Code Quiz: Service or Feeder Conductors?

What's the difference between service and feeder conductors?

Oct. 23, 2019

Fill in the blank: You are working on a large private multi-building campus where the owner provides a 15kV loop with pad-mounted transformers to supply power to each building. The conductors from the pad-mount transformer to the 480V switchgear in each building are considered to be _________ conductors.

See the answer below.

Answer: feeder

Explanation: Because the conductors originate in a privately-owned transformer and not a utility transformer, they cannot be service entrance conductors. They will be subject to the requirements of Art. 215 rather than Art. 230.

One significant difference would be that the feeder would need to include an equipment grounding conductor (EGC) that a service would not require.

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.