That's correct you only need one load controller to commission a sunlight only backup system.
Strangely enough, I am sitting in the driveway of a sunlight only backup system owner right now. I found a melted 60A solar breaker in the System Controller (not my installation, contractor is on the run). The homeowner said they have been hearing sizzling noises for 6 months! The solar breaker wasn't tripping, but the 100A load breaker was, and was too hot to touch when it did. I scolded them for not calling a licensed electrician earlier. Yikes! Anyway, they are another example of a dissatisfied owner. They said the backup performance is way too intermittent. The only thing they are powering is a refrigerator, some lights, and the 110 volt circuit for a gas water heater. They have 29 x 400W panels. Yet, they are still dissatisfied. I told them that a single 5P battery would transform their experience and likely power all of those loads throughout the night. As much as I loathe discontinuation of the IQ7, the IQ8 having no ratio to battery power restrictions is great. Jason On Thu, Sep 26, 2024, 9:16 AM Dave Tedeyan <d...@sungineersolar.com> wrote: > 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. >>> <https://www.google.com/maps/search/1653+Slaterville+Rd.+%C2%A0+%7C%C2%A0Ithaca,+NY+14850?entry=gmail&source=g> >>> >>> <https://www.google.com/maps/search/1653+Slaterville+Rd.+%C2%A0+%7C%C2%A0Ithaca,+NY+14850?entry=gmail&source=g>| >>> Ithaca, >>> NY 14850 >>> <https://www.google.com/maps/search/1653+Slaterville+Rd.+%C2%A0+%7C%C2%A0Ithaca,+NY+14850?entry=gmail&source=g> >>> 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. 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