<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD>
<META http-equiv=Content-Type content="text/html; charset=us-ascii">
<META content="MSHTML 6.00.2900.5803" name=GENERATOR></HEAD>
<BODY
style="WORD-WRAP: break-word; webkit-nbsp-mode: space; webkit-line-break: after-white-space">
<DIV dir=ltr align=left><FONT face=Arial color=#0000ff size=2><SPAN
class=296511416-21062009>Bob-O,</SPAN></FONT></DIV>
<DIV dir=ltr align=left><FONT face=Arial color=#0000ff size=2><SPAN
class=296511416-21062009></SPAN></FONT> </DIV>
<DIV dir=ltr align=left><FONT face=Arial color=#0000ff size=2><SPAN
class=296511416-21062009>I noticed your comment about the HU361 and went back
and reviewed the Data Bulletin, Direct Current and Photovoltaic Systems,
08/2005.</SPAN></FONT></DIV>
<DIV dir=ltr align=left><FONT face=Arial color=#0000ff size=2><SPAN
class=296511416-21062009></SPAN></FONT> </DIV>
<DIV dir=ltr align=left><FONT face=Arial color=#0000ff size=2><SPAN
class=296511416-21062009>This confirmed my understanding that the limiting
factor on the 30A switch in a photovoltaic applications is not 30A * 0.8.
The limiting factor is 18A per pole or 11.5A Isc per pole.</SPAN></FONT></DIV>
<DIV dir=ltr align=left><FONT face=Arial color=#0000ff size=2><SPAN
class=296511416-21062009></SPAN></FONT> </DIV>
<DIV><SPAN class=296511416-21062009><FONT face=Arial color=#0000ff
size=2>Depending on the modules used, this may or may not preclude doubling up
strings on individual poles.</FONT></SPAN></DIV>
<DIV><SPAN class=296511416-21062009></SPAN> <BR><SPAN lang=en-us><FONT
face=Arial size=2>Mark Frye</FONT></SPAN> <BR><SPAN lang=en-us><FONT face=Arial
size=2>Berkeley Solar Electric Systems</FONT></SPAN> <BR><SPAN lang=en-us><FONT
face=Arial size=2>303 Redbud Way</FONT></SPAN> <BR><SPAN lang=en-us><FONT
face=Arial size=2>Nevada City, CA 95959</FONT></SPAN> <BR><SPAN
lang=en-us><FONT face=Arial size=2>(530) 401-8024</FONT></SPAN> <BR><SPAN
lang=en-us></SPAN><A href="http://www.berkeleysolar.com/"><SPAN
lang=en-us><U><FONT face=Arial color=#0000ff
size=2>www.berkeleysolar.com</FONT></U></SPAN></A><SPAN lang=en-us><FONT
face=Arial size=2> </FONT></SPAN> </DIV>
<DIV> </DIV><BR>
<DIV class=OutlookMessageHeader lang=en-us dir=ltr align=left>
<HR tabIndex=-1>
<FONT face=Tahoma size=2><B>From:</B> re-wrenches-bounces@lists.re-wrenches.org
[mailto:re-wrenches-bounces@lists.re-wrenches.org] <B>On Behalf Of </B>Bob-O
Schultze<BR><B>Sent:</B> Saturday, June 20, 2009 2:36 PM<BR><B>To:</B>
RE-wrenches<BR><B>Subject:</B> Re: [RE-wrenches] fronius IG Plus practical
engineering WAA???<BR></FONT><BR></DIV>
<DIV></DIV>Nick,
<DIV>Fronius sells a heavy copper buss bar which will link all the six inputs
together. They look sort of like the Outback PSPV bus bars except copper and
MUCH heavier. If you need four or more inputs you'll need to get two of them.
Three or less, cut one in half. For some reason known only to Fronius
in Austria, if Fronius US orders two of those buss bars in one packet, it costs
more than two ordered separately. Drives Gord nuts, but that's the way it is. I
just installed a 11.4Plus recently with the buss bars and it worked out pretty
well. I never looked to see if there were individual fuses but it worked right
out of the box, so....?</DIV>
<DIV>Combining on the roof with HV touchsafe fuses and holders is still the way
to go, IMO, however if you are going to use a HU361 DC Disconnect at the
inverter with four strings, you will likely need to run down two sets of home
runs so as not to overload the poles which need to be derated from 30A by the
usual 20%. Or, go to a 60A Disco which is probably more expensive than a second
set of wires.</DIV>
<DIV>Hope this helps.</DIV>
<DIV>Bob-O<SPAN class=Apple-style-span
style="WORD-SPACING: 0px; FONT: medium Helvetica; TEXT-TRANSFORM: none; COLOR: rgb(0,0,0); TEXT-INDENT: 0px; WHITE-SPACE: normal; LETTER-SPACING: normal; BORDER-COLLAPSE: separate; orphans: 2; widows: 2; webkit-border-horizontal-spacing: 0px; webkit-border-vertical-spacing: 0px; webkit-text-decorations-in-effect: none; webkit-text-size-adjust: auto; webkit-text-stroke-width: 0px"></DIV></SPAN></BODY></HTML>