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--></style></head><body lang="EN-US" link="blue" vlink="purple"><div class="WordSection1"><p class="MsoNormal"><span style="font-family:"Verdana","sans-serif";color:#1f497d">James, Brian and others:</span></p><p class="MsoNormal"><span style="font-family:"Verdana","sans-serif";color:#1f497d"> </span></p><p class="MsoNormal"><span style="font-family:"Verdana","sans-serif";color:#1f497d">Thank you all for the lively discussion. I am always interested in my colleague’s perspectives and this has been illuminating.</span></p><p class="MsoNormal"><span style="font-family:"Verdana","sans-serif";color:#1f497d"> </span></p><p class="MsoNormal"><span style="font-family:"Verdana","sans-serif";color:#1f497d">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?</span></p><p class="MsoNormal"><span style="font-family:"Verdana","sans-serif";color:#1f497d"> </span></p><p class="MsoNormal"><span style="font-family:"Verdana","sans-serif";color:#1f497d">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.</span></p><p class="MsoNormal"><span style="font-family:"Verdana","sans-serif";color:#1f497d"> </span></p><p class="MsoNormal"><span style="font-family:"Verdana","sans-serif";color:#1f497d">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.</span></p><p class="MsoNormal"><span style="font-family:"Verdana","sans-serif";color:#1f497d"> </span></p><p class="MsoNormal"><span style="font-family:"Verdana","sans-serif";color:#1f497d">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.</span></p><p class="MsoNormal"><span style="font-family:"Verdana","sans-serif";color:#1f497d"> </span></p><p class="MsoNormal"><span style="font-family:"Verdana","sans-serif";color:#1f497d">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.</span></p><p class="MsoNormal"><span style="font-family:"Verdana","sans-serif";color:#1f497d"> </span></p><p class="MsoNormal"><span style="font-family:"Verdana","sans-serif";color:#1f497d">Regarding the second topic: Are we being picked on by an overly scare-mongering NFPA? </span></p><p class="MsoNormal"><span style="font-family:"Verdana","sans-serif";color:#1f497d"> </span></p><p class="MsoNormal"><span style="font-family:"Verdana","sans-serif";color:#1f497d">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.). </span></p><p class="MsoNormal"><span style="font-family:"Verdana","sans-serif";color:#1f497d"> </span></p><p class="MsoNormal"><span style="font-family:"Verdana","sans-serif";color:#1f497d">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. </span></p><p class="MsoNormal"><span style="font-family:"Verdana","sans-serif";color:#1f497d"> </span></p><p class="MsoNormal"><span style="font-family:"Verdana","sans-serif";color:#1f497d">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.</span></p><p class="MsoNormal"><span style="font-family:"Verdana","sans-serif";color:#1f497d"> </span></p><p class="MsoNormal"><span style="font-family:"Verdana","sans-serif";color:#1f497d">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?</span></p><p class="MsoNormal"><span style="font-family:"Verdana","sans-serif";color:#1f497d"> </span></p><p class="MsoNormal"><span style="font-family:"Verdana","sans-serif";color:#1f497d">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”.</span></p><p class="MsoNormal"><span style="font-family:"Verdana","sans-serif";color:#1f497d"> </span></p><p class="MsoNormal"><span style="font-family:"Verdana","sans-serif";color:#1f497d">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.</span></p><p class="MsoNormal"><span style="font-family:"Verdana","sans-serif";color:#1f497d"> </span></p><p class="MsoNormal"><span style="font-family:"Verdana","sans-serif";color:#1f497d">Thanks again to all of you for the discussion. I know what I need to do.</span></p><p class="MsoNormal"><span style="font-family:"Verdana","sans-serif";color:#1f497d"> </span></p><p class="MsoNormal"><span style="font-family:"Verdana","sans-serif";color:#1f497d">William Miller</span></p><p class="MsoNormal"><span style="font-family:"Verdana","sans-serif";color:#1f497d"> </span></p><p class="MsoNormal"><span style="font-family:"Arial","sans-serif";color:#1f497d">Miller Solar</span></p><p class="MsoNormal"><span style="font-family:"Arial","sans-serif";color:#1f497d">17395 Oak Road, Atascadero, CA 93422</span></p><p class="MsoNormal"><span style="font-family:"Arial","sans-serif";color:#1f497d">805-438-5600</span></p><p class="MsoNormal"><span style="font-family:"Arial","sans-serif";color:#1f497d"><a href="http://www.millersolar.com/"><span style="color:blue">www.millersolar.com</span></a></span></p><p class="MsoNormal"><span style="font-family:"Arial","sans-serif";color:#1f497d">CA Lic. 773985</span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span></p><p class="MsoNormal"><span style="font-family:"Verdana","sans-serif";color:#1f497d"> </span></p><p class="MsoNormal"><b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">From:</span></b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif""> James Jarvis [mailto:<a href="mailto:jj@aprsworld.com">jj@aprsworld.com</a>] <br><b>Sent:</b> Saturday, January 28, 2023 7:03 PM<br><b>To:</b> Brian Mehalic<br><b>Cc:</b> RE-wrenches; <a href="mailto:william@millersolar.com">william@millersolar.com</a><br><b>Subject:</b> Re: [RE-wrenches] Remote battery disconnects</span></p><p class="MsoNormal"> </p><div><p class="MsoNormal">Brian and William,</p><div><p class="MsoNormal"> </p></div><div><p class="MsoNormal">With all due respect, I think your geographical location of California may be limiting in your understanding of the implications of local power security. </p></div><div><p class="MsoNormal"> </p></div><div><p class="MsoNormal">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.</p></div><div><p class="MsoNormal"> </p></div><div><p class="MsoNormal">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. </p></div><div><p class="MsoNormal"> </p></div><div><p class="MsoNormal">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. </p></div><div><p class="MsoNormal"> </p></div><div><p class="MsoNormal">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.</p></div><div><p class="MsoNormal"><br clear="all"></p><div><div><div><div><p class="MsoNormal">-James Jefferson Jarvis<br>APRS World, LLC<br>+1-507-454-2727</p></div><p class="MsoNormal"><a href="http://www.aprsworld.com/" target="_blank">http://www.aprsworld.com/</a></p></div></div></div><p class="MsoNormal"> </p></div></div><p class="MsoNormal"> </p><div><div><p class="MsoNormal">On Sat, Jan 28, 2023 at 7:35 PM Brian Mehalic <<a href="mailto:brian@solarenergy.org">brian@solarenergy.org</a>> wrote:</p></div><blockquote style="border:none;border-left:solid #cccccc 1.0pt;padding:0in 0in 0in 6.0pt;margin-left:4.8pt;margin-right:0in"><div><p class="MsoNormal">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!”</p><div><p class="MsoNormal"> </p></div><div><p class="MsoNormal" style="margin-bottom:12.0pt">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]. </p><div><p class="MsoNormal">Brian Mehalic</p></div><div><p class="MsoNormal"><br><br></p><p class="MsoNormal" style="margin-bottom:12.0pt">On Jan 28, 2023, at 5:58 PM, James Jarvis via RE-wrenches <<a href="mailto:re-wrenches@lists.re-wrenches.org" target="_blank">re-wrenches@lists.re-wrenches.org</a>> wrote:</p></div><blockquote style="margin-top:5.0pt;margin-bottom:5.0pt"><div><p class="MsoNormal"><span style="font-family:"Tahoma","sans-serif""></span></p><div><p class="MsoNormal">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.</p><div><p class="MsoNormal"><br clear="all"></p><div><div><div><div><p class="MsoNormal">-James Jefferson Jarvis<br>APRS World, LLC<br>+1-507-454-2727</p></div><p class="MsoNormal"><a href="http://www.aprsworld.com/" target="_blank">http://www.aprsworld.com/</a></p></div></div></div><p class="MsoNormal"> </p></div></div><p class="MsoNormal"> </p><div><div><p class="MsoNormal">On Sat, Jan 28, 2023 at 6:22 PM William Miller via RE-wrenches <<a href="mailto:re-wrenches@lists.re-wrenches.org" target="_blank">re-wrenches@lists.re-wrenches.org</a>> wrote:</p></div><blockquote style="border:none;border-left:solid #cccccc 1.0pt;padding:0in 0in 0in 6.0pt;margin-left:4.8pt;margin-right:0in"><div><p class="MsoNormal">Esteemed wrenches:</p></div><div><p class="MsoNormal"> </p></div><div><p class="MsoNormal">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. </p></div><div><p class="MsoNormal"> </p></div><div><p class="MsoNormal">Others may prioritize their charge controller over their homes…</p></div><div><p class="MsoNormal"> </p></div><div><p class="MsoNormal">Put a cable-tie lock in the closed position to discourage kids from messing with it. Test it only after dark. </p></div><div><p class="MsoNormal"> </p></div><div><p class="MsoNormal">William</p></div><div><p class="MsoNormal"> </p><div><div><p class="MsoNormal">On Sat, Jan 28, 2023 at 2:32 PM William Bryce <<a href="mailto:wlbryce@pineridgeproducts.com" target="_blank">wlbryce@pineridgeproducts.com</a>> wrote:</p></div><blockquote style="border:none;border-left:solid #cccccc 1.0pt;padding:0in 0in 0in 6.0pt;margin-left:4.8pt;margin-right:0in"><div><p class="MsoNormal">All</p><div><p class="MsoNormal"> </p></div><div><p class="MsoNormal">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. </p></div><div><p class="MsoNormal">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.</p></div></div><p class="MsoNormal"> </p><div><div><p class="MsoNormal">On Sat, Jan 28, 2023 at 3:27 PM William Miller via RE-wrenches <<a href="mailto:re-wrenches@lists.re-wrenches.org" target="_blank">re-wrenches@lists.re-wrenches.org</a>> wrote:</p></div><blockquote style="border:none;border-left:solid #cccccc 1.0pt;padding:0in 0in 0in 6.0pt;margin-left:4.8pt;margin-right:0in"><div><div><div><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-family:"Verdana","sans-serif";color:#1f497d">Jeremy:</span></p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-family:"Verdana","sans-serif";color:#1f497d"> </span></p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-family:"Verdana","sans-serif";color:#1f497d">Thanks for posting the code references for those that had never looked them up.</span></p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-family:"Verdana","sans-serif";color:#1f497d"> </span></p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-family:"Verdana","sans-serif";color:#1f497d">Chris:</span></p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-family:"Verdana","sans-serif";color:#1f497d"> </span></p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-family:"Verdana","sans-serif";color:#1f497d">What do you mean by “</span><span style="font-size:13.5pt">a disconnect for AC wiring, not specific to which or both panel types”</span><span style="font-family:"Verdana","sans-serif";color:#1f497d">?</span></p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-family:"Verdana","sans-serif";color:#1f497d"> </span></p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-family:"Verdana","sans-serif";color:#1f497d">All:</span></p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-family:"Verdana","sans-serif";color:#1f497d"> </span></p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-family:"Verdana","sans-serif";color:#1f497d">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.</span></p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-family:"Verdana","sans-serif";color:#1f497d"> </span></p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-family:"Verdana","sans-serif";color:#1f497d">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.</span></p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-family:"Verdana","sans-serif";color:#1f497d"> </span></p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-family:"Verdana","sans-serif";color:#1f497d">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. </span></p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-family:"Verdana","sans-serif";color:#1f497d"> </span></p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-family:"Verdana","sans-serif";color:#1f497d">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.</span></p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-family:"Verdana","sans-serif";color:#1f497d"> </span></p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-family:"Verdana","sans-serif";color:#1f497d">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.</span></p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-family:"Verdana","sans-serif";color:#1f497d"> </span></p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-family:"Verdana","sans-serif";color:#1f497d"> </span></p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-family:"Verdana","sans-serif";color:#1f497d">William Miller</span></p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-family:"Verdana","sans-serif";color:#1f497d"> </span></p><div><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-family:"Arial","sans-serif";color:#1f497d">Miller Solar</span></p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-family:"Arial","sans-serif";color:#1f497d">17395 Oak Road, Atascadero, CA 93422</span></p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-family:"Arial","sans-serif";color:#1f497d">805-438-5600</span></p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-family:"Arial","sans-serif";color:#1f497d"><a href="http://www.millersolar.com/" target="_blank">www.millersolar.com</a></span></p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-family:"Arial","sans-serif";color:#1f497d">CA Lic. 773985</span></p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span></p></div><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-family:"Verdana","sans-serif";color:#1f497d"> </span></p><div><div style="border:none;border-top:solid #b5c4df 1.0pt;padding:3.0pt 0in 0in 0in"><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">From:</span></b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif""> RE-wrenches [mailto:<a href="mailto:re-wrenches-bounces@lists.re-wrenches.org" target="_blank">re-wrenches-bounces@lists.re-wrenches.org</a>] <b>On Behalf Of </b>Jeremy Rodriguez via RE-wrenches<br><b>Sent:</b> Saturday, January 28, 2023 10:12 AM<br><b>To:</b> <a href="mailto:cwarfel@entech-engineering.com" target="_blank">cwarfel@entech-engineering.com</a>; RE-wrenches<br><b>Cc:</b> Jeremy Rodriguez<br><b>Subject:</b> Re: [RE-wrenches] Remote battery disconnects</span></p></div></div><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> </p><div><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-family:"Tahoma","sans-serif""></span></p></div><div><p><strong><span style="color:blue">2020 Code Language:</span></strong></p><p><em><b><span style="color:black">480.7 DC Disconnect Methods.</span></b></em></p><p><em><b><span style="color:black">(A) Disconnecting Means.</span></b></em><b><i><span style="color:black"> </span></i></b><em><span style="color:black">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.</span></em></p><p><em><b><span style="color:black;background:#cccccc">N</span></b></em><b><i><span style="color:black"> <em>(B) Emergency Disconnect.</em> </span></i></b><em><span style="color:black">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”.</span></em></p><p><b><i><span style="color:black;background:#cccccc">N</span><span style="color:black"> <em>(C) Disconnection of Series Battery Circuits.</em> </span></i></b><em><span style="color:black">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.</span></em></p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> </p><div id="m_7115390210110525282m_-5127136963893056115m_4094476521578825074m_-1017373149271638466AppleMailSignature"><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">Jeremy Rodriguez </p><div><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">Solar Installation / Design</p></div><div><div><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">All Solar, Inc. </p><div><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">1453 M St. </p><div><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">Penrose Colorado 81240</p></div><div><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> </p></div><div><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">Sent by Jeremy's iPhone. Sorry for typos and shorthand. </p></div></div></div></div></div><div><p class="MsoNormal" style="margin-bottom:12.0pt"> </p><p class="MsoNormal" style="margin-bottom:12.0pt">On Jan 28, 2023, at 7:28 AM, Christopher Warfel via RE-wrenches <<a href="mailto:re-wrenches@lists.re-wrenches.org" target="_blank">re-wrenches@lists.re-wrenches.org</a>> wrote:</p></div><blockquote style="margin-top:5.0pt;margin-bottom:5.0pt"><div><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-family:"Tahoma","sans-serif""></span> </p><p><span style="font-size:13.5pt">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</span></p><div><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">On 1/27/2023 3:35 PM, William Miller via RE-wrenches wrote:</p></div><blockquote style="margin-top:5.0pt;margin-bottom:5.0pt"><div><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-family:"Verdana","sans-serif";color:#1f497d">Glenn:</span></p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-family:"Verdana","sans-serif";color:#1f497d"> </span></p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-family:"Verdana","sans-serif";color:#1f497d">As I wrote, a DC disconnect is required. Here is an excerpt from the Q&A with the building official:</span></p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-family:"Verdana","sans-serif";color:#1f497d"> </span></p><p style="margin-left:.5in;background:white"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#242424;background:white">4.</span><span style="font-size:7.0pt;font-family:"Calibri","sans-serif";color:#242424;background:white"> </span><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#242424;background:white">Will you be requiring an external disconnect to disconnect the AC output of the inverter system from premise wiring?</span></p><p style="margin-left:.5in;background:white"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#c82613;background:white">Yes, as required per 230.85</span></p><p style="margin-left:.5in;background:white"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#242424;background:white">5.</span><span style="font-size:7.0pt;font-family:"Calibri","sans-serif";color:#242424;background:white"> </span><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#242424;background:white">Will you be requiring an external disconnect to disconnect batteries from the inverters?</span></p><p style="margin-left:.5in;background:white"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#c82613;background:white">Yes</span></p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-family:"Verdana","sans-serif";color:#1f497d"> </span></p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-family:"Verdana","sans-serif";color:#1f497d">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…</span></p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-family:"Verdana","sans-serif";color:#1f497d"> </span></p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-family:"Verdana","sans-serif";color:#1f497d">William</span></p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-family:"Verdana","sans-serif";color:#1f497d"> </span></p><div><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-family:"Arial","sans-serif";color:#1f497d">Miller Solar</span></p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-family:"Arial","sans-serif";color:#1f497d">17395 Oak Road, Atascadero, CA 93422</span></p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-family:"Arial","sans-serif";color:#1f497d">805-438-5600</span></p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-family:"Arial","sans-serif";color:#1f497d"><a href="http://www.millersolar.com/" target="_blank">www.millersolar.com</a></span></p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-family:"Arial","sans-serif";color:#1f497d">CA Lic. 773985</span></p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span></p></div><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-family:"Verdana","sans-serif";color:#1f497d"> </span></p><div><div style="border:none;border-top:solid #b5c4df 1.0pt;padding:3.0pt 0in 0in 0in"><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">From:</span></b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif""> RE-wrenches [mailto:<a href="mailto:re-wrenches-bounces@lists.re-wrenches.org" target="_blank">re-wrenches-bounces@lists.re-wrenches.org</a>] <b>On Behalf Of </b>Glenn Burt via RE-wrenches<br><b>Sent:</b> Friday, January 27, 2023 11:46 AM<br><b>To:</b> William Miller via RE-wrenches<br><b>Cc:</b> Glenn Burt<br><b>Subject:</b> Re: [RE-wrenches] Remote battery disconnects</span></p></div></div><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> </p><div><div><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:10.0pt">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?</span></p></div><div><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:10.0pt">Obviously there is a big difference here and it may be changing as the code evolves.</span></p></div><div><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:10.0pt"> </span></p></div><div><div><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:10.0pt">-Glenn</span></p></div><div><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:10.0pt">Sent from my 'smart'phone, so please excuse typos and spelling errors.</span></p></div></div></div><div><div id="m_7115390210110525282m_-5127136963893056115m_4094476521578825074m_-1017373149271638466LGEmailHeader"><div><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:10.0pt"> </span></p></div><div><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:10.0pt">------ Original message------</span></p></div><div><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><b><span style="font-size:10.0pt">From: </span></b><span style="font-size:10.0pt">William Miller via RE-wrenches</span></p></div><div><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><b><span style="font-size:10.0pt">Date: </span></b><span style="font-size:10.0pt">Fri, Jan 27, 2023 2:26 PM</span></p></div><div><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><b><span style="font-size:10.0pt">To: </span></b><span style="font-size:10.0pt">RE-wrenches;</span></p></div><div><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><b><span style="font-size:10.0pt">Cc: </span></b><span style="font-size:10.0pt">William Miller;</span></p></div><div><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><b><span style="font-size:10.0pt">Subject:</span></b><span style="font-size:10.0pt">[RE-wrenches] Remote battery disconnects</span></p></div><div><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:10.0pt"> </span></p></div></div><div><div><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-family:"Verdana","sans-serif"">Friends:</span></p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-family:"Verdana","sans-serif""> </span></p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-family:"Verdana","sans-serif"">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.</span></p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-family:"Verdana","sans-serif""> </span></p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-family:"Verdana","sans-serif"">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. </span></p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-family:"Verdana","sans-serif""> </span></p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-family:"Verdana","sans-serif"">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. </span></p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-family:"Verdana","sans-serif""> </span></p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-family:"Verdana","sans-serif"">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.</span></p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-family:"Verdana","sans-serif""> </span></p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-family:"Verdana","sans-serif"">I have done some considerable research and have not found viable, high amperage, remotely activated shutdown equipment.</span></p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-family:"Verdana","sans-serif""> </span></p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-family:"Verdana","sans-serif"">I am wondering what hardware others may be using to achieve remote battery disconnecting in these types of cases..</span></p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-family:"Verdana","sans-serif""> </span></p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-family:"Verdana","sans-serif"">William</span></p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-family:"Verdana","sans-serif""> </span></p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-family:"Arial","sans-serif"">Miller Solar</span></p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-family:"Arial","sans-serif"">17395 Oak Road, Atascadero, CA 93422</span></p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-family:"Arial","sans-serif""><a href="tel:805-438-5600" target="_blank">805-438-5600</a></span></p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-family:"Arial","sans-serif""><a href="http://www.millersolar.com/" target="_blank">www.millersolar.com</a></span></p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-family:"Arial","sans-serif"">CA Lic. 773985</span></p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> </p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> </p></div></div></div></div><p class="MsoNormal" style="margin-right:1.0in;margin-bottom:12.0pt;margin-left:1.0in"> </p></blockquote></div></blockquote></div></div></div><p class="MsoNormal" style="margin-bottom:12.0pt">_______________________________________________<br>List sponsored by Redwood Alliance<br><br>Pay optional member dues here: <a href="http://re-wrenches.org" target="_blank">http://re-wrenches.org</a><br><br>List Address: <a href="mailto:RE-wrenches@lists.re-wrenches.org" target="_blank">RE-wrenches@lists.re-wrenches.org</a><br><br>Change listserver email address & settings:<br><a href="http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org" target="_blank">http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org</a><br><br>There are two list archives for searching. When one doesn't work, try the other:<br><a href="https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/" target="_blank">https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/</a><br><a href="http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org" target="_blank">http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org</a><br><br>List rules & etiquette:<br><a href="http://www.re-wrenches.org/etiquette.htm" target="_blank">http://www.re-wrenches.org/etiquette.htm</a><br><br>Check out or update participant bios:<br><a href="http://www.members.re-wrenches.org" target="_blank">http://www.members.re-wrenches.org</a></p></div></blockquote></div></blockquote></div></div><p class="MsoNormal">-- </p><div><p class="MsoNormal"><br>William Miller<br>Miller Solar.com<br>895-438-5600<br><a href="http://www.millersolar.com" target="_blank">www.millersolar.com</a></p></div><p class="MsoNormal" style="margin-bottom:12.0pt">_______________________________________________<br>List sponsored by Redwood Alliance<br><br>Pay optional member dues here: <a href="http://re-wrenches.org" target="_blank">http://re-wrenches.org</a><br><br>List Address: <a href="mailto:RE-wrenches@lists.re-wrenches.org" target="_blank">RE-wrenches@lists.re-wrenches.org</a><br><br>Change listserver email address & settings:<br><a href="http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org" target="_blank">http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org</a><br><br>There are two list archives for searching. When one doesn't work, try the other:<br><a href="https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/" target="_blank">https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/</a><br><a href="http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org" target="_blank">http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org</a><br><br>List rules & etiquette:<br><a href="http://www.re-wrenches.org/etiquette.htm" target="_blank">http://www.re-wrenches.org/etiquette.htm</a><br><br>Check out or update participant bios:<br><a href="http://www.members.re-wrenches.org" target="_blank">http://www.members.re-wrenches.org</a></p></blockquote></div><p class="MsoNormal" style="margin-bottom:12.0pt">_______________________________________________<br>List sponsored by Redwood Alliance<br><br>Pay optional member dues here: <a href="http://re-wrenches.org" target="_blank">http://re-wrenches.org</a><br><br>List Address: <a href="mailto:RE-wrenches@lists.re-wrenches.org" target="_blank">RE-wrenches@lists.re-wrenches.org</a><br><br>Change listserver email address & settings:<br><a href="http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org" target="_blank">http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org</a><br><br>There are two list archives for searching. When one doesn't work, try the other:<br><a href="https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/" target="_blank">https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/</a><br><a href="http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org" target="_blank">http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org</a><br><br>List rules & etiquette:<br><a href="http://www.re-wrenches.org/etiquette.htm" target="_blank">http://www.re-wrenches.org/etiquette.htm</a><br><br>Check out or update participant bios:<br><a href="http://www.members.re-wrenches.org" target="_blank">http://www.members.re-wrenches.org</a></p></div></blockquote></div></div></blockquote></div></div></body></html>