I am happy to report that these issues are resolved, and the system is operating normally after replacing the broken MC4 and re-pulling wire for the home run of the faulted string.
That second issue emanated from my guys pulling wire through a conduit underground that evidently had some rocks in it, which damaged the insulation on a wire. One thing led to another, and some bad choices led to an issue that could have been worse. It was a good learning lesson. I'm still fuming over how this causes non-affected inverters to shut down. I will definitely look into how the Midnite AIO is different. I don't want to write off the AIO concept over this one issue. Jason Szumlanski Principal Solar Designer | Florida Solar Design Group NABCEP Certified Solar Professional (PVIP) Florida State Certified Solar Contractor CVC56956 Florida Certified Electrical Contractor EC13013208 On Mon, Oct 14, 2024 at 11:18 PM Jason Szumlanski < [email protected]> wrote: > Diagnosis: No broken panels. Two different issues. We found a broken MC4 > connector, possibly due to flying debris. We also found a melted Polaris > tap that got wet (long story, our fault). > > These two issues happened at seeming the exact same time during the > hurricane, but were completely different events. The next morning it caused > faults on two of four inverters when the sun came up, and the other two > inverters faulted out as "parallel faults." That's a behavior that seems > unacceptable. Neither of the initially faulted inverters were the master, > either. > > One bad PV string on one out of four inverters should not cause a total > system failure to operate. > > Jason > > > On Fri, Oct 11, 2024, 3:59 PM Jason Szumlanski < > [email protected]> wrote: > >> That is the exact error! But I don't think that explains how I have one >> string over the expected voltage and one string under. It's definitely >> worth checking, nonetheless. This array is 12 feet in the air and pitched >> at 5 degrees, so you can't see the glass from the ground. >> >> It is conceivable that I have two issues. The voltage issue could be a >> wiring issue and the inverters may have faulted out due to broken modules. >> There were tropical force winds there at the time. >> >> Jason Szumlanski >> Principal Solar Designer | Florida Solar Design Group >> NABCEP Certified Solar Professional (PVIP) >> Florida State Certified Solar Contractor CVC56956 >> Florida Certified Electrical Contractor EC13013208 >> >> >> On Fri, Oct 11, 2024 at 3:49 PM Maverick Brown < >> [email protected]> wrote: >> >>> Jason >>> >>> Which fault are you getting? >>> >>> This spring I was getting F23-Tz_GFCLO randomly on an upper roof array. >>> >>> After further investigation, I found several modules with broken glass. >>> After replacing the mods, all is well. >>> >>> Thank you, >>> >>> Maverick >>> >>> Maverick Brown >>> Off-Grid Solar Commander since 2006 >>> Maverick Solar Enterprises, Inc. >>> • Solar Commander Remote Power >>> • SunFlow Systems Cathodic Protection >>> [email protected] >>> 512-460-9825 >>> >>> >>> >>> On Oct 11, 2024, at 1:39 PM, Jason Szumlanski via RE-wrenches < >>> [email protected]> wrote: >>> >>> >>> By shutting off the PV disconnects on the two affected inverters we were >>> able to make the system work successfully today. As I mentioned, we will >>> dig into the actual faults on Monday. From the historical data, I found >>> that this issue has actually been going on for a week before the faults >>> started happening in the inverters. I'm not sure why the faults took so >>> long to cause a shutdown of the inverters. Maybe it just "got worse" and >>> finally triggered a fault. The first faults would have been during the >>> early band of rain from Hurricane Milton, so possibly water or wind put the >>> issue over the top. >>> >>> Before the shutdown, each of the two affected inverters had one MPPT >>> with voltages out of the expected range for the last week. >>> >>> All MPPT strings are 14 modules with 7 in series, 2 in parallel. Each >>> string Voc is 342V and Vmp is 297V. >>> >>> On the first affected inverter, I was able to observe the bad string >>> operating consistently around 370V to 400V+, which is obviously well above >>> the Voc (and it's hot here in Florida). The good string on this inverter >>> operated around 260-270V during the same time, which is the expected range. >>> >>> On the second affected inverter, I observed the bad string operating >>> consistently around 100V to 130V+. The good string on this inverter >>> operated around 260-270V during the same time, which again is the expected >>> range. >>> >>> Graphs are attached for those of you who like that kind of stuff. These >>> show a typical day after the issue started to occur, but before the >>> inverter faults occurred. >>> >>> Incidentally, the average voltage of the two bad strings seems to be >>> pretty close to the normal strings, so that is a good clue. >>> >>> Jason Szumlanski >>> Principal Solar Designer | Florida Solar Design Group >>> NABCEP Certified Solar Professional (PVIP) >>> Florida State Certified Solar Contractor CVC56956 >>> Florida Certified Electrical Contractor EC13013208 >>> >>> >>> On Fri, Oct 11, 2024 at 6:55 AM Jason Szumlanski < >>> [email protected]> wrote: >>> >>>> More interesting information... When the sun went down last night, the >>>> fault cleared and the inverters started producing power again, drawing from >>>> the batteries, and restarting the generator. The master inverter >>>> "remembered" the generator was in it's charging cycle and hadn't reached >>>> full battery yet. >>>> >>>> It's good that the inverters started inverting again. That's a plus. I >>>> actually wish the generator hadn't started because it was unnecessary based >>>> on battery voltage, which was near full anyway. >>>> >>>> Which brings me to another annoying behavior of the Sol-Arks that I >>>> discovered in how the GEN Charge and GRID Charge parameters work with >>>> signaling the two-wire start. If the battery voltage is 50V and the charge >>>> parameter is set to 49V, the generator signal will not kick on of course – >>>> the generator start relay is open. However, if you change the charge >>>> parameter setpoint to, say 51V, the generator should start because the >>>> battery voltage is below the setpoint. But that does not happen. The >>>> battery voltage must "fall through" the parameter setting for the charging >>>> to be triggered and the relay to close. If you are in a situation where you >>>> need to get the generator on a charge cycle and then leave the site, the >>>> only way I have found to do this is to set it to something very close to >>>> the battery voltage, say 49.9V, put a heavy load on to drop the voltage >>>> below the setpoint, let the generator start, then change the setpoint to >>>> the desired 51V. >>>> >>>> >>>> Back to the original issue – I dug into the string voltage data history >>>> remotely and narrowed down the fault to two of the four inverters. I am >>>> sending someone to shut down the PV DC switches on these two inverters >>>> today in hopes that we can keep the power flowing during the day and >>>> through the weekend. I'm planning on a Monday boat ride out there to see >>>> what caused the fault(s). I will report back. >>>> >>>> Jason Szumlanski >>>> Principal Solar Designer | Florida Solar Design Group >>>> NABCEP Certified Solar Professional (PVIP) >>>> Florida State Certified Solar Contractor CVC56956 >>>> Florida Certified Electrical Contractor EC13013208 >>>> >>>> >>>> On Thu, Oct 10, 2024 at 6:00 PM Lou Russo via RE-wrenches < >>>> [email protected]> wrote: >>>> >>>>> Aloha All, >>>>> >>>>> Thank you Jason. This is a huge and surprising issue. So much so that >>>>> I dropped what I was doing and called Sol-Ark to confirm. Mind you this >>>>> was >>>>> level 1 support, but I was told this is what the Sol-Arks are supposed to >>>>> do and it is a feature not a bug. Their take is if there is any fault on >>>>> any one string, the Sol-Ark assumes the worst and shuts everything down. >>>>> >>>>> I wonder what solutions could be implemented on future installs to >>>>> prevent this from happening? >>>>> >>>>> Aloha, >>>>> >>>>> Lou Russo >>>>> Owner >>>>> [email protected] >>>>> Office - 808 345 6762 >>>>> Spree Solar Systems LLC >>>>> CT-34322 >>>>> >>>>> >>>>> >>>>> On Thu, Oct 10, 2024 at 11:45 AM Jason Szumlanski via RE-wrenches < >>>>> [email protected]> wrote: >>>>> >>>>>> I think it's more likely water in a J-box or possibly physical >>>>>> damage, but someone passed by the property and did not observe any >>>>>> physical >>>>>> damage to the array. >>>>>> >>>>>> Jason Szumlanski >>>>>> Principal Solar Designer | Florida Solar Design Group >>>>>> NABCEP Certified Solar Professional (PVIP) >>>>>> Florida State Certified Solar Contractor CVC56956 >>>>>> Florida Certified Electrical Contractor EC13013208 >>>>>> >>>>>> >>>>>> On Thu, Oct 10, 2024 at 5:41 PM Jay <[email protected]> wrote: >>>>>> >>>>>>> Jason >>>>>>> What’s the possibllity it was a lighting strike? >>>>>>> >>>>>>> Jay >>>>>>> >>>>>>> On Oct 10, 2024, at 2:57 PM, Jason Szumlanski via RE-wrenches < >>>>>>> [email protected]> wrote: >>>>>>> >>>>>>> >>>>>>> We have been talking a lot recently about all-in-ones. I just had a >>>>>>> massive fail during Hurricane Milton with a quad Sol-Ark 15K off-grid >>>>>>> system that deserves some discussion about whether AIO is a good idea >>>>>>> if it >>>>>>> can't build in some resilience to errors. I'm not sure if the new >>>>>>> Midnite >>>>>>> unit is better in this respect, but this is what happened to the Sol-Ark >>>>>>> system... >>>>>>> >>>>>>> Four inverters, each with 4 strings of PV paralleled to 2 MPPT per >>>>>>> inverter. One of the slave units developed some sort of PV DC fault >>>>>>> during >>>>>>> the storm. This caused the slave inverter to shut down and throw an >>>>>>> error, >>>>>>> which in turn caused a parallel fault across all four inverters. Power >>>>>>> output ceases at that point. Apparently the system keeps resetting >>>>>>> because >>>>>>> I have a cell modem that uploads data to Sol-Ark, but that cell modem is >>>>>>> powered by the inverter outputs, so it must be getting power at least >>>>>>> intermittently. The rest of the loads are basically flatlined according >>>>>>> to >>>>>>> the Sol-Ark data. It's mostly air conditioners, so they probably can't >>>>>>> turn >>>>>>> on fast enough before the PV fault causes another shutdown. >>>>>>> >>>>>>> So, in essence, one of 16 strings of PV develops a fault, and that >>>>>>> causes all four inverters to malfunction? What is the point of >>>>>>> redundancy >>>>>>> if a fault of one results in a fault of all?! If there is a true PV >>>>>>> input >>>>>>> fault, shouldn't that just shut down that MPPT, or perhaps all of the >>>>>>> PV DC >>>>>>> input to that inverter? And why can't this inverter continue to invert >>>>>>> power from the batteries and charge from a generator when there is a DC >>>>>>> input fault that could be programmatically isolated and ignored? >>>>>>> >>>>>>> This is a bad design in my opinion, and something I hadn't >>>>>>> considered. If the faulted inverter can't function with a DC input >>>>>>> fault, >>>>>>> it should just take itself out of the game. (This is 120/240 split >>>>>>> phase, >>>>>>> BTW). Is this how all AIO inverters work? One inverter fault on the DC >>>>>>> side >>>>>>> kills all paralleled units' AC output? Not good. >>>>>>> >>>>>>> This is a completely off-grid system on a remote island with no >>>>>>> vehicle access, so it's not exactly easy to do a "truck roll" on this >>>>>>> one, >>>>>>> especially post-hurricane. To make matters worse, the generator was >>>>>>> running >>>>>>> at the time of the fault, as it was being signaled to run because the >>>>>>> battery had reached the assigned charge voltage. The fault also killed >>>>>>> the >>>>>>> 2-wire start signal from the master, so the system also stopped passing >>>>>>> through generator power to the loads. The house is dark. >>>>>>> >>>>>>> >>>>>>> Jason Szumlanski >>>>>>> Florida Solar Design Group >>>>>>> >>>>>>> _______________________________________________ >>>>>>> List sponsored by Redwood Alliance >>>>>>> >>>>>>> Pay optional member dues here: http://re-wrenches.org >>>>>>> >>>>>>> List Address: [email protected] >>>>>>> >>>>>>> Change listserver email address & settings: >>>>>>> http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org >>>>>>> >>>>>>> There are two list archives for searching. 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