<html><head><meta http-equiv="Content-Type" content="text/html; charset=us-ascii"><meta name="Generator" content="Microsoft Word 14 (filtered medium)"><style><!--
/* Font Definitions */
@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}
@font-face
{font-family:Verdana;
panose-1:2 11 6 4 3 5 4 4 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0in;
margin-bottom:.0001pt;
font-size:11.0pt;
font-family:"Calibri","sans-serif";}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:blue;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{mso-style-priority:99;
color:purple;
text-decoration:underline;}
span.EmailStyle17
{mso-style-type:personal-compose;
font-family:"Verdana","sans-serif";
color:windowtext;}
.MsoChpDefault
{mso-style-type:export-only;
font-family:"Calibri","sans-serif";}
@page WordSection1
{size:8.5in 11.0in;
margin:1.0in 1.0in 1.0in 1.0in;}
div.WordSection1
{page:WordSection1;}
--></style></head><body lang="EN-US" link="blue" vlink="purple"><div class="WordSection1"><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif"">Friends:</span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif""> </span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif"">I am sure many of you are familiar with the somewhat new Outback FM100 charge controller. It allows PV input at up to 300 volts and battery feed at up to 100 amps. It has a built in GFDI fuse, much like the old XW--now branded I think Conextant-- charge controller.</span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif""> </span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif"">Outback recommends against installing an FM 100 in an installation with FM60s or FM 80s. Here is the <a href="https://outbackpower.com/downloads/documents/appnotes/fm100_fm80_app_note.pdf">tech note</a> that gives that recommendation. Below is one paragraph from that tech note.</span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif""> </span></p><p class="MsoNormal" style="margin-left:.5in"><i><span style="font-size:12.0pt;font-family:"Verdana","sans-serif"">There is little benefit to mixing an FM100 with an FM60/80. If circumstances require it, this application</span></i></p><p class="MsoNormal" style="margin-left:.5in"><i><span style="font-size:12.0pt;font-family:"Verdana","sans-serif"">note will explore an option.</span></i></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif""> </span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif"">Note the language is pretty dang squirrely. Let\u2019s parse the above paragraph:</span></p><p class="MsoNormal" style="margin-left:.5in"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif""> </span></p><p class="MsoNormal" style="margin-left:.5in"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif"">Sentence 1: I submit there may be many scenarios where there is significant benefit: Like if you already have an FM60/80 and you want to add more PV and you want to enjoy the benefits of an FM100, such as higher input voltage or higher output amperage, and not have to fork out an extra $1000 to replace a working FM60/80. Or you installing more than one PV array, one array nearby and/or smaller and one further away or larger, and you don\u2019t want to spend close to $1,000 to charge control the nearer array. </span></p><p class="MsoNormal" style="margin-left:.5in"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif""> </span></p><p class="MsoNormal" style="margin-left:.5in"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif"">Sentence 2: They are offering \u201can option,\u201d not the only option. I believe there are multiple options. In a mixed installation, the FM100 can rely on its internal GFDI fuse and the FM60 or 80 can rely on the old familiar GFDI breaker with the 1 or 0.5 amp pole connected between the negative and equipment grounding system. Alternatively, Midnite sells a 300 volt rated, multi-pole GFDI breaker that could be shared by an FM100 and an F60/80. It says right in the FM100 manual that you can use external GFDI devices (page 14).</span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif""> </span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif"">I am not at all clear as to what problem there is to mixing the two generations of charge controllers. I reviewed the NEC. There is no indication that thou shall not mix GFDI styles.</span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif""> </span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif"">If anyone has a definitive reason why or why not to mix these models of Outback charge controllers, I would be most interested.</span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif""> </span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif"">Most Sincerely,</span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif""> </span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif"">William Miller</span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif""> </span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Arial","sans-serif"">Miller Solar</span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Arial","sans-serif"">17395 Oak Road, Atascadero, CA 93422</span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Arial","sans-serif"">805-438-5600</span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Arial","sans-serif""><a href="http://www.millersolar.com/">www.millersolar.com</a></span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Arial","sans-serif"">CA Lic. 773985</span></p><p class="MsoNormal"> </p><p class="MsoNormal"> </p></div></body></html>