The NEC requirements for branch-circuit load calculations are in Art. 220, Part II. These cover three classifications of loads: Lighting loads for specified occupancies (220.12) Other loads for all ...
Feeder and service load calculation requirements can be found in Part III of Art. 220 in the 2014 NEC. As noted in Sec. 220.52(B), "A load of not less than 1,500VA ...