What correction factor is applied at 35°C for THHN insulation?

The correction factor applied at 35°C for THHN insulation is 0.96. This factor is essential for accurately determining the ampacity of conductors when the ambient temperature deviates from the standard reference temperature, which is typically 20°C or 25°C.

Using the correction factor is crucial in ensuring that the conductor can handle the electrical load without overheating due to a higher operating temperature. At 35°C, the insulation will have slightly different thermal characteristics compared to the standard. Therefore, a correction factor like 0.96 allows for a safer and more effective calculation of the conductor's capacity under those specific conditions.

This adjustment ensures that electrical systems can operate efficiently and safely in varying thermal environments, thereby preventing any potential issues such as insulation breakdown or electrical fires.