We have motors that are interlocked, preventing them from being on at the same time. Do we still have to add them up for service and feeder calculations?
Q. We have motors that are interlocked, preventing them from being on at the same time. Do we still have to add them up for service and feeder calculations?
A. No. Where the circuitry is interlocked to prevent operation of motors at the same time, only those motors that operate simultaneously (and result in the largest current) need to be counted [430.24 Ex. No. 3].
About the Author
Mike Holt
Mike Holt is the owner of Mike Holt Enterprises (www.MikeHolt.com), one of the largest electrical publishers in the United States. He earned a master's degree in the Business Administration Program (MBA) from the University of Miami. He earned his reputation as a National Electrical Code (NEC) expert by working his way up through the electrical trade. Formally a construction editor for two different trade publications, Mike started his career as an apprentice electrician and eventually became a master electrician, an electrical inspector, a contractor, and an educator. Mike has taught more than 1,000 classes on 30 different electrical-related subjects — ranging from alarm installations to exam preparation and voltage drop calculations. He continues to produce seminars, videos, books, and online training for the trade as well as contribute monthly Code content to EC&M magazine.
