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Inactive Fluorescent lights

Discussion in 'Home Power and Microgeneration' started by Walter E., Oct 23, 2003.

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  1. Walter E.

    Walter E. Guest

    In order to save energy, I deactivated every other fluorescent light fixture
    by removing its fluorescent light tubes. The ballasts were left connected to
    the power in all light fixtures, both with and without tubes..

    Recently I put new fluorescent lights in the previously deactivated
    fixtures. I found that several of the ballasts in these deactivated fixtures
    had given up their ghost.

    Do ballasts draw electric energy even when they do not supply bulbs? Do
    ballasts burn out when they are connected to power without light bulbs?
  2. Yes to the first, not usually to the second. Traditional ballasts are, in
    part, transformers, and actually use up about 10% of the electricity
    listed on the lamp ratings. So if you've got a twin 40 fixture, the
    ballast is pulling about ten additional watts when the lamps are on.

    When you've removed the lamps, the power running through the transformer
    drops below the ten watts, but not quite to zero. The actual amount will
    vary depending on the brand and type. But there will most assuredly still
    be a bit of a current draw.

    It's pretty rare for this to cause a burnout, and I've only seen it a
    couple of times - so couldn't tell if it was just age or whatever.

    Sidenote: these parasitic losses (als often called vampire losses) are
    common in any device that usese a transformer. Check the "wallwarts" - the
    boxes that plug into a wall outlet and then feed a 12 volt (or whatever)
    line to your desktop computer or phone or similar. If you're running the
    equipment, the box will be hottish. If you turn the item off, the box will
    still be a bit warm.
  3. Walter E.

    Walter E. Guest

    Thank you, Danny. I had been under the impression that ballasts were inert
    and lasted forever. My ballasts are 20+ years old (age of my house) and are
    probably suffering from old age. Just as I do.

    The Happy Iconoclast

  4. Tony

    Tony Guest

    Noooooooo, not at all.

    Having worked in a company Facilities dept., especially the old tar
    ones STINK when they die. Foul smelling, nasty messy pain in the
    butt. We had, as you would expect, we had fixtures all throughout all
    our buildings. Lots of experiance changing them, listening to
    complaints about the smell, etc.

    They have had electronic ballasts for years now. Back when I was
    replacing them, they were more expensive so we of course, didn't use
    them (pinching pennies).

  5. John Gilmer

    John Gilmer Guest

    They are part transformer and part ballast and the combination is done my
    making the "transformer" have a lot of "leakage" inductance.

    With the tubes in place, the voltage output of the transformers (and the
    stress to the insulation) is less than 100 volts. When the tubes are
    missing (or burned out) the voltage is MUCH higher. It could be that the
    extra voltage stress over a long period of time caused the failure.
  6. mark Ransley

    mark Ransley Guest

    Old ballasts and bad bulbs DO CAUSE fires . it is known
    ..... Ive seen it on several instances.....
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