I don't have but two paralleled Radian systems but I removed the FNDC in those. While I REALLY want to love and use the FNDC, I feel like that gives unintended issues in more complex systems.
Howard "Scot" Arey Owner, Solar CenTex 254-300-1228 ________________________________ From: RE-wrenches <[email protected]> on behalf of Steve Higgins via RE-wrenches <[email protected]> Sent: Friday, September 26, 2025 4:01 PM To: RE-wrenches <[email protected]> Cc: Steve Higgins <[email protected]> Subject: Re: [RE-wrenches] Dual radian system stopping selling on sunny days Dave, I've had the same thing happen with a couple of systems... Do you have the FNDC installed? Outback wont admit it but I think that there is a software conflict between the FNDC and the radian firmware. The only way I could get it to stay in sell mode was to remove the FNDC. [https://storage.googleapis.com/bucket-images-sig/RollsbySurrette.jpg] Steve Higgins ⋅ Technical Services Manager t +1.902.597.4020 m +1.206.790.5840 f +1.902.597.8447 e [email protected]<mailto:[email protected]> [http://cdn3.iconfinder.com/data/icons/free-social-icons/67/facebook_square_gray-24.png][https://cdn3.iconfinder.com/data/icons/free-social-icons/67/instagram_square-24.png][http://cdn3.iconfinder.com/data/icons/free-social-icons/67/youtube_square_gray-24.png][http://cdn3.iconfinder.com/data/icons/free-social-icons/67/linkedin_square_gray-24.png] ________________________________ CONFIDENTIALITY: The information transmitted herein is intended only for the addressee and may contain confidential, proprietary and/or privileged material. Any unauthorized review, distribution or other use of or the taking of any action in reliance upon this information is prohibited. If you receive this email in error, please contact the sender and delete or destroy this message and all copies. ________________________________ On Fri, Sep 26, 2025, 10:53 AM Dave Tedeyan via RE-wrenches <[email protected]<mailto:[email protected]>> wrote: To the Outback extraordinaires, I've got a dual radian, grid tied system that has been in service for about 9 years. Recently, it has started this behavior where it will stop selling to the grid on sunny days. Looking back at the data, this has happened intermittently and very infrequently a couple years ago. But now we are at the point where it happens every sunny day. Once the batteries get up to fully 100% charged (not 99%), the selling stops and the system only harvests enough solar to cover the backed up loads. I got a hold of the USB card data. It appears that the inverter goes from "Sell Enabled" to "Offset" when this happens. I cannot tell whether the inverter randomly decides to switch mode and then stop selling, or whether it is the stopping selling that puts it in "Offset" mode. The sell voltage is set at 52V, and float is set to 54.4V. It looks like the batteries are generally sitting around 54V when this happens. Once the inverter enters "offset" mode, then the battery voltage stays steady at 54.0V Does anyone have any idea what can be causing this to happen? Cheers, Dave -- [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: [email protected]<mailto:[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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