Code Q&A: 25-Ft Tap Rule

April 23, 2015

NEC rules on the 25-ft tape rules

Q. Please explain the 25-ft tap rules in the NEC?

Find the Answer

A. Feeder tap conductors up to 25 ft long are permitted without overcurrent protection at the tap location if the tap conductors comply with the following [240.21(B)(2)] (see Figure):

• The ampacity of the tap conductors must not be less than one-third the rating of the overcurrent device that protects the feeder [240.21(B)(2)(1)].

• The tap conductors terminate in an overcurrent device rated no more than the tap conductor ampacity in accordance with 310.15 [240.21(B)(2)(2)].

About the Author

Mike 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.