Electrician's Licensing Practice Exam

What does NEC Article 402.3 specifically address?

1. Panel board applications

2. Operating temperatures of fixture wiring

3. Grounding techniques

4. Ampacity calculations

The correct answer is: Operating temperatures of fixture wiring

NEC Article 402.3 specifically addresses the operating temperatures of fixture wiring, which is crucial for ensuring the safety and performance of electrical installations. This article provides guidelines for selecting conductors based on the temperature ratings of the fixtures they are associated with. Maintaining appropriate operating temperatures is essential to prevent overheating, which can lead to insulation failure, increased resistance, and ultimately, fire hazards. By focusing on the thermal characteristics of fixture wiring, this article helps electricians ensure that the materials they choose are suitable for the environmental conditions they will face, thereby enhancing both safety and longevity of electrical systems. In contrast, the other options pertain to different aspects of the NEC. Panel board applications deal with the installation and setup of electrical distribution systems. Grounding techniques focus on the methods employed to safely discharge electricity in case of faults. Ampacity calculations involve determining the maximum amount of current a conductor can carry without overheating. While all these topics are vital in electrical work, Article 402.3’s emphasis on fixture wiring's operating temperatures is specific and distinct.