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--></style></head><body lang="EN-US" link="#0563C1" vlink="#954F72"><div class="WordSection1"><p class="MsoNormal"><span style="color:#1f497d">Howard,</span></p><p class="MsoNormal"><span style="color:#1f497d"> </span></p><p class="MsoNormal"><span style="color:#1f497d">We haven’t installed Fronius inverters for a while, but I have some similar experience with SMA and ABB arc-fault inverters. In only one case did we have an issue where we actually had a workmanship issue – we found an MC4 connector where the terminal wasn’t fully seated in the housing. We had another case with a SunPower array where we had to update the firmware in the SMA Tripower because it was falsely tripping. We had many sites with ABB/Power-One inverters where the arc sensors needed to be replaced. We have a few sites with intermittent arc faults that were reset and haven’t occurred again – I still don’t know what caused those.</span></p><p class="MsoNormal"><span style="color:#1f497d"> </span></p><p class="MsoNormal"><span style="color:#1f497d">After researching and speaking with tech support many times, I believe that it is also possible that an AC-side arc or surge can cause an arc fault trip. Examples could be a well pump surging, a old treadmill or other appliance, faulty breaker, grid issue, etc. It seems unlikely, however, that this is your case if the same problem is occurring on two different sites.</span></p><p class="MsoNormal"><span style="color:#1f497d"> </span></p><p class="MsoNormal"><span style="color:#1f497d">All that said, I think you are on the right track in thinking it might be an issue with the Sunpreme modules or a compatibility issue between the Fronius and Sunpreme. You may need to get the manufacturers involved. If they know what is good for them, they will give you ample support to fix the problem. </span></p><p class="MsoNormal"><span style="color:#1f497d"> </span></p><p class="MsoNormal"><span style="color:#1f497d">Good luck!</span></p><p class="MsoNormal"><span style="color:#1f497d"> </span></p><p class="MsoNormal"><span style="color:#1f497d">Best,</span></p><p class="MsoNormal"><span style="color:#1f497d"> </span></p><p class="MsoNormal"><span style="color:#1f497d">August</span></p><p class="MsoNormal"><span style="color:#1f497d"> </span></p><div><div style="border:none;border-top:solid #b5c4df 1.0pt;padding:3.0pt 0in 0in 0in"><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""> RE-wrenches [mailto:<a href="mailto:re-wrenches-bounces@lists.re-wrenches.org">re-wrenches-bounces@lists.re-wrenches.org</a>] <b>On Behalf Of </b>Howard "Scot" Arey<br><b>Sent:</b> Thursday, June 18, 2015 5:31 AM<br><b>To:</b> <a href="mailto:re-wrenches@lists.re-wrenches.org">re-wrenches@lists.re-wrenches.org</a><br><b>Subject:</b> [RE-wrenches] Repetitive and unknown arc-fault codes with this combination...Sunpreme bi-facial and Fronius IG</span></p></div></div><p class="MsoNormal"> </p><p class="MsoNormal">I need some help please! I’m quickly losing credibility with two of my customers.</p><p class="MsoNormal"> </p><p class="MsoNormal">We have two installations with Sunpreme GxB 350 bi-facial modules and Fronius IG inverters. They keep throwing Error code 240 – arc fault on the Fronius IG. </p><p class="MsoNormal"> </p><p class="MsoNormal">We’ve been up and down these installation three times checking connections, replacing connectors, tightening connections, checking for chafed wires. Nothing to cause any visible angst.</p><p class="MsoNormal"> </p><p class="MsoNormal">The team here is wondering is perhaps the module itself might be the source of the problem, with some DC arcing inside the J-Box. Any thoughts? We can’t open the j-box on an broken module (be careful handling frameless glass on glass modules <span style="font-family:Wingdings">J</span>) because there doesn’t appear to anything accessible with modern potted j-boxes.</p><p class="MsoNormal"> </p><p class="MsoNormal">As for the conditions when we get these arc fault codes – typically the peak of a sunny day when they’re making max power.</p><p class="MsoNormal"> </p><p class="MsoNormal">Each of the installations is a bit different. On the 7KW install with Fronius 7.5, we’ve run the two strings (10 modules each) back to the inverter separately. On the 10.5KW install with the Fronius 10.0, we ran 3 strings of 10 to a combiner box, then one set of conductor back to the Fronius 10.0 where we used the distribution plate to spead the amperage across the six string input channels.</p><p class="MsoNormal"> </p><p class="MsoNormal">I’m stuck – any thoughts on other potential arc-fault causes?</p><p class="MsoNormal"> </p><p class="MsoNormal"><b>Howard “Scot” Arey</b></p><p class="MsoNormal">254-300-1228</p><p class="MsoNormal"><a href="mailto:scot.arey@solarcentex.com">scot.arey@solarcentex.com</a></p><p class="MsoNormal"> </p><p class="MsoNormal"><img border="0" width="209" height="205" id="Picture_x0020_1" src="cid:image001.jpg@01D0A98F.A4E3E2C0" alt="logo from letterhead"></p><p class="MsoNormal"> </p></div></body></html>