When sizing conductors, the number of current-carrying conductors installed in a raceway or cable must be considered. No conductor shall be used in such a manner that its operating temperature exceeds that which is designated for the type of insulated conductor involved [310.15(A)(3)].
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. Number of outside feeders supplying dwelling unit