<html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class="">Thanks Jay and William, sorry for the delay in response.<div class=""><br class=""></div><div class="">Jay, no breakers are tripping. Just that every so often I come to the site to find an FM80 saying 0v on the PV input side. I think your idea to add soft start controls or delay timers to the fans may be a good place to start. Perhaps that way I may be able to correlate certain batches of fans with a failure incident (assuming I have a way to know when the controllers fail since the one time I witnessed was sheer luck).</div><div class=""><br class=""></div><div class="">William, the idea of shutting off one string into each combiner/controller seems like a great option as well. Of course 4200 watts STC was well within their old suggested input specs and since this site uses everything that is generated from the sun this would ultimately mean the site will burn more fossil fuels while parts of the array are off. Can\u2019t get something for nothing though right! </div><div class=""><br class=""></div><div class="">I have used the Egauge waveform/oscilloscope feature before to investigate a problematic generator but have not used it to observe this particular site in detail yet so thanks for that thought as well. I should have thought of that awhile ago!</div><div class=""><br class=""></div><div class="">Data logging the PV side could be an option as well but could be a significant endeavor. Also, since it\u2019s only three modules in series and it happens during the hot/warm summer months there should be plenty of headroom not to exceed the 150vdc limit. A large majority of my off grid sites have 3 x 60 cell modules in series without this sort of failure rate so I don\u2019t expect the failures resulting from excessive DC voltage. </div><div class=""><br class=""></div><div class="">The isolation transformer trick seems like a good option especially before committing to re-pulling the ground. </div><div class=""><br class=""></div><div class="">Finally, thanks to Lones for reaching out as well. I will report back if I have any discoveries here.</div><div class=""><br class=""></div><div class="">Enjoy your day everyone, Nick</div><div class=""><br class=""></div><div class=""><br class=""><div><blockquote type="cite" class=""><div class="">On Jan 26, 2022, at 9:37 AM, Jay <<a href="mailto:jay.peltz@gmail.com" class="">jay.peltz@gmail.com</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><meta http-equiv="content-type" content="text/html; charset=utf-8" class=""><div dir="auto" class=""><div dir="ltr" class=""></div><div dir="ltr" class="">It\u2019s the gfi breaker that\u2019s tripping right? </div><div dir="ltr" class=""><br class=""></div><div dir="ltr" class="">There is another possibility. I\u2019ve seen extremely high loads with weak batteries cause the capacitors in the CC to dump causing the breakers to trip. </div><div dir="ltr" class=""><br class=""></div><div dir="ltr" class="">One easy fix is to install more wire between the CC and the battery or a smaller size, within ampacity ratings of course. </div><div dir="ltr" class=""><br class=""></div><div dir="ltr" class="">It acts like a choke and the CC can\u2019t dump as fast, it\u2019s worked for me many times in the past. </div><div dir="ltr" class=""><br class=""></div><div dir="ltr" class="">Another option would be to install soft start controls on the fans, and /or delay timers so they don\u2019t all turn on at the same time. </div><div dir="ltr" class=""><br class=""></div><div dir="ltr" class="">As to the classic not tripping, it\u2019s got a special circuit inside that prevents this dumping of the capacitors. </div><div dir="ltr" class=""><br class=""></div><div dir="ltr" class="">Jay</div><div dir="ltr" class=""><br class=""></div><div dir="ltr" class=""><br class=""></div><div dir="ltr" class=""><br class=""><blockquote type="cite" class="">On Jan 26, 2022, at 10:10 AM, Nick A Lucchese <<a href="mailto:lucchesesolar@me.com" class="">lucchesesolar@me.com</a>> wrote:<br class=""><br class=""></blockquote></div><blockquote type="cite" class=""><div dir="ltr" class="">\ufeff<meta http-equiv="Content-Type" content="text/html; charset=utf-8" class="">Thanks Alan, Mac, Jerry and Maverick. Alan, I like your idea of replacing all the FM80\u2019s with Classics. I have had one Classic loaner recently fail there but to be fair I\u2019ve been using it at random sites for years and it has a 2014 manu date so I\u2019m okay with it\u2019s years of service. Maybe I can find a deal on a half dozen of them from the recent DC Solar auctions. All the PV lands on a designated shunt so even though I\u2019d lose some of the granularity in Opticsre I\u2019d still be able to see the sum of current. I think perhaps all of those Classics from DC Solar don\u2019t have internet connectivity either?<div class=""><br class=""></div><div class="">Maverick, yes they are at the end of the 1300\u2019 run. I\u2019ve not gone into his building over there in a long time to check the fans but will do so next time I\u2019m out there. Thanks for the ferrite core suggestion too. Seems like an affordable effort at this point.</div><div class=""><br class=""></div><div class="">Mac, no Tigo\u2019s on this job since it\u2019s an Ironridge SGA ground mount. Yes I\u2019ve been picturing that long run as a huge antenna as well. It now makes me realize that is something else unique about this site is it\u2019s long wire run itself in addition to the lack of ground. Can\u2019t think of any other off grid sites of mine with such a significant run.</div><div class=""><br class=""></div><div class="">Jerry, I\u2019ve been through all the connections but always helps to keep looking for the fine details. I will say getting the #4 into the Classic's terminals is a bit frustrating especially with a conductor that\u2019s been in and out a few times, been wishing that part of their controller would get an upgrade for years. I\u2019ve had to trim off the ends and shorten the conductor every time to get a connection with integrity. Going to have to replace the conductor to the 100 amp GFP if this keeps up.</div><div class=""><br class=""></div><div class="">Thanks for the thoughts. I think the next logical attempt to suppress the spikes will be trying the ferrites as Mac suggested. Hope you all have a great day out there. Off to work, Nick</div><div class=""><br class=""></div><div class=""><br class=""><div class=""><blockquote type="cite" class=""><div class="">On Jan 26, 2022, at 4:57 AM, Mac Lewis <<a href="mailto:maclewis1@gmail.com" class="">maclewis1@gmail.com</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><div dir="ltr" class="">Hi Nick,<div class=""><br class=""></div><div class="">Do you have any rapid shutdown equipment on the arrays? The only charge controller (Midnite CLassic) that we have ever had that failed with a short on PV Input, had the Tigo Shutdown boxes on them (TS4-AF). I have always been curious if that failure mode was due to the Tigo signal somehow.</div><div class=""><br class=""></div><div class="">To me, the consistent failure mode of the short on the PV input is an important clue to someone (not me) as to what is happening. I was always under the impression that the isolation transformers in the inverter did a good job filtering arc faults on the AC side but that 1500' wire run is a huge antenna!</div><div class=""><br class=""></div><div class="">Good Luck out there!</div><div class=""><br class=""></div><div class=""><br class=""></div></div><br class=""><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Wed, Jan 26, 2022 at 12:29 AM Nick A Lucchese <<a href="mailto:lucchesesolar@me.com" class="">lucchesesolar@me.com</a>> wrote:<br class=""></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">Hello again Wrenches,<br class="">
<br class="">
While the failed controller topic is fresh I want to ask opinions/advice on arc faults. I know quite well that they can be mysterious so not sure I\u2019ll really get anywhere but here goes. This particular off grid system consists of two Radians, 2 GSLC\u2019s, FNDC, a 25.2 KW array and 6 FM80\u2019s. 4.2 KW STC into each controller which I now know is over their new recommended max wattage after they changed the spec sheets on us a couple years ago without renaming it an FM70. The system has been in for over 5 years now but from the beginning I\u2019ve had a large amount of failures with the FM80\u2019s failing and registering a dead short on the PV input side of the controller. Not exclusive to any one of the six arrays and I\u2019ve definitely gone through to torque and tighten all of the connections. I\u2019ve tried other controllers throughout my troubleshooting and concluded it\u2019s arc faults for a few reasons. Mainly, as long as I have a Midnite Classic installed with the other 5 FM80\u2019s it will absorb the arc fault and just go to it\u2019s temporary state of displaying an arc fault and after I reset it everything starts back up and operates normally. Survives the incident without failure unlike the FM80 and at the same time protects all the other FM80\u2019s. When the site goes back to FM80\u2019s exclusively the failures are inevitably more frequent. I\u2019ve also installed a Magnum PT100 for awhile to see if it would fail too but it survived for over a year before I terminated that particular test.<br class="">
<br class="">
Luckily, one of the times I was there when an FM80 failed so I was able to see that it coincided with some fans (obviously on the AC side) that had kicked on when I observed usage on his Egauge (system has Blue Ion 2.0\u2019s and HI's). I have also been able to determine it\u2019s likely some fans because the long durations without failures also coincide with long periods without the fans although failures are still happening sometimes and he says he\u2019s changed up his fans. The Egauge has been a very useful tool for various reasons but unfortunately I can\u2019t pinpoint when the units fail since they often go unnoticed until I am at the site or notice low PV production on Opticsre. I just happen to get lucky the one time I was there to correlate the exact moment with the fans.<br class="">
<br class="">
One major detail that makes this site different is that after my initial install work he had some other yahoos in to pull the feeders to power his other subpanel some 1300\u2019 feet away. Unfortunately they did so without pulling an equipment ground along with the power conductors so the two sides do not share a common ground. This is the most major deviation from any of the other systems I\u2019m responsible for and this is the only site I have frequent high rates of unwarranted controller failures. I\u2019m uncertain if the failures are due to AC ripples/transients from the extremely long run, lack of common ground or perhaps one particular appliance. My preferred solution in the process of elimination is fixing the lack of common ground by re-pulling all the conductors with an EGC but that would not only be expensive but quite difficult as he just informed me the other day that there are no pull boxes in between the two destinations. I wish I could just walk away from any responsibility since their foolish decision not to pull the EGC originally was not a mistake of mine but I really need to help him resolve this since replacing the FM80\u2019s so often is obviously expensive as well as time consuming. Obviously it would be extremely frustrating and defeating if he were to go to all the effort of pulling the new ground and the failures still occur.<br class="">
<br class="">
I thought about replacing the 6 FM80\u2019s with 4 FM100\u2019s but that would require a profound amount of work by the time I change up the array strings and OCPD\u2019s plus I\u2019d have to re-imagine placement due to the physical differences. To avoid nuisance tripping, I already have the Midnite 100 amp GFP assemblies in place and am adding two more Radians with GSLC\u2019s so feasibly would have the accommodations as far as space for OCPD\u2019s are concerned. We do plan on expanding his arrays soon so at some point I will have to address this known snag of mixing FM80\u2019s and 100\u2019s in the same system as recently discussed on the list. Thinking I might try this mix approach on my own house for awhile but not rushing to deploy at any client sites.<br class="">
<br class="">
Any ideas? Suck it up and have him pull a ground 1300\u2019 at today\u2019s copper prices? I\u2019ve got Midnite SPD\u2019s on all the arrays as well as the AC side but perhaps there\u2019s some other sort of additional surge suppressor or something I can install to suppress arc faults originating on the AC side? WWWMD (what would William Miller do)? Only half joking here, I often find myself asking that when I encounter some sort of unusual solution required to balance something out of the ordinary and William\u2019s procedures have impressed me for decades. No offense to the rest of you pro\u2019s though, his meticulous documentation and notes just appear levels beyond (especially speaking for myself)!<br class="">
<br class="">
Off to work, enjoy your day, Nick<br class="">
<br class="">
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</blockquote></div><br clear="all" class=""><div class=""><br class=""></div>-- <br class=""><div dir="ltr" class="gmail_signature"><div class=""><br class=""></div><div class=""><font color="#305A78" face="'times new roman', serif" class=""><br class=""></font></div><div class=""><br class=""></div>Mac Lewis<br class=""><br class=""><span style="font-family: "Times New Roman"; font-size: inherit; color: rgb(255, 153, 0);" class=""><b class=""><font face="Arial, Helvetica, sans-serif" size="3" class=""><p align="left" class=""><font face="Verdana, Arial, Helvetica, sans-serif" class=""><span style="font-size:small" class=""><span style="font-family:arial;font-weight:normal;color:rgb(48,90,120)" class=""><font face="'times new roman', serif" class="">"Yo solo sé que no sé nada." </font><span style="font-weight:700;color:rgb(104,104,104)" class=""><font face="'times new roman', serif" class="">-Sócrates</font></span></span></span></font></p></font></b></span></div>
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