Permanently installed energy storage systems are covered in NEC in

• A. NEC Article 424
• B. NEC Article 430
• C. NEC Article 706
• D. NEC Article 422

Answer: (C)

Permanently installed energy storage systems have their own code requirements compiled in a dedicated NEC article because they store large amounts of electrical energy and pose unique safety and integration concerns. This article covers how battery-based storage systems are wired, protected, and located, and it addresses things like overcurrent protection, disconnects, ventilation, and fire safety considerations. It also guides how these systems interact with other electrical installations in a building, ensuring safe operation alongside solar, grid connections, and other equipment.

The other articles focus on different categories of electrical equipment—such as motors, appliances, or other specific devices—and do not specifically address the installation and protection needs of energy storage systems. That’s why this topic is associated with the energy storage article rather than those other sections.