Wire Derating Chart !!exclusive!! | INSTANT · GUIDE |

If the air around the wire is hotter than 86°F, the wire has less capacity to dissipate its own heat. The hotter the environment, the less amperage the wire can handle.

Standard NEC Table values usually start at 30°C (86°F). wire derating chart

Every current-carrying wire generates heat due to internal resistance ( I2Rcap I squared cap R If the air around the wire is hotter