William, This is exactly the approach I've used in the off grid aio install I just completed, specifically for reliability in the event of a system failure with no one present. It works perfectly. Since there is no Bullitt in bypass switch, this is a standard item in all my battery based systems, whether on or off grid, now. I let my client decide whether they want to spring for the automatic transfer switch or stick with a less expensive manual transfer. But one or the other is standard or else the backed up loads become captive to a system failure. Howie
On Tue, Oct 15, 2024, 1:08 AM William Miller via RE-wrenches < [email protected]> wrote: > Jason: > > > > Thanks for the follow-up. Two thoughts: > > > > 1. I agree that a PV problem should not cause a system shutdown. I > seem to recall Sol-Arc said they can’t do anything to correct the issue due > to listing/testing issues. This alone would prevent me from choosing > Sol-Arc. There is a lot of design history that goes against the all-in-one > approach. For example, I remember as a teenager I got interested in stereo > equipment. The logic was developing that rather than having a console > stereo, separate components offered more flexibility and reliability: More > flexible because you weren’t stuck with a given collection of components > and more reliable because if one component failed, you had less to repair > or replace. The same logic also applies to the one big inverter versus > several small inverters discussion. > > 2. You mentioned you had bypass capabilities but no person to activate > it. I’ve had this idea for a while: If one has a generator as part of a > battery/inverter system, and reliability is critical--why not add an > Automatic Transfer switch right before the loads with the inverter as the > normal input and the generator as the emergency input? The generator still > feeds the inverter system for normal operation, but if the inverter system > errors out, the ATS can start the generator and activate the bypass-- all > unattended. > > William > > > > Miller Solar > > 17395 Oak Road, Atascadero, CA 93422 > > 805-438-5600 > > www.millersolar.com > > CA Lic. 773985 > > > > > > *From:* RE-wrenches [mailto:[email protected]] *On > Behalf Of *Jason Szumlanski via RE-wrenches > *Sent:* Monday, October 14, 2024 8:19 PM > *To:* Maverick Brown > *Cc:* Jason Szumlanski; RE-wrenches > *Subject:* Re: [RE-wrenches] All-In-Ones / Sol-Ark fail > > > > 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 > > > > > *Error! Filename not specified.* > > 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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