[RE-wrenches] Code reference request

[Dana Brandt]

I think I'm a bit confused on this point. I can't seem to find the code
that specifically exempts the GEC requirement for inverters of ungrounded
PV systems. The only exception I can find is only for AC PV modules (2014
NEC 690.47 (C) ).

I just looked in the installation manual for Solectria's new TL inverters
and found this:
"Per NEC 690.47, a GEC must be installed, and the Grounding Electrode
Terminal (GET) conductor must be sized in accordance with NEC article
250.166."

What am I missing?

Thanks,

Dana

Dana Brandt
Ecotech Energy Systems, LLC
www.ecotechenergy.com
dana at ecotechenergy.com
360.318.7646

On Tue, Oct 28, 2014 at 11:30 AM, Rebekah Hren <rebekah.hren at o2energies.com>
wrote:

> If you are on 2014:
>  690.47(B)
>
> An ac equipment grounding system shall be permitted
>
> to be used for equipment grounding of inverters and other
>
> equipment *and for the ground-fault detection reference for *
>  *ungrounded PV systems.*
>
> and 690.47(C)(3)
>
> *For ungrounded systems, this con**ductor shall be sized in accordance
> with 250.122 *and shall
>
> not be required to be larger than the largest ungrounded
>
> phase conductor.
>
> On Tue, Oct 28, 2014 at 2:22 PM, Gary Willett <
> Gary at icarussolarservices.com> wrote:
>
>> 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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