Code Quiz: Bonding & Grounding Requirements for Standby Generators
Based on the 2020 NEC.
Question: Does a standby generator installed at a building require bonding and grounding as a separately derived system?
See answer below.
Answer: It depends on the particular installation.
Explanation: The generator would only be considered a separately derived system if the transfer equipment contains a switching pole for the grounded (neutral) conductor. If the transfer switch contained a solid neutral pole, then it would not be considered a separately derived system. See Sec. 250.30 and the informational Notes in this section.
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.