[RE-wrenches] Multiple inverters

[Dave Tedeyan]

Here in upstate NY, we have certainly had multiple inverter breakers land
in the main panel. In a situation like yours, we have also left the old
system as a load side connection, and then turned the new system in to a
supply side connection so that the bus bar in the main panel is not
overloaded. No inspectors here seem to care as long as the labeling shows
what is happening. Although we are also fortunate that most inspectors
around here will not make us fix old work as long as we did not touch it
and it presents no safety hazard.

Cheers,
Dave

*Dave Tedeyan, PE*
Senior Engineer | Taitem Engineering, PC

10 Verizon Lane | Lansing, NY 14882
o. *607.930.3481* x6  f. 607.277.2119
www.taitem.com

Solar • Sustainability • Energy • Design
B-Corporation Best for the World 2018 Honoree


On Mon, Feb 25, 2019 at 11:42 AM William Miller <william at millersolar.com>
wrote:

> Friends:
>
>
>
> I have an NEC code question on an upcoming project.  It is a home that has
> an existing 8 kW ground-mounted grid-tied system.  The owner wants to add
> another 10 kW of grid-tied PV.  My question is about 705.12, point of
> connection.  Specifically section (D)(1).  That section states:
>
>
>
> *The source interconnection of one or more inverters installed in one
> system shall be made at a dedicated circuit breaker or fusible
> disconnecting means.*
>
>
>
> So if there are going to be two inverters on premise, do the outputs have
> to be aggregated to connect via one circuit breaker?  This might be
> difficult to do as the exiting inverter is connected via a different
> sub-panel than the one that is planned to receive the new inverter output.
>
>
>
> This article
> <https://iaeimagazine.org/magazine/2014/01/16/load-side-pv-connections/>
> addresses the question.
>
>
>
> I would be very grateful if any of you can share any experience you might
> have in interpreting this section of the code.
>
>
>
> Thanks in advance.
>
>
>
> William
>
>
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