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Replacing House Lights

Discussion in 'Lighting and Electrics' started by chadillac802, Jan 27, 2009.

  1. chadillac802

    chadillac802 Member

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    Does anybody know about replacing incandescent lamps with LED replacement lamps?

    We are planning on replacing our house light system- the current system uses (30) 500w flood fixtures to light the space.

    I talked with a local vendor who was pushing LED replacement lamps that would mount into the existing fixtures, but it seems to me there would need to be some kind of voltage converter involved, and this whole problem is compounded by the fact that I need them to dim like the incandescent lighting we have in place. They also need to be controlled by our light board.

    I have already looked into a dimmable CFL, but there are no CFLs, that are dimmable AND comparable to the output of these incandescent fixtures. Also I like the idea of LED- in that the life of the lamp is longer, and when they do go out- there's no need for special recycling of the lamps.

    Thanks
    chadillac802
     
  2. gordonmcleod

    gordonmcleod Active Member

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    I have been using the dimmable CFL in many houselights in cinemas they are made by Ulighting America (in china) and have a dimming range from 30v-120vac
    they also are a low colour temp
    As to LED many replacements have an internal switch mode converter in them and that may have issues with SCR dimming both for the switchmode supply and for your dimmer
    Also LED replacements to date seem to have a very high CRI rating and also exhibit a strange harshness probably due to polarization
     
  3. chadillac802

    chadillac802 Member

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    Thank you for your quick response. What is a CRI rating?
     
  4. Les

    Les Well-Known Member

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    Color Rendering Index, meaning the light output of the LED will "change" the color of its surroundings. From what I understand, at least.
     
  5. derekleffew

    derekleffew Resident Curmudgeon Senior Team Premium Member

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    Regarding LEDs, see this thread: http://www.controlbooth.com/forums/lighting/10694-philips-ew-downlight-sm-houselights.html.

    As a follow-up, this ETC White Paper: Dimming Technologies: Choosing the Right Dimmer for Your Application by David North, issued 01/23/09, announces/discusses new Sensor modules specifically for the purpose listed above. An excerpt:
    as well as a new D20FB series "...for handling 2-wire and 4-wire fluorescent ballasts with integrated battery backup." Way to stay ahead-of/on-top-of the curve, ETC!

    However, as I said in your New Member post, [user]chadillac802[/user], before getting all excited about replacing your 15kW of HouseLights with LEDs, thoroughly do the math, both on the photometrics and the ROI.

    The formulas listed in http://www.controlbooth.com/forums/collaborative-articles/7664-mathematical-formulas-lighting.html, specically:

    lumens/LUMENS = (VOLTS/volts)^3.4

    life/LIFE = (VOLTS/volts)^13
    (i.e. reduce the volts to 90% and the life increases by 393%!)

    EFFICIENCY/efficiency = (VOLTS/volts)^1.9

    watts/WATTS = (volts/VOLTS)^1.6
    (not 'squared' as you would get with a fixed resistance)

    coltemp/COLTEMP = (volts/VOLTS)^0.42

    should assist with the former. At first glance, thirty 500W fixtures seems excessive, but 1) How large is the space? [485-seat Proscenium, right?] and 2) Do the units need to run at FL to provide acceptable levels of illumination?

    [user]gafftaper[/user] can tell you horror stories about his CFL HouseLight installation (he's now using S4-PARs as performance HouseLights), and [user]SteveB[/user] can offer clever advanced Unison programming tips about his HouseLights and Worklights (the lights turn off automatically after a set period once custodial staff turn them on!).

    One more shameless plug; see this article: ETC lighting products help Palazzo Las Vegas achieve LEED standard. New terms like "daylight harvesting" and "occupancy sensors" are going to become ever more important in the future, regardless of the exact type of artificial light source.
     
  6. gordonmcleod

    gordonmcleod Active Member

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    Most of those math equations do not apply for LED as the colour temp will not change as they dim
    nor is thier lumen/volts a true square law
    I have had to do several installs of cove lighting for houselights using LED controled by dimmers
    overall the best solution was using the TEMPO modules ( Tempo Industries - Step Lighting Aisle Lighting Stair Lighting Stadium Lighting Theatre Lighting Decorative Lighting )with a powerfactor corrected transformer of a dimmer
    The curve is far from square law as that is the nature of a LED

    dimmable CFL's if one can work in there range are effective but again one must first check out that range

    Also I doubt that the ETC dimmers can handle any switchmode device either in protecting the dimmer or protecting the switchmode device
     
  7. renegadeblack

    renegadeblack Active Member

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    So are you saying that installing something like this that isn't meant for an SCR dimmer may damage the dimmer?
     
  8. gafftaper

    gafftaper Senior Team Senior Team Fight Leukemia

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    As DL mentioned. I have to say how much I hate my dimmable CFL house lights. The color temperature is wrong... everything looks sort of pink. You go to blackout and eventually they dim down and at the last second they all blink off. When you turn them back on at intermission it takes about 90 seconds for them to reach full power. So the audience sits in purple/pink semi-darkness while they wait for the lights to warm up. I had to purchase a set of 12 ETC S4 Pars with XWFL lenses for use in performances because the CFL's are so terrible.

    DO NOT BUY CFL's FOR HOUSE LIGHTS!!!
     
  9. STEVETERRY

    STEVETERRY Well-Known Member

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    The ELV series dimmer is not an SCR forward phase-control dimmer, it is a transistorized reverse phase-control dimmer designed specifically to drive switchmode electronic transformers that require reverse phase-control.

    Please read the white paper referenced by Derek for more information.

    Steve Terry
    VP R&D
    ETC
     
  10. fredthe

    fredthe Active Member

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  11. chadillac802

    chadillac802 Member

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    THANK YOU.

    All this information is wonderful. Being a newer technology, I feel I'm almost starting over from working with incandescent stage units- i.e.- a lot of the photometric math no longer applies when it comes to LEDs.

    I know of another theater in Vermont who did CFL house lights, and I heard the TD hates them. As a TD I would like the savings in electricity, but as an artist, I don't want the house lights to distract.

    I will dig through all this info and let y'all know if I have any more questions.

    Again,
    Thank You
     
  12. chadillac802

    chadillac802 Member

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    Wow, who thought you could fill the whole room with the same foot candles of light, but the colors could look different... Thank you, definitely something I did not think of. Luckily our theater is Green, Black and light brown.
    But I definitely will keep the CRI in mind.
     
  13. beachcombah15

    beachcombah15 Member

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    At least yours dim...We run into the same problem at my school with our "energy efficient" CFL's, I turn the house lights on and for the first 80 seconds or so there's this weird pinkish tint and once @ full, they are as white as snow..
     
  14. lieperjp

    lieperjp Well-Known Member

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    Our CFL's are non-dim, so we don't have a nice pink glow when they are turned on, but they do glow green for about 10-20 seconds after they are turned off. It's fun to turn off the house lights and look up to see these glowing green things on the ceiling. Looks like plutonium.

    Although we have had people complain that long periods of time under our house lights gives them headaches. I mildly get the headaches as well, but I think it's really the directors that give me headaches... Also had one lady say CFLs give her seizures.

    For a while we were converting to CFL we still had a mix of incandescent fixtures in the auditorium as well. Personally, I thought that even though the incandescent lamps put out less lumens the areas lit by the incandescents were still brighter than the areas lit by the CFLs... The CFLs are just plain ugly.
     
    Last edited: Jan 28, 2009
  15. beachcombah15

    beachcombah15 Member

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    Yeah, I get those same headaches! although ours do not dim, we do get that glow when they turn on.
     
  16. derekleffew

    derekleffew Resident Curmudgeon Senior Team Premium Member

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    I referenced the photometric formulas above, which indeed apply only to incandescent sources, to help better assess the current Houselights.

    For instance, if your current 15kW of incandescent houselights are never run at FL, limited either by the dimmer or for artistic reasons, ColorTemp will be lower, Output will be less, KWH will be less, and Life will be greatly increased.

    I just feel that the incandescent light source is not the evil villain that some people, most politicians, and all Californians:twisted:; would like us to believe. Except for followspots, moving lights, and scenic LEDs, keep those alternative light sources away from my performance spaces:!:, at least for now.;)
     
  17. cdub260

    cdub260 CBMod CB Mods

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    Bad Derek!:naughty:

    I'm one Californian who loves incandescents. In fact, I've been stockpiling them in anticipation of the day that the California state legislature finally bans them outright.
     
  18. gordonmcleod

    gordonmcleod Active Member

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    Sorry I didn't read that it as a sinewave dimmer but that said I tested 3 different "solid State" transformers that were sold by Home Depot and an electrical wholesaler and none of them like reduced voltage from an autotransformer so I suspect they wouldn't like a sineave solid state dimmer anymore than an autotransformer
    Recently we did a project that was a mixture of dimmable CFLs and LED modules
    The led modules we supplied the 12volts AC to from small custom torroid transformers mounted in the fixtures
    The only caution there is torroid transformers have tremendous inrush current to saturate them so one either has to install a large current limiting resistor in serries or a thermister
     
  19. ETCspot

    ETCspot Member

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    Dimmable incandescents make a theatre a warm, inviting and comfortable space. Our campus facilities director wanted to put in mercury vapor house lighting in our 1,200 seat theatre. We fought tooth and nail and I finally won out. He wanted to replace the incandescent house system entirely. My proposal was to install flourescent or merc vapor work lights to be used in the house during load-ins, rehearsals, work calls, etc. Keep your incandescents and just use them from the time you open the house till the show is over. Its amazing how much money we save from electricity and labor (i.e. not changing house lamps as much). And several people in this post are exactly right... Dimmable CFL's are of the devil!
     

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