<div dir="auto"><div>Very cool. We typically use Siemens panels with the "back to back" style interlock for single inverters allowing up to 125A bypass in a readily available 8/16 panel. In this fashion, multiple inverter installs necessitate an AC combiner panel with the output feeding a larger transfer switch. I like your solution as it certainly has the potential to save wall space and condense the footprint into one larger panel. We commonly install two bypasses in series for all grid tied battery backup systems; one for grid bypass and the second for generator bypass. I look forward to trying your product in the future.. I still need to plan the brand switch to QO for the right scenario(which I probably need to do anyway as I have a decent collection of QO breakers collecting dust!). Nice work and a hearty salute for coming up with a creative solution to a question most of us have asked at one point or another! </div><div dir="auto"><br></div><div dir="auto">Sunny Regards,</div><div dir="auto"><br></div><div dir="auto">Tyrone Houck</div><div dir="auto">Oregon Solarworks LLC</div><div dir="auto">CCB #204937 LRT #076</div><div dir="auto">541-787-1366</div><div dir="auto"><a href="mailto:tyrone@oregonsolarworks.com">tyrone@oregonsolarworks.com</a></div><div><br></div><div data-smartmail="gmail_signature"><br> </div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Mon, Oct 13, 2025, 10:54 PM William Miller via RE-wrenches <<a href="mailto:re-wrenches@lists.re-wrenches.org" target="_blank" rel="noreferrer">re-wrenches@lists.re-wrenches.org</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div lang="EN-US" link="blue" vlink="purple"><div><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif"">Friends:</span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif""> </span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif"">For many years I had committed to the Outback product line. The decline of Outback forced me to branch out. </span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif""> </span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif"">I just completed my first install of Fortress Envy inverters. Not long ago I installed a Sol-Ark 12K in my shop. Both experiences were mostly positive.</span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif""> </span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif"">What is interesting is the Envy and Soul-ark inverters do not come with BOS equipment. </span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif""> </span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif"">Now, if you want a PV disconnect, you need to add one manufactured by a third party. This can be accomplished with a 600 volt safety switch.</span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif""> </span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif"">If you want AC disconnecting means or distribution, you need to provide outboard equipment. This is easily provided with off-the-shelf circuit breaker panels. </span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif""> </span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif"">Since my second Radian install I have avoided putting AC breakers in the GSLC because wiring them was beyond tedious. Instead I ran my AC leads right through the GSLC and straight to one of two breaker panels: A generator-fed panel and in inverter-fed panel. Therefore I am not inconvenienced by lack of AC BOS with the new generation inverters.</span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif""> </span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif"">There is one other function that is missing with the lack of BOS cabinets: Bypass switching. I think it is imperative that bypass capabilities be provided. Inverters can fail and occasionally need service and a bypass makes these scenarios much easier to handle. As a matter of policy I will not support a batter-inverter client if they do not have a bypass.</span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif""> </span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif"">The Fortress and Sol-Ark manuals recommend use of an outboard double throw switch for bypass. These are expensive and bulky.</span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif""> </span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif"">Over the years I have developed circuit breaker interlocks that can be fitted in a standard breaker panel and take care of the bypassing function cheaply and efficiently. </span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif""> </span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif"">For a long time I have been meaning to write an article on the subject of transfer switches and bypass options. I finally got around to it and it can be found <a href="https://millersolar.com/MillerSolar/practices/Technical_Procedures/Interlock/Interlock.html" rel="noreferrer noreferrer" target="_blank">here</a>. I hope my efforts writing this might provide some insight on the subject.</span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif""> </span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif"">I think I have fine-tuned my interlock design to a final iteration, as described in the article. If any of you are interested in trying out my Universal Bypass Interlock I am willing to send one for you to try at no cost. Contact me off list if you are interested.</span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif""> </span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif"">Sincerely,</span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif""> </span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif"">William Miller</span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif""> </span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Arial","sans-serif"">Miller Solar</span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Arial","sans-serif"">17395 Oak Road, Atascadero, CA 93422</span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Arial","sans-serif"">805-438-5600</span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Arial","sans-serif""><a href="http://www.millersolar.com/" rel="noreferrer noreferrer" target="_blank">www.millersolar.com</a></span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Arial","sans-serif"">CA Lic. 773985</span></p><p class="MsoNormal"> </p><p class="MsoNormal"> </p></div></div>
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