# What size wire for 10w LED flood light.



## 0100 (Oct 14, 2015)

I am doing my 12v LED flood lights tomorrow, but not sure what wire to go with. They are 10w lights with the furthest run being about 75'.

I am thinking either 20/2 or 18/2.

Thanks!


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## 0100 (Oct 14, 2015)

Sorry can't edit my original post.

Anyways, this will be a single light for each wire not run in series.

http://www.calculator.net/voltage-d...tance=75&distanceunit=feet&amperes=1&x=74&y=8

So looking at this calculator using 75' and 18awg I am left with 11.04 volts at the end of the line. Is this ok?


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## corey872 (Jan 10, 2010)

Well, the waters are a bit muddy on this one. No LED actually runs on 12 volts. So are they using a 12V input and dropping it to 3.3ish volts with a voltage regulator to run the LED or are they running several LEDs in series which could use the 12V directly?

I guess in the worst case, you need to move about an amp or a little more to light the LED. The wire chart I use shows ~2.3 amps for "power transmission" on 18 gauge wire, so that should be acceptable. It also shows 1.5 amps for 20 gauge wire - so probably right at the limit of what you're looking for, though there is obviously a bit of safety factor built into the wire chart itself.

As far as the voltage drop - not sure if that is what you're measuring or what you calculated. If you measured it - and the LED is still working, then that voltage drop should be acceptable. If the LED is not working at that voltage, then they may have some sort of regulator which has dropped out due to low voltage. ...and that would not be acceptable.


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## 0100 (Oct 14, 2015)

Thanks for the help! Yeah it was just what I calculated not actually measured. I went with 18/2 and at 75' works great. Thanks again.


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