An all DC side charging is preferred and will have the simplest charging system. Flex net DC shunts, easy to monitor. Last l heard FM 100 were pushed out till late in the year Fun times
On Sat, Jul 30, 2022, 1:37 PM Kirk Herander via RE-wrenches < [email protected]> wrote: > Jerry- > The pole mount does not exist for a few more weeks, so I have time to > think about DC or AC coupling for it only. To clarify, the old roof 1.8 kw > array is functional and has been charging the new blue ions through an old > Outback pre-hub 60A controller(replacing it soon with a new FM60). So I do > have existing dc-coupling already to get around dark start issues for the > most part. > > Right now I'm starting to lean towards 100% DC coupling, hooking the new > pole-mount array to an OB FM100 300vdc max 100A charge controller *IF* I > can find one in time. At least then I can see everything on one dashboard > (OpticsRE). Both Mate3s and hub 10.3 are already installed. > > One of the other things influencing my decision is the request from my > customer to have it "grid-ready", which to them means the house is easier > to sell when the time comes, if the buyer wants to bring in the grid power. > I won't go into it, but it is a simpler solution (in terms of local > hardware requirements) to AC-couple the new array with these utility rules > in mind. > > So there is no fits-all solution to AC vs. DC coupling, as someone said. > > On Sat, Jul 30, 2022 at 3:58 PM Jerry Shafer via RE-wrenches < > [email protected]> wrote: > >> Its not clear to me if you will actually have a DC side coupled >> connection in talking about the pole mount. If so then it does work but if >> not then no, the big question is how would you restart the inverter to >> restart the SE to start the charging process on the AC side, answer, you >> can't in most cases. Example, SMA SI coupled with SMA 4K's, you have a dead >> battery, you need to bring up the VDC to wake up the inverter to wake up >> and count down the 4K's the trick here is to alter programming to instant >> start the 4K upon getting VAC and hertz instead of the 300 sec count down. >> Something else, LFP does not relax and get any parasitic voltage back to >> even start the SI so changing the timers may still not work. Best bet is to >> have at least some DC side PV to charge a dead battery without the >> inverters at all. I did ac coupling with Trace and SMA 20 plus years ago >> and SMA said then it was not possible. How the world has changed. fun times! >> >> On Sat, Jul 30, 2022, 9:31 AM Kirk Herander via RE-wrenches < >> [email protected]> wrote: >> >>> All, >>> Anyone out there successfully AC-coupled inverters in an off-grid >>> system? Advantages vs. pitfalls? >>> >>> In my case I'm thinking of its practicality with a Solaredge inverter >>> AC-coupled to an OB Radian inverter. OB firmware makes this pretty easy >>> now. So effectively the Radian is always operating in a grid-backup mode. >>> >>> I already upgraded the system to the Radian, and soon to add 5kw of >>> pole-mounted PV(currently only 1.8kw of 22-year old PV on the roof). This >>> system also just got 16kwh of Blue Ion LFP batteries. >>> >>> This is a last-minute thought I have instead of investing in additional >>> DC charge controllers for the new array. >>> Cost-wise there's not much of a difference between several high-quality >>> charge controllers and a smaller SE inverter w/optimisers. Thanks. >>> >>> -- >>> >>> *Kirk Herander / **[email protected] <[email protected]>* >>> >>> *Owner|Principal, VT Solar, LLC* >>> >>> *Celebrating our 31st Anniversary 1991-2022!!* >>> >>> *www.vermont.solar* >>> <https://nam02.safelinks.protection.outlook.com/?url=www.vermontsolarnow.com&data=02%7C01%7C%7C9f0330d75a244870112408d685311841%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C636842843233477645&sdata=0NjyuKeQbEK6245SNnk8X4XnP9Q%2B%2BqtvcALkdDghvk4%3D&reserved=0> >>> >>> dba Vermont Solar Engineering >>> >>> 802.863.1202 >>> _______________________________________________ >>> 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 >>> >>> _______________________________________________ >> 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 >> >> > > -- > > *Kirk Herander / **[email protected] <[email protected]>* > > *Owner|Principal, VT Solar, LLC* > > *Celebrating our 31st Anniversary 1991-2022!!* > > *www.vermont.solar* > <https://nam02.safelinks.protection.outlook.com/?url=www.vermontsolarnow.com&data=02%7C01%7C%7C9f0330d75a244870112408d685311841%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C636842843233477645&sdata=0NjyuKeQbEK6245SNnk8X4XnP9Q%2B%2BqtvcALkdDghvk4%3D&reserved=0> > > dba Vermont Solar Engineering > > 802.863.1202 > _______________________________________________ > 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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