The wiring "within" your house is not "Seperately Derived", unless you have another transformer inside, a phase converter, or something like that. The stuff on the ploe is part of a
Distribution system, all the way to the point of entry to your house. And not really covered by NEC, as much as
premises wiring systems.NEC defined it as the following:
Separately Derived System. A premises wiring system whose power is derived from a battery, from a solar photovoltaic system, or from a generator, transformer, or converter windings, and that has no direct electrical connection, including a solidly connected grounded circuit conductor, to supply conductors originating in another system.