[RE-wrenches] EGC vs GEC, separately derived system

[mac Lewis]

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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