<table cellspacing="0" cellpadding="0" border="0" ><tr><td valign="top" style="font: inherit;"><DIV>The temperature correction is the concern. I have heard lots of stories of inverters dieing when it gets to cold. Look in the code book 690.7 at the temperature correction table. Go to weather.com and find your record low temperature. Find you Tc factor and will your senerios work? I have heard from a sunny boy rep that it is OK to over power by 1.25% </DIV>
<DIV>darryl<BR><BR>--- On <B>Mon, 4/19/10, Dana <I><dana@solarwork.com></I></B> wrote:<BR></DIV>
<BLOCKQUOTE style="BORDER-LEFT: rgb(16,16,255) 2px solid; PADDING-LEFT: 5px; MARGIN-LEFT: 5px"><BR>From: Dana <dana@solarwork.com><BR>Subject: Re: [RE-wrenches] overfeed 7kW gridtie inverter or drop a mod per string?<BR>To: "'RE-wrenches'" <re-wrenches@lists.re-wrenches.org><BR>Date: Monday, April 19, 2010, 4:31 PM<BR><BR>
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<P class=MsoNormal><SPAN style="FONT-FAMILY: 'sans-serif'; FONT-SIZE: 14pt">Many times we switch to another module manufacturer as one will not fit or another inverter manufacturer. </SPAN></DIV>
<P class=MsoNormal><SPAN style="FONT-FAMILY: 'sans-serif'; FONT-SIZE: 14pt">PVPowered has a more relaxed window and we have had fine success with them when SMA does not fit. </SPAN></DIV>
<P class=MsoNormal><SPAN style="FONT-FAMILY: 'sans-serif'; FONT-SIZE: 14pt">Cold is the dictator and the 600 VDC threshold.</SPAN></DIV>
<P class=MsoNormal><SPAN style="FONT-FAMILY: 'sans-serif'; FONT-SIZE: 14pt"> </SPAN></DIV>
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<P class=MsoNormal><SPAN style="FONT-FAMILY: 'sans-serif'; FONT-SIZE: 12pt">Thanks, Dana Orzel</SPAN></DIV>
<P class=MsoNormal><SPAN style="FONT-FAMILY: 'sans-serif'; FONT-SIZE: 12pt"> </SPAN></DIV>
<P class=MsoNormal><SPAN style="FONT-FAMILY: 'sans-serif'; FONT-SIZE: 12pt">Great Solar Works, Inc</SPAN></DIV>
<P class=MsoNormal><SPAN style="FONT-FAMILY: 'sans-serif'; FONT-SIZE: 12pt">web - www.solarwork.com</SPAN></DIV>
<P class=MsoNormal><SPAN style="FONT-FAMILY: 'sans-serif'; FONT-SIZE: 12pt">E - dana@solarwork.com</SPAN></DIV>
<P class=MsoNormal><SPAN style="FONT-FAMILY: 'sans-serif'; FONT-SIZE: 12pt">V - 970.626.5253</SPAN></DIV>
<P class=MsoNormal><SPAN style="FONT-FAMILY: 'sans-serif'; FONT-SIZE: 12pt">F - 970.626.4140</SPAN></DIV>
<P class=MsoNormal><SPAN style="FONT-FAMILY: 'sans-serif'; FONT-SIZE: 12pt">C - 970.209.4076</SPAN></DIV>
<P class=MsoNormal><SPAN style="FONT-FAMILY: 'sans-serif'; FONT-SIZE: 12pt"> </SPAN></DIV>
<P class=MsoNormal><SPAN style="FONT-FAMILY: 'sans-serif'; FONT-SIZE: 12pt">"We have been slow to give up on the myth of the Earth's generosity.</SPAN></DIV>
<P class=MsoNormal><SPAN style="FONT-FAMILY: 'sans-serif'; FONT-SIZE: 12pt">Rather grandly, we have overdrawn our accounts."</SPAN></DIV>
<P class=MsoNormal><SPAN style="FONT-FAMILY: 'sans-serif'; FONT-SIZE: 12pt">Barbara Kingsolver - Water is life.</SPAN><SPAN style="FONT-FAMILY: 'sans-serif'"></SPAN></DIV></DIV>
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<P style="MARGIN-LEFT: 0.5in" class=MsoNormal><B><SPAN style="FONT-FAMILY: 'sans-serif'; FONT-SIZE: 10pt">From:</SPAN></B><SPAN style="FONT-FAMILY: 'sans-serif'; FONT-SIZE: 10pt"> re-wrenches-bounces@lists.re-wrenches.org [mailto:re-wrenches-bounces@lists.re-wrenches.org] <B>On Behalf Of </B>Jim MacDonald<BR><B>Sent:</B> Monday, April 19, 2010 2:37 PM<BR><B>To:</B> RE-wrenches@lists.re-wrenches.org<BR><B>Subject:</B> [RE-wrenches] overfeed 7kW gridtie inverter or drop a mod per string?</SPAN></DIV></DIV></DIV>
<P style="MARGIN-LEFT: 0.5in" class=MsoNormal> </DIV>
<P style="MARGIN-LEFT: 0.5in" class=MsoNormal>For a straight grid-tie system@ 10 degree tilt, 180 azimuth, zero/little shade, NYC avg 4.29 kWh/m<SPAN style="FONT-SIZE: 12pt">²/day.</SPAN><SPAN style="FONT-FAMILY: 'MS Shell Dlg'; FONT-SIZE: 8.5pt"></SPAN></DIV>
<P style="MARGIN-LEFT: 0.5in" class=MsoNormal> </DIV>
<P style="MARGIN-LEFT: 0.5in" class=MsoNormal>Feed an SMA7000 with (3) strings of 11 Suntech STP275’s [9.075 kWdc]</DIV>
<P style="MARGIN-LEFT: 0.5in" class=MsoNormal>Or</DIV>
<P style="MARGIN-LEFT: 0.5in" class=MsoNormal>Do strings of 10, so itd be 8.250 kWdc into the 7 kWac inverter.</DIV>
<P style="MARGIN-LEFT: 0.5in" class=MsoNormal> </DIV>
<P style="MARGIN-LEFT: 0.5in" class=MsoNormal>Strings of 11= 491.7 Voc; 386 Vmp</DIV>
<P style="MARGIN-LEFT: 0.5in" class=MsoNormal>Strings of 10= 447 Voc; 351 Vmp </DIV>
<P style="MARGIN-LEFT: 0.5in" class=MsoNormal> </DIV>
<P style="MARGIN-LEFT: 0.5in" class=MsoNormal>The tradeoff would be power clipping at/around noon in the sunny months in the 9.075 kW scenario;</DIV>
<P style="MARGIN-LEFT: 0.5in" class=MsoNormal>Inverter sleeping late every morning and retiring early in the evenings in the lowered voltage scenario.</DIV>
<P style="MARGIN-LEFT: 0.5in" class=MsoNormal> </DIV>
<P style="MARGIN-LEFT: 0.5in" class=MsoNormal>Trying to figure out which would yield more kWh at the end of the year.</DIV>
<P style="MARGIN-LEFT: 0.5in" class=MsoNormal> </DIV>
<P style="MARGIN-LEFT: 0.5in" class=MsoNormal>Any ideas appreciated,</DIV>
<P style="MARGIN-LEFT: 0.5in" class=MsoNormal>thanks</DIV>
<P style="MARGIN-LEFT: 0.5in" class=MsoNormal> </DIV>
<P style="MARGIN-LEFT: 0.5in" class=MsoNormal> </DIV>
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<P style="MARGIN-LEFT: 0.5in" class=MsoNormal> </DIV>
<P style="MARGIN-LEFT: 0.5in" class=MsoNormal><B><SPAN style="FONT-FAMILY: 'sans-serif'; COLOR: #002060; FONT-SIZE: 10pt">Jim MacDonald</SPAN></B><SPAN style="FONT-FAMILY: 'sans-serif'; COLOR: #002060; FONT-SIZE: 10pt"></SPAN></DIV>
<P style="MARGIN-LEFT: 0.5in" class=MsoNormal><SPAN style="FONT-FAMILY: 'sans-serif'; COLOR: #002060; FONT-SIZE: 10pt">Solar Energy Systems, LLC</SPAN><SPAN style="COLOR: #002060"></SPAN></DIV>
<P style="MARGIN-LEFT: 0.5in" class=MsoNormal><SPAN style="FONT-FAMILY: 'sans-serif'; COLOR: #002060; FONT-SIZE: 10pt">Brooklyn, NY 11222</SPAN><SPAN style="COLOR: #002060"></SPAN></DIV>
<P style="MARGIN-LEFT: 0.5in" class=MsoNormal><SPAN style="FONT-FAMILY: 'sans-serif'; COLOR: #1f497d; FONT-SIZE: 10pt"><A href="http://www.solaresystems.com/" rel=nofollow target=_blank>www.solarEsystems.com</A></SPAN><SPAN style="FONT-FAMILY: 'sans-serif'; COLOR: #002060; FONT-SIZE: 10pt"></SPAN></DIV>
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