All questions and answers are based on the 2014 NEC.
Q. What are the rules for sizing service and feeder conductors to a single dwelling unit?
A. For one-family dwellings and individual dwelling units of two-family and multifamily dwellings, service and feeder conductors supplied by a single phase, 120/240V system can be sized using the requirements set forth in Sec. 310.15(B)(7)(1) through (4) (Fig. 1).