<div dir="ltr"><div dir="ltr"><div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif">We are still on NEC 2020, but I had this issue with a jurisdiction here recently, and I am just going to cut and paste my winning argument here for your benefit. Take from it whatever you think might help. My permit was issued less than an hour after sending this.</div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif"><br></div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif">--------</div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif"><br></div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif">Dear [Insert Misinformed Plan Reviewer Name Here],</div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif"><br></div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif"><div class="gmail_default">I think you are still misinterpreting the scope of Article 702. This is a common issue that was cleared up in the 2023 language, where they removed the phrase you are referring to after it caused mass confusion in the 2020 version. Here is why Article 702 does not apply (and others do):</div><div class="gmail_default"><br></div><div class="gmail_default"><i>(all bold, italic, and underlined emphasis below is added by me)</i></div><div class="gmail_default"><br></div><div class="gmail_default">The system we are installing is connected in parallel with the utility source, which is covered by Article 705, <b>Interconnected </b>Electric Power Production Sources. Section 705.2 defines a Microgrid-Interconnect Device, which in this case is the Enphase System Controller. If you look at the last paragraph of Section 705.40, Loss of Primary Source, an interconnected source is permitted to operate in <b><i><u>island mode</u></i></b> when the primary source is lost. Head over to Section 710.1 where the scope for Stand-alone Systems is defined. This is the Article where island mode is discussed. That is why the governing section for this installation with respect to loads is <span class="gmail-il">710.15</span>(A), which allows for an <b>islanded</b> system to have less capacity than the calculated load. </div><div class="gmail_default"><br></div><div class="gmail_default">Article 702 does not apply here as that covers standby systems, and this is not a standby system. This is an islandable interconnected power source. A standby system is one that does not function in an interactive manner with the utility grid. The reason storage batteries were added to this section is that you <i><b>can</b></i> have storage batteries that are <b><i>not</i></b> capable of interacting with the utility grid, but <b><i>do</i></b> supply standby power, as is the case of an Uninterruptible Power Supply (UPS). This would also be the case if you have batteries with a multimode inverter with an integrated transfer switch that disconnects from the grid during an outage to supply selected loads, but does not "sell" power to the grid. That type of backup system <i><b>would</b></i> need to comply with Article 702 because it is not an interconnected power source. It is simply a load with respect to the primary power source (utility).</div><div class="gmail_default"><br></div><div class="gmail_default">By the way, side note... Enphase also offers a Sunlight Backup Only system, which uses microinverters with the same System Controller, but no battery whatsoever. It only provides power during the day to the extent that there is enough solar irradiance available to loads. This is a perfect example of why Article 710 rules in the case of an islanded interconnected system. It is not a standby system. The solar power supply is variable, necessitating the system to function at a capacity that is less than the connected load. A microgrid is a very different system than a standby system. A microgrid can be comprised of various sources of power, which can include utility, batteries, solar, generators, and others. The major distinction between Articles 705 and 702 is the Microgrid Interconnect Device. Article 702 relies upon a transfer mechanism with no interactive component.</div><div class="gmail_default"><br></div><div class="gmail_default">I hope that clears it up. We code nerds in the industry saw this coming, but it is pretty clear once you make the distinction between an islanded interactive system versus a standby system.</div><div class="gmail_default"><br></div><div class="gmail_default">Article 710 is small, but mighty!</div></div><br clear="all"></div><div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif">--------------</div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif"><br></div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif"><br></div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif"><br></div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif"><br></div><br></div><div><div dir="ltr" class="gmail_signature"><div dir="ltr"><br>Jason Szumlanski<div><span style="color:rgb(51,51,51);font-family:Roboto,RobotoDraft,Helvetica,Arial,sans-serif;font-size:13px">Principal Solar Designer | Florida Solar Design Group</span><br style="color:rgb(51,51,51);font-family:Roboto,RobotoDraft,Helvetica,Arial,sans-serif;font-size:13px"><span style="color:rgb(51,51,51);font-family:Roboto,RobotoDraft,Helvetica,Arial,sans-serif;font-size:13px">NABCEP Certified Solar Professional (PVIP)</span><br style="color:rgb(51,51,51);font-family:Roboto,RobotoDraft,Helvetica,Arial,sans-serif;font-size:13px"><span style="color:rgb(51,51,51);font-family:Roboto,RobotoDraft,Helvetica,Arial,sans-serif;font-size:13px">Florida State Certified Solar Contractor CVC56956</span></div><div><font color="#333333" face="Roboto, RobotoDraft, Helvetica, Arial, sans-serif">Florida Certified Electrical Contractor EC13013208</font></div></div></div></div><br></div><br><div class="gmail_quote gmail_quote_container"><div dir="ltr" class="gmail_attr">On Sat, Aug 2, 2025 at 1:56 PM Chris Sparadeo via RE-wrenches <<a href="mailto:re-wrenches@lists.re-wrenches.org">re-wrenches@lists.re-wrenches.org</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="auto">Hi all,</div><div dir="auto"><br></div><div dir="auto">I’m finding out that some jurisdictions in Texas are requiring ESS output to be equal to or greater than the calculated load of a dwelling. For example, if backing up the whole home, and the service load is calculated at 150A, the ESS would require to continuously output 150A OR EMS is required to bring the calculated load to or below that of the ESS. AHJ’s in a few areas of Texas are dying on this hill and to actually meet the calculated load, systems would need to be significantly larger than needed. </div><div dir="auto"><br></div><div dir="auto">I know that previous versions of 706 (specifically NEC 2017) could lead one to argue this point, but Texas had adopted NEC 2023, and it’s only article 710 that indicates a system operating in isolation of the grid should has sufficient output to supply load to the largest backed up load. </div><div dir="auto"><br></div><div dir="auto">Has anyone run into this issue? And if so, what have people been doing to either meet these outdated requirements or successfully push back? </div><div dir="auto"><br></div><div dir="auto">Thanks!</div><div dir="auto"><br clear="all"><br clear="all"><div dir="auto"><div dir="ltr" class="gmail_signature"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div>Chris Sparadeo</div><div><br></div><div>VT Master Electrician # EM 08220</div><div>C_802-369-4458</div><div></div></div></div></div></div></div></div>
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