UPS for a 27" iMac

Discussion in 'Mac Accessories' started by zoran, Nov 11, 2010.

  1. zoran, Nov 11, 2010
    Last edited: Nov 11, 2010

    zoran macrumors 68030

    Joined:
    Jun 30, 2005
    #1
    1. What kind of a UPS would you suggest for the 27" iMac?

    2. Ive already got an older UPS Ablerex VT1000, is it still good enough for the iMac as far as specs are concerned or will i have to get a new one? Αny suggestion?

    3. Is it lacking any new options that newer UPS offer? if so, what might those be?
     

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  2. joudbren, Nov 11, 2010
    Last edited: Nov 12, 2010

    joudbren macrumors regular

    Joined:
    Apr 13, 2007
    Location:
    Edmonton, Alberta, Canada
    #2
    Newer UPS units offer USB connections that communicate the status of the UPS to your new iMac. Most of the better APC models will work fine and OSX has built in software to deal with UPS systems. If they're compatible the iMac will be able to determine when to automatically do an unintended shutdown in the event of a power failure and properly close off your open files. A lot of the new UPS units also do full power conditioning so that you get perfectly stable and clean power to your system.

    I'm running a couple of APC ES 550's on my two ReadyNAS NV+ storage units and a 1000VA Tripplite LCD UPS on my iMac. The APC units talk to the ReadyNAS storage arrays via USB and the ReadyNAS knows when to shutdown properly and not mess up my files in the event of a power failure.

    The iMac seems to know the charge level from the Tripplite but not the available time. Don't think it matters though as you can set the iMac to automatically shutdown at a certain % remaining of battery power vs. time remaining so it should work just the same. I am going to connect one of the APC units though temporarily to see if any additional info is communicated to the iMac just out of curiosity.

    Whatever you get, make sure it has a user replaceable battery. (APC does for sure) The battery needs to be replaced every two years or so and quality replacements can usually be found for cheap from any decent battery supply house. You don't have to get it from the manufacturer who usually charge way too much for the replacements. Most of these batteries are standard off the shelf parts and use lead acid technology. Cheers!

    P.S. My company designs and builds computer data centres and I sell a lot of big iron (100kW+) UPS systems for APC, Powerware, Liebert, etc. This is technology that I know. Stay away from the cheap UPS brands... you get what you pay for when it comes to a UPS. You won't go far wrong with higher end APC or Tripplite units for consumer products. The 27" iMac can draw up to 365 watts of power and as a general rule of thumb you only want to load a UPS up to 80% of capacity or so. On that basis you'll probably be ok with a UPS that can do around 500watts of available power. Don't pay attention to the "VA" ratings most manufacturers use... look at the specs to see what the actual watts available are. As an example, the ES 550 UPS is rated at 550va but reality is only 330 watts of power when you actually read the specs.

    James
     
  3. zoran thread starter macrumors 68030

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    Jun 30, 2005
    #3
    what about what i already have, the Ablerex VT1000? is it still good enough for my 27" iMac? and if not why, where is it lacking?
     
  4. DanielCoffey macrumors 65816

    DanielCoffey

    Joined:
    Nov 15, 2010
    Location:
    Edinburgh, UK
    #4
    You may also find that you need a UPS that outputs a true sine wave (like the APC SMT1000I) rather than the stepped sine waves of cheaper UPS models.

    Source : http://discussions.apple.com/thread.jspa?messageID=12138561

    I am running an APC Back-UPS RS 800 on my mid-2007 iMac but am preparing to get a new SMT1000I when I upgrade next year. Oh, and the batteries in a quality UPS should last 3-6 years unless you are in an area with bad mains electricity quality.
     
  5. zoran thread starter macrumors 68030

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    #5
    can anyone tell me if the port (RS232) that my Ablerex VT1000 gives can it be used like USB newer modles have?
     
  6. izibo macrumors 6502

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    Oct 6, 2004
    #6
    Not easily (if at all)
     
  7. zoran thread starter macrumors 68030

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    Jun 30, 2005
    #7
    "not easily" answer gives people hope... ;) can you be more precise?
     
  8. joudbren macrumors regular

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    Apr 13, 2007
    Location:
    Edmonton, Alberta, Canada
    #8
    There are serial to USB interfaces that you can buy. They can be notoriously fussy with certain devices though so you take your chances. Not likely the Apple software will recognize your UPS connected this way. Possible but not likely.

    In regards to your question on using your old UPS, yes you can and it is an appropriate size according to the label. I recommended getting a newer model on the basis of the technology is better now and you really need the UPS to communicate with the iMac so that it can handle shutdowns without intervention by you. Otherwise the battery backup will just finally run out of juice and the computer will shutdown even if you have files open. That leaves a risk of data corruption and/or data loss. Cheers!

    James
     
  9. joudbren macrumors regular

    Joined:
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    Location:
    Edmonton, Alberta, Canada
    #9
    Thanks for the feedback Daniel. In regards to battery life, we still recommend to our customers to change them every 2 to 2.5 years. You are right that in some systems you can get longer life but there are a lot of variables involved.

    How often the UPS goes on battery (bad power as you mentioned) will reduce the life, warm environments will shorten battery life, quality of the battery, quality and sophistication of the charging circuit, size of the UPS, etc are all variables. I also see a lot of people who buy too small of a UPS and constantly just run it to death.

    The problem with waiting too long on the batteries is that if they do fail they have a tendency to bulge the cell casing which can mean difficult battery removal and sometime the casing can split causing damage to the UPS. I've seen this many times on customers units. Changing the battery on a regular basis is cheap insurance and then you know it's going to work properly when required. Cheers!

    James
     
  10. zoran thread starter macrumors 68030

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    Jun 30, 2005
    #10
    i have no clue what type (line interactive, standby, online) of UPS is the one i have (Ablerex VT1000) and i also dont know if its ok nowadays to have sutch a UPS, what do i loose if its an older outfashioned model?
     
  11. joudbren macrumors regular

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    Apr 13, 2007
    Location:
    Edmonton, Alberta, Canada
    #11
    Sorry Zoran, I really don't know the specs of your UPS either as I'm not familiar with that brand at all.

    You lose the automated shutdown as mentioned previously and it's highly unlikely that your old UPS does any effective power conditioning. It's obviously your call if you want to use it and it will work for the purposes of providing a basic battery backup but it's really only half a solution if the UPS is not talking to the computer.

    That SMT1000i that Daniel recommended looks like a good choice for you and offers AVR (automatic voltage regulation) so it is conditioning the power as well. At 635 watts it has slightly more capacity than your old unit and is appropriately sized for your 27" iMac.

    James
     
  12. zoran thread starter macrumors 68030

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    Jun 30, 2005
    #12
    thanx for the interest and the answer James, a few questions:
    1. can you please tell me in simple words what are the differences between Standby, Online and Line Interactive UPS?
    2. why is it important that the UPS to be "talking" to the computer?
    3. do you have any idea which of the three above types does my old Ablerex UPS fit in?
    thanx
     
  13. joudbren macrumors regular

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    Apr 13, 2007
    Location:
    Edmonton, Alberta, Canada
    #13
    Check out the following link for a description of the different types of UPS. HIGHLY unlikely that your old UPS is Line Interactive and is most likely just a backup UPS.

    http://www.upsforless.com/differentupstechnologies-whatsthedifferencetutorialbyupsforless.aspx

    In regards to the UPS talking to the computer, as I've previously mentioned, the UPS needs to be able to communicate to the computer so that it can tell the computer how much battery power is left. You can set your computer then to automatically do a proper shutdown when the battery is getting too low to keep the system running. Then your open files will be saved and you eliminate the risk of file corruption from a power failure or a battery failure. Cheers!

    James
     

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