Why not? You obviously wouldn’t do it to a THHN conductor that is rated for 600v, but there are certainly #12 AWG conductors rated for higher voltages. They hav

Why not? You obviously wouldn’t do it to a THHN conductor that is rated for 600v, but there are certainly #12 AWG conductors rated for higher voltages. They have a whole lot more insulation/layers than a regular 600v rated conductor, see: https://www.powerandcables.com/wp-content/uploads/2019/10/Figure-2.jpg https://www.powerandcables.com/wp-content/uploads/2019/10/Fi... High voltage utility distribution lines aren’t insulated by anything other than porcelain bushings and air.