Tapping a smaller conductor from a larger conductor is common in many electrical installations. Article 240 provides information on the minimum size of tap conductors for installations based upon the overcurrent protection device’s size and location.
Jim Dollard has an extensive background in codes and standards. If you have a query about the National Electrical Code (NEC), Jim will help you solve it. Questions can be sent to email@example.com. Answers are based on the 2014 NEC. Required labeling