Wrenches. You might want to consider turning off the inverter as a solution to turning off the batteries, we have this feature as part of our installs with outback real simple then no chance of AC anywhere, Not going to pop a CC, no chance of run on and it has passed every time. Just a thought that's a safe solution. With Outback you just have to turn off the master nothing else. "Fun time in a crazy world"
On Mon, Jan 30, 2023, 7:58 AM Brian Mehalic via RE-wrenches < re-wrenches@lists.re-wrenches.org> wrote: > Hey folks - love the Code, hate it, don’t care about it or follow it: it > doesn’t matter to me. But if you want to change it you have to realize it > is a process with rules and procedures, and posting on this list that “the > NEC” should immediately “issue a memo” to do what you want or change what > you don’t like has ZERO effect. > > Brian > > On Jan 30, 2023, at 4:47 AM, Christopher Warfel via RE-wrenches < > re-wrenches@lists.re-wrenches.org> wrote: > > > > I don't think the discussion has forked at all. A solution to this > problem, and it is the best solution all things considered, including > firefighter exposure to 10 ft of conductors that I have a hard time imaging > them being exposed to, is for the NEC to issue a memo IMMEDIATELY > indicating that this section of the code is no longer to be considered a > requirement and that the next Code cycle will eliminate this requirement. > > The other solutions discussed would only work for a few configurations > realistically and would introduce more danger. Chris > > > > On 1/29/2023 2:41 PM, William Miller via RE-wrenches wrote: > > James, Brian and others: > > > > Thank you all for the lively discussion. I am always interested in my > colleague’s perspectives and this has been illuminating. > > > > It appears to me the discussion has forked: One topic is how to deal with > the reality of the new code regarding a very narrow scenario: ESS inside of > a residence. The other topic is: has the NEC evolved to be overly > restrictive without factual basis? > > > > Regarding the first topic, it’s in black and white that we must provide > battery disconnecting means for energy storage systems located in one or > two family homes if the battery voltage exceeds 60 VDC. There are very few > areas that do not adopt the NEC. If you install ESS you will eventually > have to deal with this code requirement one way or another. > > > > Due to lax enforcement or unfamiliarity on the part of local building > departments, some of you may be able to skirt this requirement. This is > great until something happens. If your non-compliant installation causes a > loss, you will end up in the defendants chair, not the building inspector. > > > > Here is how I approach these compliance conundrums: If I could argue the > code does not apply or there is a good reason to waive the requirement; if > the building official agrees; if I feel the installation is really and > truly safe without meeting the requirement—only then could I proceed > without the disconnect. Otherwise I am going to have to find a way to > comply. > > > > As contractors, each of you makes those decisions every day: What is safe > enough for my clients? If any of you think you know more than the people > who write the codes, then install what you can get away with and keep your > fingers crossed. I am not willing to live like that. > > > > Regarding the second topic: Are we being picked on by an overly > scare-mongering NFPA? > > > > What is interesting here is that while most electrical codes are trying to > prevent house fires, this particular section is trying to protect fire > fighters after a fire starts (or an earthquake happens or a dump truck runs > into your house, etc.). > > > > When California first adopted roof clearances for fire fighters, I got my > feelings hurt because I was losing business and I did not understand what > it takes to fight a house fire. I spoke with a few fire fighters and > learned about roof and wall venting and how it is affected by prevailing > winds. I came around to appreciate there is a real need for rooftop fire > setbacks. > > > > It is self-evident why firefighters would not want to cut into a wall with > a demo saw if there are energized, high amperage conductors in or on that > wall. This code requirement for battery disconnecting means is > fundamentally sensible. That ends the discussion for me. > > > > Oh, yeah, the charge controller blowing up thing: Does anyone have any > factual data to share on this? Regardless of that, does it really matter > if the charge controller is saved but the house burns down? > > > > The islanding thing: To be compliant, all ungrounded battery conductors > need to be disconnected. This includes the charge controller circuit(s). > With the charge controllers and inverters disconnected from the batteries > and from each other there cannot be DC “islanding”. > > > > The house flooding thing: At the surface, it appears you have a choice of > disasters: flood or fire. I submit that fire is more destructive (I don’t > think many people have died from a ruptured water pipe). I don’t think it > has to be either or: Find a way to provide emergency power to freeze > protection devices with that disconnect waived or under key in cooperation > with the fire department. This may mean the batteries need to remain > connected. Put those leads in metal raceway and mark their locations from > the outside. Work with building and fire officials. Limit your liability. > > > > Thanks again to all of you for the discussion. I know what I need to do. > > > > William Miller > > > > Miller Solar > > 17395 Oak Road, Atascadero, CA 93422 > > 805-438-5600 > > www.millersolar.com > > CA Lic. 773985 > > > > > > *From:* James Jarvis [mailto:j...@aprsworld.com] > *Sent:* Saturday, January 28, 2023 7:03 PM > *To:* Brian Mehalic > *Cc:* RE-wrenches; will...@millersolar.com > *Subject:* Re: [RE-wrenches] Remote battery disconnects > > > > Brian and William, > > > > With all due respect, I think your geographical location of California may > be limiting in your understanding of the implications of local power > security. > > > > Where I am in Minnesota and where I work in Alaska, loss of power and > backup power can have very expensive consequences. When it is -30F outside > and howling wind, buildings only have a matter of hours before their > interiors will drop below freezing. A few hours after that pipes start to > freeze and break. Pressurized water then starts to spray everywhere and > then things can very quickly run into six-figure dollars amounts of damage. > So one way of reducing this risk is by installing an ESS. > > > > Around here, prior to the latest NEC, we didn't have exterior disconnects > available for anyone to shut off power. We still don't for businesses. > > > > My point is that NEC is mandating that there be zero security of a > buildings electrical systems by requiring publicly accessible disconnects > on backup systems. And if NEC wasn't so prescriptive, there could be > slightly more secure alternatives such as a KNOXBOX or access controlled > disconnects. > > > > William: I also disagree with your premise that you'll test the battery > disconnect system after dark. That's not a test; that's just cheating. You > had a knowledge person tell you that the MPPT controllers can and do blow > up when they lose their voltage reference (battery) under load. And > removing the battery from the circuit does allow the charge controllers to > island with the inverter and DC loads and do other damage. I know of a > telecom customer that had hundreds of thousands of dollars of damage when > their battery became disconnected. If you are unwilling to test it at full > load, I'd guess you know that the whole concept is a dumb idea. > > > -James Jefferson Jarvis > APRS World, LLC > +1-507-454-2727 > > http://www.aprsworld.com/ > > > > > > On Sat, Jan 28, 2023 at 7:35 PM Brian Mehalic <br...@solarenergy.org> > wrote: > > Every single house I’ve looked at in my town has a breaker panel with a > main service disconnect on the outside of the house already. So in many > cases we are well beyond worrying about someone “flicking your switch!” > > > > In fact, in addition to the emergency disconnect requirement for > stationary standby batteries [480.7(B)] and ESS [706.15(B)] in one- and > two-family dwellings, also added in 2020 was the requirement for an > emergency disconnect for services on those same one- and two-family > dwellings [230.85]. > > Brian Mehalic > > > > On Jan 28, 2023, at 5:58 PM, James Jarvis via RE-wrenches < > re-wrenches@lists.re-wrenches.org> wrote: > > > > It would be nice if the decision was up to the owner / occupant of the > property. I, for one, do not want any random person to be able to turn off > my house or business with the flick of a switch. I feel strongly that there > is far too much fear mongering in NEC with relation to renewable energy. > > > -James Jefferson Jarvis > APRS World, LLC > +1-507-454-2727 > > http://www.aprsworld.com/ > > > > > > On Sat, Jan 28, 2023 at 6:22 PM William Miller via RE-wrenches < > re-wrenches@lists.re-wrenches.org> wrote: > > Esteemed wrenches: > > > > Well if my house is on fire and the entry of fire responders is delayed > for lack of a disconnect, I choose having the disconnect. I can worry about > the charge controllers later. > > > > Others may prioritize their charge controller over their homes… > > > > Put a cable-tie lock in the closed position to discourage kids from > messing with it. Test it only after dark. > > > > William > > > > On Sat, Jan 28, 2023 at 2:32 PM William Bryce < > wlbr...@pineridgeproducts.com> wrote: > > All > > > > One thing that no one is talking about is what happens to the MPPT charge > controllers when the Battery Disconnect trips when the charge controllers > are under full load. > > Many will blow up. Try turning off the battery breaker on a SolaArk when > the charge controllers are maxed, and see if you get lucky. > > > > On Sat, Jan 28, 2023 at 3:27 PM William Miller via RE-wrenches < > re-wrenches@lists.re-wrenches.org> wrote: > > Jeremy: > > > > Thanks for posting the code references for those that had never looked > them up. > > > > Chris: > > > > What do you mean by “a disconnect for AC wiring, not specific to which or > both panel types”? > > > > All: > > > > Code references are handy when receiving edicts from building officials, > but not required, IMHO, for two reasons: The contractor should already be > versed in the codes and, building departments can mandate their own > requirements above and beyond the code. > > > > It may seem redundant to require an AC disconnect for premise wiring as > well as a DC battery disconnect. In most cases if you disconnect the > inverter from the batteries the AC power goes off. However if the > generator is running at the time, some battery inverters can operate when > disconnected from batteries. So to completely de-energize all components > of an off-grid home you need to disconnect the generator and the battery > leads. > > > > In this case the home is required to have fire sprinklers. There is > pressure pump to provide flow to these fire sprinklers-- said pump being > powered by the inverter/battery system. I am going to apply for a waiver > to remove the DC disconnect requirement on the grounds that the pressure > pump is essential fire suppression equipment. Instead I will propose to > supply an AC disconnect (meeting all requirements for accessibility and > marking) that will disconnect all premise wiring except the pressure pump. > > > > By the way, I will of course be trying to apply the logic that the voltage > specification is for nominal battery voltage and this project having a > nominal 48 volt bank does not require the battery disconnect. > > > > I will let the group know what response I receive. Regardless of how this > works in this jurisdiction, I think these are both valid arguments worth > trying in any jurisdiction requiring the battery disconnect. Some > officials are amenable to dialog and negotiation and some are less so. > > > > > > William Miller > > > > Miller Solar > > 17395 Oak Road, Atascadero, CA 93422 > > 805-438-5600 > > www.millersolar.com > > CA Lic. 773985 > > > > > > *From:* RE-wrenches [mailto:re-wrenches-boun...@lists.re-wrenches.org] *On > Behalf Of *Jeremy Rodriguez via RE-wrenches > *Sent:* Saturday, January 28, 2023 10:12 AM > *To:* cwar...@entech-engineering.com; RE-wrenches > *Cc:* Jeremy Rodriguez > *Subject:* Re: [RE-wrenches] Remote battery disconnects > > > > > > *2020 Code Language:* > > *480.7 DC Disconnect Methods.* > > *(A) Disconnecting Means.* *A disconnecting means shall be provided for > all ungrounded conductors derived from a stationary battery system with a > voltage over 60 volts dc. A disconnecting means shall be readily accessible > and located within sight of the battery system.* > > *N** (B) Emergency Disconnect. **For one-family and two-family dwellings, > a disconnecting means or its remote control for a stationary battery system > shall be located at a readily accessible location outside the building for > emergency use. The disconnect shall be labeled “EMERGENCY DISCONNECT”.* > > *N (C) Disconnection of Series Battery Circuits. **Battery circuits > exceeding 240 volts dc nominal between conductors or to ground and subject > to field servicing shall have provisions to disconnect the series-connected > strings into segments not exceeding 240 volts dc nominal for maintenance by > qualified persons. Non-load-break bolted or plug-in disconnects shall be > permitted.* > > > > Jeremy Rodriguez > > Solar Installation / Design > > All Solar, Inc. > > 1453 M St. > > Penrose Colorado 81240 > > > > Sent by Jeremy's iPhone. Sorry for typos and shorthand. > > > > On Jan 28, 2023, at 7:28 AM, Christopher Warfel via RE-wrenches < > re-wrenches@lists.re-wrenches.org> wrote: > > > > Seems confusing that the AHJ is requiring a disconnect for AC wiring, not > specific to which or both panel types, and then a dc disconnect with no > code reference. Was trying to convey a reasonable, safe approach. A lot > of bad information from fire department solar consultants making a lot of > money fear mongering, which has led to this type of situation. Chris > > On 1/27/2023 3:35 PM, William Miller via RE-wrenches 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-boun...@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 > > > > > > > > _______________________________________________ > List sponsored by Redwood Alliance > > Pay optional member dues here: http://re-wrenches.org > > List Address: RE-wrenches@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 > > -- > > > William Miller > Miller Solar.com > 895-438-5600 > www.millersolar.com > > _______________________________________________ > List sponsored by Redwood Alliance > > Pay optional member dues here: http://re-wrenches.org > > List Address: RE-wrenches@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 > > Pay optional member dues here: http://re-wrenches.org > > List Address: RE-wrenches@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 > > Pay optional member dues here: http://re-wrenches.org > > List Address: RE-wrenches@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 > > -- > Christopher Warfel > ENTECH Engineering, Inc. > PO Box 871, Block Island, RI 02807 > 401-466-8978 > <http://entech-engineering.com> > > <http://entech-engineering.com> > > > _______________________________________________ > List sponsored by Redwood Alliance > > Pay optional member dues here: http://re-wrenches.org > > List Address: RE-wrenches@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. 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