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<DIV dir=ltr align=left><SPAN class=824255101-02032011><FONT color=#0000ff
size=2 face=Arial>"</FONT><FONT face=Arial><FONT color=#0000ff><FONT size=2>I
have considered using a drop out contactor to isolate the inverters from the
generator following a loss of line voltage.<SPAN
class=824255101-02032011>"</SPAN></FONT></FONT></FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=824255101-02032011><FONT face=Arial><FONT
color=#0000ff><FONT size=2><SPAN
class=824255101-02032011></SPAN></FONT></FONT></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=824255101-02032011><FONT face=Arial><FONT
color=#0000ff><FONT size=2><SPAN class=824255101-02032011>I suggest that method
above as the best. Generators can change frequencies under load and other
conditions, etc. so there would not be such a precise
control.</SPAN></FONT></FONT></FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=824255101-02032011><FONT face=Arial><FONT
color=#0000ff><FONT size=2><SPAN
class=824255101-02032011></SPAN></FONT></FONT></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=824255101-02032011><FONT face=Arial><FONT
color=#0000ff><FONT size=2><SPAN class=824255101-02032011>Line voltage coil
relays are also cheaper and easier to get as compared to frequency
controls.</SPAN></FONT></FONT></FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=824255101-02032011><FONT face=Arial><FONT
color=#0000ff><FONT size=2><SPAN
class=824255101-02032011></SPAN></FONT></FONT></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=824255101-02032011><FONT face=Arial><FONT
color=#0000ff><FONT size=2><SPAN class=824255101-02032011>The voltage drop out
contactor might be easier to implement using the KISS
method.</SPAN></FONT></FONT></FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=824255101-02032011><FONT face=Arial><FONT
color=#0000ff><FONT size=2><SPAN
class=824255101-02032011></SPAN></FONT></FONT></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=824255101-02032011><FONT face=Arial><FONT
color=#0000ff><FONT size=2><SPAN class=824255101-02032011>Good
Luck!</SPAN></FONT></FONT></FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=824255101-02032011><FONT face=Arial><FONT
color=#0000ff><FONT size=2><SPAN
class=824255101-02032011></SPAN></FONT></FONT></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=824255101-02032011><FONT face=Arial><FONT
color=#0000ff><FONT size=2><SPAN
class=824255101-02032011>Maverick</SPAN></FONT></FONT></FONT></SPAN></DIV><FONT
color=#0000ff size=2 face=Arial></FONT><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>Mark
Frye<BR><B>Sent:</B> Tuesday, March 01, 2011 11:20 AM<BR><B>To:</B>
'RE-wrenches'<BR><B>Subject:</B> [RE-wrenches] Home Brew Frequency
Switch<BR></FONT><BR></DIV>
<DIV></DIV><!-- Converted from text/rtf format -->
<P><FONT size=2 face=Arial>Folks,</FONT> </P>
<P><FONT size=2 face=Arial>I am back on the project where I want to install grid
tied inverters (Enphase) on a feeder located downstream of a generator and
ATS.</FONT></P>
<P><FONT size=2 face=Arial>I have considered using a drop out contactor to
isolate the inverters from the generator following a loss of line
voltage.</FONT></P>
<P><FONT size=2 face=Arial>As an alternative, how well might it work to reset
the generator frequency so that it is outside the inverter range? In this way
the inverter would always see the generator as "bad" energy and therefore would
never connect to the generator, only the utility.</FONT></P>
<P><FONT size=2 face=Arial>The nominal frequency range for the inverter is 59.3
to 60.5.</FONT> </P>
<P><FONT size=2 face=Arial>What is the effect on the loads in the household if
the generator frequency is adjusted to say 58 or 62 hertz? Would the higher or
lower number be better? Would this fry everything in the house? I can't see that
making a relatively small change like this would effect the overall impedance
such that a problem with current capacities would be a problem. It seems like
the frequency would be more of a problem for some devices.</FONT></P>
<P><FONT size=2 face=Arial>Anyone have experience with deliberately adjusting
generator frequency away from 60 hertz as described above?</FONT> <BR><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
face=Arial> </FONT> </P></BODY></HTML>