Lightswitch Rave… LED edition

I’ve talked a lot about our LED under cabinet lights, mostly because the electrical inspector made a big deal bout the wire we used for them. Two Thursdays ago, with all of our cabinets in, I got to finish wiring them up. I purchased two 24″ long Waterproof LED Light Bars from Elemental LED, one under each of our wall cabinets. The price was better than LED lights from Lowes and better than halogens from Ikea. Plus they come in a variety of sizes to you can customize. This is what our setup looks like.

LED Light Layout

The red lines represent wires that are run inside the wall. The blue arrows are where I had to solder wires together. Why did I solder them? The alternative is to use wire nuts to connect wires but then I would have to put that connection inside an enclosure of some sort. The other reason I can get away with soldering the connections is the voltage is 12V DC, just like a car! The lights themselves have a plug-in connector. Elemental sells solder adapters that have the other side of the connector on them. They also sell units you can plug in to an outlet.

The soldering itself went painlessly, except I forgot one piece of heat shrink tube. I put a piece of heat shrink tube on each individual wire (positive and negative) and another larger piece to enclose the two wires into a cable. Out of the three connections I forgot this larger, outer heat shrink tubing once. So I just wrapped the wires in electrical tape. *hangs head in shame*

Next I hooked up the driver, which is the white box. This device takes your house’s 120V AC power supply and turns it into 12V DC for the LEDs. I located it in the basement, just below the light switch. You could put it inside of a cabinet but we have glass front cabinets and I needed to enclose the 120V connection in a box of some sort. The smallest box I could find is an ugly 2″x3″ metal or plastic thing. I did use wire nuts to make the connections here. The thick white wire going into the metal box is the 120V from the switch over the counter top. The small white wire coming out the other side carries 12V DC to the first light bar.

LED driver and enclosure for wire connections

LED driver and enclosure for wire connections

With great anticipation I turned the breaker back on and flipped the light switch. At first nothing happened. I had to guess which of the two wires on the solder adapters was positive and I guessed wrong. For anyone else using Elemental LED’s solder adapters the side with the black dashes on it is actually the negative side. The solution was simple, I just had to flip-flop the two 12V wires coming off the driver. Again I flipped the light switch and again nothing happened… then lights flicked on for a split second and quickly turned off. It did this once per second. Not Good!

I triple checked everything and couldn’t find anything wrong so I turned to my old friend Google. Unfortunately Google was not any help in this matter. Any searches for blinking or flashing LED lights turned up a bunch of posts about Audis. LOL After thinking about it for a bit my hunch was that the driver was not powerful enough. Each light bar used 2.9W and I bought a 6W driver. Resistance in the wiring could be eating up more than 0.2W.

I emailed Elemental LED and they confirmed my hunch, it was most likely that the driver was underpowered. I would need to buy the next size up, a 10W driver. They told me they usually bump the power requirements by 10%. I don’t remember seeing that on the website and I wish they would have caught it when I placed my order. This mistake cost me $33.

Last Friday the 10W driver arrived and I installed it along with the other lights I was installing last Saturday. With the more powerful driver the lights work as advertised.

LED lights on by themselves

LED lights on by themselves

PS Lightswitch rave came from one of my favorite youtube videos:
Strong Bad – Techno

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2 Responses to Lightswitch Rave… LED edition

  1. John says:

    Nice project. I have a question: dont you prefer warm white for the kitchen? I put some LED Light Bars in mine, with warm white and it seems that food looks better.

    I bough them from http://www.solidapollo.com.

    J

  2. Paul says:

    We think the “natural white” goes better with our colors. The “warm white” is too yellow for our tastes.

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