transformer secondary conductor rules are similar to tap conductor rules. Article 240.21 of the National Electrical Code (NEC) covers the location and sizing requirements of overcurrent protection for tap conductors and transformer secondary conductors.
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 firstname.lastname@example.org. Answers are based on the 2014 NEC. Phase converters and fire-pump service