<html><head><style type="text/css"><!-- DIV {margin:0px;} --></style></head><body><div style="font-family:times new roman,new york,times,serif;font-size:12pt"><div style="font-family: times new roman,new york,times,serif; font-size: 12pt;">Aloha Solar Bozos:<br> I haven't posted here in ages, and I hope I am cutting out the appropriate stuff? Probably not, but I will give it a try. I want to reply to Topic 3 regarding backfeeding an off-grid inverter with a grid-tied inverter.<br> In 2004, I back-fed a SWR-2500U into an Outback FX inverter's back-up power panel. It required a transformer to step down to 120VAC and a voltage controlled relay to shut the Sunny Boy off when the batteries were charged. Greg at OB said that the inverters would regulate the AC output voltage at ~120V, so when the voltage would rise up from the Sunny Boy's production, the FX was forced to take the power in, resulting
in the batteries being charged. You probably realize that the Sunny Island controls the grid-tied inverter's output but fluctuating the Hertz, which eliminated that issue for them.<br><div style="font-family: arial,helvetica,sans-serif; font-size: 10pt;"><font size="2" face="Tahoma"><hr size="1"><b><span style="font-weight: bold;">From:</span></b> "re-wrenches-request@lists.re-wrenches.org" <re-wrenches-request@lists.re-wrenches.org><br><b><span style="font-weight: bold;">To:</span></b> re-wrenches@lists.re-wrenches.org<br><b><span style="font-weight: bold;">Sent:</span></b> Monday, August 3, 2009 6:47:22 AM<br><b><span style="font-weight: bold;">Subject:</span></b> RE-wrenches Digest, Vol 2, Issue 818<br></font><br>
Send RE-wrenches mailing list submissions to<br> <a ymailto="mailto:re-wrenches@lists.re-wrenches.org" href="mailto:re-wrenches@lists.re-wrenches.org">re-wrenches@lists.re-wrenches.org</a><br><br>To subscribe or unsubscribe via the World Wide Web, visit<br><span> <a target="_blank" href="http://lists.re-wrenches.org/listinfo.cgi/re-wrenches-re-wrenches.org">http://lists.re-wrenches.org/listinfo.cgi/re-wrenches-re-wrenches.org</a></span><br>or, via email, send a message with subject or body 'help' to<br> <a ymailto="mailto:re-wrenches-request@lists.re-wrenches.org" href="mailto:re-wrenches-request@lists.re-wrenches.org">re-wrenches-request@lists.re-wrenches.org</a><br><br>You can reach the person managing the list at<br> <a ymailto="mailto:re-wrenches-owner@lists.re-wrenches.org"
href="mailto:re-wrenches-owner@lists.re-wrenches.org">re-wrenches-owner@lists.re-wrenches.org</a><br><br>When replying, please edit your Subject line so it is more specific<br>than "Re: Contents of RE-wrenches digest..."<br><br><br>When responding to posts within the Digest, be sure to restore the Subject: line to the original, and please edit out any extraneous lines from the quoted message.<br> <br><br>Today's Topics:<br><br> 1. Re: AC Backfeed Battery Over-Charging (Jeff Yago)<br> 2. Broken Modules (Doug Wells)<br> 3. Re: AC Backfeed Battery Over-Charging (Tump)<br> 4. Re: Broken Modules (Jeff Yago)<br><br><br>----------------------------------------------------------------------<br><br>Message: 1<br>Date: Mon, 3 Aug 2009 06:21:56 -0700<br>From: "Jeff Yago" <<a ymailto="mailto:jryago@netscape.com" href="mailto:jryago@netscape.com">jryago@netscape.com</a>><br>Subject: Re: [RE-wrenches] AC Backfeed Battery
Over-Charging<br>To: RE-wrenches <<a ymailto="mailto:re-wrenches@lists.re-wrenches.org" href="mailto:re-wrenches@lists.re-wrenches.org">re-wrenches@lists.re-wrenches.org</a>><br>Message-ID: <<a ymailto="mailto:20090803062156.CD9B16AE@resin17.mta.everyone.net" href="mailto:20090803062156.CD9B16AE@resin17.mta.everyone.net">20090803062156.CD9B16AE@resin17.mta.everyone.net</a>><br>Content-Type: text/plain; charset="us-ascii"<br><br>An HTML attachment was scrubbed...<br><span>URL: <<a target="_blank" href="http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org/attachments/20090803/af3227a5/attachment-0001.htm">http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org/attachments/20090803/af3227a5/attachment-0001.htm</a>></span><br><br>------------------------------<br><br>Message: 2<br>Date: Mon, 3 Aug 2009 09:32:08 -0400<br>From: Doug Wells <<a ymailto="mailto:dwells@thesolarspecialists.com"
href="mailto:dwells@thesolarspecialists.com">dwells@thesolarspecialists.com</a>><br>Subject: [RE-wrenches] Broken Modules<br>To: <a ymailto="mailto:RE-wrenches@lists.re-wrenches.org" href="mailto:RE-wrenches@lists.re-wrenches.org">RE-wrenches@lists.re-wrenches.org</a><br>Message-ID:<br> <<a ymailto="mailto:D6573665-38CE-4E54-A70F-F7AC8F630DF3@thesolarspecialists.com" href="mailto:D6573665-38CE-4E54-A70F-F7AC8F630DF3@thesolarspecialists.com">D6573665-38CE-4E54-A70F-F7AC8F630DF3@thesolarspecialists.com</a>><br>Content-Type: text/plain; charset=US-ASCII; format=flowed<br><br>Wrenches,<br><br>I am curious what other installers are doing with broken modules?<br>I know some manufacturers are starting recycling programs.<br><br><br>Doug Wells<br>The Solar Specialists<br>Morrisville, VT 05661<br>(p) 802-223-7014<br>(c) 802-498-5856<br><a target="_blank"
href="http://www.thesolarspecialists.com">www.thesolarspecialists.com</a><br><br><br><br><br><br><br><br>------------------------------<br><br>Message: 3<br>Date: Mon, 3 Aug 2009 09:39:21 -0400<br>From: "Tump" <<a ymailto="mailto:tump@hughes.net" href="mailto:tump@hughes.net">tump@hughes.net</a>><br>Subject: Re: [RE-wrenches] AC Backfeed Battery Over-Charging<br>To: <<a ymailto="mailto:jryago@netscape.com" href="mailto:jryago@netscape.com">jryago@netscape.com</a>>, "'RE-wrenches'"<br> <<a ymailto="mailto:re-wrenches@lists.re-wrenches.org" href="mailto:re-wrenches@lists.re-wrenches.org">re-wrenches@lists.re-wrenches.org</a>><br>Message-ID: <CAFB0B2FF97B4386BB4EF00DF46766F9@tumpdggfbh2yn6><br>Content-Type: text/plain; charset="us-ascii"<br><br>Hey Jeff this was something that Greg @ OB was working on summer of 06.....<br>Should have it tump, almost got it little problem .... Ahhh sorry we are no<br>longer working
on that! I was in the middle of a large AC Coupled system &<br>had been waiting for 4 months for this "trick" soft ware to come on line.<br>Perhaps CF might be able to update us on this software. Kinda of a no<br>brainier perhaps, John B & the boys @ SMA patented this "trick" software.<br> <br> <br> <mailto:<a ymailto="mailto:Tump@swnl.net" href="mailto:Tump@swnl.net">Tump@swnl.net</a>> <a ymailto="mailto:Tump@swnl.net" href="mailto:Tump@swnl.net">Tump@swnl.net</a><span> <<a target="_blank" href="http://www.swnl.net/">http://www.swnl.net/</a>></span><br><a target="_blank" href="http://www.SWNL.net">www.SWNL.net</a><br> Solarwinds Northernlights <br> Serving Mid Coast Maine & Northern California<br> Me.# 207-832-7574 Cl.# 610-517-8401<br> <br>
Blair "TUMP" May<br> ******** MAINE'S CHARTER ********<br> NABCEP "Certified PV Installer" <br> <br> ******** MAINE'S CHARTER ********<br> Trace Xantrex "Certified" Dealer / Installer"<br> <br> <br><br>-----Original Message-----<br>From: <a ymailto="mailto:re-wrenches-bounces@lists.re-wrenches.org" href="mailto:re-wrenches-bounces@lists.re-wrenches.org">re-wrenches-bounces@lists.re-wrenches.org</a><br>[mailto:<a ymailto="mailto:re-wrenches-bounces@lists.re-wrenches.org" href="mailto:re-wrenches-bounces@lists.re-wrenches.org">re-wrenches-bounces@lists.re-wrenches.org</a>] On Behalf Of Jeff Yago<br>Sent: Monday, August 03, 2009 9:22 AM<br>To: RE-wrenches<br>Subject: Re: [RE-wrenches] AC Backfeed Battery Over-Charging<br><br><br>I have a question that may be one of those that everyone wants to know
the<br>answer but feel they are the only one that doesn't know the answer, or<br>perhaps I am the only one that doesn't know!. <br> <br>In an AC-coupled system, i.e. the 240 VAC output solar inverter mounted at a<br>distant array (240 VAC out to reduce long line loss) is wired to the 120/240<br>VAC output emergency panel supplied from a battery based inverter. This<br>allows the solar inverter to stay up when the grid goes down since it thinks<br>the grid is still up on the load side of the battery based inverter. The<br>battery based inverter will use any excess backfed power from the solar<br>inverter that is in excess of the other supplied loads to re-charge the<br>battery. However, when this happens the battery charging process can boil<br>the batteries when there are no other loads running. <br> <br>I have been told this is because the battery based inverter does not<br>regulate its charging of the battery when using
backfed power from its<br>output panel, but I still don't understand why. If the battery charger in<br>the inverter can provide regulated 3-stage battery charging when the power<br>is supplied from the grid or a generator, why does it suddenly become a full<br>output un-regulated battery charger when power is supplied from backfeed and<br>will keep charging regardless of reaching a high battery voltage? <br> <br>I would have assumed the battery charger section would charge the same way<br>regardless of where the power is being supplied from, or perhaps just<br>shutdown on some kind of backfeed safety. As far as I know, this<br>over-charging problem in an AC coupled dual inverter system is true for all<br>battery-based inverters. Any inverter techs out there that can explain<br>why? Perhaps this would be a nice feature in future high-end battery-based<br>inverters so we no longer need the custom power relay field
wiring to<br>provide this high voltage cut-out?.<br> <br>Thanks,<br> <br>Jeff Yago<br><br> <br><br> _____ <br><br>Netscape. Just the Net You Need.<br><br>-------------- next part --------------<br>An HTML attachment was scrubbed...<br><span>URL: <<a target="_blank" href="http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org/attachments/20090803/040f6858/attachment-0001.htm">http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org/attachments/20090803/040f6858/attachment-0001.htm</a>></span><br><br>------------------------------<br><br>Message: 4<br>Date: Mon, 3 Aug 2009 06:47:21 -0700<br>From: "Jeff Yago" <<a ymailto="mailto:jryago@netscape.com" href="mailto:jryago@netscape.com">jryago@netscape.com</a>><br>Subject: Re: [RE-wrenches] Broken Modules<br>To: RE-wrenches <<a ymailto="mailto:re-wrenches@lists.re-wrenches.org"
href="mailto:re-wrenches@lists.re-wrenches.org">re-wrenches@lists.re-wrenches.org</a>><br>Message-ID: <<a ymailto="mailto:20090803064721.CD9B1303@resin17.mta.everyone.net" href="mailto:20090803064721.CD9B1303@resin17.mta.everyone.net">20090803064721.CD9B1303@resin17.mta.everyone.net</a>><br>Content-Type: text/plain; charset="UTF-8"<br><br>We have only had one broken module due to shipping damage and this was the bottom 200 watt module in a shipment where each 2 modules on the pallet were in heavy cardboard shipping boxes. Of course this not discovered for several weeks until we worked our way down the stack. However, since suppliers like Evergreen have switched to the plasic corners that allow stacking modules without any cardboard packaging, we have had no more breakage in shipment. I assume the fork truck drivers now see a large stack of glass and take a little more care whenre thay ram the forks. <br><br>As far as what we
did with our broken module (which taught a very expensive lesson about checking shipments), we keep it to show students in our training classes what happens when things go wrong.<br><br>Jeff Yago<br><br>_____________________________________________________________<br>Netscape. Just the Net You Need.<br><br><br>------------------------------<br><br>_______________________________________________<br>List sponsored by Home Power magazine<br><br>List Address: <a ymailto="mailto:RE-wrenches@lists.re-wrenches.org" href="mailto:RE-wrenches@lists.re-wrenches.org">RE-wrenches@lists.re-wrenches.org</a><br><br>Options & settings:<br><span><a target="_blank" href="http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org">http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org</a></span><br><br><span>List-Archive: <a target="_blank"
href="http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org">http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org</a></span><br><br>List rules & etiquette:<br><a target="_blank" href="http://www.re-wrenches.org/etiquette.htm">www.re-wrenches.org/etiquette.htm</a><br><br>Check out participant bios:<br><a target="_blank" href="http://www.members.re-wrenches.org">www.members.re-wrenches.org</a><br><br><br><br>End of RE-wrenches Digest, Vol 2, Issue 818<br>*******************************************<br></div></div></div><br>
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