<div dir="ltr">I would definitely check the insulation on the AC-side wiring as Lloyd mentioned. Sometimes small faults don't show up until there is moisture in the air (or conduit) or until max current conditions. As long as you have time delay fuses property sized, it would be rare for them to blow more than once or twice over a period of many years. You could try checking the insulation with a megger, but pulling it out and replacing it might be a more sure fire bet. If it still faults after that, at least you know the wire is good. <div><br></div><div>August<br><br></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Mon, Nov 1, 2021 at 3:50 PM Dave Tedeyan <<a href="mailto:dave@sungineersolar.com">dave@sungineersolar.com</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"><div>The fuses are Ferraz Shawmut Trionic TR60R. 60A, 250V. I looked them up to find that they are time delay, RK5 type. </div><div dir="auto"><br></div><div dir="auto">I would imagine that there is monitoring, but not being my installation, I don't have access to it. That's a good idea though to get access to see when this is happening.</div><div dir="auto"><br></div><div dir="auto">I am also waiting to hear back as to whether it is both legs, or only one. I've been to the site only once so far, to initially diagnose the bad fuse. At the time, I was hoping that it was just a bad fuse since everything else looked okay.</div><div dir="auto"><br></div><div dir="auto">Lloyd, thanks for the insulation tip. Next time I head out there, I should pull out the wires and take a closer look. Unfortunately it's a line side tap, so I'm not excited about removing the tap, but may be worth it if I can't find anything else. Although come to think of it, I did find a ground fault in the wires for another system at the same site, so the original installers' wire pulling technique is certainly suspect.</div><div dir="auto"><br></div><div dir="auto">Cheers,</div><div dir="auto">Dave<br><br><div class="gmail_quote" dir="auto"><div dir="ltr" class="gmail_attr">On Mon, Nov 1, 2021, 6:05 PM Jerry Shafer <<a href="mailto:jerrysgarage01@gmail.com" target="_blank">jerrysgarage01@gmail.com</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">Does this system have monitoring, what time of day is this happening, the monitoring site should show output at time of failure, what leg is tripping both or one side? You may want to look at the fuses they are using, rapid blow, slow blow, rated for the duty these are being used for. You can also use a data logger to get a better idea of what and when<div dir="auto"><br><div dir="auto">Jerry</div></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Mon, Nov 1, 2021, 1:45 PM Lloyd Hoffstatter <<a href="mailto:lloyd@sunstruckconsulting.com" rel="noreferrer" target="_blank">lloyd@sunstruckconsulting.com</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 lang="EN-US" style="overflow-wrap: break-word;">
<div>
<p class="MsoNormal">Dave,</p>
<p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal">My first thought would be a small nick in wire insulation going to ground, causing the fuse to fail over time.</p>
<p class="MsoNormal">We had a similar situation with a much larger system where the culprit was hard to notice\u2026</p>
<p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal">Best regards,</p>
<p class="MsoNormal">Lloyd</p>
<p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal">Lloyd Hoffstatter</p>
<p class="MsoNormal">Sunstruck Consulting</p>
<p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal">Sent from <a href="https://go.microsoft.com/fwlink/?LinkId=550986" rel="noreferrer noreferrer" target="_blank">
Mail</a> for Windows</p>
<p class="MsoNormal"><u></u> <u></u></p>
<div style="border-right:none;border-bottom:none;border-left:none;border-top:1pt solid rgb(225,225,225);padding:3pt 0in 0in">
<p class="MsoNormal" style="border:none;padding:0in"><b>From: </b><a href="mailto:dave@sungineersolar.com" rel="noreferrer noreferrer" target="_blank">Dave Tedeyan</a><br>
<b>Sent: </b>Monday, November 1, 2021 4:26 PM<br>
<b>To: </b><a href="mailto:re-wrenches@lists.re-wrenches.org" rel="noreferrer noreferrer" target="_blank">RE-wrenches</a><br>
<b>Subject: </b>[RE-wrenches] SolarEdge inverter blowing fuses</p>
</div>
<p class="MsoNormal"><u></u> <u></u></p>
<div>
<p class="MsoNormal">Hi All,<u></u><u></u></p>
<div>
<p class="MsoNormal"><u></u> <u></u></p>
<div>
<p class="MsoNormal">I am servicing a system that keeps blowing fuses on the AC side, although it<u></u><u></u></p>
</div>
<div>
<p class="MsoNormal"> appears that everything is sized correctly. It is a SolarEdge SE11400A-US inverter.<u></u><u></u></p>
</div>
<div>
<p class="MsoNormal"> Max continuous output current is 47.5A x 1.25 = 59.4A. There is a GE TG3222R<u></u><u></u></p>
</div>
<div>
<p class="MsoNormal"> 60A AC disconnect, and it is wired up with #6 THHN wire. The terminals were tight<u></u><u></u></p>
</div>
<div>
<p class="MsoNormal"> and there was no evidence of arcing or burning in the past. This is indoors, and not<u></u><u></u></p>
</div>
<div>
<p class="MsoNormal"> exposed to sunlight. No extra conductors are in the conduit.<u></u><u></u></p>
</div>
<div>
<p class="MsoNormal"><u></u> <u></u></p>
</div>
<div>
<p class="MsoNormal">But they say that they need to replace a fuse roughly once per month. Has anyone<u></u><u></u></p>
</div>
<div>
<p class="MsoNormal"> seen this before? Could there be some kind of fault in the inverter itself that<u></u><u></u></p>
</div>
<div>
<p class="MsoNormal"> occasionally induces extra current? Is there any way to tweak the settings so that it<u></u><u></u></p>
</div>
<div>
<p class="MsoNormal"> actually produces a bit more than 11.4kw? I appreciate your thoughts.<u></u><u></u></p>
</div>
<div>
<p class="MsoNormal"><u></u> <u></u></p>
</div>
<div>
<p class="MsoNormal">Cheers,<u></u><u></u></p>
</div>
<div>
<p class="MsoNormal">Dave<br clear="all">
<u></u><u></u></p>
<div>
<p class="MsoNormal"><u></u> <u></u></p>
</div>
<p class="MsoNormal">-- <u></u><u></u></p>
<div>
<div>
<div>
<div>
<table border="0" cellspacing="0" cellpadding="0" width="525" style="width:393.75pt;border-collapse:collapse">
<tbody>
<tr>
<td width="125" rowspan="2" valign="top" style="width:93.75pt;border-top:none;border-bottom:none;border-left:none;border-right:1pt solid rgb(236,189,0);padding:0in 7.5pt 0in 0in">
<p class="MsoNormal"><a href="https://www.sungineersolar.com/" rel="noreferrer noreferrer" target="_blank"><span style="font-size:10pt;font-family:Arial,sans-serif;color:rgb(51,122,183);text-decoration:none"><img border="0" width="105" height="103" style="width: 1.0916in; height: 1.075in;" id="gmail-m_-2326349728819178011m_-8043050400055745145m_9031545640300701482_x0000_i1025" src="https://sungineersolar.com/wp-content/uploads/2019/08/Logo-Image-Only-1.png" alt="Logo"></span></a><span style="font-size:10pt;font-family:Arial,sans-serif;color:rgb(68,68,68)"><u></u><u></u></span></p>
</td>
<td style="padding:0in 0in 0in 7.5pt">
<table border="0" cellspacing="0" cellpadding="0" style="border-collapse:collapse;border-spacing:0px">
<tbody>
<tr>
<td width="400" valign="top" style="width:300pt;padding:0in 0in 3.75pt 7.5pt">
<p class="MsoNormal"><b><span style="font-family:Arial,sans-serif;color:rgb(236,189,0)">Dave Tedeyan, P.E.<br>
Owner | Sungineer Solar</span></b><span style="font-family:Arial,sans-serif"><u></u><u></u></span></p>
</td>
</tr>
<tr>
<td valign="top" style="padding:3.75pt 0in 3.75pt 7.5pt">
<p class="MsoNormal" style="line-height:12.75pt"><b><span style="font-size:10pt;font-family:Arial,sans-serif;color:rgb(236,189,0)">p: </span></b><span style="font-size:10pt;font-family:Arial,sans-serif;color:black">he | him | his</span><b><span style="font-size:10pt;font-family:Arial,sans-serif;color:rgb(236,189,0)"><br>
a: </span></b><span style="font-size:10pt;font-family:Arial,sans-serif;color:black">1653 Slaterville Rd.</span><span style="font-size:10pt;font-family:Arial,sans-serif"> <span style="color:black">| Ithaca, NY 14850</span><br>
<b><span style="color:rgb(236,189,0)">w:</span></b><a href="http://www.sungineersolar.com/" rel="noreferrer noreferrer" target="_blank"><span style="color:black"> www.sungineersolar.com</span></a><br>
<b><span style="color:rgb(236,189,0)">c:</span></b><span style="color:black"> (607) 288-2898</span><u></u><u></u></span></p>
</td>
</tr>
</tbody>
</table>
</td>
</tr>
<tr>
<td style="padding:0in"></td>
</tr>
</tbody>
</table>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
<p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal"><u></u> <u></u></p>
</div>
</div>
_______________________________________________<br>
List sponsored by Redwood Alliance<br>
<br>
Pay optional member dues here: <a href="http://re-wrenches.org" rel="noreferrer noreferrer noreferrer" target="_blank">http://re-wrenches.org</a><br>
<br>
List Address: <a href="mailto:RE-wrenches@lists.re-wrenches.org" rel="noreferrer noreferrer" 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" rel="noreferrer noreferrer noreferrer" 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/" rel="noreferrer noreferrer noreferrer" 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" rel="noreferrer noreferrer noreferrer" 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" rel="noreferrer noreferrer noreferrer" 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" rel="noreferrer noreferrer noreferrer" target="_blank">http://www.members.re-wrenches.org</a><br>
<br>
</blockquote></div>
_______________________________________________<br>
List sponsored by Redwood Alliance<br>
<br>
Pay optional member dues here: <a href="http://re-wrenches.org" rel="noreferrer noreferrer" target="_blank">http://re-wrenches.org</a><br>
<br>
List Address: <a href="mailto:RE-wrenches@lists.re-wrenches.org" rel="noreferrer" 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" rel="noreferrer noreferrer" 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/" rel="noreferrer noreferrer" 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" rel="noreferrer noreferrer" 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" rel="noreferrer noreferrer" 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" rel="noreferrer noreferrer" target="_blank">http://www.members.re-wrenches.org</a><br>
<br>
</blockquote></div></div></div>
_______________________________________________<br>
List sponsored by Redwood Alliance<br>
<br>
Pay optional member dues here: <a href="http://re-wrenches.org" rel="noreferrer" 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" rel="noreferrer" 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/" rel="noreferrer" 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" rel="noreferrer" 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" rel="noreferrer" 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" rel="noreferrer" target="_blank">http://www.members.re-wrenches.org</a><br>
<br>
</blockquote></div>