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Code Quiz: Avoiding Additional Temperature Correction Adjustments

April 25, 2019

A question about temperature correction and raceway on the roof.

Question: What minimum clearance above a roof is required for a raceway exposed to direct sunlight to avoid the application of additional temperature correction adjustments?

See the answer below.

Answer: 7/8 in.

Explanation: Section 310.15(B)(3)(C) requires an adder of 60°F to be added to the design temperature for ampacity correction purposes for a raceway exposed to direct sunlight on a roof when the clearance above the roof is less than 7/8 in.

Lupacchino is a senior design engineer with Gaylor Electric, Inc. in Noblesville, Ind. and serves as an alternate on NEC Code-Making Panel No. 3. He is currently licensed in more than 80 jurisdictions. He can be reached at [email protected].

About the Author

John Lupacchino | Senior Design Engineer

John began his career in electrical construction as an apprentice and worked his way through the trade. He is currently licensed in more than 80 jurisdictions. With more than 35 years of experience, he now plays a vital role in Gaylor Electric’s Engineering Department, where he serves as a senior design engineer. With a focus on design engineering, quality assurance, and code compliance, he has earned the highest level of respect from industry professionals alike. John currently serves as an alternate on NFPA 70 Code Making Panel No. 3. In addition, he enjoys sharing his electrical knowledge through education. As an Associated Builders and Contractors instructor, he continues to help grow a new generation of high-performing construction leaders.