What is the ampacity of a 1 AWG THW copper conductor at an ambient temperature of 55°C?

To determine the ampacity of a 1 AWG THW copper conductor at an ambient temperature of 55°C, it is important first to refer to the National Electrical Code (NEC) tables which provide the ampacity ratings for conductors under different conditions.

For a 1 AWG copper conductor, the standard ampacity at an ambient temperature of 30°C is typically around 100 amps. However, when the ambient temperature rises, the ampacity of the conductor is affected because higher temperatures can increase resistance and consequently heat in the conductor.

The ampacity must be adjusted according to the temperature correction factors specified in the NEC. At 55°C, a correction factor of 0.82 is commonly applied to the ampacity value determined at 30°C.

To calculate the adjusted ampacity at 55°C:

1. Start with the standard ampacity: 100 A at 30°C.

2. Apply the temperature correction factor: 100 A * 0.82 = 82 A.

Considering common applications and safety practices, it is essential to further take into account specific usage environments and installation conditions that might adjust this final rating. However, the appropriate choice from the options provided, which rounds closely to the adjusted ampacity