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

[William Miller]

Jerry:



Yes it is required.  Rapid Shutdown:  NEC 690.12.  All buildings except
dedicated solar buildings.  Read it and weep.



William



Miller Solar

17395 Oak Road, Atascadero, CA 93422

805-438-5600

www.millersolar.com

CA Lic. 773985





*From:* Jerry Shafer [mailto:jerrysgarage01 at gmail.com]
*Sent:* Monday, January 31, 2022 7:21 PM
*To:* William Miller; RE-wrenches
*Subject:* Re: [RE-wrenches] Rapid Shutdown for Off-grid systems



William

Are you sure RSD is required on a non habitable building, historically its
not required. Now that being said we use fire raptor with the best results,
yes it takes an extra conduite and might require a button and power supply
depending on inverter application.

Jerry



On Mon, Jan 31, 2022, 9:57 AM William Miller <william at millersolar.com>
wrote:

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





_______________________________________________
List sponsored by Redwood Alliance

Pay optional member dues here: http://re-wrenches.org

List Address: RE-wrenches at lists.re-wrenches.org

Change listserver email address & settings:
http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org

There are two list archives for searching. When one doesn't work, try the
other:
https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/
http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org

List rules & etiquette:
http://www.re-wrenches.org/etiquette.htm

Check out or update participant bios:
http://www.members.re-wrenches.org
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.re-wrenches.org/pipermail/re-wrenches_lists.re-wrenches.org/attachments/20220131/8b98fd86/attachment.htm>