Hi Jason, Thanks for your detailed response here. What tech support told me was what I wanted to hear, although I just did not totally trust them.
As for the powerline filter, I planned on that from the beginning, based on their planning guide. Having it in there cannot hurt, right? For the Sunlight Backup, I have found that having a detailed conversation about what it can and cannot do is quite helpful. If you keep the bar really low, its not difficult to step over it. I find some people here like it as an intermediate if they aren't quite ready for batteries for some reason or another. Also, note that you only need one load controller now. And I use that more to provide on/off load control rather than a turn on sequence. Theoretically, you could just have the sunlight backup provide power to an entire MSP (although that would not be a good idea). I'll be heading out to the site in the near future to try again to get the crosstalk issues sorted. I'll let you know if your sequence here works. I've talked to three of their storage techs about it so far, and none have suggested this. You would think they would have some more standardization around these sorts of issues. Cheers, Dave On Wed, Sep 25, 2024 at 5:15 PM Jason Szumlanski < ja...@floridasolardesigngroup.com> wrote: > With IQ8 series microinverters, there is an absolute limit of 64A > connected to the IQ Combiner input lugs of the System Controller. The DER > port is not for PV. It is for batteries that exceed the limits of the > storage port. You can have up to (8) 5P on the Storage lugs and (8) on the > DER lugs. But these will be power limited to the output of (4) 5P batteries > per input. In other words, this is a way to connect 80kWh of capacity to > the system, but you will only have 128A of power output even though the > (16) batteries are capable of 256A. Anyway, 64A is the PV limit for backup > systems, and there is no way around it with IQ8. > > You CANNOT connect any additional IQ8 microinverters on the load side of > the System Controller when there is backup involved. All IQ8 must be > connected to the IQ Combiner lugs on the System Controller. The relay in > the system controller must be able to turn off the IQ8 micros. This relay > also disconnects the rooftop micros when the RSD switch is turned off. > > The additional microinverters can be connected to the line side of the > System Controller (as a feeder tap or anywhere upstream of the System > Controller that complies with code). You do need a separate IQ Gateway, > because these microinverters need to be configured for grid-tie only. All > microinverters connected to the same Gateway must have the same mode. The > micros connected to the backup system will be set up as multi-mode. > > Don't bother with a line filter unless it becomes truly necessary. There > are things that Enphase can do on its end to reduce the crosstalk by > establishing separate domains. They SAY you need a line filter, but this is > rarely the case. Don't listen to anything that Tier 1 customer service > tells you regarding powerline communications. That's their go-to response > when they can't figure something out. > > As for the Sunlight Backup system, I don't have a single client that is > satisfied with this setup. It really needs at least one IQ Battery 5P to be > functional, in which case you can forget about the ridiculous limitations > of 8 x 120V or 4 x 240V circuits and the rigmarole of two load controllers > that Sunlight Backup requires, especially with that much PV. I would avoid > Sunlight Backup at all costs. It's not useful for anything but the smallest > loads during the best conditions > > As for your crosstalk issues, here is what I would do. Have customer > service retire one of the IQ Gateways and all associated microinverters. > Provision the other IQ Gateway and get those microinverters working. Then > turn OFF power to the working Gateway and microinverters. Turn ON power to > the other Gateway and microinverters and have customer service unretire > everything. Reprovision using ITK. Once everything is working on the second > Gateway, turn the first one back on and all microinverters, and you will > probably be up and running without further issues. > > > I was really disappointed with the discontinuation of the IQ7 because of > this 64A hard limit of PV on a backup system. With IQ7 you could have 96A > of PV with the previous generation battery. The IQ8 was a step backward for > large backup systems. I provided this feedback to Enphase, and they were > working on a possible workaround to make something work, but I would not > hold your breath. I even wrote this article when the issue first came to > light: > > https://floridasolardesigngroup.com/enphase-iq7-versus-iq8-microinverters/ > > > 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 Wed, Sep 25, 2024 at 3:02 PM Dave Tedeyan via RE-wrenches < > re-wrenches@lists.re-wrenches.org> wrote: > >> Hi all, >> >> All this talk about Enphase recently and I have a design question that I >> am having trouble getting a straightforward answer to. The IQ system >> controller can take up to 64A of PV AC output on the DER port (coming from >> the IQ combiner for example). When there is more solar on site, the >> question is what do you need to do with the rest of the solar. >> >> They have a system planning guide that talks about some of this and you >> can find it here: >> https://enphase.com/download/planning-enphase-energy-system-tech-brief >> >> Page 59 bullet point 6 says that with IQ8 micros, the excess PV must be >> split into a grid-tied system. I recently did this, got a separate IQ >> gateway, and a power line filter, and the system continues to have cross >> talk issues between the two gateways, and the microinverters will just not >> report properly no matter how many times tech support re-provisions the >> devices and prevents each gateway from looking for more devices. >> >> Then I noticed that with M series micros (page 62 bullet point 9) it says >> that microinverters exceeding 64A can be added to the main panel. In this >> scenario, there will be more than 64A of solar flowing through the IQ >> system controller, even though the DER port is limited to 64A. I would like >> to do something similar to this for my system with crosstalk issues and get >> rid of the second IQ Gateway. >> >> I asked tech support why there was a difference in the planning document >> for IQ8 and for M series and whether I could add the extra IQ8 into the >> backed up subpanel (This is a Sunlight backup system). They did not give me >> a fully complete answer, but they did say this, "You can add the panels up >> to 64A into the system controller and exceeding PV can be connected to the >> backup subpanel." >> >> I fear that this was a level 1 tech and that they may not have completely >> understood the situation. This is the answer that I wanted, but I am not >> sure I trust it yet. Has anyone here tried something similar to this? >> >> Thanks! >> -Dave >> >> -- >> >> [image: Logo] <https://www.sungineersolar.com/> >> Dave Tedeyan, P.E. >> Owner | Sungineer Solar >> p: he | him | his >> a: 1653 Slaterville Rd. | Ithaca, NY 14850 >> w: www.sungineersolar.com <http://www.sungineersolar.com/> >> c: (607) 270-0370 >> _______________________________________________ >> List sponsored by Redwood Alliance >> >> Pay optional member dues here: http://re-wrenches.org >> >> 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 >> >> There are two list archives for searching. When one doesn't work, try the >> other: >> https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/ >> 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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