Hello wrenches, What constitutes a separately derived system? Would you consider a breaker tied enphase system a separately-derived system? Suddenly, inspectors in our AHJ are considering all PV systems separately derived systems and thus requiring applying GEC sizing (as opposed to EGC sizing) from the inverter(s) to the tie in point. This does not jive with my understanding. Would like to hear other thoughts about this.
Here is the definition of a separately derived system as per 2008 NEC Article 100 Definitions: *Separately Derived System*: *A premises wiring system whose power is derived from a source of electric energy or equipment other than a service. Such systems have no direct electrical connection, including a solidly connected grounded circuit conductor, to supply conductors originating in another system.* For your enphase systems do you size your ground from roof to the breaker panel as an EGC or a GEC? Thanks in advance for your thoughts. -- Mac Lewis * "Yo solo sé que no sé nada." -Sócrates *
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