<div dir="ltr"><div>We have not had any issues with fuses blowing in the field without cause. If a module has a ISC for 9.44 a 15 amp fuse is plenty but it sounded like the sunpower string was being combined elsewhere then you need to use the lug in the middle of the SMA combiner fuse holders its there to bypass the fuses altogether. You still need protection somewhere in the system between the modules and inverter with few exceptions.<br>
</div>Jerry<br><div> </div></div><div class="gmail_extra"><br><br><div class="gmail_quote">On Thu, Feb 6, 2014 at 10:51 AM, Steve Jefferson <span dir="ltr"><<a href="mailto:Steve.Jefferson@sma-america.com" target="_blank">Steve.Jefferson@sma-america.com</a>></span> wrote:<br>
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Morning Wrenches,<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">SMA disconnects come with 15A fuses. If required by the module, you can bump the series fusing to a maximum of 20A.<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">If you are combining the string before the disconnect, you need to land the combined input on the terminal labeled “Combined”. This terminal is located in the
middle of the series fusing terminals.<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Do not land a combined input to the standard fuse block and put a 20A (or greater) fuse in it, this could over amp the fuse terminal, resulting in a fire.<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Thanks
<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial","sans-serif";color:#1f497d">SMA America, LLC<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial","sans-serif";color:#1f497d">Steve Jefferson<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial","sans-serif";color:#1f497d">Service Line Supervisor<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial","sans-serif";color:#1f497d">3925 Atherton Ave<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial","sans-serif";color:#1f497d">Rocklin, CA 95765 - 3714<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial","sans-serif";color:#1f497d">U.S.A.<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial","sans-serif";color:#1f497d">Tel: <a href="tel:%2B1%20916%20625%203185" value="+19166253185" target="_blank">+1 916 625 3185</a> (direct)<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial","sans-serif";color:#1f497d">Fax: <a href="tel:%2B1%20916%20625%200871" value="+19166250871" target="_blank">+1 916 625 0871</a><u></u><u></u></span></p>
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</span><u><span style="font-size:10.0pt;font-family:"Arial","sans-serif";color:blue"><a href="mailto:Steve.jefferson@SMA-America.com" target="_blank">Steve.jefferson@SMA-America.com</a></span></u><span style="font-size:10.0pt;font-family:"Arial","sans-serif";color:#1f497d"><u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:blue"><a href="http://www.sma-america.com/" target="_blank"><span style="font-size:10.0pt;font-family:"Arial","sans-serif"">www.SMA-America.com</span></a></span><span style="font-size:10.0pt;font-family:"Arial","sans-serif";color:blue"><u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial","sans-serif";color:#1f497d"><u></u> <u></u></span></p>
<p class="MsoNormal"><a href="http://www.youtube.com/watch?v=yQWzPuyqhzo&feature=youtu.be" target="_blank"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d;text-decoration:none"><img src="cid:image001.png@01CF2324.CAAF88D0" alt="cid:image001.png@01CF1CFA.FE18BEB0" border="0" height="90" width="432"></span></a><span style="font-size:10.0pt;font-family:"Arial","sans-serif";color:#1f497d"><u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial","sans-serif";color:#1f497d"> <u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:"Arial","sans-serif";color:#1f497d">This email and any attachments thereto may contain SMA America, LLC confidential, privileged and private material for the sole use of the intended recipient. Any
review, copying, or distribution of this email (or any attachments thereto) by others is strictly prohibited. If you are not the intended recipient, please contact the sender immediately and permanently delete the original and any copies of this email and
any attachments thereto. Thank you.<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial","sans-serif";color:#1f497d"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> <u></u></span></p>
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<p class="MsoNormal"><b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">From:</span></b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif""> <a href="mailto:re-wrenches-bounces@lists.re-wrenches.org" target="_blank">re-wrenches-bounces@lists.re-wrenches.org</a> [mailto:<a href="mailto:re-wrenches-bounces@lists.re-wrenches.org" target="_blank">re-wrenches-bounces@lists.re-wrenches.org</a>]
<b>On Behalf Of </b>Kirpal Khalsa<br>
<b>Sent:</b> Thursday, February 06, 2014 10:12 AM<br>
<b>To:</b> <a href="mailto:glenn.burt@glbcc.com" target="_blank">glenn.burt@glbcc.com</a>; RE-wrenches<br>
<b>Subject:</b> Re: [RE-wrenches] DC Series Fusing in inverters<u></u><u></u></span></p><div><div class="h5">
<p class="MsoNormal"><u></u> <u></u></p>
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<p class="MsoNormal">Jason...as you know, the fusing should match the max series fuse ratings of the module requirements per the module manufacturer....If strings are individually fused and combined before the fused disconnect box then the fuses often need
to be changed from the factory supplied 15A fuses....Note the maximum allowed by SMA per the disconnect limitations per string of their disconnect.....Fronius used to supply metal slugs that fit in the fuse holders if no fusing was required on the input.....<u></u><u></u></p>
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<p class="MsoNormal">Didn't some of the Evergreen modules call for 20A series fuses?<u></u><u></u></p>
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<p class="MsoNormal">Good luck..<u></u><u></u></p>
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<p class="MsoNormal">Sunny Regards,<br>
Kirpal Khalsa<br>
NABCEP Certified PV Installation Professional<br>
Renewable Energy Systems<br>
<a href="http://www.oregonsolarworks.com" target="_blank">www.oregonsolarworks.com</a><br>
<a href="tel:541-218-0201" value="+15412180201" target="_blank">541-218-0201</a> m<br>
<a href="tel:541-299-0402" value="+15412990402" target="_blank">541-299-0402</a> o<u></u><u></u></p>
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<p class="MsoNormal">On Thu, Feb 6, 2014 at 9:56 AM, Glenn Burt <<a href="mailto:glenn.burt@glbcc.com" target="_blank">glenn.burt@glbcc.com</a>> wrote:<u></u><u></u></p>
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<div>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">I think I just read that SMA has changed their long-standing 15A per string fuses to 20A.</span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">You might look to see if it applies to existing systems.</span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Hope it helps.</span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Glenn</span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span><u></u><u></u></p>
<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"">From:</span></b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">
<a href="mailto:re-wrenches-bounces@lists.re-wrenches.org" target="_blank">re-wrenches-bounces@lists.re-wrenches.org</a> [mailto:<a href="mailto:re-wrenches-bounces@lists.re-wrenches.org" target="_blank">re-wrenches-bounces@lists.re-wrenches.org</a>]
<b>On Behalf Of </b>Jason Szumlanski<br>
<b>Sent:</b> Thursday, February 06, 2014 12:50 PM<br>
<b>To:</b> RE-wrenches<br>
<b>Subject:</b> [RE-wrenches] DC Series Fusing in inverters</span><u></u><u></u></p>
</div>
<div>
<div>
<p class="MsoNormal"> <u></u><u></u></p>
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<div>
<p class="MsoNormal"><span style="font-family:"Verdana","sans-serif"">SMA inverters typically come with 15A KLKD fuses pre-installed. I have seen a bunch of blown fuses recently (after cold weather)...
It seems that some dealers are just assuming the 15A fuse is okay for series strings and not doing the calculations. I've been finding quite a few Evergreen systems or parallel connected two-string SunPower systems that should have 20A fuses per NEC 690.8.
The problem does seem to be worse where inverters are exposed to direct sunlight, presumably from fuses that no longer meet their ampacity rating due to heat.</span><u></u><u></u></p>
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<p class="MsoNormal"><span style="font-family:"Verdana","sans-serif""> </span><u></u><u></u></p>
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<p class="MsoNormal"><span style="font-family:"Verdana","sans-serif"">Anyone else run into this frequently?</span><u></u><u></u></p>
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<p class="MsoNormal"> <u></u><u></u></p>
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<p class="MsoNormal"><span style="font-family:"Verdana","sans-serif"">Jason Szumlanski</span><u></u><u></u></p>
</div>
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<p class="MsoNormal"><span style="font-family:"Verdana","sans-serif"">Fafco Solar</span><u></u><u></u></p>
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<p class="MsoNormal"><span style="font-family:"Verdana","sans-serif""> </span><u></u><u></u></p>
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