LED strip lighting


New member
Fort Lauderdale
I have several questions regarding LED strip lighting installation, I seem to get may different answers from manufacturers where no two answers are ever the same. I have been told that using LED 5050 strip lighting uses 30 or 60 LED's per meter with a power consumption of either 7.2/14.4 watts per meter respectively, total for a 16' reel or 5 meters is 36w or 72w.

1) When calculating load of a 120v/12v/150 watt transformer using LED strip lighting do we calculate our amperage on the line or load side?
2) What would be the correct sizing of the transformer if using 32' or 2-16' reels @ 72 watts each reel?
3) If varying the voltage on the line side of a magnetic transformer what effect will it have on the lighting circuit?
4) Is it necessary to use a LED/CFL dimmer when dimming the line voltage or can a standard dimmer be used in place of?
5) What wire is required or can be substituted for proper operation and compliance?
6) Is the transformer/driver required to be dimmable in order to operate properly?

I do not know much about LED lighting and any help would be greatly appreciated.



Senior Member
First, determine the footage of what you are installing. Then, do the math to determine the total connected wattage. Second, determine the type of strip. There are many types, but the typical is the 5050 single row. You can buy 12volt, 24volt, and 120 volt. Determine what voltage best suits the installation. I stay with 12 volt for most apps due to pricing and availability, and I'm usually not installing long runs. Next, determine the amperage of the installed strip. Power supplies, dimmers, etc...for the LED strips are usually rated in amps. Since it is lighting, exceed amperage by 125% for the power supply. Now it's time to decide how you will control it. You can install a dimmable power supply if installing low volt cable in walls is out of the question. I prefer running low volt cable to switch boxes ( with voltage barriers as needed ) and using Lutron 12 vdc dimmers as the dimmable power supplies are much more expensive. There are many control options like RF dimmers, PBX controllers, WiFi, etc...just make sure the controllers are rated for the current. PS...if you install a dimmable power supply, you must use an LED rated dimmer. PSS...a power supply includes the driver.

LED strips come in different widths, like 8mm, 10mm, etc...make sure your connectors and fittings are correct
soldered joints are the best, if the strip is installed in hard to reach areas...I would use solder
test polarity and connections before installation
after 10 foot of series connected length, strips may become slightly more dim as the run gets longer. you can install an amplifier or you can install a parallel feeder from supply. If I am running longer runs, I use a 16 or 18 awg cable assembly.

I just got into the market about 6 months ago and now I am installing it everywhere. I've learned a lot of this by trial and error, hope this helps! Let me know if I can be of any further assistance.


New User
Dallas, TX
I have a project (i'm forced to take over from electricians) that involve 15 of the 5M RGB LED strip lights. These are 300 LED / reel and my calculations are about 1000W are required. The strips are mounted in a coffered ceiling and wiring is homerun back to a closet.

I'm wondering what power supplies you guys would suggest and how would you wire them ... one for each color? separate out 4 or 5 stripes and use a single power supply for the 4 or 5 strips?