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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">Jason:</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">Sol-Arc does provide generator support. They call it “grid peak load shaving” and it is described on page 22 of the manual. Below is an excerpt.</span></p><p class="MsoNormal"><span style="font-family:"Verdana","sans-serif";color:#1f497d"> </span></p><p class="MsoNormal"><img width="1556" height="359" id="Picture_x0020_1" src="cid:image001.png@01DA7FB7.4CC62E10"><span style="font-family:"Verdana","sans-serif";color:#1f497d"></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">For those that may not be familiar with the concept of generator support, here is how I describe it: The inverter(s) are programmed for the generator capacity. If the generator is powering loads and the demand exceeds that programmed generator capacity, the inverter can start inverting and synchronize output to the generator to add power. This is only possible if battery charge levels are adequate. In the Sol-Arc this function can be adjusted or turned off.</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 my recommendations on wire sizing: I may have done a poor job describing how I see your project best approached. Below is a diagram that may do a better job. Power flow is from left to right:</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"><img width="1093" height="618" id="Picture_x0020_3" src="cid:image004.jpg@01DA7FC4.BBDEA860"></span><span style="font-family:"Verdana","sans-serif";color:#1f497d"></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">If you follow what I am laying down, you can see there is no single inverter or inverter wire that can pass or create more than 80 amps. Ergo #4 copper. The money and time you save can easily purchase 8 80 amp breakers. If you look at Diagram 10 in the April 5, 2022 Sol-Arc manual you will see this concept shown, albeit without bypass capabilities and with a separate “LOAD AC Combiner panel.” The separate panel is redundant,-- all of the breakers in the AC combiner panel could be located in the “Main Breaker Panel.”</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">Contemplate this: Just because an inverter can pass-through 200 amps, does not mean it can pass through amps above what the input breaker provides.</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">I hope I have been more clear. I also hope you don’t spend a lot of money on and wrassle wire larger than is needed. </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">Call me if I can help in any way.</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</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">PS: Below is a diagram on how to provide bypass. I tried to depict the bypass interlock graphically. The point is you cannot turn <u>on</u> the bypass breaker without turning <u>off</u> the inverter output breakers. See photos of the actual hardware on the web page linked below. I find bypass very handy because if there is an inverter or battery failure the client can restore power immediately and I can respond at a more convenient time.</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"> </span></p><p class="MsoNormal"><span style="font-family:"Verdana","sans-serif";color:#1f497d"><img width="1446" height="817" id="Picture_x0020_4" src="cid:image005.jpg@01DA7FBA.FA069170"></span><span style="font-family:"Verdana","sans-serif";color:#1f497d"></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"> </span></p><p class="MsoNormal"><span style="font-family:"Verdana","sans-serif";color:#1f497d">Wm</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""> Jason Szumlanski [mailto:<a href="mailto:jason@floridasolardesigngroup.com">jason@floridasolardesigngroup.com</a>] <br><b>Sent:</b> Tuesday, March 26, 2024 6:41 PM<br><b>To:</b> William Miller; RE-wrenches<br><b>Subject:</b> Re: [RE-wrenches] Sol-Ark 15K AC Output</span></p><p class="MsoNormal"> </p><div><p class="MsoNormal">#4 wire as the output of each inverter is definitely not adequate, as each inverter can pass through 150A of generator power. In theory it would be spit across all four, but that doesn't matter. It's an open spigot, so at a minimum the output conductors would need to be 150A rated in my opinion. The complication arises when you don't know whether the inverter can supplement this AC output all the way to the 200A load OCPD integral to the inverter. For that reason, I believe you need to size the output conductors to 200A, not 150A in this case. I am trying to find out definitively if generator support mode is supplied by Sol-Ark s.</p><div><p class="MsoNormal"> </p></div><div><p class="MsoNormal">As for paralleling the outputs, landing the outputs on breakers becomes problematic and very expensive. Since the outputs need to be 150A minimum or 200A maximum (as discussed previously), how would you do a 400A panelboard with four of these large breakers in it, keeping in mind that all four need to be fastened as backfed main breakers? I don't see a practical way to make that happen.</p></div><div><p class="MsoNormal"> </p></div><div><p class="MsoNormal">The same thing applies to combining the generator inputs. You would need 4 x 150A backfed breakers, all fastened to the bus. Is there a cost effective way to accomplish this?</p></div><div><p class="MsoNormal"> </p></div><div><p class="MsoNormal">Serviceability and bypass are obvious desires, but at what cost? If an inverter needs to be taken out of service, it's fairly easy to remove the supply and load conductors. And this highlights my issue... What if three of four inverters need to be removed from service? Then absolute 150A generator power can flow through the remaining single inverter, meaning the output conductors need to be sized accordingly. </p></div><div><p class="MsoNormal"> </p></div><div><p class="MsoNormal">Jason</p></div><div><p class="MsoNormal"> </p></div></div><p class="MsoNormal"> </p><div><div><p class="MsoNormal">On Tue, Mar 26, 2024, 9:15 PM William Miller via RE-wrenches <<a href="mailto:re-wrenches@lists.re-wrenches.org">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><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-family:"Verdana","sans-serif";color:#1f497d">Jason:</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 am wondering on the advisability of hardwiring the outputs of all four inverters together. If one inverter fails the other three can backfeed into it without any means to disconnect the failed inverter and without over-current protection. Have you considered landing the output of each inverter on a separate, appropriately sized 2 pole breaker in the output load-center? </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 the same vein, how are you feeding generator input into the inverters? Are these hard-wired paralleled as well? You might consider having the generator feed a dedicated load-center with an appropriately sized breaker to feed each inverter. You protect the conductors as required and you can isolate any inverter for service</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 size should these breaker be? If your inverter can supply 62.5 AAC, upsizing for continuous duty and to the next higher standard breaker size you get 80 amps. If you use 80 amp breakers into and out of each Sol-Arc you require #4 copper at 75°C. Each inverter and all of the conductors are protected for the max current they will see and you get the combined amperage at your output. There should be no need to run 400 amp wire.</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">BTW, you can easily contrive a bypass system by creating a sliding mechanical interlock. You run an appropriately sized feeder between the generator fed and inverter fed panels. The bypass breaker in the inverter-fed panels is interlocked with the inverter output breakers. The installation might look like <a href="https://millersolar.com/MillerSolar/Portfolio/Inverters/battery_iinverters/Chimney_Rock/Chimney_rock.html" target="_blank">this</a>. This is way cheaper and easier than installing an additional 200A, double-throw safety switch. (A home-made interlock may not be listed but what is the worse that will happen if all breakers are on? The inverters will detect backfeed and shut down. No harm will come of it.)</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">Hope this helps.</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><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><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"><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>Jason Szumlanski via RE-wrenches<br><b>Sent:</b> Tuesday, March 26, 2024 2:26 PM<br><b>To:</b> RE-wrenches<br><b>Cc:</b> Jason Szumlanski<br><b>Subject:</b> [RE-wrenches] Sol-Ark 15K AC Output</span></p><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-family:"Arial","sans-serif"">I am going to have a quad-stack of Sol-Ark 15K for an off-grid 120/240V system with a 150A generator. I know the max real power is 62.5A each inverter including battery and PV. That would be 62.5A x 4 = 250A total. I intend to connect the output of the 4 inverters together with a 5-port Polaris tap, with the output of the Polaris Tap going to a 400A main lug only panelboard. </span></p></div><div><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-family:"Arial","sans-serif""> </span></p></div><div><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-family:"Arial","sans-serif"">My question revolves around the 200A passthrough capability for the generator, which is 150A max output and would be connected to the Grid input on each inverter. Since each inverter would need to handle the full pass-through current, that would require minimum 150A conductors on the input side of each inverter. I am under the impression that the inverters can supplement the "grid" or generator in this case if the current exceeds the available input. That means the inverter would have 150A of input plus 62.5A of inverter power for a total of 212.5A. But there is a 200A load OCPD, so I could size the load conductors from each inverter for 200A.</span></p></div><div><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-family:"Arial","sans-serif""> </span></p></div><div><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-family:"Arial","sans-serif"">Obviously the 4 inverters can only pass through 150A from the generator in total, which would probably be split among them, but could go through a single unit if the rest fail.</span></p></div><div><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-family:"Arial","sans-serif""> </span></p></div><div><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-family:"Arial","sans-serif"">Now, is it possible for each inverter to output 62.5A each PLUS 150A of generator power spread across them for a total of 400A? That is important because I would need to size the combined output conductors for 400A if that is the case.</span></p></div><div><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-family:"Arial","sans-serif""> </span></p></div><div><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-family:"Arial","sans-serif"">I guess I'm not clear on how Sol-Ark 15K handles grid/generator assist/supplement. It does not seem to be documented clearly.</span></p></div><div><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-family:"Arial","sans-serif""> </span></p></div><div><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-family:"Arial","sans-serif"">Jason Szumlanski</span></p></div><div><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-family:"Arial","sans-serif"">Florida Solar Design Group</span></p></div><div><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-family:"Arial","sans-serif""> </span></p></div><div><div><div><div><div><div><div><div><p class="MsoNormal" align="center" style="text-align:center"><b> </b></p></div></div></div></div></div></div></div></div></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. 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