I have a small group of lights, 2 lights x 5w each=10w total, about 120ft from a 300watt transformer. Is 14/2 enough for this run or do I really need 12/2?
Mike, We use a rule-of-thumb to use #12/2 for LEDs in a run between 100 ft. and 200 ft. But, with such a small load, #14/2 would result in a voltage loss of only about 1 volt. Still, the advantages of #12/2 for such long runs are increased durability of the heavier gauge and the capability of using that wire to expand the system in the future. There are many pros who use #12/2 or #10/2 for all their installations.
We have been doing installs for many years. We have always used 12/2 on all of our installs. This gives us system expandability into the future. There is little cost difference to upgrade to 12/2. 12/2 has been good to us !!!!
I like carrying 14 or even 16. It has it's purpose, if you do a lot of home runs the savings can add up. For example, instead of doing six 10-20ft strings of 12awg off of one 12awg feed you can do the strings in 14 or 16. Depending on how much installing you do it can amount to a substantial savings.
