Q. What is the Code rule for the overcurrent protection of flexible cords and fixture wires?
Find the Answer
A. As outlined in Sec. 240.5(A), flexible cord must be protected by an overcurrent device in accordance with its ampacity as specified in Table 400.5(A)(1) or Table 400.5(A)(2). Fixture wires must be protected against overcurrent in accordance with their ampacity as specified in Table 402.5. Supplementary overcurrent protection, as discussed in Sec. 240.10, is permitted to provide this protection.
As noted in Sec. 240.5(B)(1), if flexible cord is used with a specific listed appliance or luminaire, the conductors are considered protected against overcurrent when used within the appliance or luminaire listing requirements. Note: The NEC only applies to premises wiring, not to the supply cords of listed appliances and luminaires.
As noted in Sec. 240.5(B)(2), fixture wires can be tapped to the following circuits:
- 20A – 18 AWG, up to 50 ft of run length
- 20A – 16 AWG, up to 100 ft of run length
- 20A – 14 AWG and larger
As noted in Sec. 240.5(B)(3), flexible cord used in listed extension cord sets is considered protected against overcurrent when used within the extension cord’s listing requirements.
About the Author
Mike HoltMike Holt
Mike Holt is the owner of Mike Holt Enterprises (www.MikeHolt.com), one of the largest electrical publishers in the United States. He earned a master's degree in the Business Administration Program (MBA) from the University of Miami. He earned his reputation as a National Electrical Code (NEC) expert by working his way up through the electrical trade. Formally a construction editor for two different trade publications, Mike started his career as an apprentice electrician and eventually became a master electrician, an electrical inspector, a contractor, and an educator. Mike has taught more than 1,000 classes on 30 different electrical-related subjects — ranging from alarm installations to exam preparation and voltage drop calculations. He continues to produce seminars, videos, books, and online training for the trade as well as contribute monthly Code content to EC&M magazine.