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Running mains fluorescents from inverter

Discussion in 'Home Power and Microgeneration' started by The Other Mike, Jun 19, 2011.

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  1. Currently got a remote observation site (wildlife) with no grid fed
    power nor any prospect of it.

    Half the site has a few modified 4ft T5's (36W) retrofitted with 12v
    IOTA Ballasts (2D12-1-32) fed from a lead acid battery charged by a
    solar panel. The other half of the site has 5ft T5's with magnetic
    ballasts fed by a Honda EU20i generator which despite being a quiet
    suitcase model and loads of additional soundproofing is still way too
    noisy. Near silent operation is essential. Hauling fuel is also a
    PITA as its a long way from the road.

    So I need a way of powering the 5ft T5's (58W) from a low voltage DC
    supply. IOTA only make ballasts up to 40W and they need a circa 50v
    supply, realistically I need to keep to 12v to keep the solar array
    price down.

    So thoughts turned to an inverter fed from an uprated solar array and
    battery.

    A cheap modified sine wave inverter (circa 500W capacity) on a 100Ah
    brand new battery fails to even kick even one 5ft tube into life. The
    manufacturer says these inverters are not compatible with fluorescent
    tubes but doesn't elaborate any further.

    Does anyone have any ideas on how to get these lights working off
    grid?

    A change of ballast to an electronic type? (all indications are this
    could won't work?)

    Moving to a pure sine wave inverter (extremely expensive) ?

    A different inverter supplier rather than 'one hung lo china inc' ?'

    A ballast supplier that offers 12v ballasts that will drive a 58W
    tube?

    A homebrew 12V fluorescent inverter, running at high frequency that
    will drive 5ft tubes and costs not a lot? :)


    --
     
  2. Gazz

    Gazz Guest

    prolly cheapest and easiest to change the 5 foot fittings to 4 footers with
    the 12 volt ballasts you know work.

    you'll need a pure sine wave inverter to run a ferromagnetic ballast, bit of
    a waste of money just to run a few lights, if you wanted to run laser
    printers, charge electric toothbrushes etc at the site, then it may be
    worthwhile.
     
  3. Mho

    Mho Guest

    Did you try rubbing the tubes to get them started, especially with a static
    generating material like nylon or wool?

    ----------

    "The Other Mike" wrote in message

    Currently got a remote observation site (wildlife) with no grid fed
    power nor any prospect of it.

    Half the site has a few modified 4ft T5's (36W) retrofitted with 12v
    IOTA Ballasts (2D12-1-32) fed from a lead acid battery charged by a
    solar panel. The other half of the site has 5ft T5's with magnetic
    ballasts fed by a Honda EU20i generator which despite being a quiet
    suitcase model and loads of additional soundproofing is still way too
    noisy. Near silent operation is essential. Hauling fuel is also a
    PITA as its a long way from the road.

    So I need a way of powering the 5ft T5's (58W) from a low voltage DC
    supply. IOTA only make ballasts up to 40W and they need a circa 50v
    supply, realistically I need to keep to 12v to keep the solar array
    price down.

    So thoughts turned to an inverter fed from an uprated solar array and
    battery.

    A cheap modified sine wave inverter (circa 500W capacity) on a 100Ah
    brand new battery fails to even kick even one 5ft tube into life. The
    manufacturer says these inverters are not compatible with fluorescent
    tubes but doesn't elaborate any further.

    Does anyone have any ideas on how to get these lights working off
    grid?

    A change of ballast to an electronic type? (all indications are this
    could won't work?)

    Moving to a pure sine wave inverter (extremely expensive) ?

    A different inverter supplier rather than 'one hung lo china inc' ?'

    A ballast supplier that offers 12v ballasts that will drive a 58W
    tube?

    A homebrew 12V fluorescent inverter, running at high frequency that
    will drive 5ft tubes and costs not a lot? :)


    --
     
  4. vaughn

    vaughn Guest

    But what about swapping to a newer electronic ballast? I would expect them to
    have a pulse-mode input which should even work off a cheap square wave inverter.
    (But I haven't tried) Besides, they are more efficient.

    Anyhow, thanks to this thread, I now know how to find 12 volt ballasts without
    breaking the bank.

    Thanks!
    Vaughn
     
  5. F Murtz

    F Murtz Guest


    Try this, and oatleyelectronics have lots more goodies.

    http://secure.oatleyelectronics.com...d=229&osCsid=e1382db5b7e8301a03011e405258f2ca
     
  6. They also have power factor correction inputs (usually achieving 0.95 - 0.98)
    and these might not like square wave. Many nowadays are rated 50-60Hz or DC,
    and the DC voltage can be lower than mains in many cases, 180V is not
    uncommon, and I have one here which says 160V.

    One thing you do have to be careful about when running off batteries is not
    to allow the ballasts to run below their minimum rated voltages, as that
    causes excessive current in the transformer primary, and quick burnout.
    Some of the better ones include protection circuitry to switch-off below
    the min rated voltage.
     
  7. So presumably I could rectify and smooth and regulate the near sine
    wave inverter output of circa 340v pp within the lamp housing and feed
    an electronic ballast with say 200v?

    Any indication of suitable makes and models?


    --
     
  8. I can't see the economics working, yes its wasteful with multiple
    stages of conversion but the fluorescents are already there, also
    LED's seem way more expensive because of the number of light sources
    required.

    Dimming isn't a requirement. Its for work lighting as its a near
    windowless building, the requirement is for an even spread of light
    such as provided by a fluorescent tube (operating microscopes and
    laptops in the same room is very common occurrence)

    T5 fluorescents are somewhere around 70-100 lumens per watt. Most
    LED's at appear to be much lower efficiency with a holey spectrum and
    providing a very directional light source. but I'll ignore those
    deficiencies for now.

    Currently there are I guess somewhere around 17000 lumens lighting an
    area of about 20 x 8ft so make that around 1000 lux, but we might get
    away with a little bit less.

    At about the typical "90 lumens" per white LED package that would
    require about 180 separate light sources costing anything from GBP 2 -
    4 a piece. All requiring heatsinking and being around 1/3 the
    efficiency of the fluorescents, almost certainly requiring a bigger
    solar array and a bigger battery.

    So before those LED's are mounted and wired that's GBP 500 - 700 for
    the equivalent of the fluorescents that are already in situ which cost
    significantly less than a 10th of that.

    GBP 500-700 buys a very nice pure sine inverter.


    --
     
  9. Two?

    Really?

    USD 10?

    I thought this was the only one worth bothering with?

    http://www.gelighting.com/na/energysmartLED/home.html

    450 lumens output

    USD 50 a piece

    To give me 17000 lumens equivalent (100 lumens /watt * 58W * 3
    fittings) that requires 37 lamps costing USD1800

    Giving a total load of more than 300W compared to circa 170W

    You might be able to see why I keep coming back to conventional
    fluorecents every time :)


    --
     
  10. The IOTA ones are a bit crude (check the wiring layout!) They don't
    like cold temperatures and light output is also down quite a bit.


    --
     

  11. I looked at them a long time ago but it's been suggested that they are
    not ideal for external DC supplies as their heatsinking isn't up to
    the job. The supplied battery packs have a limited run time 0of a
    couple of hours and this isn't enough to 'break' them.

    A bit like a computer UPS. Rated at say 1000VA for 10 minutes to get
    though short breaks in supply or to enable an orderly shutdown but no
    good for long term use 'on battery' Feed them from an external
    battery with a higher capacity and they can go into meltdown without
    extensive cooling modifications.

    --
     
  12. LED lighting is evolving very quickly, you can get strips these days
    with LEDs mounted every few inches, rather individual "bulbs".

    I wouldn't like to say how their efficiency compares to florry
    though...

    Or there are GU10 LED or R50 sized reflectors that only take a watt
    or two at mains voltages. The aldli/lidl 3W Warm White 3000K LED R50
    ES "reflector" I got to try is a pretty close match to a 60W R50 ES
    tungsten.
    "Livarno EdiLight".

    Directional of course not spray light everywhere like a florry.
     
  13. I would replace the 5-footers with 4-footers. More 4-footers are made
    than all other sizes of fluoros combined. Going with the flow will
    greatly improve your ballast choices.
     
  14. m II

    m II Guest

    "Man at B&Q" wrote in message

    More like 30W or less equivalent in a real world comparison.
    15W LED v. 58W flourescent, not a hope.

    MBQ


    -----------------------

    and very bad light colour.


    mike
     
  15. Whilst that is likely in the US (I'm always somewhat surprised to see
    large US supermarket lit with rows and rows of 4' T12 tubes), it's not true
    here. 4' was a popular size in the home in the 1960's, but in supermarkets
    and other similar installations, they tend to be 5', 6' or 8' tubes (8' is
    becoming rarer now), but never 4', possibly because of their low loading
    compared with the longer tubes.
    In offices, you can find 4' tubes in 1200x600mm modular ceiling lights,
    but 2' tubes in 600x600mm modular ceiling lights are much more common.
    (These are giving way to externally ballasted compact fluorescents now.)
     
  16. My feeling is that magnetic ballast mains florries fed via an inverter
    would be very little more efficient than 12 volt halogen lighting.
     
  17. Guest

    Depends entirely where you NEED the light. The LED can provide as much
    light in a restricted area as the flourescent does - but will NOT
    light as large an area to that brightness. So the question is - how
    much light do you need and where???
    If the light scattered all over by the flourescent is needed - use
    flourescent. If it is just wasted (not needed anyway) try the LED
    solution.
     
  18. Guest

    I agree - if the inverter is run in it's "sweet spot" - but if,
    say, a 1200 watt inverter is used to power a 13 watt load, the
    efficiency drops WAY DOWN because the quiescent load (what it takes to
    run the inverter with no load) becomes a sizeable percentage of the
    total power consumed. - and just how efficient IS a magnetic ballast??
    Likely something closer to 80 than 90 - so combine that (let's say
    80) with the (possibly) 70% efficiency of a lightly loaded inverter,
    and you are down to about 56% efficiency - where, particularly for
    task lighting, a low voltage halogen is DEFINITELY worth considering.
    (and an LED positively SHINES.) (pun intended)
     
  19. That may well be their peak efficiency. But driving an inductive load
    which requires a decent sine wave? And the efficiency of the fittings is
    likely poorer too if not getting the correct waveform.

    It would be very interesting to know the actual efficiency of this setup
    in practice. I'd say you'd be surprised.
     
  20. Plenty of camping style 12v fluorescents available, and I can totally
    confirm the battery lasts about 5 times as long as using normal 12v
    bulbs, since I have both.

    Generally 8 or 16watts fittings are less than £20.


    http://www.the12voltshop.co.uk/Shop/lighting-12-volt-and-230-volt/fluorescent-lights/
     
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