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<DIV><SPAN class=964180105-15052015><FONT face=Arial color=#0000ff size=2>We
have lots of C40's out there, though not generally with such small PV input,
don't recall any issues with drifting. I just installed one and verifying the
potentiometer settings with DVM was bang on. </FONT></SPAN></DIV>
<DIV><SPAN class=964180105-15052015><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=964180105-15052015><FONT face=Arial color=#0000ff size=2>For a
recommended substitute, consider the Blue Sky units such as:</FONT></SPAN></DIV>
<DIV><SPAN class=964180105-15052015><FONT face=Arial color=#0000ff size=2><A
href="http://www.blueskyenergyinc.com/products/details/solar_boost_1524ix">http://www.blueskyenergyinc.com/products/details/solar_boost_1524ix</A></FONT></SPAN></DIV>
<DIV><SPAN class=964180105-15052015><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=964180105-15052015><FONT face=Arial color=#0000ff size=2>We use
in lots of industrial telemetry sites with similar configs - small PV with AGM
batts. Solid performing controller with a bonus of some datalogging.
</FONT></SPAN></DIV>
<DIV><SPAN class=964180105-15052015><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=964180105-15052015><FONT face=Arial color=#0000ff
size=2>Kevin</FONT></SPAN></DIV>
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<DIV class=OutlookMessageHeader dir=ltr align=left><FONT face=Tahoma
size=2>-----Original Message-----<BR><B>From:</B> RE-wrenches
[mailto:re-wrenches-bounces@lists.re-wrenches.org]<B>On Behalf Of
</B>Drake<BR><B>Sent:</B> May 14, 2015 4:12 PM<BR><B>To:</B>
re-wrenches@lists.re-wrenches.org<BR><B>Subject:</B> [RE-wrenches] Xantrex
C-40 Drifting<BR><BR></FONT></DIV>I have a Xantrex C-40 that won't keep its
settings. It is important that it does because it is for a maintainer array
(80 W) on an AGM battery bank, on an AC coupled backup system. Not only could
high voltage damage the batteries, but when the voltage goes over 30 Volts,
the AUX relay opens and the grid tie inverter is isolated from the
grid.<BR><BR>After numerous sessions of reprogramming, Xantrex tech support
sent me a new unit. The problem persisted as before. A new temperature sensor
helped, but the settings still drift. It seems that rebooting the charge
controller helps for a day or so, but then it drifts again.<BR><BR>The
potentiometer settings are way below the calculated setting for 29.4 V, but it
still peaks in the high 30s. I check the temperature compensated voltages on
the Outback Mate, and the temp compensated voltage runs high. <BR><BR>In a
related side issue, the AUX relay of the FX inverters is not based on
temperature compensated voltage, which makes setting AC coupling charge set
points more problematic. <BR><BR>Has anyone experienced a C-40 CC that drifts
in its settings. What would be a good (inexpensive) charge controller to
accurately control 80 W of PV?<BR><BR>Thanks,<BR><BR>Drake <BR><BR><A
name=_MailAutoSig></A>Drake Chamberlin<BR><I>Athens Electric LLC<BR>OH License
44810<BR>CO License 3773<BR>NABCEP Certified Solar PV
<BR>740-448-7328<BR></I><A
href="http://athens-electric.com/">http://athens-electric.com/</A>
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