Electrician's Licensing Practice Exam

Which NEC Article outlines the restrictions for using plastic junction or device boxes?

1. NEC 314.3

2. NEC 320.5

3. NEC 340.7

4. NEC 350.5

The correct answer is: NEC 314.3

The National Electrical Code (NEC) Article that outlines the restrictions for using plastic junction or device boxes is indeed Article 314.3. This article provides specific guidelines regarding the installation and usage of junction boxes, including those made of plastic. It focuses on factors such as suitability, environmental conditions, and the types of wiring methods permitted within these boxes. For instance, Article 314.3 includes stipulations about the use of nonmetallic boxes in specific situations, such as where they may be exposed to moisture or where enhanced mechanical strength is necessary. Understanding these restrictions is crucial for ensuring safety and compliance with electrical standards, as improper use of plastic boxes can lead to failure under certain conditions, which may result in hazards like electrical fires or shock. This reinforces the importance of adhering to the NEC guidelines when selecting and installing junction boxes in any electrical project.