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Thread: LED lamps in new fluorescent fixtures

  1. #1
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    LED lamps in new fluorescent fixtures

    I'd like to use fluorescent fixtures in a few cases where there is not a LED fixture available that works as well for the application. 4' T8 or T5 fixtures
    But I want LED lamps.
    (this is a new installation situation)
    What is best from a. installation point of view & b. long tem maintenance point of view?

    1. Direct LED replacement lamps leaving the ballast in place.

    2. LED replacement lamp (with internal driver) and bypass/remove ballast in field.

    3. LED lamp and replace ballast with driver.

    4. Other suggestions (other than "use a LED light fixture)

  2. #2
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    Quote Originally Posted by olc View Post
    I'd like to use fluorescent fixtures in a few cases where there is not a LED fixture available that works as well for the application. 4' T8 or T5 fixtures
    But I want LED lamps.
    (this is a new installation situation)
    What is best from a. installation point of view & b. long tem maintenance point of view?

    1. Direct LED replacement lamps leaving the ballast in place.

    2. LED replacement lamp (with internal driver) and bypass/remove ballast in field.

    3. LED lamp and replace ballast with driver.

    4. Other suggestions (other than "use a LED light fixture)
    Interesting new twist on things!

    I would suggest that you find a fixture you want. This is new construction and you are re-manufacturing fixtures. You will have no UL listing this way.
    I can't believe you cannot find a LED fixture the customer likes.

  3. #3
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    They make a "bare fixture" with no ballast. The tombstones (sockets) are prewired for 120V. They are already connected to a disconnect that you wire to the line/neutral conductors. Then all you need is the LED tubes/lamps.
    I've used these a few times.
    If you aim at nothing, you will hit it every time!

  4. #4
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    Quote Originally Posted by Little Bill View Post
    They make a "bare fixture" with no ballast. The tombstones (sockets) are prewired for 120V. They are already connected to a disconnect that you wire to the line/neutral conductors. Then all you need is the LED tubes/lamps.
    I've used these a few times.
    Me too.
    Once in a while you get shown the light
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  5. #5
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    Thanks for the replies.
    The UL listing issue is something I am concerned with also.

    A large local university insists on new fixtures with LED tubes (fluorescent replacements). This is not an uncommon thing.

    Here is a example (nothing to do with the larger university) for multi-family housing:
    A typical 4 foot "cloud" light you would typically find in kitchens.

  6. #6
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    Update:
    Lithonia does make a LED fixture as described above.
    The question is if/when it fails what is the repair?
    Entire fixture?
    A plug in part (lamp) that can be purchased at Lowes?
    A replaceable part (like replacing a ballast)?

  7. #7
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    Quote Originally Posted by olc View Post
    I'd like to use fluorescent fixtures in a few cases where there is not a LED fixture available that works as well for the application. 4' T8 or T5 fixtures
    But I want LED lamps.
    (this is a new installation situation)
    What is best from a. installation point of view & b. long tem maintenance point of view?

    1. Direct LED replacement lamps leaving the ballast in place.

    2. LED replacement lamp (with internal driver) and bypass/remove ballast in field.

    3. LED lamp and replace ballast with driver.

    4. Other suggestions (other than "use a LED light fixture)
    I had one project where I found at least one manufacturer offered fixtures with LED tubes and drivers as an option. I'll try to find it.
    The more they overthink the plumbing, the easier it is to stop up the drain

  8. #8
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    Quote Originally Posted by olc View Post
    Thanks for the replies.
    The UL listing issue is something I am concerned with also.

    A large local university insists on new fixtures with LED tubes (fluorescent replacements). This is not an uncommon thing.

    Here is a example (nothing to do with the larger university) for multi-family housing:
    A typical 4 foot "cloud" light you would typically find in kitchens.
    You could ask a fixture sales rep if they could ship pre-lamped Philips-Advance ballast + Instant Fit or OSI ballast with with SubstiTube. You have to be certain that ballast is certified for use with the specific LED lamp. The electrical parameters of drop-in lamps are obviously not the same as fluorescent lamps which can cause ballasts to be operated outside of design parameters and fail prematurely that would not be covered under warranty.

    That's a smart move on the buying staff.

    HID and fluorescent ballasts are industry standard parts that maintain compatibility. LED ballasts are proprietary. The fixture might have great specs, but when something goes wrong, it can be very difficult to get it back up with truck stock parts.

    Philips InstantFit works with any of the ballasts listed on their site, or their InstantFit optimized LED ballast, but you can't run fluorescent lamps on it. I think the difference is that it's a lower wattage ballast so the efficiency sweet spot lines up with the Philips LED lamps rather than 4' T8 lamps, but as far as I know the difference is rather inconsequential and it might be better to have the ability to fall back onto normal T8 lamps due to product volatility around LED anything.

    Most T8 ballasts can operate 2, 3, and 4' lamps, but almost all of them suffer efficiency when you're using 2 and 3', because its designed for best efficiency for 4', because there are more millions of 4' lamps made.

    http://www.usa.lighting.philips.com/...hts/instantfit

    This is the link to their LED ballast: http://images.philips.com/is/content...7V-7-28-15.pdf

    Many cheaper LED fixtures are made of essentially the guts of TLED lamps double-side taped or RTV'ed onto the fixture frame and wired to a proprietary LED ballast.

    Plastic TLEDs are non-shattering, but they don't have the stiffness of a fluorescent lamp and can flop around and potentially make annoying noise. Glass TLEDs are stiff and shatterable like fluorescent.

  9. #9
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    Quote Originally Posted by olc View Post
    Update:
    Lithonia does make a LED fixture as described above.
    The question is if/when it fails what is the repair?
    Entire fixture?
    A plug in part (lamp) that can be purchased at Lowes?
    A replaceable part (like replacing a ballast)?
    You just replace the lamp like you would on any fixture. The driver for the LED is in the tube. Not sure about Lowes but I can get the tubes the same place as the fixture, from my supply house.

    You can also buy them at www.1000bulbs.com
    If you aim at nothing, you will hit it every time!

  10. #10
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    Thanks for the info above.

    Update to my update: The Lithonia fixture I mentioned is produced over seas. It has a 5 year warranty but the parts are not available (I infer from the reps response) so the entire fixture would have to be replaced.

    Thinking out loud:
    For new installations I would think either:
    1. Remove ballast and install LED tube with integral driver.
    or
    2. Remove ballast and install driver and LED tube.

    I would not think installing a fixture with (fluorescent) ballast and LED replacement tube on day 1 is a good idea.

    I'm trying to think what is best for long term maintenance.
    I know the local university uses fluorescent fixtures with LED tubes because of maintenance because the decision maker is the head maintenance supervisor.

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