Well, that didn't resolve it. The main breaker and a branch circuit breaker tripped again a few days ago. It was the same branch this time.
As my next diagnostic step I swapped two circuits (on which breaker they are landed). If history is a guide, it will work for about two weeks and then trip again. I'm dumbfounded. I really don't want to have to tear this whole system apart. At this point, if I have to remove all the modules, I feel that I need to replace all of the trunk cable which is an expensive proposition. I really don't know what else to do at this point. Jason On Mon, May 25, 2020, 10:43 AM Jason Szumlanski < ja...@floridasolardesigngroup.com> wrote: > I strongly suspect the CH240 combined breaker was compromised (we will > see). Since it happened that two different strings tripped, I doubt I have > two microinverters with internal faults. It has to be the combined breaker. > I was just surprised that branch circuit breakers were tripping > simultaneously with the combined output breaker. > > Of all the supply side connected systems I have installed, I have never > seen a combined output fusible disconnect fuse blow, but I have seen many > combined output breakers tripped. I was worried early on that I would be > replacing fuses constantly, but that has not been an issue whatsoever. > > > > > > > On Thu, May 21, 2020 at 11:15 AM <scot.a...@solarcentex.com> wrote: > >> Actually, we had a IQ7 string loaded up to its max panel size and max >> string length and in the spring on cool, clear day, it tripped the string’s >> associated breaker in the Enphase combiner. >> >> >> >> We reset but of course that breaker was impaired and it tripped again. We >> replaced and never had an issue going forward. We suspect the breaker was >> less than perfect from the start as we’ve add equally nice days since. >> >> >> >> This almost reminds me of loading up Outback FM80. It says 4,000 watts >> but in reality, 3,600 is the max when amps spike. I will be extra careful >> going forward on IQ7 string length when going to the max published… >> >> >> >> My story. >> >> >> >> Scot >> >> >> >> *From:* RE-wrenches <re-wrenches-boun...@lists.re-wrenches.org> *On >> Behalf Of *Jason Szumlanski >> *Sent:* Thursday, May 21, 2020 8:57 AM >> *To:* RE-wrenches <re-wrenches@lists.re-wrenches.org> >> *Subject:* [RE-wrenches] Enphase intermittent breaker trippjng >> >> >> >> I'm trying to resolve an intermittent frustrating problem with and >> Enphase IQ system. There are three AC Branch circuits of 9 microinverters >> each coming into an Enphase AC combiner. >> >> >> >> What has been happening is one of the BR220 branch circuit breakers and >> the combine CH240 breaker in the main backfed load center have been >> tripping simultaneously. It has happened about four times in the last 6 >> months. It was always the same branch circuit breaker, so we kept >> investigating that string, checking the junction box, trunk cable, and cap, >> etc. Finally we swapped out the BR220 breaker. >> >> >> >> Fast forward 4 weeks, and we got another call. This time a different >> branch circuit breaker and the main breaker tripped simultaneously. We >> checked that branch circuit and could not find any fault. It seems unlikely >> that two branch circuit breakers would be faulty, so we have now switched >> out the CH240 main breaker in hopes that it is the culprit. >> >> >> >> I'm not totally confident in this resolution and I have my fingers >> crossed. If that doesn't work, does anyone have any suggestions on another >> diagnostic step? These intermittent problems are a major hassle. One >> thought I had was to switch to a supply side interconnection with a fusible >> disconnect. Maybe the intermittent fault would blow one of the two line >> fuses so at least I could narrow it down to which line the fault is on if >> there is in fact a fault. >> >> >> >> I have experienced two other tripping breaker issues with Enphase systems >> in the past. Neither of them were systems I installed. One turned out to be >> branch circuits that were not properly paired up and landed on different >> breakers. Another time we had an inverter with an internal fault which >> eventually"blew up" with a loud popping noise and smoke billowing out of >> it. That happened after resetting a trip breaker multiple times. This case >> seems to be unrelated to those issues. I'm perplexed. >> >> >> >> Jason Szumlanski >> >> Florida Solar Design Group >> >> >> >> >> _______________________________________________ >> List sponsored by Redwood Alliance >> >> List Address: RE-wrenches@lists.re-wrenches.org >> >> Change listserver email address & settings: >> http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org >> <https://mailtrack.io/trace/link/796b1796eb4c075a74298513a530f62e4a496cb2?notrack=1&url=http%3A%2F%2Flists.re-wrenches.org%2Foptions.cgi%2Fre-wrenches-re-wrenches.org&userId=1613865&signature=c7dea131fd9cb45a> >> >> List-Archive: >> http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html >> <https://mailtrack.io/trace/link/c06e48af2da3d129a58c08ef2043bd2d8fcbef6f?notrack=1&url=http%3A%2F%2Fwww.mail-archive.com%2Fre-wrenches%40lists.re-wrenches.org%2Fmaillist.html&userId=1613865&signature=06899a19621f54d8> >> >> List rules & etiquette: >> www.re-wrenches.org/etiquette.htm >> <https://mailtrack.io/trace/link/215cb4d0fcfb04e4124aae9b2616249f1eef5542?notrack=1&url=http%3A%2F%2Fwww.re-wrenches.org%2Fetiquette.htm&userId=1613865&signature=8bc84049c81c183c> >> >> Check out or update participant bios: >> www.members.re-wrenches.org >> <https://mailtrack.io/trace/link/27c3e706e7f2b4836b1669b31c9454db7fee1b52?notrack=1&url=http%3A%2F%2Fwww.members.re-wrenches.org&userId=1613865&signature=4a75a2d55681f39a> >> >>
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