712 – Direct Current Microgrids

712.2 – Grounded, Functionally

Change at a Glance:

The term “Resistively Grounded” in Article 712 was revised to “Grounded, Functionally” to correlate with the same definition in Article 690.

712.2 Definitions. (Direct Current Microgrids)

The definitions in this section shall apply only within this article.
Resistively Grounded, Functionally. A system with a high-resistance connection between the current carrying conductors and the equipment grounding system that has an electrical ground reference for operational purposes that is not solidly grounded.
Informational Note: Examples of operational reasons for functionally grounded systems include ground-fault detection and performance-related issues for some power sources.

712.10(B) – Building Directory for Direct Current Microgrids

Change at a Glance:

New outdoor plaque or directory requirement added to denote all sources of dc power to a building installed at each outside service equipment location or at an approved readily visible location.

712.10 Directory. (Direct Current Microgrids)

(A) Source Directory. A permanent directory denoting all dc electric power sources operating to supply the dc microgrid shall be installed at each source location capable of acting as the primary dc source.

(B) Building Directory. A building supplied by a dc microgrid system shall have a permanent plaque or directory installed outside the building at each service equipment location or at an approved readily visible location. The plaque or directory shall denote the location of each power source disconnecting means on or in the building or be grouped with other plaques or directories for other on-site sources.
Exception: Multiple power production sources that are grouped at one location shall be permitted to be identified as a group.