12/3 L5-15 extension cord safe for 20a service?
 

I plan to run 2 2000W elements of two circuits, both of which have outside outlets. One is a T-blade style L5-20, but the other is a standard household L5-15. They're definitely on separate circuits and both definitely have 20A breakers in the main panel.

Any issue using a run-of-the-mill 12/3 extension cord with L5-15 ends to power a 2000W element on an otherwise up to code circuit, since 12/3 can handle 20+ amps?

12/3 is safe for 20 amps but you may have some voltage drop across the cord if you run a long one. I would not run over 12'.

I agree completely that this is best practice, I have used a 25 footer without issue FWIW. No naps w/ the power on:mug:

The problem with the length of the run would be voltage drop. The heat given by the conductors in the cord is not an issue for 2 reasons. 1) the heat is dissipated over a greater length. 2) The conductor is sized appropriately for the amperage anyway. An underpowered television may suffer with insufficient voltage. An underpowered element would just produce less.

Thanks for the info. After more thought, I've gone back to my original plan of a single element on a 240v system. Simpler, more power, and less hassle with only one power source to worry about.