[RE-wrenches] Rapid Shutdown for Off-grid systems

[William Miller]

Friends:



It is quite rare for us to install off-grid systems on roof-tops.  We have
one coming up with about 20kW on a large barn roof.  This will be our first
off-grid with a module-level rapid shutdown requirement.  I see no
exemptions from RSS for off-grid systems in the code.  I have looked at the
options and this is what I have found:



1.   Fire Raptor

2.   Tigo TS4-F

3.   AC coupling with micro-inverters or optimizers



No one of these approaches seems ideal.  The fire raptor requires extra
wiring for control leads.  The Tigo requires a wireless control system
which worries me about reliability.  With AC Coupling systems floating the
proposed AGM batteries may be awkward.  Furthermore, with AC coupled
systems one cannot charge batteries unless the mini-grid is operational, a
big problem.



Have any of you implemented module-level RSS on a battery-based inverter
system?  I looked in the archives and found no threads that apply.  Thank
in advance.



William Miller



Miller Solar

17395 Oak Road, Atascadero, CA 93422

805-438-5600

www.millersolar.com

CA Lic. 773985
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.re-wrenches.org/pipermail/re-wrenches_lists.re-wrenches.org/attachments/20220131/4ba624e4/attachment.htm>