<html><head></head><body bgcolor="#FFFFFF"><div>Either inverter will become the master at many times during the life of the system, likewise the slave. </div><div><br></div><div>SW inverters didn't stack so much as live together under the same roof and stay 180 degrees out of the other's way. We've all seen marriages like that ;-)</div><div><br></div><div>Phil<br><br><br><div><br></div></div><div><br>On May 25, 2012, at 1:08 PM, "Dana" <<a href="mailto:dana@solarwork.com">dana@solarwork.com</a>> wrote:<br><br></div><div></div><blockquote type="cite"><div><meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1"><meta name="Generator" content="Microsoft Word 12 (filtered medium)"><style><!--
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</o:shapelayout></xml><![endif]--><div class="WordSection1"><p class="MsoNormal"><span style="font-size:14.0pt;font-family:"Century Gothic","sans-serif";color:windowtext">If you totally power down do you always need to power up the “master” first or if you reverse the power up will the slave become the master now?<o:p></o:p></span></p><p class="MsoNormal"><span style="font-size:14.0pt;font-family:"Century Gothic","sans-serif";color:windowtext"><o:p> </o:p></span></p><div><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Century Gothic","sans-serif";color:windowtext"><o:p> </o:p></span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Century Gothic","sans-serif";color:windowtext">Dana Orzel - Great Solar Works, Inc - E - <b><a href="mailto:dana@solarwork.com">dana@solarwork.com</a></b> - V <b>970.626.5253</b><o:p></o:p></span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Century Gothic","sans-serif";color:windowtext">F - 970.626.4140 C - 970.209.4076 web - <a href="http://www.solarwork.com">www.solarwork.com</a> <o:p></o:p></span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Century Gothic","sans-serif";color:windowtext">"Responsible Technologies for Responsible People since 1988"<o:p></o:p></span></p><p class="MsoNormal"><b><i><span style="font-size:13.5pt;font-family:"Calibri","sans-serif";color:green">P </span></i></b><b><i><span style="font-size:7.5pt;font-family:"Calibri","sans-serif";color:green">Please consider the environment before printing this email</span></i></b><b><i><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#99CC00"><o:p></o:p></span></i></b></p></div><p class="MsoNormal"><span style="font-size:14.0pt;font-family:"Century Gothic","sans-serif";color:windowtext"><o:p> </o:p></span></p><div><div style="border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in"><p class="MsoNormal"><b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif";color:windowtext">From:</span></b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif";color:windowtext"> <a href="mailto:re-wrenches-bounces@lists.re-wrenches.org">re-wrenches-bounces@lists.re-wrenches.org</a> [mailto:re-wrenches-bounces@lists.re-wrenches.org] <b>On Behalf Of </b>Allan Sindelar<br><b>Sent:</b> Friday, May 25, 2012 7:47 AM<br><b>To:</b> RE-wrenches<br><b>Subject:</b> Re: [RE-wrenches] SW master & slave<o:p></o:p></span></p></div></div><p class="MsoNormal"><o:p> </o:p></p><p class="MsoNormal">Mac,<br>Unlike the later Outback, for which you designate a master, the SWs had no way to do such designation. I think that when you boot them up (apply DC power), whichever unit receives power first becomes the master, and the other becomes the slave. <br><br>According to the manual, the issue of master/slave generator control applies only to parallel-stacked inverters operating at 120V AC output with a SWI/PAR stacking cable, and not with series stacking (120/240 VAC) configuration. Page 96:<o:p></o:p></p><p class="MsoNormal">When using two units in parallel, it is recommended that only the SLAVE inverter be used to control the<br>generator. This is required because the generator control system includes a cool down timer that causes<br>the controlling inverter to disconnect from the generator before it turns the generator off. If the MASTER<br>controls the generator, then the SLAVE may not stay in sync with the MASTER during the cool-down<br>period since it will remain in sync with the generator and not follow the MASTER. There currently is no<br>adjustment for the cool-down period, so restricting the generator control to the SLAVE is the only solution<br>available at this time.<o:p></o:p></p><p class="MsoNormal" style="margin-bottom:12.0pt">Allan<o:p></o:p></p><div><p class="MsoNormal"><b>Allan Sindelar</b><br><span style="font-size:10.0pt"><a href="mailto:Allan@positiveenergysolar.com"><span style="color:#000099">Allan@positiveenergysolar.com</span></a></span><br><span style="font-size:10.0pt">NABCEP Certified Photovoltaic Installer<br>NABCEP Certified Technical Sales Professional<br>New Mexico EE98J Journeyman Electrician<br>Founder and Chief Technology Officer<br><b>Positive Energy, Inc.</b><br>3209 Richards Lane (note new address)<br>Santa Fe, New Mexico 87507<br><b>505 424-1112</b><br><a href="http://www.positiveenergysolar.com/" target="_blank">www.positiveenergysolar.com</a></span> <o:p></o:p></p><p class="MsoNormal" style="mso-margin-top-alt:auto;margin-right:722.25pt;mso-margin-bottom-alt:auto"><o:p> </o:p></p><p class="MsoNormal"><o:p> </o:p></p></div><p class="MsoNormal"><br>On 5/25/2012 7:16 AM, mac Lewis wrote: <o:p></o:p></p><p class="MsoNormal">Hello wrenches, <o:p></o:p></p><div><p class="MsoNormal"><o:p> </o:p></p></div><div><p class="MsoNormal">I recently series stacked two SW 4024s. Everything seems to work fine. I want to follow the recommendation that the slave device is the generator controlling inverter. How do I tell which is the master and which is the slave?<o:p></o:p></p></div><div><p class="MsoNormal"><o:p> </o:p></p></div><div><p class="MsoNormal">Thanks<br clear="all"><o:p></o:p></p><div><p class="MsoNormal"><o:p> </o:p></p></div><p class="MsoNormal">-- <o:p></o:p></p><div><p class="MsoNormal"><o:p> </o:p></p></div><div><p class="MsoNormal"><o:p> </o:p></p></div><div><p class="MsoNormal"><o:p> </o:p></p></div><p class="MsoNormal" style="margin-bottom:12.0pt">Mac Lewis<b><span style="font-family:"Arial","sans-serif";color:#FF9900"><o:p></o:p></span></b></p><p><span style="color:#305A78">"Yo solo sé que no sé nada." </span><b><span style="color:#686868">-Sócrates</span></b><b><span style="font-family:"Arial","sans-serif";color:#FF9900"><o:p></o:p></span></b></p><p class="MsoNormal"><o:p> </o:p></p></div><p class="MsoNormal"><br><br><br><o:p></o:p></p><pre>_______________________________________________<o:p></o:p></pre><pre>List sponsored by Home Power magazine<o:p></o:p></pre><pre><o:p> </o:p></pre><pre>List Address: <a href="mailto:RE-wrenches@lists.re-wrenches.org">RE-wrenches@lists.re-wrenches.org</a><o:p></o:p></pre><pre><o:p> </o:p></pre><pre>Options & settings:<o:p></o:p></pre><pre><a 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><o:p></o:p></pre><pre><o:p> </o:p></pre><pre>List-Archive: <a href="http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org">http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org</a><o:p></o:p></pre><pre><o:p> </o:p></pre><pre>List rules & etiquette:<o:p></o:p></pre><pre><a href="http://www.re-wrenches.org/etiquette.htm">www.re-wrenches.org/etiquette.htm</a><o:p></o:p></pre><pre><o:p> </o:p></pre><pre>Check out participant bios:<o:p></o:p></pre><pre><a href="http://www.members.re-wrenches.org">www.members.re-wrenches.org</a><o:p></o:p></pre><pre><o:p> </o:p></pre></div></div></blockquote><blockquote type="cite"><div><span>_______________________________________________</span><br><span>List sponsored by Home Power magazine</span><br><span></span><br><span>List Address: <a href="mailto:RE-wrenches@lists.re-wrenches.org">RE-wrenches@lists.re-wrenches.org</a></span><br><span></span><br><span>Options & settings:</span><br><span><a 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><span></span><br><span>List-Archive: <a 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><span></span><br><span>List rules & etiquette:</span><br><span><a href="http://www.re-wrenches.org/etiquette.htm">www.re-wrenches.org/etiquette.htm</a></span><br><span></span><br><span>Check out participant bios:</span><br><span><a href="http://www.members.re-wrenches.org">www.members.re-wrenches.org</a></span><br><span></span><br></div></blockquote></body></html>