What type of circuits does Article 690 pertain to primarily?

Article 690 of the National Electrical Code specifically pertains to DC circuits in photovoltaic systems. This is primarily because the article addresses the unique requirements and safety considerations involved in the installation and operation of solar photovoltaic (PV) systems, which generate electrical energy in direct current (DC) form.

Photovoltaic systems convert sunlight into electricity, and the output is typically a DC current, which must be handled according to specific guidelines to ensure safety and efficiency. This includes aspects related to circuit protection, grounding, system layout, and interconnection with other electrical sources, all of which are governed under Article 690. By focusing on DC circuits, Article 690 directly addresses the primary function of solar power generation and the specific challenges and codes necessary to manage them effectively.

While the other options involve various electrical systems such as low voltage AC circuits, high voltage industrial circuits, or residential wiring systems, they do not align with the primary focus of Article 690, which is exclusively centered on the peculiarities of photovoltaic systems and their DC circuits.