LED Lighting Help

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Old 11-25-11, 07:49 AM
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LED Lighting Help

I am not sure this is the correct forum for this question but if not maybe you can lead me to the correct place.

I have be trying for weeks to convert some of my lights to LED with little success.

They have some great products in the market now but the one problem I keep having has to do with dimming.

I have 4 recessed lights in the living room with typical 65 watt floods and a dimmer. Home Depot has several options that I have tried. They have beautiful flood like lights that look similar to regular floods.

I tried it and it looked great. Good color, brightness was very even but when I went to dim it the light stayed at least 3 - 4xs brighter than the incandescent floods.

I tried 3 different dimmers and nothing so I exchanged it for one of their complete LED flood recessed trim fixtures, T85, and it worked great on full power but as soon as I dimmed it all the way down it remained at least 3 - 4xs brighter than the regular floods.

I have spoken to people at home depot and all say that it should go down to about 5% of the output which is about 3 - 5 watts. This should be pretty dim but it was no where near that dim.

Anyone have any experience with these bulbs or can tell me what to look for to get better dimming out of it.

Any help appreciated.
Thanks
 
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Old 11-25-11, 08:08 AM
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Welcome to the forums. Yes, you posted in the right place.

Have you tried using a dimmer made specifically for LEDs? Are the LEDs you used labeled as dimmable? If not that is a big part of you problem. Here is a page from one of the major dimmer makers which explains the problem. http://www.lutron.com/Education-Trai...LsandLEDs.aspx
 
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Old 11-25-11, 09:50 AM
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LEDs and CFL need a minimum load to function or they drop off and do not turn on. For LED's it's about 5% as you state, but at this moment they cannot dim down to incandescent levels, . at 5 to 6 watts that still pretty bright for a LED fixture. I have 10 watt LEDs in my bathroom ( 3 of them ) and they are plenty bright for my needs. Keep in mind dimming also decreases the life span pf the LED / driver. And as the LEDs get older over time and reach ther end of life hours, they lumen output also drops off, to about 50% to 70% of stated value. A lot depends of the quality of the LED chips. Cheap LEDs will not last long, higher quality ones ( those made by CREE or Phillips ) last longer and maintain the out put levels for longer hours, but of course cost more.

see the link below to read up on LED and CFL dimming

http://cool.conservation-us.org/byor...mming_leds.pdf
 
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Old 11-25-11, 10:11 AM
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Does the package for the lights you bought say they are dimmable? Don't go by what some dude in the store says. Some are dimmable and some are not.

I am guessing that your bulbs are not dimmable. The electronics inside the bulb are seing the voltage drop as you turn the dimmer and are compensating to keep the output of the bulb constant. Basically the bulb is fighting you by trying to always produce consistent light. A bulb intended for dimming will recognize the voltage drop as an indication to dim the bulb.
 
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Old 11-26-11, 04:42 AM
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Yes.. all the LEDs I purchased were dimmable as written on their packages. When I mentioned I spoke with someone at home depot I was referring to someone standing in an isle but I called corporate and they gave me the number for the manufacturer.

I spoke with the manufacturer directly and like in the old computer days everyone blames everyone else. The bulb people say it is the dimmer switch and the dimmer people say it is the bulb.

The point is it is a shame that we cannot just get a simple answer to a simple question. Why can't I get an LED bulb to dim as low as a regular bulb?

I also bought smaller bulbs replace me regular 60 watt bulbs in my light and the light patter is awful.

LEDs not ready for prime time IMHO.
 
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Old 11-26-11, 06:10 AM
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An LED bulb can not get as low as an incandescent bulb for a simple reason: It is not an incandescent bulb. While they both produce light, they are doing it in very different ways. You are comparing apples to oranges and are trying to get an apple to taste like an orange (or at least a Granny Smith to taste like a Red Delicious).

The others have mentioned why it wont dim the way you want ("LEDs and CFL need a minimum load to function or they drop off and do not turn on.") but you still have not mentioned anything about changing the dimmer as Ray mentioned. As dimmer specifically designed to run LED bulbs may get you the dimming range you are looking for. Google LED Dimmer.
 
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Old 11-26-11, 07:00 AM
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LOL! I have been part of this forum since 2002 and with no disrespect to anyone here, does anyone read my actual post?

In my original post I wrote: "I tried 3 different dimmers". Do you really think that none of those dimmers were LED specific? They all are!

I also mentioned that I spoke to the manufacturer of the LEDs. Do you really not think they would have NOT mentioned the dimmers?

The reason I even start on the quest of LEDs is that in HD they had a recessed LED connected to a dimmer as a display and guess what happened when I tried dimming it? It dimmed almost to nothing!!!

I do not doubt that there are many people who write to these forums that have no clue about anything but please read what I am writing and it will save a lot of these types of posts.

I have spoken to EcoSmart, Commercial Electric, Lutron & Leviton and believe me they all have made many recommendations that I did try.

So you may say then why did I write to this forum. I wrote here because there are times when other people have the same problem and find an ingenious solution that may have not been noticed.

In any event I always appreciate the help I have received here in the past and look forward to the future of this forum.
 
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Old 11-26-11, 07:09 AM
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I will admit, I did miss the part of you trying the different dimmers. I blame not being awake yet.

So, you said that the display in HD will dim down to nothing. (I know exactly the disply you are referring to) are you using the same parts as in the display? If not then all bets are off.

Rereading your first post, are you judging brightness but eye or are you using a light meter? Watts are not an indication of light output.

Again, you are expecting an LED bulb to perform as an incandescent. While that would be ideal, it likely will not happen for quite some time, if at all. As you said, LEDs might not be ready for prime time.
 
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