Code Basics

Understanding the foundation of the National Electrical Code and applying its principles on the job and in the field


Fig. 1. A motor branch-circuit OCPD must be able to carry the motor’s starting current.

NEC Requirements for Motors – Part 2 of 2

Aug. 9, 2023
Do you know how to protect motors and related equipment from overcurrent and ground faults?
Fig. 1. Use the rules in Art. 430 to calculate and apply overcurrent protection for motors.

NEC Requirements for Motors – Part 1 of 2

July 12, 2023
Do you know the basics of Art. 430, including what overload protection is and what the requirements are for overload protection?
Fig. 1. The rating, type, and installation of receptacles, attachment plugs, and flange inlets can be found in Art. 406 of the NEC.

NEC Requirements for Receptacles

June 14, 2023
It’s easy to commit Code violations with receptacle applications if you don’t have a solid understanding of the NEC requirements.
Fig. 1. The scope of Art. 404 can be found in Sec. 404.1.

NEC Requirements for Switches

May 9, 2023
Don’t let switch-related Code violations darken your reputation.
Fig. 1. Rigid metal conduit requirements can be found in NEC Art. 344.

NEC Requirements for Metal Conduits

April 14, 2023
Do you know the rules for installing the four types of metal conduit listed in the NEC?
Fig. 1. This example shows how to size the primary-only protection overcurrent device and conductor for a fully loaded 45kVA, three-phase, 480V transformer.

NEC Requirements for Transformers

Oct. 13, 2022
Knowing the NEC rules for transformers is only a start.
Fig. 1. If you have a temporary installation, you don’t just apply the requirements of Art. 590 and consider the installation Code-compliant. Instead, you apply the relevant requirements of Chapters 1 through 4, and check Art. 590 for modifications of those.

Temporary Installations

Sept. 14, 2022
Do you understand how the requirements for temporary installations differ from the requirements for permanent installations?
Fig. 1. Transformers used as a Class 2 power source must be listed.

Remote Control and Signaling Circuits, Class 2

Aug. 10, 2022
Using Class 2 circuits may eliminate shock or fire hazards, but only if you install them correctly.
Fig. 1. Protecting a cable’s outer insulation layer is vitally important to its integrity and longevity.

Remote Control and Signaling Circuits, Class 1

July 12, 2022
Boost your understanding of NEC requirements for Class 1 circuits.