[RE-wrenches] Code reference request

[Gary Willett]

Kirk:

A DC grounding electrode conductor (GEC) is not required for inverters 
that do NOT have a ground reference for the PV+ and PV- conductor(s) 
from the PV array.

A GEC is not required if the string inverter is one of the new TL 
(transformerless) types.  Also, this applies to micro-inverters such as 
the new Enphase M250 and later versions of the M215.

Where this applies, only a properly sized equipment grounding conductor 
(EGC) is required.

The EGC is sized according to [NEC 690.45] and can be a minimum of 
#14AWG when not exposed to damage, or #6AWG when exposed to potential 
damage.

Regards,

Gary Willett PE
Icarus Engineering LLC

On 10/28/14, 12:53 PM, Kirk wrote:
> Hi,
> I'm on a jobsite without my code book. Could someone tell me where in the code ungrounded systems do not require the inverter GEC? Basically my onsite electrician doesn't believe me. Thanks.
>
> Kirk Herander
> VSE
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