What is the ampacity of three 1/0 AWG THW aluminum conductors installed in rigid metal conduit at an ambient temperature of 104°F?

To determine the ampacity of three 1/0 AWG THW aluminum conductors installed in rigid metal conduit at an ambient temperature of 104°F, it's essential to refer to the National Electrical Code (NEC) tables that provide the ampacity ratings for conductors.

For 1/0 AWG aluminum conductors, the base ampacity rating typically starts from a standard ambient temperature, which is often 30°C (86°F). However, since the installation is at an ambient temperature of 104°F (which is approximately 40°C), an adjustment is necessary based on the ampacity adjustment factors that consider the temperature.

According to NEC guidelines, when referencing Table 310.16, at an ambient temperature of 104°F, the ampacity of the conductors is reduced due to the increase in temperature. For three conductors in a raceway, the correction factor will slightly reduce the effective ampacity from the base value.

Given that a single aluminum 1/0 AWG conductor has a base ampacity around 120 A at 30°C, applying the correction for three conductors and considering the increased ambient temperature provides an ampacity of approximately 106 A. Thus, this aligns with the selected choice, making