and state funding, tax incentives, and even cash from your power company.

        See http://www.dsireusa.org/ [dsireusa.org] for more info on your local photo volatile power system incentives

        -Rick
        • It's only worth it in California, really. Few other states have the incentives or the climate to make this worthwhile.
          • have you looked at the dsire site? Here in Wisconsin I can get half of the expence paid for by the state, tax exemptions on any increase in property value becuase of it, net metering on the juice (If I produce more juice then I use, I get paid for it) and my power company will pay me $1000 up front and I can apply for up to $500 maintenance every few years if needed. I can even take out a $30k interest free loan to pay for the system.

            Also, Cali isn't the best place for solar power. AZ has it beat, but yo
            • Okay, I'll admit ahead of time this is me speaking out the lesser end of my body. That said...

              What very very little I know of solar panels and Windmills (wind turbines to be exact) is that solar panels are (last I knew?) very inefficient in that it takes more power to make the panels than what they can create over the span of their lifetime, thus the reason I've never bothered looking at them.

              Wind turbines rock. They're fun to look at, dangerous to make (huge freaking magnets that you're trying to *gently
              • Re:Just go PV (Score:3, Interesting)

                by RingDev (879105)
                "is that solar panels are (last I knew?) very inefficient in that it takes more power to make the panels than what they can create over the span of their lifetime,"

                No longer true. current theoretical limits put the power generation at 30% of the power received by the sun. And life spans of 20+ years. New thin film technology is allowing PV cells to be made cheaper and easier, and in much better applications. Gone are the huge 6 foot panels. Now you can get a PV sheet that can be rolled up and put in a ba
              • Re:Just go PV (Score:3, Informative)

                by Intron (870560)
                There was just an article on this in one of the pop science magazines. PV cells pay back about 7 times their energy cost to build. Wind turbines only pay back about 5 times. Corn-based ethanol is currently the worst energy source out there, costing 1.3 liters of oil per liter produced, about the same ratio as hydrogen produced using electrolysis.

                Best energy sources (in terms of payback and renewability) are wood heat (1:22) and hydroelectric power (1:28). They didn't cover nuclear, since it isn't an opti
                • They didn't cover nuclear, since it isn't an option in the current political climate.
                  And that's a shame, because if the US hopes to achieve any kind of realistic energy independence, nuclear power holds the key. It's the cleanest, most efficient energy source we have available. The advances in reactor design have eliminated any perceived "disaster possibilities," and dramatically reduced the amount of waste product.
                  • And that's a shame, because if the US hopes to achieve any kind of realistic energy independence, nuclear power holds the key.

                    Interestingly, that's the exact point being made by many global warming scientists. The only drawback to nuclear power generation is disposal of waste materials. However, a very small quantity of fuel lasts a really long time, so disposal isn't a constatnt issue, only a periodic one.

                    • Who'd a thunk it.

                      The article doesn't mention the technology that these new plants will utilize. I certainly hope they're planning on pebble-bed...

            • Re:Just go PV (Score:3, Informative)

              by geoffspear (692508)
              Repeat after me: a watt is a unit of power, not of energy.

              Do you mean you can generate a megawatt hour every year, or you can constantly have an output of 1 million watts for a year?

              • My bust. You are correct, a small roof in wisconsin can produce 800+ kWh of energy.

                -Rick
                • Unless you can get that small Wisconsin roof to undergo spontaneous nuclear fusion ... then I think you'd get a bit more out of it!!!

                  Just harnessing the damn power is the clincher.
                  • Fussion exists. Heck the guys down at the UW are playing with it. The problem with Fussion is that it takes almost as much power to get to atoms close enough together for strong forces to take over. It's not economically sound. We'll see what the french can do though.

                    -Rick
          • NJ has some of the highest incentives and rebates in the country. http://www.solaraenergy.com/ [solaraenergy.com] "Solara has completed the installation of an 88kW PV installation for a school in New Jersey. The project was made possible by the enticing rebate offered by the New Jersey BPU which will cover 60% of the project's cost."
          • It's only worth it in California, really. Few other states have the incentives or the climate to make this worthwhile.

            Here's a table of financial incentives [dsireusa.org] by state. It lists them by Federal, private, state, utility, and local incentives. While pv may not be practical in some locations there are a number of financial incentives available that cover more than just pv.

            Falcon

      • Seperable by a plug, eh?

        So: Break the feed heading into the server room. Terminate one side in a male plug, and the other side in a female. Plug the UPS into this pair of connectors.

        Done*.

        And then, if required need to disconnect the UPS appliance, simply do so, much as you would any other appliance.

        (*Variations might (and probably should) include using double-insulated stranded wire, installing a panel directly after said male plug with fusing/breakers appropriate for the wire and connectors, and also so
        • It is safe: If someone does something stupid, the panel's fuse pops before the UPS does. No smoke. No fire.

          I wouldn't rely on a fuse, but rather put a GFCI in at the panel. Now one concern I'd have is whether or not the UPS can handle all that power going through a single socket. You're not even supposed to hook up a single splitter or extension cord to most UPSes. Hooking up an entire circuit likely won't work.

          • You misunderstand the purpose of a fuse, and a GFCI.

            The fuse exists to protect against fire. It heats up and melts, breaking the circuit, before any series-connected wire gets a chance to.

            The GFCI exists to protect against electrocution by way of detecting ground faults and shutting down.

            Different animals for different problems.

            You always have a fuse, even if you don't install one: If things short for whatever reason, something is going to fuse/flash/melt/burn, and it may not be. Everyone agrees that it
            • The GFCI exists to protect against electrocution by way of detecting ground faults and shutting down.

              And a ground fault can't cause a fire?

              A GFCI, even if generally a good idea, is only needed in situations where ground faults are likely. Like wherever there's water. Which, hopefully, is not one's server room.

              I assume the UPS would be installed at the circuit breaker panel, not in the server room. If you're going to put it in the circuit room, what's the point? Just plug the stuff directly into the

              • If you're going to put it in the circuit room, what's the point? Just plug the stuff directly into the UPS using extension cords if necessary.
                Because in many places, using extension cords/power strips* permanently is against code.

                It does if you use one of those GFCI circuit breakers that you install in your panel box
                Well, that would be a circuit breaker, wouldn't it?
                Not just a longer length of wire, it's also splitting a single outlet into multiple loads.
                And a power strip isn't?

                Even if it can, b
                • Because in many places, using extension cords/power strips* permanently is against code.

                  And hooking up a standard UPS to your circuit isn't?

                  Well, that would be a circuit breaker, wouldn't it?

                  Yep, not sure where I said it wasn't.

                  "Not just a longer length of wire, it's also splitting a single outlet into multiple loads."

                  And a power strip isn't?

                  I wouldn't recommend hooking up a power strip to a UPS either.

                  "Even if it can, by increasing the distance of the cable you're increasing the potential inte

                  • And hooking up a standard UPS to your circuit isn't?

                    What? You'd expect a non-standard UPS to be somehow more suitable?

                    People do this shit all the time. Properly. Safely. To code. With "standard" UPSs.

                    There's even documentation describing at least two ways to make it happen here [powerware.com], from people who have a vested interest in not being sued over improper installations.

                    I wouldn't recommend hooking up a power strip to a UPS either.

                    Is there anything that you do recommend?

                    I mean, clearly, it's just impossible to
                    • What? You'd expect a non-standard UPS to be somehow more suitable?

                      A UPS that is meant to be hooked up to a whole house circuit is more suitable for hooking up to a house circuit than a UPS that is meant to be plugged into the wall. I thought that was kind of obvious.

                    • And if the obvious uses were the only safe, reasonable, and useful ones, you could just forget about this whole Intar-web thing, let alone discussions about how to integrate a UPS. We'd still be trying to reliably create fire for heat.

                      Thanks for playing. You're still a moron.

            • In some countries, all new power outlets need a GFCI (called an RCD in New Zealand).
              Not just in water-prone places.
              A kid can stick a fork into any outlet. An RCD will save lives.
      • If you want to wire it like this, my advice would be to obtain a separate consumer unit and treat the output of the UPS into it as you would the normal phase in. Bear in mind the power limitations - if your UPS is rated at a maximum, of, say, 2500W, then you can only have just over 10 amps on it.

        Depending on the power requirements of your computers (think about getting TFT monitors, for example), you could perhaps five sockets each of two amps, (about 450W/socket, easily enough for most PCs and an attached
        • if your UPS is rated at a maximum, of, say, 2500W, then you can only have just over 10 amps on it.

          Keep in mind that the UPS the submitter referenced is a 120V solution, which will be around 22-24 amps for the 3000 VA......
      • Don't even think about doing this without talking to your city's electrical inspector.

        I would think in the US the constitutional right to privacy would preclude Big Brother from getting involved in this, as long as you don't sell or rent the house, anyway. Besides, it's not like the govt. is going to find out. Personally I'd talk to someone who knows what they're talking about, but not necessarily the city's electrical inspector, since it's just a temporary and easily removable hack.

        • by GoRK (10018)
          You can have your privacy, but when your house burns down and takes your neighbor's homes with it and they find this... you are going to be in a world of hurt with your insurance companies and probably the police. You can do a lot of stuff in your own home that's not legal for various reasons. Regardless of whether or not the idea has merit or is valid or even could be done safely, wiring a UPS into the breaker box is most assuredly against electric code and in the event of an inspection or investigation wo
          • You can have your privacy, but when your house burns down and takes your neighbor's homes with it and they find this... you are going to be in a world of hurt with your insurance companies and probably the police.

            I didn't say you should be able to do something unsafe. I'm just saying you shouldn't have to have Big Brother check off on it.

            Regardless of whether or not the idea has merit or is valid or even could be done safely, wiring a UPS into the breaker box is most assuredly against electric code an

        • the constitutional right to privacy only applies to abortion

          if you want to grow a plant in your basement then burn that plant without ever leaving your property you have not only engaged in commercial activity, you have engaged in interstate commercial activity. because of this the Federal government will put you in jail.
          • the constitutional right to privacy only applies to abortion

            Considering that it also applies to sodomy, you're clearly wrong.

            if you want to grow a plant in your basement then burn that plant without ever leaving your property you have not only engaged in commercial activity, you have engaged in interstate commercial activity.

            That's probably not true, but no case has yet been brought over such a thing. Wickard v. Filburn is close, but if there's no legal market for the plant you're talking about the

            • I guess there are two ways the right to privacy applies i was not aware that was the basis for the ruling against sodomy laws.

              Possessing almost any significant quantity of pot (btw i do not use pot) counts as intent to distribute. without requiring any evidence that distribution actually occured
              • I guess there are two ways the right to privacy applies i was not aware that was the basis for the ruling against sodomy laws.

                No, there are many more than two. Read about it some time, you don't seem to be aware what the right to privacy is.

                Possessing almost any significant quantity of pot (btw i do not use pot) counts as intent to distribute.

                Not under federal law it doesn't. It might create a rebuttable presumption of intent to distribute, but that's not the same thing.

    • by Anonymous Coward
      I would suggest that anything connected to the computer at least be run through a surge protector - so you won't have any surges finding their way into your computer through them.

      But the only thing you should have running on the uninterruptable power supply itself is the computer and monitor - the essentials only. You want to be able to save documents and safely turn the machine off should the mains power fail (or have PowerChute do it). Do not make the solution more complicated than the problem.
    • by Roadkills-R-Us (122219) on Thursday September 22, 2005 @12:00PM (#13622086) Homepage
      1) Many houses and apartments are not wired the way
            you think; all the outlets in one room may not be
            on the same breaker. Other rooms may have outlets
            on that breaker. Lights may or may not be on the
            outlet with that breaker. IOW, you would need to
            test thoroughly, and probably do some rewiring.
            And you still might miss something.
      2) If you miswire anything and the house burns down,
            your insurance may not cover you. You'll need to
            check what the code is where you live and look into
            inspections. Getting a licensed electrician involved
            is a good idea.
      3) You don't want to plug your vacuum cleaner into the
            output side of your UPS; not great for either one
            of them. Sooner or later, something like that will
            happen.
      4) If you have a laser printer, startup surges can be
            huge; not a good idea to be on the UPS.

      There are others, but this should be enough. I have
      to go along with the people who receommended running
      one (or however many) separate outlets for the UPS.
      These can be current or new outlets wired to the UPS
      and *clearly labeled*. Maybe use red covers or something,
      with a label "Computer equipment only" or "Ask Fred
      before plugging anything in here". Of course, you'd
      have to change your name to Fred.... Depending on who
      could possibly be plugging things in, you could even
      consider switching to no normal outlets; hardwire some
      power strips into a junction box, and bolt them underneath
      the desks the equipment sits on. The biggest problem with
      that is moving the desks.

      And finally, what happens when you move? You need to make
      sure this isn't too hard to reverse, or consider what
      happens if you leave it. You don't want someone coming
      after you with an axe or lawyer later.
  • 18 amps (Score:5, Insightful)

    by MobyDisk (75490) on Wednesday September 21, 2005 @10:39PM (#13618974) Homepage
    The specs say 2250 watts. 2250 watts divided by 120 volts = 18.75 amps. So, in theory, you could hook this to a circuit with an 18 amp fuse or breaker.

    Of course, doing this is surely a crazy violation of electrical codes. Would it be that hard just to plug the computers into the UPS? It has plenty of outlets, it really looks like that is how it was intended. Wiring it right to the electrical box might get you some geek points, but you might also become a Darwin awards nominee.

    I doubt it is worth it.
    • Re:18 amps (Score:5, Interesting)

      by Bastian (66383) on Wednesday September 21, 2005 @11:12PM (#13619111)
      On top of that, wiring the entire room up to the UPS would result in a crazy waste of the UPS's power.

      If the power suddenly goes out, do you really want the lights in the room simultaneously drawing extra power from the UPS and hiding from you a pretty good clue that the power just went out?

      This is surely not the way a UPS meant to be used. I've certainly never seen one hooked up this way.
      • What I do is keep one light plugged into the UPS. All the other lights aren't. So if the power goes out, I'll know but still be able to see.
      • Where I live it is illegal to connect your lights and power outlets on the same circuit. You need a seperate breaker for the lights and one for other appliances...
      • Connecting the UPS in any way that might possibly allow the output to come in contact with commercial main power ("backfeed" into the mains) could result in an explosion and fire. It could also kill a utility worker, although utility workers are trained to expect this when working with outages (and they fill fix the problem by grounding your backfeed, which will knock you offline or worse.)

        Any competent electrician can install a transfer switch for the branch circuit, but you will ne astounded as the cost v
    • I have installed a few of these units at customers' sites. In the U.S. they require a dedicated 120V 30A circuit -- something you most likely will NOT have in your house; such a circuit would need to be installed by a qualified person.

      While you could replace the plug on the cord to fit in your present outlet, you must consider the following:

      1) Your existing circuit will either be rated 15A or 20A

      2) There will be other things on the circuit "upstream" of the UPS, and therefore the available capacity for the
  • Specific loads.... (Score:5, Informative)

    by karnal (22275) on Wednesday September 21, 2005 @10:40PM (#13618980)
    First off, you do not want to put the UPS in like that for the whole room. I'd say if you really want to put it in in this fashion, make dedicated circuits (like in some datacenters) beside the regular circuits that are UPS'd. That way you have a choice of outlets... Anyways...

    You kind of need to specify the kind of loads you'd like to put on the UPS. What you'd need to do is look at how many machines, how many monitors, etc.

    For instance, you do NOT want to put lighting (flourescent or otherwise) on a UPS.

    I have an older APC 900 that has external modules that I can add battery packs to, if I want a long runtime.

    I'm rambling, but a 3000 will power a lot of equipment, for a short amount of time. The batteries for the "higher numbered" UPS's seem to be pretty small, so you don't get much runtime out of them. For a quick-and-dirty of how long, get an estimated wattage you're going to draw from the UPS. Then, take battery voltage, multiply by number of batteries in the UPS, then multiply by the AH of ONE battery. That gives you the watt-hours of your UPS.

    If you're going to draw 450 watts from a UPS and the batteries add up to 450 or so, then you'll get about 1 hour - 20%.... Efficiency losses run about 20% (I'm guessing here)...

    Anywho. My 900 runs a file server, switch, cable modem, sipura phone box, and the gateway for about 2 hours. It only has one battery pack, but my battery packs are 4x(12v*18AH), which is around 864Watt Hours. So I'm probably drawing 400 watts continuously through the UPS....
  • UPS (Score:4, Insightful)

    by HotNeedleOfInquiry (598897) on Wednesday September 21, 2005 @10:41PM (#13618982)
    First of all, don't muck with your house wiring. It would be far better to reorganize your room around the UPS than to change the wiring inside your breaker box. It's unlikely that it would be legal and if there ever was an issue concerning fires or insurance, your ass would be in a sling.

    As to batteries, I have an old surplus 700 watt APC UPS that I run 4 servers and a couple of switches on. The batteries were dead when I got it and I jury-rigged 2 garden tractor batteries in series to it. It works perfectly, but your mileage may vary. The UPS manufacturers generally *do not* want you to do this, so do it at your own risk.
    • As to batteries, I have an old surplus 700 watt APC UPS that I run 4 servers and a couple of switches on. The batteries were dead when I got it and I jury-rigged 2 garden tractor batteries in series to it. It works perfectly, but your mileage may vary. The UPS manufacturers generally *do not* want you to do this, so do it at your own risk.

      While you may have had good luck with this, I'd encourage others not to hook oversized batteries to their UPS. The rationale is that, by massively expanding the battery

  • by NanoGator (522640) on Wednesday September 21, 2005 @10:57PM (#13619052) Homepage Journal
    "Basically I want to find the breaker for the room, and after the breaker, run the power through the UPS and back out to the room. Is the UPS that I have sufficient to run a whole small office?"

    Considering that you're married, are you really sure that you want to embark on a project that has the potential to make you a permenant laughing stock at the beauty salon?
  • Keep in mind (Score:5, Informative)

    by Guspaz (556486) on Wednesday September 21, 2005 @11:02PM (#13619070)
    Line-interactive UPS units like the 3000NET DO NOT filter power. They have AVR, which only filters huge changes in voltage. It will not kick in for even extremely dirty power. It is simply meant to boost up the voltage if your power drops down to, say, 90 volts, or goes up to 150 volts.

    So keep in mind that really all the UPS is going to give you that a good power supply can't is battery backup and surge protection.
    • I knew I was going wrong somewhere.... my line voltage is well over 240 volts!
      • I was referring to North American voltage, IE that in Canada.

        AVR works based on percentages. If your voltage drops more than x percent below optimal, it boosts by x percent. It does not boost back up to optimal, it boosts by x percent, no matter how low it goes.

        On my APC unit, AVR is totally useless; the UPS unit is configured to switch to battery power before AVR could kick in. TO be honest I sort of feel like APC is misrepresenting the capabilities of AVR, and what AVR does. When you actually email APC to
  • What you really want (Score:3, Informative)

    by ReverendRyan (582497) on Wednesday September 21, 2005 @11:03PM (#13619078) Homepage

    If you're trying to keep working during a blackout (as opposed to keeping your RAID consistent), look into these: a Kohler Generator [kohlerpowersystems.com]. Sure, you still need a small UPS for your server/desktop, but it only has to last ~45 seconds until the generator kicks in. Have an electrician (or authorized Kohler rep) install it. I wish I had one sometimes.

    YMMV

    • Another good brand is Generac. Home Depot and Habor Freight both sell them. We got a 15 kilowatt one to power most of our office (which is in a small house). All the computers are covered, plus a lot of lights and a fridge and freezer. It runs on natural gas (or LP if desired), so we don't have to worry about fuel.

      One thing to keep in mind - many UPS's don't like generator power. I'm in the process of replacing our old cheap-as-possible UPS's with APC SmartUPS's (used with new batteries, of course) because
  • not everything can be run off of a ups. most ups waveforms outputs are sawtooth rather than sine wave. most things are down converted to DC so it doesn't matter what the waveform is as long as it's 60hz and goes to the right voltage peaks. but some things care about the waveforms. i think flourscent lights are one, and i remember my ups came with a warning to not run a laser printer off of the ups.

    if you want to mess with internal wiring then i suggest two circuits for your home office, one connected
    • You can't run laser printers off of normal UPSs because laser printers consume huge amounts of power (thousands of watts) when they are printing. It would probably overload the UPS and trip its breaker or at least drain the battery quite a bit.
    • laser printers just consume too much juice for any UPC lacking a nuclear reactor. My clock/radio goes nuts when i try to power it off a UPS, not only lost the time the display flickered random lights but somehow it wasn't damaged.
  • As with any other electrical question on slashdot, here's the thing you should keep in mind:

    Electricity can kill you and/or burn your house down if you are not 100% sure of what you are doing.

    Seek the help of a professional who should then measure the loads in the area you want to protect and recommend an appropiate product.

    Don't even think of using an off-the-shelf UPS in any configuration other than the one the manufacturer recommends (regardless of capacity).

    A/C and lights can put a heavy strain on UPS.
    • By the way, you don't need to deal with a regular electrician that might not understand the details of a UPS -- there are companies out there that specialize in UPSs and backup power, etc.. My uncle Pete has a business that does exactly that [synergisticpower.com], so I know they exist. [sorry for the shameless plug...]

      Even if you're keen on doing it yourself and you have the electrical knowhow, you can get some good advice -- since you're looking to buy batteries for the thing, you've got their ear. Personally, I suspect they
  • by zogger (617870)
    here, homepower magazine

    http://www.homepower.com/index.cfm [homepower.com]

    you will like this mag if you have never seen it

    This is the sort of project that alternate energy folks do all the time, ie, using battery backups then to the house circuits. It is common. Whether the original juice is from solar PV or wind gennys or microhydro, fuel generators-or the grid,or a combination of the above, which most enthusiasts have, the wiring is very similar. They have a nice searchable archive of all their past articles, and you can
  • If I were you I'd only run the computer and monitor, perhaps a small desk lamp, and maybe the wall wart for your phone, through the UPS. All the rest will just run it down more quickly in exchange for protection from something they can weather easily enough anyway. This is especially important if you leave the computer on while you're away; the UPS could keep the machine powered through a blackout of moderate duration if it only ran the PC, while it'd cut off early if it had to power everything else.
  • I can understand you wanting backup power for your server, but is it really that important that your gaming machine have uninterruptable power? How many times do you get killed in a game and have to go back you your last saved game anyway? Come on..

    I have a rig in my office that is sort of like you proposed. I have a Belkin 1100 UPS, I have both my desktop & monitor and my headless server drawing power from it, it's rated to cover both systems for about 15 minutes. Around here there are occasional 2 or
    • If the server gets the signal, it does a clean shutdown, but my desktop doesn't, it has no way to know it's about to lose power.

      if your model is supported then this [networkupstools.org] might help you.

      • Darn it, looks like my UPS is unsupported officially, but it probably wouldn't be hard to hack in support. Thanks for the tip.
    • why not just shut it off at minute nine when it starts beeping?
      • Well yeah, that is the obvious move, if I'm at the desktop I'd shut down if the outage was more than 1 minute, to maximize power reserves to the server. I thought this was obvious enough that I didn't bother to say it. But I also leave my desktop CPU running unattended for hours on end doing file compression or downloads, in those cases I'd rather leave it up and running to avoid the loss of hours of work.
  • by WoTG (610710) on Thursday September 22, 2005 @03:22AM (#13619772) Homepage Journal
    Besides the electrical code violations, you'll loose flexibility in what you can power in the room. Laser printers and other very high current appliances (maybe microwaves?) will not be good for your UPS. I've seen laser printers cause UPS's reset themselves. It's not fun having workstations loose power every time someone tries to print. =)

  • In my post-doc days a housemate got hold of a UPS powered by a massive array of car batteries in the garage. He wired it into the house such that in a power outage, only his room (admitedly containing the house servers as well as his personal computers, lights, TV etc) would have power.

    We did have a half-hour power outage during a storm and it worked fine when the rest of us were looking for candles. The main drawback was it did SAVAGE things to our electricity bill, more than doubleing it. Keeping an ar

  • by SillyNickName4me (760022) <dotslash@bartsplace.net> on Thursday September 22, 2005 @04:51AM (#13619976) Homepage

    For whatever reason, over the last 10 years, I have seen more power failures being caused by a UPS then being handled properly by one.

    The idea seems to be good and usefull, but so far reality tells me that those devices do not have the kind of reliability that is needed.

    One of my customers has their entire computer room wired up to a HUGE UPS, and has a few smaller ones in place for very important servers. The big UPS is supposed to keep them running for as long as power lasts, the small ones are to allow those servers to properly shutdown when power runs out on the main UPS.

    In the last month, they had 2 major failures of the main UPS, resulting in a substantial amount of downtime. They cannot remember the last failure of mains power (I do, and it is a few years ago now)

    My own company used to have a very nice IBM AS/400 with UPS (one made specifically for this machine), which failed during the one power failure we have had in the last couple of years here, not to mention it deciding to just switch off a few times over the years.

    Another one of my customers runs a bunch of servers with redundant power supplies where each power supply has its own UPS. That setup sees to work a lot better already.

    To me the story seems pretty simple:

    1. Make sure your software infrastructure can deal well with the consequences of a power failure. Determine what would be an acceptable recovery time in case things go wrong and make sure you have the procedures in place to do such a recovery, and that it is well tested (and retested every so often). There is no amount of hardware redundancy that will be as effective for dealing with the consequences of power failures as this bit of software related efford.
    2. Make sure you have redundant power supplies with a seperate UPS for each.
    3. Consider a UPS as a means to be able to save your work and properly shutdown your machines. It is not something for actually keeping your machines running during a power failure, if that is really what you need, consider a generator instead.
    • I've been saying this for years. Unfortunately my only multiple-power supply box (second-hand, cheap) has a single inlet plug, so it would take some work to run each power supply from its own UPS.

      In the telecomm infrastructure, everything runs from a DC battery bank, which is maintained by rectifiers. (Or you could say it runs from rectifiers, backed up by batteries. Semantics.) All the equipment has 2 power supplies, and is always fed from two separate DC inputs, known as A and B. In very small (remote equ
      • I am not sure about power supplies using ACPI for this, but I am rather sure that on systems I dealt with, it is quite possible to detect failure of one of the power supplies. I just never looked at what interface it uses.

        The problem I see with what you suggest is that you will have to have the UPS connected to mains power anyway so it stays charged. In that case it is pretty easy to just let the UPS tell the system about the power failure, and it still does not address the main reason why I suggest a setup
        • Around here, commercial power isn't very reliable. Every summer storm produces at least a few momentary dropouts, and we're typically out for a few hours each year. Sometimes several days, but that hasn't happened recently.

          My point was that the main building supply would be the giant UPS, or generator, either of which can fail in various ways. Two small UPS units, one per power supply, would just add expense. All you need is one, to sustain the server until the generator kicks in, or the main UPS is back on
          • My point was that the main building supply would be the giant UPS, or generator, either of which can fail in various ways. Two small UPS units, one per power supply, would just add expense. All you need is one, to sustain the server until the generator kicks in, or the main UPS is back online, or the server shuts itself down.

            Ok, I understand that, and as I mentioned already, one of my customers is using such a setup (huge UPS for their computer room, and small UPSes for specific servers). As I also mentione
      • Most servers with built-in redundant power supplies have additional monitoring software.

        If you mean two power supplies in the space of a normal ATX p/s, then the only monitoring you would have is if there was an additional serial/usb connection to the board.
    • I've had a load of small APC UPI (plural of UPS :-)) which kill the outlet power when the internal logic decides that the battery's dead. The engineer in me says "sound a loud alarm, page the swashbuckling sysadmin, but don't cut the doddam power!!"

      This may just be me being picky.
    • And that is crap.....

      We have ALWAYS had a while room UPS. Call Liebert or whoever your vendor or electrician is and have them fix it. We have in our center a UPS to cover the interim time it takes for the generator to kick on. Our Generator is across the street. While we had issues after we first moved in, they have been resolved and we have lost power since and our room stayed up and so did our website. God pless the power fairies....
      • We have ALWAYS had a while room UPS. Call Liebert or whoever your vendor or electrician is and have them fix it. We have in our center a UPS to cover the interim time it takes for the generator to kick on. Our Generator is across the street. While we had issues after we first moved in, they have been resolved and we have lost power since and our room stayed up and so did our website. God pless the power fairies....

        Within some time, where I live I will have the option of contracting 2 seperate electricity pr
        • A UPS is only supposed to give you either enough time to turn everything off safely, or to give you enough power to keep everything up while the generator starts. If you value every single minute of up time, you have at least a UPS and a generator for cutting over. They UPS's are not supposed to last a long time. On the otherhand if you don't have a service contract and you do not do maintenance like checking the batteries and what not, then you have noone but yourself to blame. UPS's are not designed t

  • APC has a UPS sizing tool on their website... just enter all of the items in it that you plan to connect to the UPS, and it will not only tell you whether or not you are within its abilities, it'll tell you how much room you have to grow, and more importantly - how much run-time you'll have.

  • by droyad (412569)
    This UPS requires a 15A circuit (for 240V, 30A for 120V). You will need to get a special plug. As for is it enough? Yes. You can run 3 _real_ servers off that.

    Downside is the battery is going to be expensive. You will be better off getting two 740VA back-ups units.
    • by karnal (22275)
      Actually, his UPS uses the RBC-11, which you can get full packs for (4x12v, 18ah batteries) from Ebay for around 100$ shipped.

      And yes, they are brand new batteries.

      Additionally, the batteries used in this UPS are bigger than typical rack-mount setups (in terms of energy and size.)
  • Car Batteries (Score:3, Interesting)

    by ers81239 (94163) on Thursday September 22, 2005 @07:52AM (#13620315) Homepage
    I know a guy who gets old UPS' from the junkyard and then hooks them up to regular car batteries. They work great and last for a lot longer than the batteries that come with them. Not sure what you would need to do to scale that up to your application, but you should be able to save a ton of cash.
    • Check out the Ghetto UPS [dansdata.com] which I believe has been discussed here before.
      Warning: building something like will probably kill you and others through electrocution, fire, or something completely unexpected.
  • Somebody above said you had to contact your city's electrical inspector. That's a little heavy handed. Hire a certified electrician. Inspectors only show up on new construction, if I'm not mistaken. Now, my two cents . . .

    Go ahead and mount a whole house surge protector. They cost a couple of hundred dollars, take a couple hundred more to mount. But, then you'll have (I think) somewhere on the order of 40,000 joules of protection. Some smart house sites have more information--let Google do the walking.

    Secon
  • by HaloZero (610207) <protodeka&gmail,com> on Thursday September 22, 2005 @09:51AM (#13621011) Homepage
    ...for a couple of reasons. Firstly, you don't want to run the entire room off of the UPS; just your critical computer equipment. My UPS runs my workstation, the router, one display monitor, and typically a linux file/web/services server. It also runs my desk lamp. The UPS I use in particular is nice (and I believe mine is related to yours, in brand) because it has this warning alarm when it's power becomes the primary source of energy. The reason for this is that my particular outlet (I live in an apartment with three other people) is wired to a pair of lightswitches on anterior corners of my desk. We've also noticed that when you turn something on in one part of the apartment, the power will occasionally spike, and without the UPS, reset someone's workstation. But I digress, don't plug the whole room into your UPS. Just what you need on to perform an adequate shutdown of your equipment, in the event of a power failure. Secondly, if you put the UPS on the source side of your breaker, and your house gets struck by lightning, your UPS is going to BLOW UP. And I don't want to be anywhere near it if and when that happens. Circuit breakers are there for a reason. Sure, they aren't the end of the line in protection, you need a surge protector, too. Now, my UPS does have a surge protector in it, but still, I'm sure you see my point by now.
  • by InitZero (14837) on Thursday September 22, 2005 @11:32AM (#13621858) Homepage
    > Is the UPS that I have sufficient to run a whole small office?

            Yes.
            I, too, had a surplus UPS about the size of yours. When I
    was in my apartment, it sat in the same room as my computers.
    The UPS was loud, ugly and produced lots of heat. (Much like
    a girl I used to date... but that's an another story for
    another day.) It protected my computer equipment but not my
    TiVo or home stereo equipment because they were in another
    room. So, I had to have a seperate UPS for them.
            When I bought a house, I didn't want UPSes spread all over
    the place nor did I want the heat or sound inside the house.
            So, I put the UPS in the garage and then wired UPS outlets
    where I needed them. I have a quad-outlet in the office for all
    our computer equipment. I have a quad-outlet in the living room
    for the TiVo, stereo and TV. My cordless phone and answering
    machine also plug into a UPS outlet.
            For nearly five years, this setup has worked great. Every
    two or three years, I have to replace the two batteries ($90).
    Other than that, it has been great.
            Plus, I have disaster-recovery outlets spread throughout
    my house. When last year's hurricanes knocked out power to
    my house, I was able to plug the UPS into our small generator.
    I didn't run the computers or television (but did keep the
    TiVo online so I wouldn't miss my shows) but I was able to
    keep some lights on without having extension cords pulled all
    over the house.

    > I want to find the breaker for the room, and after the
    > breaker, run the power through the UPS and back out

            If I were you, I'd run a new circuit. You never really
    know what outlets and appliances are where. When I moved
    in, the toaster's outlet in the kitchen was on the same
    circuit as the outlet on the front porch where I plugged
    in my hedge clippers.
            I'm sure there is more on your office circuit than
    you know about. It is best to start clean. Plus, electrical
    work is really easy if you have attic or basement access.

            Matt
  • Why run your web server at home?

    I'm serious. Having a local print and file server is fine. I ran a mail and web server at home for several years.

    But I eventually said screw it - I was always a little uncomfortable leaving that equipment on 24/7 when I was nowhere around. It's one thing to take off for the day, but are you really comfortable leaving it on during a two-week trip?

    When you leave consumer grade equipment running 24/7 for years you will encounter problems. I've had several disks fail, once tr
  • by unitron (5733) on Thursday September 22, 2005 @12:13PM (#13622201) Homepage Journal
    Do not touch your house wiring. The fact that you have asked the question which you have asked shows that you don't know enough to do it safely even if it were practical. Don't take this as a personal insult. Almost everybody who isn't an electrician falls into this category (not to mention some who are, allegedly, electricians).

    It's almost certain that the wall sockets in the room are daisy chained with sockets in other rooms and all off of the same breaker. Same deal with the overhead lights. This makes your plan somewhat physically impractical.

    If you are going to use this unit (the UPS), get the proper replacement battery or batteries. Do not even think of using automobile batteries or anything like that anywhere indoors. Do not think of using those types of batteries outdoors with a long cord running indoors to the UPS.

    Get a licensed electrician to install a separate 30 amp circuit from your breaker panel to a single outlet in the room you have set aside as an office and plug the UPS into that outlet. Make sure that the UPS is working properly before going to the expense of installing the outlet.

    Use the UPS to power your computer equipment (and perhaps a low wattage lamp), excepting of course any laser printers or the like.

    As long as you're going to be talking to a real electrician you might inquire about the feasibility of setting up a generator and the necessary equipment to switch between it and the power company's wires. Unless you get a *very* large generator you'll need to have things set up so that the generator feeds selected circuits in the house (lights, refrigerator, wall outlets, but not the stove, the washer, the dryer, the water heater, the heat pump, etc.) while disconnecting the power company so that there's absolutely no way for the generator to feed power back into the power company's lines or for the power company to feed into the generator's output. Whether you get a generator that starts automatically and automatically disconnects the power company and connects itself, or one that has to be started and switched manually depends on how much money you can afford to throw at it.

    You may want to look into swapping this unit (the UPS) for 2 or 3 lesser ones that can be plugged into your existing 15 amp outlets if you can find someone in the reverse of your situation. That way you won't need any special wiring (unless you go with the generator idea).

  • I picked up a new (but old stock) APC 2000 a few years ago, and tried this solution until the batteries died. When it came time to replace them, I found it was much cheaper to just buy APC 1000s for each machine I wanted to stay up. My server will run for ~45+ minutes on it's UPS, and having a smaller (%) load on the system makes the batteries last longer. I ran the 2000 for a year with no problem, but by the end of 2 years the batteries were useless. I've been running the 1000 with my server for well ove
  • Consider this and dig through the Fire Marshals web site for a lot of interesting info on fires caused by consumer electronics.

    A GFCI detects faults _to_ground_ but will not trip to stop a little arc between hot and neutral that can still start a fire.

    Arc Fault Interrupters are new technology. Know about this stuff, it's significant.

    [PDF] NASFM Science Advisory Committee Recommendations Regarding Arc Fault ... Typical conditions where arc faults may occur include damaged wires by ... The most serious of th

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