[RE-wrenches] 120% rule for hybrid inverters

[Howie Michaelson]

Mark,  I read that section as stating that *both* must be true, which I
would take to mean if one is using a 20 amp breaker to protect the output
from a 3 kW inverter, you need to count it as 20 amps toward the 120% rule,
not the 15.63 amps the 125% calculation would infer.  I know that 2014 was
changed to allow for larger breakers to feed hybrid inverters, but I can't
recite the code that allows that (unless I am misreading the intent of the
section you quoted). Can you clarify this for me?

Thanks,
Howie

*Howie Michaelson*
*NABCEP Certified Solar PV Installer™*
Sun Catcher, LLC
Renewable Energy Systems Sales and Service
VT Solar Electric Incentive Partner
802-272-0004

On Fri, Aug 12, 2016 at 9:39 AM, Mark Westbrock <
westbrock at positiveenergysolar.com> wrote:

> Hi Mac,
>
> The wording changed because in the 2011 NEC 705.12(D) you had to use the
> size of your backfeed breaker in calculating the busbar loading, but in
> 2014, 705.12(D)(2)(3)(b) now says "125 percent of the inverter output
> circuit current and the rating of the OCPD protecting the busbar shall not
> exceed 120%".
>
> So, the 2014 wording basically allows all inverters to follow the
> exception that used to be there for hybrid inverters.  I hope that helps.
>
> Cheers,
>
> Mark
>
> ----
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>
> On Fri, Aug 12, 2016 at 7:26 AM, Mac Lewis <maclewis1 at gmail.com> wrote:
>
>> Hello wrenches,
>>
>> I am looking for the exception to the 120% rule in the 2014 code that
>> allowed for compliance to the 120% rule to be based on the
>> utility-interactive current as opposed to the backfeed breaker size for
>> hybrid inverter.  I hope this still exists, but I'm having a hard time
>> finding it in the 2014 code.  In 2011 it was 705.12(D)2 Exception.  That
>> was nice clear language that all inspectors accepted, I'm hoping the same
>> exists for the 2014 code.
>>
>> Thanks in advance code experts
>>
>>
>>
>> --
>>
>>
>>
>> Mac Lewis
>>
>> *"Yo solo sé que no sé nada." -Sócrates*
>>
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