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<DIV dir=ltr align=left><SPAN class=000380018-17022011><FONT color=#0000ff
size=2 face=Arial>Thanks Everyone for the feedback.</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=000380018-17022011><FONT color=#0000ff
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<DIV dir=ltr align=left><SPAN class=000380018-17022011><FONT color=#0000ff
size=2 face=Arial>I am going to go ahead and reduce my projected yield by an
additional 5% and increase the install cost to include a 2kva buck/boost xfmr as
an option. If the economics hold up, I have confidence that we can go forward
without the xfrm, but we will have it in the wings to address voltage faults if
they occur.</FONT></SPAN></DIV>
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<DIV dir=ltr align=left><SPAN class=000380018-17022011></SPAN><SPAN
lang=en-us><FONT size=2 face=Arial>Mark Frye</FONT></SPAN> <BR><SPAN
lang=en-us><FONT size=2 face=Arial>Berkeley Solar Electric Systems</FONT></SPAN>
<BR><SPAN lang=en-us><FONT size=2 face=Arial>303 Redbud Way</FONT></SPAN>
<BR><SPAN lang=en-us><FONT size=2 face=Arial>Nevada City, CA
95959</FONT></SPAN> <BR><SPAN lang=en-us><FONT size=2 face=Arial>(530)
401-8024</FONT></SPAN> <BR><SPAN lang=en-us></SPAN><A
href="http://www.berkeleysolar.com/"><SPAN lang=en-us><U><FONT color=#0000ff
size=2 face=Arial>www.berkeleysolar.com</FONT></U></SPAN></A><SPAN
lang=en-us><FONT size=2 face=Arial> </FONT></SPAN> </DIV>
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<FONT size=2 face=Tahoma><B>From:</B> re-wrenches-bounces@lists.re-wrenches.org
[mailto:re-wrenches-bounces@lists.re-wrenches.org] <B>On Behalf Of </B>Mark
Frye<BR><B>Sent:</B> Monday, February 14, 2011 7:42 PM<BR><B>To:</B>
'RE-wrenches'<BR><B>Subject:</B> [RE-wrenches] Can I handle the voltage
drop?<BR></FONT><BR></DIV>
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<P><FONT size=2 face=Arial>Folks,</FONT> </P>
<P><FONT size=2 face=Arial>I am working on a proposal. It's a ground mount 300+
feet from the meter. There is an existing, near by run of #2 copper I can tap
into. The desired system is relatively large, 64 amps AC max. I have modeled the
yield using PV watts hourly data, applying a power loss based on the voltage
drop at the varying current. This model shows a 3% loss in annual yield with the
#2 copper. Because of the economics of the system, we can absorb this
loss.</FONT></P>
<P><FONT size=2 face=Arial>My concern however is that I do not want the
inverters to shut down when operating at higher currents. I do not want a high
AC line voltage fault due to the voltage drop on the line. At the 64 amps max,
the drop would be about 4%. Of course all the manufactures I talk with
recommend keeping the drop on the AC below 1.5%.</FONT></P>
<P><FONT size=2 face=Arial>I am looking at using Enphase inverters which spec an
AC voltage range up to 264V, or 10% above 240V nominal.</FONT> </P>
<P><FONT size=2 face=Arial>What experience have folks had out there? How far can
one realistically push the 1.5% limit and still avoid AC voltage faults when
there is high voltage drop on the line?</FONT></P>
<P><FONT size=2 face=Arial>My guess is that everything would work out fine, but
I stand to loss a huge amount of energy if the inverters are spending all their
time faulting and resetting during daily peaks.</FONT></P>
<P><FONT face=Arial></FONT> <BR><FONT size=2 face=Arial>Mark Frye</FONT>
<BR><FONT size=2 face=Arial>Berkeley Solar Electric Systems</FONT> <BR><FONT
size=2 face=Arial>303 Redbud Way</FONT> <BR><FONT size=2 face=Arial>Nevada
City, CA 95959</FONT> <BR><FONT size=2 face=Arial>(530) 401-8024</FONT>
<BR><A href="http://www.berkeleysolar.com"><U><FONT color=#0000ff size=2
face=Arial>www.berkeleysolar.com</FONT></U></A><FONT size=2
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