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.