Would like to convert flourescent circle light to LED

[SciGuy]

My wife and I have a circular flourescent lighting fixture in our entryway that is run via a motion detector and utilizes both 40 and 32 watt circular flourescent tubes. We love the fixture but have had way to frequent failure of the bulbs over the past 20 years. Would it make sense to retrofit the fixture with several LEDS and an appropriate driver?

The fixture is ~20" in diameter and has a white diffuser. There is plenty of space behind the diffuser for new innards.

I would love to hear any ideas in regards to specific LEDS and drivers including sources for said items.

Thanks for any informed replies.

Hugh

 

[csshih]

hmm.. Xitanium drivers and a few crees

 

[ponygt65]

hmm.. Xitanium drivers and a few crees

Does Xitanium have restrictions on their controls? (motion sensor)

How many Cree's will it take to make ~4700 lumens?


OP - unless you are really interested in going with LED, I'd look into a good electronic 4-pin drum fixture. This company makes a 2x26W CFL 14" drum (not shown on their site). Here is a 1x26W setup: http://www.enertron.com/products/residential_fixtures/elec._non-programmed_start_26_watt_11_d

A 2L version will only give you 3500 Lumens though.

I was never a fan of those old Circline drum fixtures. :sick2:

 

[blasterman]

How many Cree's will it take to make ~4700 lumens?

I know were thinking in terms of absolute lumen value of those circle tubes, but the reality is that the fixture is horribly inefficient. That's a big reason why circle tubes have lost favor in the market - other than being fugly

I would bet it will take far fewer lumen in terms of LEDs because they won't waste as much light. I'd guess that 30 or so neutral white Crees would seem just as bright (if not brighter) as the old tubes because they will already be firing down.

 

[jrmcferren]

Does Xitanium have restrictions on their controls? (motion sensor)

How many Cree's will it take to make ~4700 lumens?


OP - unless you are really interested in going with LED, I'd look into a good electronic 4-pin drum fixture. This company makes a 2x26W CFL 14" drum (not shown on their site). Here is a 1x26W setup: http://www.enertron.com/products/residential_fixtures/elec._non-programmed_start_26_watt_11_d

A 2L version will only give you 3500 Lumens though.

I was never a fan of those old Circline drum fixtures. :sick2:

If the motion sensor hasn't failed with the current florescent ballast, you shouldn't have any problem with an LED driver. The only time you are restricted to incandescent is if the control uses a TRIAC for switching which is obviously not the case. What is killing your bulbs is the constant on/off cycles.

 

[SciGuy]

If the motion sensor hasn't failed with the current florescent ballast, you shouldn't have any problem with an LED driver. The only time you are restricted to incandescent is if the control uses a TRIAC for switching which is obviously not the case. What is killing your bulbs is the constant on/off cycles.

and if LEDs and their drivers would not be harmed by this cycling that would be a good reason to convert would it not?

Hugh

 

[SciGuy]

I know were thinking in terms of absolute lumen value of those circle tubes, but the reality is that the fixture is horribly inefficient. That's a big reason why circle tubes have lost favor in the market - other than being fugly

I would bet it will take far fewer lumen in terms of LEDs because they won't waste as much light. I'd guess that 30 or so neutral white Crees would seem just as bright (if not brighter) as the old tubes because they will already be firing down.

and 30 Crees plus their driver would cost?????

Hugh

 

[lolzertank]

The 30 neutral white Q3-5A Cree XR-Es on stars should be about $150. The drivers should run about another $50-100. IMO, LEDs are not ready yet for general lighting. Too expensive.

 

[ponygt65]

I know were thinking in terms of absolute lumen value of those circle tubes, but the reality is that the fixture is horribly inefficient. That's a big reason why circle tubes have lost favor in the market - other than being fugly

I would bet it will take far fewer lumen in terms of LEDs because they won't waste as much light. I'd guess that 30 or so neutral white Crees would seem just as bright (if not brighter) as the old tubes because they will already be firing down.

True to a point. I forgot to add ballast factor into that, so take a .88 multiplier and there you have it. THe inefficiency of that fixture is the lens though, not the lamp/ballast combo. Because of that, the LED"s will also be subject to poor outlook. The light will have a 'crisper' look though. That I can agree with. IT will be diffused horribly IMO. That lens is roughly 2" deep and maybe 3/32" thick. You'll see the diodes fairly easily with that lens. YOu do have a good point that the diodes will be more position orientated and that will help some. The 'good' (losely used) thing about teh fixture with the circline's is the housing is a 'bright white' sheet metal. That helps with reflectance.

I do agree that they are fugly. I can't stand those things. LOL

If the motion sensor hasn't failed with the current florescent ballast, you shouldn't have any problem with an LED driver. The only time you are restricted to incandescent is if the control uses a TRIAC for switching which is obviously not the case. What is killing your bulbs is the constant on/off cycles.

I should have clarified. I wasn't speaking about the motion sensor failure. I was speaking in regards to compatability issues between driver and motion sensor. The OP may end up having problems due to the sensor not being rated to handle the driver. Motion sensors and dimmers are 'finicky' when it comes to that. I could be here all day with dimming fluorescents. It really depends on the sensor. I'd contact the motion sensor company to see if they've run any tests on LED driven setups.

In fact, I just spoke to a customer the other day about dimming his Juno LED can. He thought he could use any old dimmer, when in fact, it HAS to be an Electronic Low Voltage dimmer.

If the OP has a problem with that setup, he could always swap out the sensor with a regular $0.79 toggle switch though.

I do agree that the motion sensor is part of the problem with lamp failure though. It's a good thing that ballast isn't an Instant Start ballast. He'd be changing it twice as often.

 

[blasterman]

If the motion detector is acting as nothing more than a mains switch to the current ballast (off or on) , why would it make a difference with an LED supply? The LED supply is certainly going to be able to handle power cycling better than a magnetic ballast / fluorescent tube, correct? I don't understand how a dimmer is even relevant here.

As for building this, it's simply a question of price. You need about 30 Crees, a 12-13" square alu plate, and the power supply.

Again, this is something more easily done with 3-4 big Bridgelux emitters, but then you have to figure out how to drive them. The Crees cost more, but are easier/cheaper to drive because big drivers typically come in 350/700mA multiples.

 

[ponygt65]

If the motion detector is acting as nothing more than a mains switch to the current ballast (off or on) , why would it make a difference with an LED supply? The LED supply is certainly going to be able to handle power cycling better than a magnetic ballast / fluorescent tube, correct? I don't understand how a dimmer is even relevant here.

As for building this, it's simply a question of price. You need about 30 Crees, a 12-13" square alu plate, and the power supply.

Again, this is something more easily done with 3-4 big Bridgelux emitters, but then you have to figure out how to drive them. The Crees cost more, but are easier/cheaper to drive because big drivers typically come in 350/700mA multiples.

Compatability issues between the driver and the Sensor. I used the dimming as an example, because some wouldnt' think there would be an issue there either.

Just like some motion sensors aren't compatible with some ballasts or CFL's.

Dimming fluorescents: same thing. Some think any dimmer and any dimming ballast, should work. And that is incorrect. Brands/setups vary.

It's merely a precaution that most dont' think about that could save him some grief potentially. Tis all.:thumbsup:


EDIT: Basically, he has to worry about minimum load. He won't have a high draw going to LEDs and the motion sensor might not be able to function properly. THat's why Low Voltage Dimmers are required for some setups.