need help to build a 2.5kva ups

Discussion in 'The Projects Forum' started by etiboy, Jun 15, 2011.

  1. etiboy

    Thread Starter New Member

    Jun 15, 2011
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    i want to build a 2.5kva ups,can you help me with hits on cct diagram and others
     
  2. beenthere

    Retired Moderator

    Apr 20, 2004
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    There is not nearly enough information. What frequency and what voltage is the UPS supposed to output? Do you want a pure sine wave output?

    At that level, a 12 volt battery would have to produce 208 amps to drive the inverter at 100% efficiency. A generator may be a better solution.
     
  3. SgtWookie

    Expert

    Jul 17, 2007
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    Actually, the 208A number is without figuring in the efficiency. An 85% efficient inverter would require ~245A current from 12v batteries.

    I used to have a link for a 2KW inverter project, but not on this computer.
     
  4. #12

    Expert

    Nov 30, 2010
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    and I used to have a link to a 3000 amp-hour battery...but not on this computer.
     
  5. SgtWookie

    Expert

    Jul 17, 2007
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  6. #12

    Expert

    Nov 30, 2010
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    About 6 of those batteries and this project could work! Now for a 300 amp, 12 volt charger.
     
  7. etiboy

    Thread Starter New Member

    Jun 15, 2011
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    0
    Thanks,for your hints,the 2.5kva ups i want will give an output of 22ov and 5ohz.can u help with a good cct and details.also will a 12v battery power it for an hr.then how is the transformer going to look like.
     
  8. beenthere

    Retired Moderator

    Apr 20, 2004
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    With almost 300 amps in the primary windings, it's going to be very large. Coupling that much flux will require a large core.

    No. See post #5. That is stretching the batteries quite a bit.

    You also have the problem of all that heat in the circuitry.
     
  9. SgtWookie

    Expert

    Jul 17, 2007
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    For an hour's worth of power without killing the battery bank too quickly (lifespan) for 2.5KW output, you would need around 800AH of deep-cycle battery capacity. You could place two 400AH 12v batteries in parallel. Automotive batteries would not last long at all; they must be deep-cycle type batteries.

    The closest thing you will get to a finished circuit for your project from this board is the link I provided. There are a lot of details missing, the project is an old one (14 years old), the transformers will be hard to find, and the software will require modification to generate 50Hz instead of 60Hz, and you will need to change some parts to get 220VAC instead of 120VAC.
     
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