National Electrical Code

An NEC Crash Course to Get You Started — Part 7

Aug. 3, 2021

The importance of Chapter 4

Chapter 4 of the National Electrical Code (NEC) covers specific types of equipment for general use.

It’s a big chapter, and it contains the biggest article in the NEC. That’s Art. 430, which provides the requirements for motors. Article 430 has Fig. 430.1, which is a “key” that helps you see how to apply Art. 430 to each discreet phase of a motor installation. For example, to size the motor circuit conductor, you need to follow the requirements in Part II. While Fig. 430.1 is very helpful, you still must be familiar with Art. 430 overall.

You also should be familiar with motor theory and motor application principles. We size motor conductors and circuit protection differently from how we size conductors and circuit protection for other types of circuits. A person familiar with motor theory will tell you that’s because we need to allow for inrush current.

Other articles in Chapter 4 aren’t exactly light reading, either. We see that in the very first one, Art. 400 “Flexible Cords and Flexible Cables.” Table 400.4 runs five full pages.

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.