[RE-wrenches] Outback AC coupling Sunpower?

[Ray Walters]

Corey;

Would you mind sharing what relay didn't work, and which ones did, along 
with inverter output current?  Since the relays will be running for 
hours at inverter rated output,  my thinking would be to oversize the 
relay by at least a factor of three.  I might try Outback's relay/ 
breaker ( ROCB) if possible.

Thanks again for sharing,

R.Ray Walters
CTO, Solarray, Inc
Nabcep Certified PV Installer,
Licensed Master Electrician
Solar Design Engineer
303 505-8760

On 7/31/2013 12:24 PM, Corey Shalanski wrote:
> Mac,
>
> We have installed about ten AC coupled Magnum systems over the past year.
>
> Overcharge protection is accomplished by frequency shift, but Magnum 
> recommends an auxiliary form of battery management. The cheapest way 
> to do this is to program the relay driver on the Magnum advanced 
> remote control (ARC) to open/close a solid state relay at specified 
> battery voltage setpoints - similar to what Kelly mentioned. 
> Unfortunately the "cheapest way" sometimes comes back to haunt us in 
> the form of unanticipated extra costs. We had two customer callbacks 
> indicating their inverter had mysteriously shut down - site visit 
> revealed a fried relay in each case.. so I would recommend at least 
> investing in a good quality relay if you choose this route.
>
> One other thing we have learned is that not all grid interactive 
> inverters are compatible with the Magnum inverters. Specifically Power 
> One Aurora string inverters cannot seem to synchronize in off-grid 
> mode - we have had to switch out Auroras on two projects because of 
> this. We have had no such synchronization issues with SMA inverters so 
> far.
>
> --
> Corey Shalanski
> Joule Energy
> New Orleans, LA
>
>
>
> On Wed, Jul 31, 2013 Mac Lewis <maclewis1 at gmail.com 
> <mailto:maclewis1 at gmail.com>> wrote:
>
>
>     Here is a paper on AC coupling the magnum.
>     http://www.wholesalesolar.com/pdf.folder/inverter%20pdf%20folder/MagnumACcoupling.pdf
>
>     The key is to connect the AC input terminals on the Magnum to the main
>     panel (or a panel closer to the utility feed) and then feed the
>     utility
>     interactive inverter to a subpanel that is connected to the AC output
>     terminals on the Magnum.  Under normal operation, the Magnum
>     passes the
>     power through and the utility interactive inverter is connected to the
>     grid.  If the grid goes down, the internal relays isolate the
>     Magnum and
>     the critical load panel from the grid and the Magnum starts to
>     make a sine
>     wave that the UI inverter will export power to.
>
>     You have to keep the critical load panel amperage below the pass
>     through
>     rating on the internal relays on the Magnum, and the grid connected
>     inverter needs to have a lower output than the Magnum (I think by
>     10%).
>      Also, I'm not sure if the diversion controller Magnum has been
>     working on
>     is out yet or not.
>
>     I've never done this, but I am about to.  Any wrenches have experience
>     doing an AC coupled magnum?
>
>
>
> _______________________________________________
> List sponsored by Home Power magazine
>
> List Address: RE-wrenches at lists.re-wrenches.org
>
> Change email address & 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
>

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org/attachments/20130731/83667eab/attachment-0003.html>