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What makes light bulbs go bad in dimmers

Posted by chefwong (My Page) on
Sat, Dec 26, 09 at 21:56

My entire basement is using Lutron Vareo Dimmers...love the looks, hate the cheap buttons on this series of dimmers.

We rarely adjust the dimmer level and the bulbs in my recessed cans attached to them constantly go bad. We are using generally Sylvania bulbs of Westinghouse . I have primarily used 75W flood reflectors (R20).

Before I try new PAR series bulbs, I'd figured I'd give it a shot on solving what constantly causes my bulbs to go bad. All of them in all the cans go bad at LEAST 1-2 times year ! This is in a residential application so it's not like they are constantly on.

On our 1st and 2nd floors using Lutron Maestro series dimmers, I had yet to have a single bulb go bad.

Is it the dimmers ? Wiring ? Vibration from the 1st floor since obviously the main floor sees the most foot traffic ?

Whaddya guys suggest could be that causes these bulbs to go bad. I can change a bulb in one can, only to have the bulb in that can or the other bulb that is on the same dimmer switch go bad a couple days later.

Will running 130V bulbs help. I have noticed NO difference in bulbs not going bad by using Long Life 120V bulbs.


Follow-Up Postings:

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RE: What makes light bulbs go bad in dimmers

"Vibration from the 1st floor since obviously the main floor sees the most foot traffic ?"

This is very common casue of shrtened bulb life.


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RE: What makes light bulbs go bad in dimmers

Vibration could be a culprit. I don't think they make a rough service PAR bulb but you could try a regular "A" type rough service bulb to if it lasts longer for you.

The other alternative would be to use a compact fluorescent.


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RE: What makes light bulbs go bad in dimmers

Don't know the bulbs you're using, but if they're halogen, know that halogen bulbs can't stand being dimmed all the time. They need to be switched on to full brightness regularly.


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RE: What makes light bulbs go bad in dimmers

Guido,

Could you explain the science behind your statement about halogen bulbs not being able to "stand being dimmed all the time"? I don't understand how providing higher voltage to a bulb could make it last longer. It would seem to me that higher voltage would just increase the heat output from the bulb, which would shorten its life.

Thanks.


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RE: What makes light bulbs go bad in dimmers

The reason halogen bulbs last longer is that filament material emitted from the filament is eventually redeposited on the filament. The redepositing does not work as well if the temperature of the bulb is too low, which happens when a dimmer is used.

I have seen claims that when the temperature is too low, metal is deposited on the quartz envelope, but is removed and put back on the filament if the bulb is operated at full output for some time. I do not know if that is true.

Here is a link that might be useful: How Halogen Works, by Sylvania


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RE: What makes light bulbs go bad in dimmers

Along with vibration, heat is also a prime cause of premature bulb failure. Not taking the bulb to its rated voltage will reduce the operating temperature, When I buy 130v bulbs instead of 120v, they seem to last a lot longer.
YMMV


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RE: What makes light bulbs go bad in dimmers

What is the age of the Vareo dimmers? Are the buttons breaking or do you not like them for another reason? Older Vareo had plastic as the springy mechanism to allow the center button to push in. New ones have metal.


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RE: What makes light bulbs go bad in dimmers

Hi Dim4fun -

I love the look of the dimmers but yes, the buttons are constantly breaking on us. I suspect we have the older designs. Is the new *buttons* the same buttons but with metal springs -- meaning can I retrofit them into our older switches.

Would you believe me if I told you I have a box with at least 30+ spare buttons...Since our reno, I must replace at least 5-7 buttons a year !


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RE: What makes light bulbs go bad in dimmers

New buttons fit old dimmers. Call Lutron and explain the problem. They may send them for free.


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RE: What makes light bulbs go bad in dimmers

Thx dim4fun Go figure. I hope you're not a sparkie == callbacks on these .

I did the reno ourselves but I can only imagine the headaches for a pro to install them and do callbacks.

I was very tempted this summer to replace all of out Vareo switches as I was tired of replacing the #$@$#$# buttons.

Hmmm, me wonders how much more durable the metal spring design will hold up...


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