About the Author

Ray C. Mullin is a former electrical instructor for the Wisconsin Schools of Vocational, Technical and Adult Education. Prior to his retirement, he served as district manager, regional manager, regional vice president and ultimately, director technical liaison for a major electrical manufacturer. He also served on the National Fire Protection Association (NFPA) Code Making Panel 4 of the National Electrical Code® (NEC®). A former journeyman and supervisor for residential, commercial and industrial installations, Mr. Mullin has taught electrical apprentice and journeyman courses, conducted numerous technical and code seminars, written many articles for electrical trade publications and consulted for electrical equipment manufacturers on legal issues. He is also a former member of the Executive Board of the Western Section of the International Association of Electrical Inspectors and a member of the Institute of Electrical and Electronic Engineers and NFPA, Electrical Section. Mr. Mullin attended the University of Wisconsin, Milwaukee School of Engineering, and Colorado State University. Phil Simmons is the founder of Simmons Electrical Services, where he consults on the National Electrical Code® (NEC®) and other codes. He also writes, edits, illustrates and produces technical publications, and he previously provided plan reviews of electrical construction documents and inspections of complex electrical installations. In addition to developing training programs related to electrical codes and safety, Mr. Simmons has presented on these subjects at numerous seminars and conferences for universities, the National Fire Protection Association (NFPA), the International Association of Electrical Inspectors (IAEI), the U.S. Department of Defense and private clients. He has authored and illustrated numerous textbooks on electrical topics and consulted on several lawsuits involving electrical injury and property damage. Mr. Simmons serves NFPA on Code Making Panel 5 of the NEC Committee (grounding and bonding), and he previously served on several other Code Making Panels, the NFPA Standards Council, the NEC Technical Correlating Committee, the IAEI and Underwriters Laboratories. He is a retired member of the International Brotherhood of Electrical Workers. Derek Vigstol is an electrical safety consultant for e-Hazard Management, LLC, where he provides training and other consulting services such as electrical safety audits and electrical safety program development based on OSHA and NFPA 70E®: Standard for Electrical Safety in the Workplace®. Derek earned his master electrician license in the state of Minnesota, where he began his journey into the world of electrical construction. He was also the founder and President of Rum River Home Inspections, LLC. He found his way into a classroom for the Minneapolis Electrical JATC, where he taught both pre-apprentice and apprentice-level electrician students. As an instructor, he participated in the first-ever NEC® Challenge hosted by the National Fire Protection Association (NFPA). Derek became the inaugural NEC Challenge Champion after competing against electrical code experts from across the country. This title then earned him a position working as a member of the technical staff at NFPA. Starting in a staff liaison role guiding NFPA members and AHJs on all things electrical-related, Derek worked his way up to electrical technical lead and eventually senior electrical content specialist. In these roles, he had the opportunity to act as a technical contributor to several key projects -- most notable was his role in the 2017 and 2020 editions of the NEC® Handbook. He is a member of the International Association of Electrical Inspectors (IAEI), the Institute of Electrical and Electronics Engineers (IEEE) and the National Fire Protection Association. Derek has presented on various electrical topics at conferences around the globe and is a regular contributor to several publications in the electrical industry.