[RE-wrenches] More on AC coupling

[Tump]

Matt, I have long been interested in installing the SMA SI & SBs but I have
a VERY tough time selling $9ks worth of inverters, just to get things
started.
In the system below I would not of hesitated in installing the SMA SI & SB!
I too agree that w/this type of scenario described below, I  would have
given quite a bit of thought to using the SMAs. Can't beat the battery
charging, no charge controllers & expandability.
 Please if there is someone out there that has had experience w/ the SMA SI
& SB let us know if it is all that it is cracked up to be!
With passport in hand, I offer my help if someone out there  has a large
system like this, that will be using the SI & SB/WB  type of set up.
TUMP

-----Original Message-----
From: re-wrenches-bounces at lists.re-wrenches.org
[mailto:re-wrenches-bounces at lists.re-wrenches.org] On Behalf Of Matt Tritt
Sent: Tuesday, November 25, 2008 9:21 PM
To: RE-wrenches
Subject: Re: [RE-wrenches] More on AC coupling


I am curious as to why OutBacks were used for this system instead of using
SunnyIslands and SunnyBoys? From what I can tell about the SI system,
virtually no aspect of battery charging, auto gen-start/stop, and
interactive inverter control has been overlooked - or remains to be
engineered in the field by the installer. Because SunnyIslands have the
ability to "talk" to Sunny (or Windy)Boys, excess energy is taken care of by
"integrated load shedding" - no need for multiple relays, dumpoads and
voltage sensors. :-) The only limitation to these systems (and only in 60 Hz
land) is a maximum of 20 kW single, and 15 kW three phase per autonomous
load. I really like the flexibility of being able to connect all AC inputs
on the same line, as well as having the option to do direct battery charging
from a DC source (as long as you use a shunt to measure current).

I know this doesn't answer your questions, but for similar applications in
the future it would be good to take a close look at the SunnyIsland system.
They're cool.



Matt T

Mark Dickson wrote: 

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.





  _____  


_______________________________________________

List sponsored by Home Power magazine



List Address: RE-wrenches at lists.re-wrenches.org



Options & settings:

http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org



List-Archive:
http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org



List rules & etiquette:

www.re-wrenches.org/etiquette.htm



Check out participant bios:

www.members.re-wrenches.org



  


  _____  



Internal Virus Database is out of date.

Checked by AVG - http://www.avg.com 

Version: 8.0.175 / Virus Database: 270.9.4/1794 - Release Date: 11/17/2008
8:48 AM



  

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org/attachments/20081126/ad15aa82/attachment-0003.html>