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. When one doesn't work, try the > other: > https://www.mail-archive.com/[email protected]/ > http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org > > List rules & etiquette: > http://www.re-wrenches.org/etiquette.htm > > Check out or update participant bios: > http://www.members.re-wrenches.org >
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