<div dir="ltr"><div>My read: EG4 likely omitted 15A and 20A because these are <span class="gmail_default" style="font-family:arial,helvetica,sans-serif"></span>c<span class="gmail_default" style="font-family:arial,helvetica,sans-serif">ontemplated</span> as high-current smart load or AC-coupled inverter ports, not branch circuit protection for small loads. The GridBOSS is sized for things like EV chargers, HVAC, <span class="gmail_default" style="font-family:arial,helvetica,sans-serif"></span>w<span class="gmail_default" style="font-family:arial,helvetica,sans-serif">ater heaters \u2013</span> not standard household <span class="gmail_default" style="font-family:arial,helvetica,sans-serif"></span>r<span class="gmail_default" style="font-family:arial,helvetica,sans-serif">eceptables and lighting. They expect those to be regular backup loads</span>.<span class="gmail_default" style="font-family:arial,helvetica,sans-serif"> The biggest example I have to support the need to shed a 20A load is a pool pump.</span></div><div><span class="gmail_default" style="font-family:arial,helvetica,sans-serif"><br></span></div><div><span class="gmail_default" style="font-family:arial,helvetica,sans-serif">Anyway, when I use a GridBOSS for an off-grid installation, I almost always use Port 4 for a 15A multiwire branch circuit to support a convenience outlet and lighting for the area on one leg and a generator battery charging circuit on the other leg. I see no issue with it.</span></div><div><span class="gmail_default" style="font-family:arial,helvetica,sans-serif"><br></span></div><div><span class="gmail_default" style="font-family:arial,helvetica,sans-serif">One thing that supports my theory that the breaker ratings are the maximum supported per port <span class="Asgive ng" style="border-style:none;background:none">is that the ratings in the table overlap.</span> Looking at the table, <span class="Asgive ng" style="border-style:none;background:none">on line 1, port 1 supports 90-125A breakers, then the table goes on to support 30-80A breakers for port</span> 1. The whole <span class="Q6ibn ng" style="border-style:none;background:none">tables</span> is a confusing mess. And what about 35A breakers? 45A? These are common for some mini-split units. They are not in the table, but surely would not be a problem.</span></div><div><span class="gmail_default" style="font-family:arial,helvetica,sans-serif"><br></span></div><div><span class="gmail_default" style="font-family:arial,helvetica,sans-serif">EG4 needs to revamp this table for clarity.</span></div><div><span class="gmail_default" style="font-family:arial,helvetica,sans-serif"><br></span></div><div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif">P.S. I have started using Port 1 as the main load port for smaller off-grid jobs without even using the 200A backup load port. I just set port 1 to operate 24 hours a day. This way, you don't need additional overcurrent protection from an external main breaker. The downside is that the manual bypass becomes non-functional, but otherwise it has worked out well for me.</div><br></div><div><div dir="ltr" class="gmail_signature" data-smartmail="gmail_signature"><div dir="ltr"><div><br>Jason Szumlanski<br>Principal Solar Designer | Florida Solar Design Group<br>NABCEP Certified Solar Professional (PVIP)<br>Florida State Certified Solar Contractor CVC56956<br>Florida Certified Electrical Contractor EC13013208<br></div><div><br></div><div><br></div></div></div></div><br></div><br><div class="gmail_quote gmail_quote_container"><div dir="ltr" class="gmail_attr">On Thu, Jul 23, 2026 at 9:24\u202fPM Dave Tedeyan 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="ltr"><div>Hi All, </div><div><br></div><div>I will soon be installing one of these in a detached shed, where it would be useful to have a light installed. There will be no panel in there other than the GridBOSS, inverters and batteries. The manual says that the smallest breaker size that is supported is a 30a breaker. See table below.</div><div><br></div><div>I emailed their tech support to ask if there would be a problem with a 20a breaker. They gave a very basic answer pointing me back to this same table, and then recommended to add a subpanel, and then run a 20A circuit from there. That seems a bit overkill for a light. I cannot see why if a 30A breaker is allowed, a 20A breaker would not be allowed. It is just a simple Eaton breaker. Am I missing something here?</div><div><br></div><div>Cheers, </div><div>Dave</div><div><br></div><div><img src="cid:ii_mry8vs6c2" alt="image (4).png" width="542" height="135"><br></div><div><br></div><span class="gmail_signature_prefix">-- </span><br><div dir="ltr" class="gmail_signature"><div dir="ltr"><br style="color:rgb(34,34,34)"><div dir="ltr" style="color:rgb(34,34,34)"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"></div></div></div><div dir="ltr"><table cellpadding="0" cellspacing="0" style="border-spacing:0px;border-collapse:collapse;color:rgb(68,68,68);width:525px;font-size:11pt;font-family:Arial,sans-serif"><tbody><tr><td width="125" valign="top" rowspan="6" style="padding:0px 10px 0px 0px;font-size:10pt;border-right:1px solid rgb(236,189,0);width:125px;vertical-align:top"><img width="96" height="95" src="https://ci3.googleusercontent.com/mail-sig/AIorK4w9B8ItkbLOVj_3kXSEToNSG4GqEc1qAkl0q-KvGLgH-Zo8UhpcOQ_YebOrq3ZUuLGNqPigeSx2_7i8"><br></td><td style="padding:0px 0px 0px 10px"><table cellpadding="0" cellspacing="0" style="border-spacing:0px;border-collapse:collapse;background-color:transparent"><tbody><tr><td valign="top" style="padding:0px 0px 5px 10px;width:400px;vertical-align:top"><span style="color:rgb(236,189,0);font-size:11pt;font-weight:700">Dave Tedeyan, P.E.<br></span><span style="font-size:11pt;font-weight:700"><font color="#ecbd00">Owner | Sungineer Solar</font><br></span></td></tr><tr><td valign="top" style="padding:5px 0px 5px 10px;font-size:10pt;vertical-align:top;line-height:17px"><span style="color:rgb(236,189,0)"><span style="font-weight:700">p: </span></span><span style="font-size:10pt;color:rgb(0,0,0)">he | him | his</span><span style="color:rgb(236,189,0)"><span style="font-weight:700"><br>a: </span></span><span style="font-size:10pt;color:rgb(0,0,0)">1653 Slaterville Rd.</span> <span style="font-size:10pt;color:rgb(0,0,0)">| Ithaca, NY 14850</span><br><span style="color:rgb(236,189,0)"><span style="font-weight:700">w:</span></span><a href="http://www.sungineersolar.com/" rel="noopener" style="color:rgb(51,122,183);background-color:transparent" target="_blank"><span style="font-size:10pt;color:rgb(0,0,0)"> www.sungineersolar.com</span></a><br><span style="color:rgb(236,189,0)"><span style="font-weight:700">c:</span></span><span style="font-size:10pt;color:rgb(0,0,0)"> (607) 270-0370</span></td></tr></tbody></table></td></tr></tbody></table></div></div></div></div></div></div>
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