TemperatureCorrection

Temperature Correction of Ampacity

Ampacity Correction
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Where a conductor is expected to occupy a space where the surrounding (ambient) temperature will exceed 86 degrees Fahrenheit, then a reduction (derating) in the table ampacity will produce the corrected ampacity for that specific use.

Temperature correction is ALWAYS made based on maximum temperature (over 86 degrees F) the conductor will encounter on its travel from source to load.

Example: What is the corrected ampacity for a #2 THWN copper conductor expected to pass through a maximum temperature of 100 degrees F?

Solution: The table ampacity of this conductor is 115 amps. Follow down the table 310.16 to find the correction factor for temperature of .88. Then multiply these two numbers together.

Result: The corrected ampacity for this specific use is 101.2 amps.

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