[RE-wrenches] Remote battery disconnects

[William Miller]

Glenn:



As I wrote, a DC disconnect is required.  Here is an excerpt from the Q&A
with the building official:



4.   Will you be requiring an external disconnect to disconnect the AC
output of the inverter system from premise wiring?

Yes, as required per 230.85

5.   Will you be requiring an external disconnect to disconnect batteries
from the inverters?

Yes



If the DC disconnect was not required I would not be wasting everyone’s
time with my post.  I try to be careful about that, researching on my own
before posting and trying to make my questions very clear.  I also try not
to embarrass myself with dumb questions, but that does happen occasionally…



William



Miller Solar

17395 Oak Road, Atascadero, CA 93422

805-438-5600

www.millersolar.com

CA Lic. 773985





*From:* RE-wrenches [mailto:re-wrenches-bounces at lists.re-wrenches.org] *On
Behalf Of *Glenn Burt via RE-wrenches
*Sent:* Friday, January 27, 2023 11:46 AM
*To:* William Miller via RE-wrenches
*Cc:* Glenn Burt
*Subject:* Re: [RE-wrenches] Remote battery disconnects



Does the AHJ really want the batteries disconnected from conductors, or
does he really just want the inverters to stop operating and producing AC
within the house?

Obviously there is a big difference here and it may be changing as the code
evolves.



-Glenn

Sent from my 'smart'phone, so please excuse typos and spelling errors.



------ Original message------

*From: *William Miller via RE-wrenches

*Date: *Fri, Jan 27, 2023 2:26 PM

*To: *RE-wrenches;

*Cc: *William Miller;

*Subject:*[RE-wrenches] Remote battery disconnects



Friends:



We have a large-ish residential off-grid system install coming up.  The AHJ
has said they will require a remote battery disconnect.  I suspect there
will be fire sprinkler controls and a pressure pump that would become
inoperable if this system were engaged.  In this case we will apply for a
waiver.



The last time this was discussed here as far as I can find was October of
2020.  At that time no one suggested any specific battery disconnect
equipment.



To further clarify my needs:  There will be 4 or 5 Radian 8048 inverters (5
or 6 4/0 battery circuits, ~350A each) and two 175 amp PV recombiner
outputs.  That is 6 poles of high amperage DC disconnects.



The battery array will be either a UnigyII VRLA or a lithium of a brand yet
to be determined.  In the case of lithium we will look for a system that
can remotely enable a BMS shutdown.  In the case of a VRLA lead-acid, we
will not have that luxury.



I have done some considerable research and have not found viable, high
amperage, remotely activated shutdown equipment.



I am wondering what hardware others may be using to achieve remote battery
disconnecting in these types of cases..



William



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-re-wrenches.org/attachments/20230127/cd7008fd/attachment.htm>