Backfed PV Breaker and the Rule of Six

Hi,

I searched this forum for an answer to the question, "does a backfed PV breaker count as one of the six throws to disconnect a building from its electrical supply" (note: no batteries are in this installation), and I found an answer that was written in 2016 saying "it varies greatly by AHJ".

In 2020, is it still hotly debated, or is it clarified a bit more these days? If it does not count, what kind of evidence could I show the building department? I'm in California, which will start enforcing the NEC 2017 pretty soon.

Also, would a multimode inverter w/ a battery change the argument?

Thanks in advance.
 

ggunn

PE (Electrical), NABCEP certified
Location
Austin, TX, USA
Occupation
Electrical Engineer - Photovoltaic Systems
Hi,

I searched this forum for an answer to the question, "does a backfed PV breaker count as one of the six throws to disconnect a building from its electrical supply" (note: no batteries are in this installation), and I found an answer that was written in 2016 saying "it varies greatly by AHJ".

In 2020, is it still hotly debated, or is it clarified a bit more these days? If it does not count, what kind of evidence could I show the building department? I'm in California, which will start enforcing the NEC 2017 pretty soon.

Also, would a multimode inverter w/ a battery change the argument?

Thanks in advance.
Mike Holt comes down on the side of PV not counting as a 7th handle. My local AHJ took some convincing, but in part because of some materials I brought in from one of Mike's presentations, they eventually agreed. They did, however, require that I install a bladed disco on the wall and tap the bus rather than add a seventh breaker.

To your question, though, I believe it is still very much up to the AHJ. I don't see why the presence of batteries should make a difference.
 

jaggedben

Senior Member
In my experience most panelboards that provide for multiple service disconnecting breakers don't allow for seven anyway, per the label. So with panelboards I think it's usually a moot question. With disconnects and field installed conductors I don't know.

I think a multi-mode/battery inverter would change the equation if there are loads connected through it.
 
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