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Proper (ab)use of UPS

Discussion in 'Hardware' started by Ricky Romaya, Jun 17, 2005.

  1. Ricky Romaya

    Ricky Romaya Guest


    I'm told from several sources/friends not to connect some appliances to the
    UPS, like printers, but not provide some explanations. So, what kind of
    appliances I couldn't connect to the UPS? Can I connect, say, my TV,
    DVDPlayer, stereo systems, etc. And why?

    Ricky Romaya, Jun 17, 2005
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  2. Ricky Romaya

    kony Guest

    Some, like lasers that pre-heat a lamp, simply have very
    high peak current draw. Any device with high current
    potential should not be connected to (any UPS not capable of
    this event, the additive current of all devices it could
    possibly see).

    Depends on the UPS, IT'S current capability, for peak as
    well as sustained current. Kinda silly to connect things
    that don't NEED to stay up during an outtage, IMO, and if
    you have frequent outtages, completely draining the battery
    gets pretty expensive.

    If you don't know the average or peak current of a piece of
    gear, you're facing an uphill battle- will need do a lot of
    research. Offhand, a TV depends on size but may draw a
    couple amps, a DVD player, under 0.4A, a stereo can vary a
    lot depending on size, type, and loudness, crude guess would
    be an amp in typical light use, or a little less.

    A modern computer can drain a (typical consumer grade) UPS
    fairly quickly, most people would likely want it powering
    only manditory gear as long as possible (read: needed).
    Keep in mind that attaching UPS to everything in sight means
    replacing all those batteries every 3-5 years too, even if
    they're seldom used... shelf life still degrades their
    kony, Jun 17, 2005
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  3. Ricky Romaya

    Cool_X Guest

    I totally agree with your post you're very good at anything I've seen you discuss so far!

    However, I just don't get why laser printers use up so much power, I always thought they were
    more efficient in every way than inkjets...

    And how long would it take an average laser (like a Samsung ML-1210) to pre-heat the lamp?

    And how much power does it take to do that?

    And once the lamp's warm, does the laser then use much more power than an inkjet?

    Once again, please answer these questions, because they really confuse me as to how much more
    efficient a laser printer is (and why?, and even more important question).

    Hope to hear from you soon, and keep up the good work kony!!!

    Cool_X, Jun 17, 2005
  4. Ricky Romaya

    Stephen Guest

    In the standby mode, the fuser and other sections of the printer are
    turned off. The fuser needs a lot of current to heat up the rollers
    quickly and to maintain the temperature.

    Stephen, Jun 17, 2005
  5. Ricky Romaya

    Clyde Guest

    I always thought that the reason you wouldn't plug a printer into a UPS
    is that it doesn't need it. If the power goes off you will not lose
    anything or damage anything in the printer. Generally you want to plug
    in only computer equipment that needs a shutdown procedure or that
    really needs protection from spikes. Most UPS devices have plugs that
    will protect from spikes that are not on the battery. That would be good
    for the printer and most of your equipment. Generally I just have my
    computer, my monitor, and my network devices plugged into the battery.

    My Epson printer is supposed to be shutdown with a button and not by
    unplugging, but this is a procedure to preserve the ink from drying out.
    A few minutes shutdown with the power off does not affect it.

    Clyde, Jun 17, 2005
  6. Ricky Romaya

    kony Guest

    No lasers in their sleep modes may use fairly low power but
    during printing use at least as much as inkjets- though it
    would depend on the particular printer, on average a laser
    is a larger printer.

    The other difference is that lasers often have a far more
    sophisticated onboard processor and memory, that in itself
    uses a (non-trivial) amount of power. All of this is still
    relatively minor compared to heated up the fuser, which may
    easily use 5A or more. Some people note the lights in their
    room dim when their laser heats the fuser. One of the more
    popular methods of fuser heating is a long thin halogen bulb
    rated for 500W or more- but again depends on the size of the
    printer, a larger printer with larger drum will need more
    heating but will typically curl pages less.

    I"d cal that a pretty low-end printer, not average for a
    laser, but perhaps typical budget consumer printer. Length
    of time isn't very long a few seconds but I don't have the
    ML-1210, I can't time it for you. A good clue is the "time
    to first page" spec for a printer, take that and subtract a
    small % of the time to end up with heating time.

    The lamp has to be kept warm when it continues to print.
    Some, until they go into sleep mode, will periodically
    reheat the fuser over and over- though I believe newer
    lasers are better in this regard, conserving a little more
    power but I dont' have any comparison numbers, do not
    benchmark laser current draws and don't put mine on an UPS.
    Then again, the ones I use most are old as the hills, they
    just won't die so they get used for most text (IBM/Lexmark
    4039 & HP Laserjet III, both with over 200,000 pages- lost
    track a few years back). It gets really cheap to run a
    laser if you just buy bulk toner and only need text, so you
    don't even have to be very picky about the toner unlike some
    newer cheap lasers, which IIRC, may need lower-temp toner
    (no proof, just a vague recollection of this).

    They aren't more efficient power-wise. They're faster, and
    cheaper over the long haul, and you dont' have to fool with
    dry carts or clogged inkjets.

    I'd expect all of them to be too power hungry for a typical
    1000VA or lower UPS combined with a modern system and CRT.
    If you dont' use a CRT monitor then you might be able to run
    a small laser on a larger UPS, but it's still not something
    I'd advise when it can be avoided. Many lasers do list
    their current requirements so if you have that need you can
    proceed from there sizing an ups for it. Large UPS get
    really expensive though, might be cheaper to just buy an
    inkjet if you anticipate regularly needing to print during
    power outtages.
    kony, Jun 18, 2005
  7. Ricky Romaya

    Cool_X Guest

    Thanks so much for your continued time spent helping me, you are a TRUE EXPERT. And on that
    note, how did you learn everything you're an expert on regarding computers? Master's degree in
    computer engineering???

    I still have a few more questions:

    1. About my Samsung ML1210, that was bought years ago brand new, so I definitely don't think
    it was a low-end printer then...At the time it was bought, it cost $321 CDN...Sorry that wasn't
    a question, just a clarification...(and BTW, I gave it as an example not b/c it was a current
    printer, but b/c its was the only one I ever owned - but I don't own it anymore...)

    2. You said:

    "A good clue is the "time to first page" spec for a printer, take that and subtract a small %
    of the time to end up with heating time."

    I disagree with that b/c even after a few seconds after the lamp had completely warmed up (a
    first print job), the data going over USB to the printer took quite a few seconds before the
    printer actually started printing (the second print job, done a few seconds after the first).
    My point is that data transfer (here over USB, probably MUCH worse for parallel, although
    PLEASE let me know about THAT TOO) from the computer to the printer's buffer RAM takes quite a
    few seconds, which I don't think you took into consideration (And BTW, it wasn't an ancient
    system either - it was a Compaq Evo N600c laptop with a P3 1.2GHz and 256 MB PC 133 SDRAM, 30
    GB HD (probably 5400 RPM))

    3. Sorry for a silly question, but I don't speak Usenet very well. Can you quickly tell me
    what IIRC meant (I think it's something to do with the first person's recollection).

    4. You said:

    "They aren't more efficient power-wise. They're faster, and cheaper over the long haul, and
    you dont' have to fool with dry carts or clogged inkjets."

    Can you give me an average percentage for all lasers vs. similar inkjets as to how much more
    power a laser uses in comparison?

    5. Continuing #4, does that percentage change when comparing low, middle, high, and
    professional lasers vs. similar inkjets (BTW, I'm trying my hardest to compare apples to apples
    like you)

    6. If it does, than can you give me the average percentage for the class of printers (laser
    and inkjet - categories described in #5), for those categories (see brackets in this question #6)?

    The rest of your post I fully understand and agree with (BTW, I read an APC manual that said
    not to connect any laser to a UPS less than 1400 VA, but this was a manual for a big SmartUPS
    less than 1400VA (APC's professional UPSs) - just so you know the exact figure quoted by a
    reputable manufacturer IMO!)

    7. BTW, in your opinion, who makes the best UPSs (consumer and business/professional). I
    haven't heard of any better OEM than APC...(who also resells through retail, as everyone should

    Thanks once again for all of your priceless advice and expertise (as well as accurately reading
    everything I post), and please let me know about these questions (once again).

    Cool_X, Jun 18, 2005
  8. Ricky Romaya

    kony Guest

    I may've been thinking of the ML-1740, and it seems
    backwards that the lower model # is a better printer.

    I can't help it if your printer is odd... typically the
    majority of the time is warm-up, and sending data to a laser
    shouldn't take long at all, for a page of text. If your
    spool settings are such that you try to send a lot of pages
    (if yours even allows it- large enough buffer for that).

    If you get a print job qued up and ready to go and then when
    you try to send it, the system can't connect to the printer
    (because it's off) then right after turning it on, that
    "time till first page" should be the majority of the warm-up
    period, very few seconds after that. That doesn't
    necessarily mean your system is done sending that first
    page, only that the printer was ready.

    No parallel is about the same as USB1, unless one uses SPP
    instead of EPP or ECP. Either way, data transfer rates are
    a minor amount of time unless you're sending raw data, which
    seems unlikely for typical jobs unless you'd reconfigured
    the driver to do that (if the driver even supports it).
    No, for a page of text it's under a second. Depends on the
    job though, if you're trying to spool out a novel, then sure
    it'll take a little bit longer.
    Even on a old 486 system, the parallel port can send a few
    pages of text in a second. If your driver and/or windows
    and/or the printing applicaton (for example, Adobe Acrobat
    is sometimes dreadfully slow at printing) is a bottleneck,
    that's entirely separate from "laser printers" in general.

    No I can't... haven't been lurking around all the printers
    at the store or anything. I can tell you that the typical
    inkjet uses less than 20W, while the warmup on a business
    class laser printer's drum is over 350W, usually over 450W.
    We can't really ignore the warmup current even though it's
    only for a short duration of the total printer "on-time" but
    the remainder of the time can depend on how well the
    printeris built. A big heavy-duty printer is going to likely
    have more powerful motors, more memory, and it's own
    mainboard with a RISC processor on it.
    Win(software)printers like most inkjets are little more than
    a buffer and a microcontroller or two plus 2 or 3 smaller

    If I had to guess- and that guess might be quite wrong, I'd
    guess the typical laser's _average_ on-time power usage is
    3X that of a similar (in this case, meaning light-duty,
    low-cost consumer grade) laser printer. Seek the
    manufacturer's spec sheets if you need compare two specific
    Yes... though I'd expect less difference in inkjets.
    Apples-to-apples is somewhat meaningless though, you'd have
    to consider two specific printers- and you can do that
    yourself. Bottom line is, don't put a laser on an UPS
    unless your UPS is rated to handle the peak current the
    laser's manufacturer specs.

    I don't claim to be a laser printer expert. An average
    percentage is meaningless as you'd have to consider a
    specific printer than may vary a lot from any average. I
    gave a rough guess above.

    Unless you NEED a laser printer running during an outage,
    just don't do it. The goal should not be seeing whether you
    can wear out the UPS battery in least time possible. That
    gets expensive and wasteful, unless it's really an
    emergency... in which case I'd suggest you get a cheap
    inkjet for such an occasion as even when you could run a
    laser on an UPS, you'd still get much longer runtime from
    the inkjet. Or, get a generator if it's that much of an

    "Best" is sorta pointless IMO, determine the budget then if
    you're not in a rush, use that budget to buy the highest
    rated capacity unit when you see a good deal/sale on 'em.
    Sales make all the difference in what you get for the buck,
    an UPS is not new technology and for your concerns the main
    issue will be how much capacity you can get for the budget.
    kony, Jun 18, 2005
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