…Dimming LED’s.

So every day we take calls about people trying to find the right dimmer for their LED product. This can get very confusing and why we only stock a select number of LED products and manufacturers of LED products that we have experience with and know their abilities and limitations.

Apples vs. apples, doesn’t apply. We have seen a huge number of LED lamps, bulbs, retro-fit recessed kits, and linear LED. Some of which are dimmable others do not dim. Those that dim, dim well or not so well…. If you are in the market for a LED product and want it to dim, make sure it says specifically that it is. The good thing is those that dim are proud of the fact and usually market the fact, those that don’t dim neglect to mention the fact. Another off-topic point to mention is some LED’s are more efficient than others. We’ve seen 4watt MR16 LED’s put out a significant amount more light that 6watt versions from certain manufacturers. So we can’t really compare Watts or even lumens, we should look at the lumen-per-watt spec. if we are looking for the most efficient lamp.

Percentages… Like fluorescent dimming LED typically only dim down to a certain range. Some of the LED are incredibly pathetic in their dimming range, others get down to 15% or better. Lutron has luckily come out with a product to solve and improve on some of these attributes and if nothing else, improves the end-users satisfaction & perception. The newer Diva dimmer has a trim adjustment to you can slide the dimming slider to it’s lowest point and adjust the trim setting to the lowest stable low light level your LED or CFL can produce.  This makes use of the full range of the slider to within the stable dimming range of the product you are trying to dim.  This is a great dimmer for 90% of us trying to dim LED or CFL. Please note the maximum wattage is 150watts, which is roughly 10 LED recessed lights. This dimmer is also single pole and 3-way for a very reasonable price.

Smart Dimmers & Loading.  Smart dimmers are like the Lutron Maestro series and others like it that typically have LED level indicators and/or ‘fade-to-on’ & ‘fade-to-off’ control. The electronics in these type of dimmers typically have a ‘Minimum wattage’. They always have but until recently it hasn’t been much of an issue, and these numbers weren’t typically published. Most normal smart dimmers require minimum loading of about 50watts. and this typically needs to be over a fair amount if you are planning on dimming into a low end. Some newer dimmers are beginning to pop up called phase-adaptive, or phase compensating. These are an extension of the smart dimmer to adjust it self to the load type to compensate for some of these issues. Other ways to combat the minimum load is using electronic low voltage dimmers. The ELV dimmers inherently have a low minimum but aren’t necessary the best or right type of dimmer depending on your power supply, transformer or driver.

Over loading, perhaps a poor choice of words, but another problem facing dimming LED loads is in-rush current. Thus the diva above can only handle 150watts of LED. The drivers of these LED products can have huge in rush and certain dimmers can handle them better than other. This problem is just being recognized by some manufacturers and company’s like Lutron are publishing their findings n products they have tested. Have a look at Lutrons LED page [Click Here]. Here you will find a lot of information on dimming LED’s what dimmers can handle what in terms of minimum and maximums, light levels to expect etc… You can also click on some of the tested products to see what Lutron calls their ‘report card’ for those product so you can know what to expect.

Low Voltage Dimming. Or dimming the low voltage side of the LED system. This problem started popping up when some LED manufactures with non-dimmable power supplies or drivers said they could be dimmed. They simply added a potentiometer to the low voltage side of the driver or a 0-10v control to their constant current drivers. These are usually in the form of some ugly black box with a knob that is intended to be surface mounted.

So what to do?? Before you buy I would ask to see the product dim and ask what they are using to dim it. I would be very hesitant to purchase anything super cheap right now and I would surge you to purchase from manufacturers and stores that you knw and trust. One last thing, check the warranty, I’ve seen a few LED warranties that are longer than mortgage paperwork….

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