[RE-wrenches] NEC for Batteries < 60v ??
Kent Osterberg
kent at coveoregon.com
Tue Oct 20 01:33:03 EDT 2020
Ray,
Per NEC 480 batteries below 48 volts didn't need a readily accessible
disconnect within site of the batteries. That's unchanged in the 2020
Code, you don't have to have a readily accessible disconnect within site
of the batteries. That's a good thing considering the environment near
lead acid batteries. A disconnect switch still isn't required in the
48-volt battery room.
Yes, if you put a 48-volt battery in a one or two-family dwelling, an
outside (remote) emergency disconnect is required. That is going to be a
pain that may add hundreds of dollars to the cost of small off-grid
systems. You might get away with a mushroom switch and a 24-volt tap on
the batteries to activate a remote trip breaker. But considering that it
is a fire-safety related circuit it is probably best to spend the money
for the bird box.
At the very least 480.7(B) should make off-grid folks think about using
a power shed. The power shed is not a dwelling so 2020 NEC 480.7(B)
doesn't apply.
Kent Osterberg
Blue Mountain Solar
On 10/19/2020 8:34 PM, Ray wrote:
>
> I've used Blue Planet, so I guess I have used an actual UL listed ESS,
> even though they don't include the charge controller or inverter. I
> knew they were UL, but I double checked and it is the UL 9540 standard
> mentioned in 706. So in this case, we could ignore 480, but are held
> to 706. Regardless of 480 or 706, both are possibly requiring the
> outside remote disconnect. Besides Midnite's remote trip breakers, and
> the dreaded Bird House, what other options are there to meet this new
> requirement? Can the Blue Planet be tripped remotely?
>
> and still my initial question:
>
> Under 480.7, are batteries below 60v still required to have the remote
> disconnect? They are exempted from having a disconnect at all in
> 480.7(A)......quite confusing.
>
> Ray Walters
> Remote Solar
> 303 505-8760
> On 10/19/20 7:06 PM, Jerry Shafer wrote:
>> Wrenches
>> Blue planet are fire and UL listed systems both on there 48 Volt and
>> the LX flavors
>> Jerry
>>
>> On Mon, Oct 19, 2020, 5:51 PM Ray <ray at solarray.com
>> <mailto:ray at solarray.com>> wrote:
>>
>> The notes in the NEC 2020 Handbook for article 706 clearly state
>> that 706 only covers ESS which is an assembly of components, and
>> that the total assembly must be listed under UL 9540.
>>
>> Further it states: "/A group of separate components that includes
>> storage batteries, that is provided with support systems (racks),
>> charge controllers, and inverters, and that does NOT have an
>> overall listing as an ESS is a storage battery system and as such
>> is subject to the requirements of article 480"/
>>
>> and just in case someone says the notes don't matter, 706.5 says:
>> "/Energy Storage systems shall be listed"/.
>>
>> So, since I have never used an actual listed ESS, I'm back to
>> 480. Specifically, 480.7 (A) says we need a disconnect for
>> batteries over 60 vdc (48v should be exempt) and then 480.7(B)
>> says houses need to have an outside disconnect for the batteries
>> labeled "Emergency Disconnect".
>>
>> So here's the real question: Does 480.7(A) exempt us from
>> 480.7(B)?
>>
>> Ray Walters
>> Remote Solar
>> 303 505-8760
>>
>> On 3/9/19 8:08 PM, Brian Mehalic wrote:
>>> Hi Glenn, I don't completely agree with your interpretation of
>>> ESS systems and the application of Article 706. Yes, an ESS
>>> /could/ provide 120/240 VAC (e.g. the Powerwall), but the
>>> figures in Article 690 show three different configurations where
>>> the output of the ESS is not AC, and where the ESS disconnect
>>> comes before any power electronics (like a multimode inverter,
>>> as shown in the AC and DC coupled systems) or loads (as shown in
>>> the stand-alone system). Are those ESS connected to other
>>> systems which utilize stored energy to provide AC power? Yes,
>>> but the key is "connected to other systems" - in many cases the
>>> ESS only provides DC. In fact the definition of ESS clearly
>>> states this - it /can/ have AC or DC output, and it /may/
>>> include power electronics (but may not).
>>>
>>> My understanding is that the 60 volt limit (which is obviously
>>> problematic in a world where 48 VDC batteries and ESS are very
>>> common) was inserted in order to exempt other devices that store
>>> energy (such as UPS, or battery backup in fire alarms/exit
>>> signage/etc.) from the 706 requirements.
>>>
>>> Cheers,
>>>
>>> Brian Mehalic
>>> NABCEP Certified Solar PV Installation Professional™ R031508-59
>>> National Electrical Code® CMP-4 Member
>>> (520) 204-6639
>>>
>>> Solar Energy International
>>> http://www.solarenergy.org
>>>
>>> SEI Professional Services
>>> http://www.seisolarpros.com <http://www.seisolarpros.com>
>>>
>>>
>>>
>>> On Sat, Mar 9, 2019 at 4:07 PM Glenn Burt <glenn.burt at glbcc.com
>>> <mailto:glenn.burt at glbcc.com>> wrote:
>>>
>>> Hi Ray,
>>>
>>> This is a conversation I have had some time ago with a
>>> number of my fellow inspectors and code experts. When the
>>> 2017 NEC came out, I agreed with Mike Holt and Bill Brooks'
>>> assessment that the new article was poorly written and did
>>> not apply to most systems being installed today. After much
>>> discussion through my Cadmus network of authorities, it
>>> emerged that indeed 706 apples to the typical residential
>>> systems.
>>> So Energy Storage Systems (ESS) are the point of article
>>> 706, and I believe that the key point is that the SYSTEM is
>>> generating AC voltage of 120VAC or 240VAC, making the system
>>> fall under article 706.
>>>
>>> Batteries themselves are minimally covered by NEC 480, NFPA
>>> 1, and the IFC as applicable locally.
>>> So, the bottom line is that the new article does cover the
>>> work we do when systems provide or interface with 120VAC or
>>> above (making the system operation exceeding the 60V AC
>>> trigger).
>>>
>>> My initial problem was believing that the article applied to
>>> a component (the battery bank), and not the system (all
>>> components taken together as a generator/storage system). It
>>> is an easy misunderstanding to make.
>>>
>>> Hope this helps!
>>>
>>> -Glenn Burt
>>>
>>> -----Original Message-----
>>> From: RE-wrenches <re-wrenches-bounces at lists.re-wrenches.org
>>> <mailto:re-wrenches-bounces at lists.re-wrenches.org>> On
>>> Behalf Of Ray
>>> Sent: Saturday, March 09, 2019 12:41 PM
>>> To: RE-wrenches <re-wrenches at lists.re-wrenches.org
>>> <mailto:re-wrenches at lists.re-wrenches.org>>
>>> Cc: Bill Brooks <billb at energy808.com
>>> <mailto:billb at energy808.com>>; Bill Brooks
>>> <billbrooks7 at yahoo.com <mailto:billbrooks7 at yahoo.com>>
>>> Subject: [RE-wrenches] NEC for Batteries < 60v ??
>>>
>>> Hi Everyone;
>>>
>>> I'm updating all my verbage on plansets, and I just realized
>>> that the newly created article 706 covering Energy Storage
>>> Systems is only for Over 60 VDC (706.1) Also article 480
>>> for batteries only requires disconnecting means over 60 VDC
>>> ?! (480.7). I'm not about to not have a disconnect, so now
>>> that NEC pulled battery systems out of 690, where do we go
>>> for guidance on normal battery systems: 12, 24, 48 VDC?
>>>
>>> Overall, I welcome most of the changes in NEC 2017, like
>>> separating off grid systems into articles 706, and 710, but
>>> it seems us off grid installers need some more clarification.
>>>
>>> Thanks,
>>>
>>> --
>>> Ray Walters
>>> Remote Solar
>>> 303 505-8760
>>>
>>> _______________________________________________
>>> List sponsored by Redwood Alliance
>>>
>>> List Address: RE-wrenches at lists.re-wrenches.org
>>> <mailto:RE-wrenches at lists.re-wrenches.org>
>>>
>>> Change listserver email address & settings:
>>> http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
>>>
>>> List-Archive:
>>> http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html
>>>
>>> List rules & etiquette:
>>> www.re-wrenches.org/etiquette.htm
>>> <http://www.re-wrenches.org/etiquette.htm>
>>>
>>> Check out or update participant bios:
>>> www.members.re-wrenches.org <http://www.members.re-wrenches.org>
>>>
>>>
>>> _______________________________________________
>>> List sponsored by Redwood Alliance
>>>
>>> List Address: RE-wrenches at lists.re-wrenches.org
>>> <mailto:RE-wrenches at lists.re-wrenches.org>
>>>
>>> Change listserver email address & settings:
>>> http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
>>>
>>> List-Archive:
>>> http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html
>>>
>>> List rules & etiquette:
>>> www.re-wrenches.org/etiquette.htm
>>> <http://www.re-wrenches.org/etiquette.htm>
>>>
>>> Check out or update participant bios:
>>> www.members.re-wrenches.org <http://www.members.re-wrenches.org>
>>>
>>>
>>> _______________________________________________
>>> List sponsored by Redwood Alliance
>>>
>>> List Address:RE-wrenches at lists.re-wrenches.org <mailto:RE-wrenches at lists.re-wrenches.org>
>>>
>>> Change listserver email address & settings:
>>> http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
>>>
>>> List-Archive:http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html
>>>
>>> List rules & etiquette:
>>> www.re-wrenches.org/etiquette.htm <http://www.re-wrenches.org/etiquette.htm>
>>>
>>> Check out or update participant bios:
>>> www.members.re-wrenches.org <http://www.members.re-wrenches.org>
>>>
>> _______________________________________________
>> List sponsored by Redwood Alliance
>>
>> List Address: RE-wrenches at lists.re-wrenches.org
>> <mailto: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
>>
>>
>> _______________________________________________
>> List sponsored by Redwood Alliance
>>
>> 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
>>
>
> _______________________________________________
> List sponsored by Redwood Alliance
>
> 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/20201019/b3b8855d/attachment.htm>
More information about the RE-Wrenches
mailing list