Code Basics

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


Fig. 1. An electrically powered passenger vehicle needs a dedicated charging circuit. Article 625 provides the requirements for installing the conductors and equipment for electric vehicle charging, power export, or bidirectional current flow.

NEC Requirements for EV Equipment

Nov. 9, 2023
The electrical conductors and equipment for connecting an electric vehicle to premises wiring must meet specific guidelines.
Fig. 1. Locations are classified according to the properties of the hazard.

NEC Requirements for Hazardous Locations

Oct. 11, 2023
Article 500 prepares you for properly applying Articles 501 through 516.
Fig. 1 The rules of Art. 445 include where generators can be installed, nameplate markings, conductor ampacity, and disconnect requirements.

NEC Requirements for Generators

Sept. 13, 2023
Conductor sizing and the requirements for disconnecting means are the main electrical considerations in a generator installation.
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 width of the working space can be measured from left to right, from right to left, or simply centered on the equipment.

NEC Requirements for Working Clearances

Feb. 9, 2023
Don’t let adequate working space be “the final frontier” at your facility.
Fig. 1. When all conductors within a raceway are the same size and have the same insulation type, you can use Annex C (Table 1) to determine the number of conductors permitted for a specific raceway size.

Wiring Methods, Part 2 of 2

Jan. 12, 2023
Following the conductor and raceway installation rules makes for a safer installation process and a better final product.
Fig. 1. Not all underground conductors of the same circuit have to be installed in the same raceway.

Wiring Methods, Part 1 of 2

Dec. 16, 2022
Do you know the rules for installing cables, conductors, and raceways?
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.