The 2026 NEC re-located information on systems and equipment over 1000 volts ac, 1500 dc, nominal. These distribution voltages in facilities are often referred to as “medium voltage.” Though there is no official definition in the NEC, there is reference to use of the term medium voltage and it is explained in this EC&M Tech Talk.

This Tech Talk provides an overview of the new and existing articles now addressing medium voltage circuits, systems, conductors and equipment. This includes a new article providing the rules for grounding and bonding. This information was taken from Part X of article 250 of the 2023 Code edition.

The NFPA 70B Standard for Electrical Equipment Maintenance provides the necessary information for establishing an electrical maintenance program, determining the frequency of maintenance and the maintenance requirements for equipment. The maintenance and electrical testing requirements are listed and explanations provided.

This Tech Talk is a practical overview of the information for installing and maintaining electrical systems and equipment. It can be used as an introduction to medium voltage or as a review for those who work with these systems and the Tech Talk points to detailed information for further review.