Parts of Chapter 2 provide the requirements for services, feeders, and branches. Parts of Chapter 3 tell you how to size conductors. How can you put all of this together for an actual application or to solve a problem on an electrical license exam? Doing either one accurately and efficiently takes practice, but to get the feel of how these requirements work together there is a solution right in the NEC.
It’s called Informative Annex D. It contains examples of various kinds of problems you might solve in the field or on an exam. While the level of explanation is less than what you’d have with a structured program of study, it is nonetheless very helpful for nailing down the concepts.
If you walk through Example D3 (Store Building), you will cover the major steps for calculating the loads, sizing the conductors, and sizing the overcurrent protection for most commercial applications. If your applications are primarily industrial, then you will also want to walk through Example D3(a).
About the Author
Mark Lamendola
Mark is an expert in maintenance management, having racked up an impressive track record during his time working in the field. He also has extensive knowledge of, and practical expertise with, the National Electrical Code (NEC). Through his consulting business, he provides articles and training materials on electrical topics, specializing in making difficult subjects easy to understand and focusing on the practical aspects of electrical work.
Prior to starting his own business, Mark served as the Technical Editor on EC&M for six years, worked three years in nuclear maintenance, six years as a contract project engineer/project manager, three years as a systems engineer, and three years in plant maintenance management.
Mark earned an AAS degree from Rock Valley College, a BSEET from Columbia Pacific University, and an MBA from Lake Erie College. He’s also completed several related certifications over the years and even was formerly licensed as a Master Electrician. He is a Senior Member of the IEEE and past Chairman of the Kansas City Chapters of both the IEEE and the IEEE Computer Society. Mark also served as the program director for, a board member of, and webmaster of, the Midwest Chapter of the 7x24 Exchange. He has also held memberships with the following organizations: NETA, NFPA, International Association of Webmasters, and Institute of Certified Professional Managers.