Electrician's Licensing Practice Exam

Why does NEC not require ampacity requirements for fixture wiring?

1. They are not relevant

2. All fixtures must undergo UL approval

3. Fixture wiring is generally low voltage

4. They are irrelevant for most installations

The correct answer is: All fixtures must undergo UL approval

The choice indicating that all fixtures must undergo UL approval is correct because the National Electrical Code (NEC) assumes that fixtures that have been tested and certified by Underwriters Laboratories (UL) have been independently evaluated for safety and performance. This approval process includes assessment of how the fixture manages electrical loads, including its wiring and any potential hazards. As a result, because these fixtures are subjected to rigorous standards during the UL approval, the NEC does not specify ampacity requirements for their wiring. The aim is to allow professional electricians to focus on overall installation safety and compliance without redundancy in regulations concerning fixtures that have already been certified for safety and performance. Other choices, while related, do not accurately reflect the rationale behind the NEC's approach. For instance, while fixture wiring may often be at lower voltages, this does not inherently negate the need for ampacity requirements—it's the UL approval that is critical. Similarly, stating that requirements are irrelevant or that they are irrelevant for most installations overlooks the fact that the UL certification process effectively addresses safety concerns.