What is the ampacity of a 1 AWG THW copper conductor in an ambient temperature of 110°F?

To determine the correct ampacity of a 1 AWG THW copper conductor in an ambient temperature of 110°F, it’s important to refer to the National Electrical Code (NEC) tables, which provide ampacity ratings based on specific conditions, including the type of conductor and the ambient temperature.

At an ambient temperature of 86°F (which is the standard reference temperature for ampacity ratings), a 1 AWG THW copper conductor has a base ampacity of 130 amps. However, the ampacity must be adjusted due to the higher ambient temperature of 110°F.

According to NEC guidelines, when the ambient temperature exceeds 86°F, a temperature correction factor is applied. For the temperature of 110°F, a correction factor of approximately 0.87 is typically used.

Calculating this adjustment, you would take the base ampacity of 130 amps and multiply it by the correction factor:

130 A × 0.87 ≈ 113.1 A.

This value typically rounds down to consider further de-rating factors.

The closest value from the options provided is 107 A. This is the ampacity that reflects the adjustments made for the elevated temperature, making it the correct answer for the scenario