What is the primary focus of Article 450?

The primary focus of Article 450 in the National Electrical Code (NEC) is on transformers and transformer vaults. This article provides guidelines for the proper installation, protection, and maintenance of transformers, which are crucial components in electrical systems for stepping voltage up or down for transmission and distribution. It addresses the requirements for different types of transformers, including their ratings, grounding, overcurrent protection, and necessary clearances, ensuring safety and efficiency in electrical installations.

In contrast, the other options pertain to different aspects of electrical installations. Fire pumps are covered under Article 695, which outlines specific requirements for fire pump installations to guarantee reliability in emergency situations. Motors, motor circuits, and controllers are discussed in Article 430, focusing on their installation and safety standards, while solar systems would fall under Article 690, which details the requirements for photovoltaic systems. Each of these articles serves a distinct purpose and is tailored to specific components or systems in electrical work.