How much current can twelve 12 AWG THHN copper conductors carry at an ambient temperature of 32°C when subjected to nonlinear loads?

To determine the correct current-carrying capacity for twelve 12 AWG THHN copper conductors at an ambient temperature of 32°C when subjected to nonlinear loads, it is important to refer to the National Electrical Code (NEC) guidelines, which specify the ampacity of conductors based on various factors such as temperature and load type.

For 12 AWG copper conductors rated under typical conditions, the basic ampacity is usually around 20 amps for a single conductor in free air. However, when considering the impact of nonlinear loads, conductor derating factors must be taken into account. Nonlinear loads can produce harmonics that create additional heating in conductors, requiring further reduction of the ampacity.

At an ambient temperature of 32°C, and considering the conditions described, the effective ampacity might be modified. When referencing the NEC tables for ampacity, the current should be reduced for bundling multiple conductors as well as for nonlinear loading, which leads to lowering the allowable current even more than the normal sat button.

Given these considerations, the answer reflects an adjustment due to those derating factors, leading to a reduced current-carrying capacity of 14 A for the twelve 12 AWG THHN copper conductors in