12VDC, 1.5 amp capacity wire - Electrical Questions. Read Only. No more posting. - PlanetChristmas! Forums. Read Only. We've moved to http://talk.planetchristmas.com - The Forums of PlanetChristmas have moved to http://talk.PlanetChristmas.com
What gauge wire should be used to run power to Wirekat's MR16 low voltage DC LED's? These are the 12VDC, 1.5 amp LEDs. I am looking at runs of about 50 - 75 feet. Would 20 or 22 gauge wire be sufficient?
Do they really take 1.5A? That sounds too high by about a factor of ten, as the ones the MR16 LED lights that I obtained last year from him measured much lower (using an oscilloscope).
pshort wrote: Do they really take 1.5A? That sounds too high by about a factor of ten, as the ones the MR16 LED lights that I obtained last year from him measured much lower (using an oscilloscope).
Just remember that amps at 12V will be 10x the amps at 120V, given the same wattage... But you probably know that already
I ran a sweep of regulated DC voltages from 1V to 18V and measured DC current at each half volt step. For red, green, blue, and warm white, the highest current reading I ever saw was 210mA, or 0.21A. Attached is a graph of current (mA) and power (mW) from one of the Green LED's.. I'm still working on some other tests and ideas that I plan to share eventually.
Those numbers (around 200 mA) make more sense than 1.5A.
The resistance of 20AWG wire is around 20 Ohms/1000 Feet (10 Ohms times 2 directions). At fifty feet the total resistance is around 1 Ohm, and a .2A current draw means that the voltage is down by 0.2V. So 20 AWG (or 22 AWG, for that matter) should be fine if you are using the wire to supply power to just one lamp.
