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<DIV dir=ltr align=left><SPAN class=156015923-02092011><FONT color=#0000ff
size=2 face=Arial>Allen,</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=156015923-02092011><FONT color=#0000ff
size=2 face=Arial></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=156015923-02092011><FONT color=#0000ff
size=2 face=Arial>The other inverters do not simulate the SI. The SI can be
paired with a SB such that there is some degree of proportional control of the
SB output power via frequancy shifts generated by the SI. Consult SMA
documentation of SI operation available on-line at SMA
website.</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=156015923-02092011><FONT color=#0000ff
size=2 face=Arial></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=156015923-02092011><FONT color=#0000ff
size=2 face=Arial>Other inverters have a one step frequency shift that will
cause most grid tied inverters to see a line frequecy fault, in turn causing
them to go off-line until the frequecy is corrected.</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=156015923-02092011><FONT color=#0000ff
size=2 face=Arial></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=156015923-02092011><FONT color=#0000ff
size=2 face=Arial>I guess that the folks at Magnum are not totally confident in
this setup so they recommend a back-up safety system which could be either a
diversi9on load or a contactor that disconnects the grid tied inverters all
together.</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=156015923-02092011></SPAN> <BR><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>
<DIV> </DIV><BR>
<DIV dir=ltr lang=en-us class=OutlookMessageHeader align=left>
<HR tabIndex=-1>
<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>Allan
Sindelar<BR><B>Sent:</B> Friday, September 02, 2011 4:45 PM<BR><B>To:</B>
RE-wrenches<BR><B>Subject:</B> Re: [RE-wrenches] AC
Coupling<BR></FONT><BR></DIV>
<DIV></DIV>Brian,<BR>Could you speak a bit more to this, please? My
understanding is that the need with a string (or, I suppose, micro-) inverter
and a battery-based inverter is for a way to disconnect full batteries from
being overcharged when the grid is down and sell is disabled. The SMA approach
is to shift frequency to reduce string inverter output. I thought that the
battery-based (Outback, Magnum) approach is to use a contactor to open string
inverter AC based on voltage (crude, but effective). <BR><BR>So what I
understand is that the PAE inverters shift frequency: do you mean it simulates
the shift that a Sunny Island would do? And if so, why is a diversion load
recommended, and how is it configured into the system? And where can we read
more about how this is designed to work?<BR>Thank you,<BR>Allan<BR> <BR>
<DIV class=moz-signature><FONT face="Times New Roman, Times, serif"><B>Allan
Sindelar</B></FONT><BR><SMALL><A
href="mailto:Allan@positiveenergysolar.com"><FONT color=#000099
face="Times New Roman, Times, serif"><U>Allan@positiveenergysolar.com</U></FONT></A></SMALL><FONT
face="Times New Roman, Times, serif"><BR><SPAN style="FONT-SIZE: 10pt">NABCEP
Certified Photovoltaic Installer<BR>NABCEP Certified Technical Sales
Professional<BR>New Mexico EE98J Journeyman Electrician<BR><B>Positive Energy,
Inc.</B><BR>3201 Calle Marie<BR>Santa Fe, New Mexico 87507<BR><B>505
424-1112</B><BR><A href="http://www.positiveenergysolar.com/"
target=_blank><U>www.positiveenergysolar.com</U></A><O:P></O:P></SPAN></FONT>
<SPAN style="FONT-SIZE: 10pt"><BR></SPAN></DIV><BR>On 9/2/2011 4:39 PM, Brian
Faley wrote:
<BLOCKQUOTE
cite=mid:29F6EE1B9DE8E648A7615A315B840161C9E585@MAGNUMMAIL.MagnumEnergy.local
type="cite"><PRE wrap="">Hi Larry,
Magnum MS PAE inverters do indeed shift the inverter output frequency
when the battery is full in order to disconnect grid-tied inverters used
in AC coupled systems. It was designed to work in conjunction with a DC
diversion load - which is recommended if the system is larger than a
couple panels.
Regards,
Brian Faley
Chief Engineer
Magnum Energy
2111 W Casino Rd
Everett, WA 98204
425-353-8833
<A class=moz-txt-link-abbreviated href="mailto:bfaley@magnumenergy.com">bfaley@magnumenergy.com</A></PRE></BLOCKQUOTE></BODY></HTML>