[RE-wrenches] More on AC coupling

[Mark Dickson]

Hello Wrenches,

On the heels of the previous thread:

We just got finished installing a system that utilizes an Outback Quad stack
and a 5.2kW array coupled to the AC panel via a Fronius IG5100--due to a
long home-run.  The VFX's are wired into the home in their traditional
manner, providing the "grid" for the Fronius.  As the solar comes in, excess
power not used in the home back feeds the batteries through the VFX's.  I
have a series of relays operating dump loads and finally a power cut-off for
when the batteries reach critical level.  We installed the system yesterday
and turned it on for a test run (then back off to power it up in 2009 for
the ITC's)-it worked great!

 

I have a couple questions for you all:

*	Seems how we are back feeding the inverters and forfeiting their
charge control, where would you set the dump loads to kick on? 

*	For now I have them set at: 1st load to kick on at float voltages,
2nd to kick on at bulk voltages and 3rd to kick the solar power off at the
EQ voltages.  Does this make sense?  The bank is made up of Rolls 4ks-25ps
batteries. 

*	Following a recent discussion on the Wrenches list with a similar
system:  Do I need to worry about back feeding the generator if it is runnin
in the morning when the sun comes up?  Do I need a relay that will shut it
down when solar comes on line? 
*	I plan on setting the Absorb and Float set times to a miimum.  Would
you recommend this? 

 

Thanks for your input!

 

Mark Dickson

Oasis Montana Inc.

 

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org/attachments/20081125/49274796/attachment-0002.html>