Temperature Correction of Ampacity
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
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.
Find practice problems HERE.
Find audio support HERE.
Click on any of these titles from Amazon.com which may be of interest to
Order them directly from Amazon.com with a debit or credit card.