Which of the following topics relates to Article 680?

Article 680 of the National Electrical Code (NEC) specifically addresses the requirements for the installation and maintenance of electrical systems related to swimming pools, fountains, and similar installations. This article focuses on ensuring safety in locations where water and electrical systems interact, addressing aspects such as grounding, bonding, and equipment placement to prevent electrocution or accidental injuries.

Swimming pools and similar water features pose unique hazards, which necessitate specific electrical guidelines that are outlined in this article. It emphasizes the importance of protecting equipment and users from potential electrical shock, due to the conductive nature of water and the various types of electrical equipment that may be installed in or around these installations. Hence, this subject matter aligns directly with the requirements of Article 680.

The other topics listed—solar photovoltaic systems, industrial machinery, and dielectric heating equipment—each belong to different areas of the NEC, and they address separate concerns that do not specifically pertain to the electrical safety of aquatic environments.