For general-use conductors' ampacity, insulation, and temperature ratings, which article applies?

• A. Article 310: Conductors for general use: ampacity, insulation, and temperature ratings.
• B. Article 334: Nonmetallic-sheathed cable (NM).
• C. Article 400: Flexible cords and cables.
• D. Article 300: General wiring methods.

Answer: (A)

The key idea here is which NEC article sets the rules for general-use conductors’ current-carrying capacity, insulation, and temperature ratings. That role is filled by the article that covers conductors rated 0 to 2000 volts used for general electrical distribution. It provides the ampacity tables, specifies the insulation types and their temperature ratings (such as 60°C, 75°C, 90°C), and explains how those ratings interact with ambient conditions and the number of conductors in a raceway to determine allowable current. The other articles focus on specific types or aspects—nonmetallic-sheathed cable is addressed separately, flexible cords have their own article, and general wiring methods are in another—so they don’t address the broad, general-use conductor requirements in one place. Therefore, Article 310 is the correct and most comprehensive source for these general-use conductor requirements.