Article 396 is primarily concerned with which wiring method?

The focus of Article 396 is on messenger-supported wiring, which involves a method of hanging conductors from a supporting messenger wire. This method is often used in applications where conductors need to span long distances without needing additional supporting structures, making it particularly useful in outdoor settings like across roadways or in industrial environments.

Messenger-supported wiring provides several advantages, such as reducing the risk of damage to the conductors and ensuring they remain properly spaced apart. The article outlines necessary safety measures, installation practices, and proper sizing requirements for the wire and supporting system, ensuring that installations are both functional and compliant with safety standards.

In contrast, open wiring refers to installation methods where conductors are run exposed without any enclosing throughout buildings, which can pose different hazards and doesn't align with the specifics outlined in Article 396. Similarly, cable trays are a distinct method used for supporting and managing multiple cables, while switches pertain to devices for controlling electrical circuits. Each of these has separate regulations and guidelines not covered under the provisions of Article 396.