A common task for electrical system designers is to design separately derived systems. It is difficult to imagine a building that does not contain a separately derived system.
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. GFCI protection of dishwashers in dwelling units