William, What is your string configuration? The SMA TL inverters have a very low operating voltage window, going down to 125 Vdc, but you still have the issue of the disconnect. [cid:image001.png@01CFE248.3F9A1920]
Have you looked at ABB’s (PowerOne) TL inverters: http://www.abb.us/product/us/9AAC179447.aspx?country=US? They can be programmed to operate down to 90 Vdc, and they give you the ability to combine upstream and have the 2 MPPT’s operate as one, allowing you to combine outside of the inverter and bring a single set of PV output conductors to the inverter’s DC disconnect: Isaac Opalinsky | Technical Trainer | SunPower Corporation Desk 443-569-3476 | Cell 443-277-6286 From: RE-wrenches [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of William Miller Sent: Tuesday, October 07, 2014 12:01 AM To: RE-wrenches Subject: Re: [RE-wrenches] TL inverter with long DC Feeder Friends: If only an SMA would work here. But DC volts too low. We are using Solectria PVI5200TLS. We do not use PV wire. We transition to THWN-2 in conduit immediately. William Miller Solar On Oct 6, 2014, at 8:30 PM, Chris Mason <cometenergysyst...@gmail.com<mailto:cometenergysyst...@gmail.com>> wrote: I presumed SMA TL series. On Mon, Oct 6, 2014 at 10:02 PM, Jerry Shafer <jerrysgarag...@gmail.com<mailto:jerrysgarag...@gmail.com>> wrote: As i read the thread you say TL which TL SMA, AE ect. They have defferent dc input designs On Oct 6, 2014 12:21 PM, "jay peltz" <j...@asis.com<mailto:j...@asis.com>> wrote: I do believe the outback and midnite combiners have a lock hole to prevent exactly your concern. unauthorized access. jay peltz power On Oct 6, 2014, at 11:40 AM, William Miller wrote: Wrenches: We are getting up to speed on using transformer-less inverters. I have advocated long for the additional safety offered by these inverters but I am realizing the trade-offs with the new technology: The implementation gets more complicated with the requirement for PV wire, OCPD and disconnecting means for plus and minus and plus providing Arc Flash rated equipment. I am currently designing a system that will locate the PV about 400 feet from the residence. The system will utilize 2 Solectria 5200 watt inverters at the residence. I would like to provide disconnecting means for the 4 strings at the array, in case of any needed service or excavating. Preferably I’d like the disconnecting means to be deployable by a lay person (i.e. the gardener). Finding an 8 pole, arc flash, 600 VDC rated disconnect is not easy. I could install an Outback 8 circuit combiner with 8 touch-safe fuse holders. The new combiners have had dead-fronts for a while now. The gardener needs only to have a Philips screw driver to open this cover. Any better ideas out there? Thanks, William <image002.jpg> Lic 773985 millersolar.com<http://www.millersolar.com/> 805-438-5600<tel:805-438-5600> _______________________________________________ List sponsored by Redwood Alliance List Address: RE-wrenches@lists.re-wrenches.org<mailto:RE-wrenches@lists.re-wrenches.org> Change listserver email address & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html List rules & etiquette: www.re-wrenches.org/etiquette.htm<http://www.re-wrenches.org/etiquette.htm> Check out or update participant bios: www.members.re-wrenches.org<http://www.members.re-wrenches.org> _______________________________________________ List sponsored by Redwood Alliance List Address: RE-wrenches@lists.re-wrenches.org<mailto:RE-wrenches@lists.re-wrenches.org> Change listserver email address & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html List rules & etiquette: www.re-wrenches.org/etiquette.htm<http://www.re-wrenches.org/etiquette.htm> Check out or update participant bios: www.members.re-wrenches.org<http://www.members.re-wrenches.org> _______________________________________________ List sponsored by Redwood Alliance List Address: RE-wrenches@lists.re-wrenches.org<mailto:RE-wrenches@lists.re-wrenches.org> Change listserver email address & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html List rules & etiquette: www.re-wrenches.org/etiquette.htm<http://www.re-wrenches.org/etiquette.htm> Check out or update participant bios: www.members.re-wrenches.org<http://www.members.re-wrenches.org> -- Chris Mason NABCEP Certified Solar PV Installer™ Solar Design Engineer Generac Generators Industrial technician www.cometsolar.com<http://www.cometenergysystems.com> 264.235.5670 869.662.5670 Skype: netconcepts _______________________________________________ List sponsored by Redwood Alliance List Address: RE-wrenches@lists.re-wrenches.org<mailto:RE-wrenches@lists.re-wrenches.org> Change listserver email address & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html List rules & etiquette: www.re-wrenches.org/etiquette.htm<http://www.re-wrenches.org/etiquette.htm> Check out or update participant bios: www.members.re-wrenches.org<http://www.members.re-wrenches.org>
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