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<DIV dir=ltr align=left><FONT color=#0000ff size=2 face=Arial><SPAN
class=734393218-21122009>Walt,</SPAN></FONT></DIV>
<DIV dir=ltr align=left><FONT color=#0000ff size=2 face=Arial><SPAN
class=734393218-21122009></SPAN></FONT> </DIV>
<DIV dir=ltr align=left><FONT color=#0000ff size=2 face=Arial><SPAN
class=734393218-21122009>You are so right. Thanks for reminding us all that,
when using a charge controller, we need to make sure we have overcurrent
protection on that end of the PV Output circuit.</SPAN></FONT></DIV>
<DIV dir=ltr align=left><FONT color=#0000ff size=2 face=Arial><SPAN
class=734393218-21122009></SPAN></FONT> </DIV>
<DIV dir=ltr align=left><FONT color=#0000ff size=2 face=Arial><SPAN
class=734393218-21122009>Seasons Greetings everyone,</SPAN></FONT></DIV>
<DIV dir=ltr align=left><FONT color=#0000ff size=2 face=Arial><SPAN
class=734393218-21122009></SPAN></FONT> </DIV>
<DIV dir=ltr align=left><FONT color=#0000ff size=2 face=Arial><SPAN
class=734393218-21122009>Matt Lafferty</SPAN></FONT></DIV>
<DIV><FONT color=#0000ff size=2 face=Arial></FONT> </DIV>
<DIV class=Section1>
<HR tabIndex=-1>
<FONT size=2 face=Tahoma><B>From:</B> Walt Ratterman
[mailto:wratterman@sunenergypower.com] <BR><B>Sent:</B> Sunday, December 20,
2009 9:49 PM<BR><B>To:</B> gilligan06@gmail.com;
'RE-wrenches'<BR><B>Subject:</B> RE: [RE-wrenches] DC disconnect
placement<BR></FONT><BR></DIV>
<DIV></DIV>
<DIV class=Section1>
<P class=MsoNormal><SPAN
style="FONT-FAMILY: 'Calibri','sans-serif'; COLOR: #1f497d; FONT-SIZE: 11pt">Hello
all,<o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN
style="FONT-FAMILY: 'Calibri','sans-serif'; COLOR: #1f497d; FONT-SIZE: 11pt"><o:p> </o:p></SPAN></P>
<P class=MsoNormal><SPAN
style="FONT-FAMILY: 'Calibri','sans-serif'; COLOR: #1f497d; FONT-SIZE: 11pt">While
this may be excellent advice, I think it would be good to clarify that this may
apply primarily to grid tied systems. <o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN
style="FONT-FAMILY: 'Calibri','sans-serif'; COLOR: #1f497d; FONT-SIZE: 11pt"><o:p> </o:p></SPAN></P>
<P class=MsoNormal><SPAN
style="FONT-FAMILY: 'Calibri','sans-serif'; COLOR: #1f497d; FONT-SIZE: 11pt">In
Off Grid systems we have different considerations, such as (a) we are working
with lower voltages and need to limit the size of the wire and the voltage drop,
and (b) there IS protection at the equipment room on the homeruns from the
combiners to the equipment room (assuming the combiners are at the array) as
long as we have individual circuit breakers on the input of each charge
controller.<o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN
style="FONT-FAMILY: 'Calibri','sans-serif'; COLOR: #1f497d; FONT-SIZE: 11pt"><o:p> </o:p></SPAN></P>
<P class=MsoNormal><SPAN
style="FONT-FAMILY: 'Calibri','sans-serif'; COLOR: #1f497d; FONT-SIZE: 11pt">Thanks,<o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN
style="FONT-FAMILY: 'Calibri','sans-serif'; COLOR: #1f497d; FONT-SIZE: 11pt"><o:p> </o:p></SPAN></P>
<P class=MsoNormal><SPAN
style="FONT-FAMILY: 'Calibri','sans-serif'; COLOR: #1f497d; FONT-SIZE: 11pt">Walt<o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN
style="FONT-FAMILY: 'Calibri','sans-serif'; COLOR: #1f497d; FONT-SIZE: 11pt"><o:p> </o:p></SPAN></P>
<P class=MsoNormal><SPAN
style="FONT-FAMILY: 'Calibri','sans-serif'; COLOR: #1f497d; FONT-SIZE: 11pt"><o:p> </o:p></SPAN></P>
<P class=MsoNormal><B><SPAN
style="FONT-FAMILY: 'Arial','sans-serif'; COLOR: #1f497d; FONT-SIZE: 10pt">Walt
Ratterman<o:p></o:p></SPAN></B></P>
<P class=MsoNormal><B><SPAN
style="FONT-FAMILY: 'Arial','sans-serif'; COLOR: #1f497d; FONT-SIZE: 10pt">SunEnergy
Power International</SPAN></B><B><SPAN
style="COLOR: #1f497d; FONT-SIZE: 10pt"><o:p></o:p></SPAN></B></P>
<P class=MsoNormal><B><SPAN
style="COLOR: #1f497d; FONT-SIZE: 10pt"><o:p> </o:p></SPAN></B></P>
<P class=MsoNormal><SPAN
style="FONT-FAMILY: 'Arial','sans-serif'; COLOR: #1f497d; FONT-SIZE: 8pt">11
Laurel Lane South Washougal, WA
98671<o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN
style="FONT-FAMILY: 'Arial','sans-serif'; COLOR: #1f497d; FONT-SIZE: 8pt">(360)-837-3680
▪ fax (360)-837-1315 ▪ Skype
Walt-Mobile<o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN
style="FONT-FAMILY: 'Arial','sans-serif'; COLOR: #1f497d; FONT-SIZE: 8pt"><A
href="mailto:wratterman@SunEPI.org">wratterman@SunEPI.org</A> </SPAN><SPAN
style="FONT-FAMILY: 'Arial','sans-serif'; COLOR: #1f497d; FONT-SIZE: 10pt"> </SPAN><SPAN
style="FONT-FAMILY: 'Arial','sans-serif'; COLOR: #1f497d; FONT-SIZE: 8pt">▪
<A href="http://www.sunepi.org/">www.SunEPI.org</A><o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN
style="FONT-FAMILY: 'Arial','sans-serif'; COLOR: #1f497d; FONT-SIZE: 10pt"><o:p> </o:p></SPAN></P>
<P class=MsoNormal><SPAN
style="FONT-FAMILY: 'Arial','sans-serif'; COLOR: #1f497d; FONT-SIZE: 8pt"><o:p> </o:p></SPAN></P>
<P class=MsoNormal><SPAN
style="FONT-FAMILY: 'Arial','sans-serif'; COLOR: #1f497d; FONT-SIZE: 10pt"><o:p> </o:p></SPAN></P>
<P class=MsoNormal><SPAN
style="FONT-FAMILY: 'Calibri','sans-serif'; COLOR: #1f497d; FONT-SIZE: 11pt"><o:p> </o:p></SPAN></P>
<P class=MsoNormal><SPAN
style="FONT-FAMILY: 'Calibri','sans-serif'; COLOR: #1f497d; FONT-SIZE: 11pt"><o:p> </o:p></SPAN></P>
<P class=MsoNormal><SPAN
style="FONT-FAMILY: 'Calibri','sans-serif'; COLOR: #1f497d; FONT-SIZE: 11pt"><o:p> </o:p></SPAN></P>
<DIV>
<DIV
style="BORDER-BOTTOM: medium none; BORDER-LEFT: medium none; PADDING-BOTTOM: 0in; PADDING-LEFT: 0in; PADDING-RIGHT: 0in; BORDER-TOP: #b5c4df 1pt solid; BORDER-RIGHT: medium none; PADDING-TOP: 3pt">
<P class=MsoNormal><B><SPAN
style="FONT-FAMILY: 'Tahoma','sans-serif'; FONT-SIZE: 10pt">From:</SPAN></B><SPAN
style="FONT-FAMILY: 'Tahoma','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>Matt
Lafferty<BR><B>Sent:</B> Sunday, December 20, 2009 4:10 PM<BR><B>To:</B>
'RE-wrenches'<BR><B>Subject:</B> Re: [RE-wrenches] DC disconnect
placement<o:p></o:p></SPAN></P></DIV></DIV>
<P class=MsoNormal><o:p> </o:p></P>
<P class=MsoNormal><SPAN
style="FONT-FAMILY: 'Arial','sans-serif'; COLOR: blue; FONT-SIZE: 10pt">William,</SPAN><o:p></o:p></P>
<P class=MsoNormal> <o:p></o:p></P>
<P class=MsoNormal><SPAN
style="FONT-FAMILY: 'Arial','sans-serif'; COLOR: blue; FONT-SIZE: 10pt">Put the
inverters at the array. Run the AC underground. If the AC
feeder gets dug up by some rowdy backhoe operator in the future, the
breaker (or series of breakers) will open, de-energizing the circuit immediately
(and maybe the main to the residence at the same time).</SPAN><o:p></o:p></P>
<P class=MsoNormal> <o:p></o:p></P>
<P class=MsoNormal><SPAN
style="FONT-FAMILY: 'Arial','sans-serif'; COLOR: blue; FONT-SIZE: 10pt">If you
are dead-set on putting the inverters in the pump shed, put any combiner(s) at
the inverters. This affords the maximum overcurrent protection for the
underground feeders. Install DC disconnecting means in each string before
leaving the array if you go this route.</SPAN><o:p></o:p></P>
<P class=MsoNormal> <o:p></o:p></P>
<P class=MsoNormal><SPAN
style="FONT-FAMILY: 'Arial','sans-serif'; COLOR: blue; FONT-SIZE: 10pt">For
maximum protection of conductors and to minimize arc hazards, The SAFEST
location for a combiner is ALWAYS at the inverter. All conductors on the
inverter (load) side of a fused combiner are unprotected by anything other than
their ampacity rating. If a fault occurs on the load side of a combiner, it will
burn until it clears or welds to a dead short. </SPAN><o:p></o:p></P>
<P class=MsoNormal> <o:p></o:p></P>
<P class=MsoNormal><SPAN
style="FONT-FAMILY: 'Arial','sans-serif'; COLOR: blue; FONT-SIZE: 10pt">Cheers,</SPAN><o:p></o:p></P>
<P class=MsoNormal> <o:p></o:p></P>
<P class=MsoNormal><SPAN
style="FONT-FAMILY: 'Arial','sans-serif'; COLOR: blue; FONT-SIZE: 10pt">Matt
Lafferty</SPAN><o:p></o:p></P>
<DIV>
<P class=MsoNormal><BR> <o:p></o:p></P></DIV>
<DIV style="TEXT-ALIGN: center" class=MsoNormal align=center>
<HR align=center SIZE=2 width="100%">
</DIV>
<P style="MARGIN-BOTTOM: 12pt" class=MsoNormal><B><SPAN
style="FONT-FAMILY: 'Tahoma','sans-serif'; FONT-SIZE: 10pt">From:</SPAN></B><SPAN
style="FONT-FAMILY: 'Tahoma','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>William
Miller<BR><B>Sent:</B> Sunday, December 20, 2009 11:02 AM<BR><B>To:</B>
RE-wrenches<BR><B>Subject:</B> [RE-wrenches] DC disconnect
placement</SPAN><o:p></o:p></P>
<P class=MsoNormal>Friends:<BR><BR>I am embarking on a 10 Kw ground mount
grid-tie installation. The client prepared for this installation some time
ago by stubbing a PVC conduit underground towards the future location of the PV
array. Prior to beginning this job, an excavation contractor intercepted
the empty conduit with a backhoe.<BR><BR>No harm was done because this conduit
was empty. Had this conduit been filled with PV feeders, it would have
been very necessary to be able to disconnect the PV arrays, both for safety and
to prevent a brush fire in our very dry climate.<BR><BR>The inverters will be
located in a pump house about 130 feet from the PV arrays. I would not
normally put disconnects at the array and they are not required. This
scenario, however, has caused me to reconsider. The design now calls for a
disconnect at each row of modules. I feel that it would not be prudent to
delete this important safety item.<BR><BR>I wish there were a better selection
of compact, low profile disconnects suitable for a roof-top
installation. I have put external handle disconnects on roof but they look
terrible. I may specify touch-safe fuse holders inside of a Sola Deck for
future comp roof jobs. I am not sure what we will do with tile
roofs.<BR><BR>It seems to me that every source of power should have a means of
disconnection as close to the source as possible. This is just common
sense.<BR><BR>William Miller<BR><BR><BR><o:p></o:p></P>
<P><U>Please note new e-mail address and domain:<BR><BR></U>William Miller
<BR>Miller Solar<BR>Voice :805-438-5600<BR>email: william@millersolar.com<BR><A
href="http://millersolar.com/">http://millersolar.com<BR></A>License No.
C-10-773985<o:p></o:p></P></DIV></BODY></HTML>