NM cables installation is governed by which article?

• A. Article 300
• B. Article 230
• C. Article 334
• D. Article 430

Answer: (C)

Nonmetallic-sheathed cables (NM), the kind commonly called Romex, have their own, specific installation rules in the NEC. Those rules are found in Article 334, which covers where NM can be used (dry interior locations), how it must be run and secured (within 12 inches of every box and at intervals not exceeding 4.5 feet), and how it must be protected from physical damage (such as using nail plates when running through framing members near the surface). This focus on a particular wiring method is why Article 334 is the right place for NM cable installation. In contrast, Article 300 covers general wiring methods, Article 230 deals with services and feeders, and Article 430 addresses motors, so they don’t specifically govern NM installation.