Electrician's Licensing Practice Exam

Does NEC maintain ampacity requirements for fixture wiring?

1. Yes, for all fixture wiring

2. No, because all fixtures undergo UL approval

3. Yes, but only for specific types of fixtures

4. No, but only under certain conditions

The correct answer is: No, because all fixtures undergo UL approval

The National Electrical Code (NEC) sets forth requirements to ensure safety in electrical installations, including provisions related to the ampacity of conductors. Ampacity refers to the maximum amount of electric current a conductor or device can carry before sustaining immediate or progressive deterioration. While the NEC does provide guidelines for many applications, it does not maintain specific ampacity requirements for all fixture wiring because the expectation is that lighting fixtures have undergone rigorous testing and certification processes through Underwriters Laboratories (UL) or other recognized testing laboratories. When fixtures are UL-approved, they are deemed safe to operate at certain ratings without necessarily needing the NEC to provide explicit ampacity limits for these fixtures. This reliance on third-party testing allows the NEC to focus on broader standards and practices without needing to specify ampacity for each type of fixture, as those factors have already been addressed during the UL certification process. In contrast, other responses imply that the NEC either does not address ampacity requirements, or that such considerations are applicable only under specific scenarios or for certain types of fixtures, which does not accurately reflect the NEC's approach regarding fixtures certified by independent testing organizations.