LED Bulbs with a dimmer

[John Timmins]

OK we took down the one bulb lamp fixture in the dining room and replaced it with a 5 bulb fixture that is more attractive. It was in another home and has 5 bulbs in it already. The one bulb fixture had a 750 lumens bulb. The 5 bulb fixture has 5 bulbs at 800 Lumens each, and that 32000 lumens is like a train headlight in there ! My question is about dimmers and LED bulbs. I know some say NOT DIMABLE. How much can that dimmer take to dim those 5 bulbs? Are dimmers rated. Should I get 5 new lower Lumen bulbs and then add a dimmer switch ? I'm not trying to save money; having a dimmer is what I really want, but I'm asking if a dimmer only will dim that brightness down by itself or is it too big a job for it. I understand dimmers put off a lot of heat. A new dimmer will be next to another dimmer although both will probably not be used at the same time.

 

[BLUE72CAMARO]

I think you need to know what the power consumption of the 5 bulbs is to be able to answer that question. So how many watts are the bulbs you are planning to run in it?

 

[John Timmins]

The fine print is very hard to read. I believe the bulb is A19 8.2W 800 Lumen for one of 5 bulbs.

 

[dave*99]

The 5 bulb fixture has 5 bulbs at 800 Lumens each, and that 32000 lumens is like a train headlight in there !

5x800=4000. Where does 32000 come from?

 

[cybrdyke]

Determine if your specific lamp is dimmable or not.
Try to find a "dimmer compatibility list" from that manufacturer.
If no list is available, look for Lutron C-L dimmers. They 'should' work fine.
CD

 

[John Timmins]

40,000 is correct ! the bulb says SATCO on it. I suppose that's the brand ?

 

[dave*99]

Color temperature is rated in Kelvins and 2700,3000,4000,5000 are common values.

Light output (brightness) is in Lumens.

Which value are you quoting?

 

[cybrdyke]

40,000 is correct ! the bulb says SATCO on it. I suppose that's the brand ?

No. You've got something very very wrong.
You have 4000 lumens. (5x800).
Satco makes 243 different A19 lamps. Not all of them are dimmable.
CD

 

[Zeus36]

40,000 is correct ! the bulb says SATCO on it. I suppose that's the brand ?

Where did 40,000 come from? See post #4

 

[engineer2]

I just did 15 wafer lights and simply bought a dimmer that said "LED compatible" on the package.
It also has a tiny adjustment wheel to get the low-level setting to your liking.

 

[isb cornbinder]

I wanted to dim the dashboard instrument back-lighting in my 1940 Ford. The resistance dimmer in the light switch will not work with LED. I bought a pulse frequency generator for this specifically. If I remember, it cost about $25. I will try and find a picture. There are lots of options for home LED light dimmers.

 

[John Timmins]

I found the bulbs . Medium screw E26, dimable, 8,2W 120W A19/SW/LED E26/930/120V Satco bulb 12420 3000K is on the bulb. 800Lm is on the bulb.

It seems to me that a Home Depot dimmer should be OK.

 

[no704]

From my small knowledge on this subject, dimmers now are more of a pulse width control vs the old style ones that were parisidic loads.

 

[whateg01]

It's not the wattage that is a concern with LED bulbs. The LED draws much less current, so there is less power to be dissipated by the dimmer. As no704 stated, a dimmer that works via PWM will work with LEDs.

 

[iadr]

I bought a number of Legrand Radiance dimmers and had to bend the truth and nearly beg to get a refund. I had wanted them b/c they were lit when off.
They had minimum wattage of something like 60 in order to function (expressed as amps verbally by tech line, and NOT anywhere on the packaging or the web description of the product on their website), and ... neither 4 wafers in the kitchen nor the bedroom ceiling fixture were enough. In the mainfloor bedrooms, that's original to the house wiring and there was no neutral. So they worked in 0 of 6 locations.
When I replaced them with Home Depot Canada ones, they worked but the kitchen fixture (not quite a chandelier) needed its bulbs replaced, as they were not dimmable.
All almost irrelevant here, I know, but... fact is you can still have issues sourcing and installing LED dimmers.
Between phone calls to Legrand tech, a contractor (who was in for something else and I offered cash for his time), return costs, reshopping for, and the bulbs etc, I've got 5x more cost, and easily that in my time into this project. Maybe I experienced worst case, IDK.

 

[dave*99]

The majority of the dimmers you will see are triac dimmers.

Dimming LEDs can be frustrating. Flashing, strobing, flickering, pulsing issues can occur.

Some LED manufacturers post compatibility lists for dimmers that work with their lights.

Lutron has a good reputation for their LED compatible dimmers.

I have the latest offering from Leviton. Not perfect.

 

[Metal-Marc]

5x800=4000. Where does 32000 come from?

Just keep on adding and you'll get there.

 

[dave*99]

Just keep on adding and you'll get there.

Must be that new math.

 

[yatg]

Must be that new math.

inflation

 

[Citation]

For what it's worth, I've found some dimmable LEDs go nearly to zero others perhaps to 50. They also can be somewhat grumpy when dimmed. Switching to a lower output lamp would be my first choice. Those Edison style bulbs can be a good choice. Avoid the cheap ones that don't have a good smoothing circuit. They can have a noticable 60hz flicker.

 

[fitter30]

Need a led dimmer not a incandescent one. Incandescent dimmers work by cycling power not reducing voltage.

 

[dave*99]

The most common LED dimmers are phase-cutting dimmers.

All phase-cutting dimmers work by switching the AC mains supply to the LED lamp on and off twice in every mains cycle. This has the effect of reducing the flow of electrical energy to the LED lamp or fixture, so reducing its light output.

There are two types of phase-cutting dimmers.

• Leading edge phase-cutting dimmers (also known as triac dimmers and rising edge dimmers). These work by switching the current off at the zero-crossing point (see diagram) and on again later in the same mains cycle. The amount of energy flowing to the LEDs depends on the duration of the “off” period. The longer the off period the dimmer the LEDs will appear to be.

• Trailing edge phase-cutting dimmers. These work by switching the current on at the zero crossing point (see diagram) and off later in the mains cycle. Usually this is done with an electronic component called an isolated gate bipolar transistor (IGBT). The amount of energy flowing to the LEDs depends on the duration of the “off” period. The longer the off period the dimmer the LEDs will appear to be.

 

[dave*99]

Triac (leading edge) dimmers are the most common types and readily found in the big box stores.
Trailing edge dimmers are about 3X the cost.

 

[dogdog]

OK we took down the one bulb lamp fixture in the dining room and replaced it with a 5 bulb fixture that is more attractive. It was in another home and has 5 bulbs in it already. The one bulb fixture had a 750 lumens bulb. The 5 bulb fixture has 5 bulbs at 800 Lumens each, and that 32000 lumens is like a train headlight in there ! My question is about dimmers and LED bulbs. I know some say NOT DIMABLE. How much can that dimmer take to dim those 5 bulbs? Are dimmers rated. Should I get 5 new lower Lumen bulbs and then add a dimmer switch ? I'm not trying to save money; having a dimmer is what I really want, but I'm asking if a dimmer only will dim that brightness down by itself or is it too big a job for it. I understand dimmers put off a lot of heat. A new dimmer will be next to another dimmer although both will probably not be used at the same time.

Other than you need to match the load, I don't think most LED bulbs will pull that much to overload most dimmers. Most dimmers are average 600Watt (physical wattage not equivalent wattage, for example... my 100Watt LED bulb actually consums about 23Watt. )... your biggest problem will be the bulbs themself... Some LED are dim-able, some are not, unless otherwise specified, assume it is not. The ones that "dim-able" they are not that great with the triac type dimmers.not that greats means dimming is not linear. The better ones are the ones that uses 0-10v dimming, but requires 2 extra wires pulled to the power supply.not even sure if screw on type bulbs have 0-10v dimming.. just something to think about.

 

[Zeke]

I have multiple LED can lights in a room. Recently one began to flash on and off at about half brightness. It's fine above that threshold. This thread is of interest to me as I also have some LED bulbs in a ceiling fan and one is doing the same thing at near full brightness. OK, 2 different animals because the can lights have drivers and the old fan was simply fitted with E26 bulbs. The dimmers were all purchased in 2016 and were listed as LED compatible.

This fact may be interesting to you EE's, when the can lights are first switched on they go full bright for a half a second and then light up at the setting on the slide. It's all Leviton. I was about to pull the guts out of the offending can light. Then I opened this thread.

Should I be thinking about changing out the dimmer switches? I can get the model numbers if needed. Just have to pull one out of the box.

 

[dave*99]

In a word. Yes change the dimmer. I have the latest Leviton units. I believe the Lutron units might be better.
My 4” Sylvania puck lights flash sometimes. Usually they are ok. Dimming LEDs can be frustrating. I discussed this with the local electrician that wires a ton of new houses each year and he expressed similar frustration.