Code Quiz: Protection of Fixed Industrial Process Heating Equipment
Based on the 2020 NEC.
Question: What is the maximum size permitted for protection of resistance type heating elements in a fixed industrial process?
See answer below.
Answer: 150A
Explanation: In the 2020 NEC, Sec. 425.22(B) was revised to allow heating elements to be subdivided into circuits of 120A and protected at 150A if the one of the following conditions are met:
- Elements are integral with and enclosed within a process heating surface
- Elements are completely contained within an enclosure identified as suitable for this use
- Elements are contained within an ASME-rated and stamped vessel
If the installation does not meet one of the three listed conditions, the previous rules of elements subdivided into 48A circuits protected at not more than 60A would apply.
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.