I have an early vintage SW unit (which is overdue for retirement but refuses to break...)<br><br>Those early models had to be physically removed from the wall to get the cover off, so a chipset replacement was difficult. Then Series II came out (which can be identified by the easier method for removing the cover). <br>

<br>There were additional  revisions to the physical hardware when Series II came out, and I've carried the notion that Series II was not backward compatible to Series I.<br><br>Dave Katz' suggestion is something that I'm sure you'll want to pursue, but I advise that all digits of the firmware revision should match...and that both inverters should be Series I or II, not mixed.<br>

<br>I have an extra chipset that I never installed...owing to the difficult replacement process...so we could compare notes further if you wish.<br><br>Jolliness,<br><br clear="all">Mick Abraham, Proprietor<br><a href="http://www.abrahamsolar.com">www.abrahamsolar.com</a><br>

<br>Voice: 970-731-4675<br>
<br><br><div class="gmail_quote">On Fri, Oct 30, 2009 at 7:05 PM, Allan Sindelar <span dir="ltr"><<a href="mailto:allan@positiveenergysolar.com">allan@positiveenergysolar.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">










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<p class="MsoNormal"><span style="font-size: 12pt; font-family: "Times New Roman","serif";">Esteemed
Wrenches:</span></p>

<p class="MsoNormal"><span style="font-size: 12pt; font-family: "Times New Roman","serif";">Wrench
esoterica time… another contest like Mick’s to win the chance to
take time off…</span></p>

<p class="MsoNormal"><span style="font-size: 12pt; font-family: "Times New Roman","serif";"> </span></p>

<p class="MsoNormal"><span style="font-size: 12pt; font-family: "Times New Roman","serif";">A
customer has a late-2005 SW4024 with Rev. 4.30 firmware. He needs to add a
second inverter for series stacking to increase output to run a big well pump. We
have an early SW4024 with Rev 1.0 firmware, and we have both Rev. 4.01 and 4.10
firmware chipsets in our parts archives. Are the two inverters compatible if
series-stacked with a firmware upgrade?</span></p>

<p class="MsoNormal"><span style="font-size: 12pt; font-family: "Times New Roman","serif";"> </span></p>

<p class="MsoNormal"><span style="font-size: 12pt; font-family: "Times New Roman","serif";">Thank
you.</span></p>

<p class="MsoNormal"><span style="font-size: 12pt; font-family: "Times New Roman","serif";"> </span></p>

<p class="MsoNormal"><span style="font-family: "Times New Roman","serif";">Allan
Sindelar</span></p>

<p class="MsoNormal"><span style="font-size: 10pt; font-family: "Times New Roman","serif";"><a href="mailto:Allan@positiveenergysolar.com" target="_blank"><span style="color: blue;">Allan@positiveenergysolar.com</span></a></span><span style="font-family: "Times New Roman","serif";"></span></p>



<p class="MsoNormal"><span style="font-size: 10pt; font-family: "Times New Roman","serif";">NABCEP
Certified Photovoltaic Installer</span><span style="font-family: "Times New Roman","serif";"></span></p>

<p class="MsoNormal"><span style="font-size: 10pt; font-family: "Times New Roman","serif";">EE98J
Journeyman Electrician</span><span style="font-family: "Times New Roman","serif";"></span></p>

<p class="MsoNormal"><b><span style="font-family: "Times New Roman","serif";">Positive
Energy, Inc.</span></b></p>

<p class="MsoNormal"><span style="font-family: "Times New Roman","serif";">3201
Calle Marie</span></p>

<p class="MsoNormal"><span style="font-family: "Times New Roman","serif";">Santa
Fe, New Mexico 87507</span></p>

<p class="MsoNormal"><span style="font-family: "Times New Roman","serif";">505
424-1112</span></p>

<p class="MsoNormal"><span style="font-size: 10pt; font-family: "Times New Roman","serif";"><a href="http://www.positiveenergysolar.com/" target="_blank"><span style="color: blue;">www.PositiveEnergySolar.com</span></a></span><span style="font-family: "Times New Roman","serif";"></span></p>



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