[RE-wrenches] Remote battery disconnects

[Mac Lewis]

Hi William,

Keep in mind that the bigger Midnite remote trip breakers aren't UL listed
last I checked.

Let us know what you come up with.



On Fri, Jan 27, 2023 at 2:39 PM Bradley Bassett via RE-wrenches <
re-wrenches at lists.re-wrenches.org> wrote:

> Wiliam,
>
> I designed a system for this using the MidNite RT breakers. They use 24VDC
> to trigger them, but you must then open the 24VDC to them once they have
> tripped or it will burn out the coil in the breaker. What I designed was a
> 48VDC to 24VDC power supply and a EPO button that is normally open. We have
> both of these, the N.O. button is rare. The power supply is from OutBack.
> Then once the breaker has tripped the power is no longer supplied to the
> switch or RT breaker. It does require a manual reset of the breaker. I've
> attached a drawing of this.
>
> Brad
> AEE Solar
>
> On Fri, Jan 27, 2023 at 12:54 PM William Miller via RE-wrenches <
> re-wrenches at lists.re-wrenches.org> wrote:
>
>> 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
>>
>>
>>
>>
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-- 



Mac Lewis

*"Yo solo sé que no sé nada." -Sócrates*
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