[RE-wrenches] Changing from 2 battery cable setup to single cable for Outback?

Ray Walters ray at solarray.com
Sat Aug 9 14:54:47 PDT 2014


Midnite makes several good things for this situation, including their E 
Panel for the Radian, which I'm sure is better than Outback's version.
They also have low cost AC bypass switch assemblies, and I've recently 
used their PV Combiner boxes for AC distribution with AC rated DIN rail 
mountable breakers.
I wish they made an indoor version though with more KOs.

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

On 8/9/2014 12:24 PM, William Miller wrote:
>
> Scot:
>
> I won't comment on the battery wiring sizing here.  What I will say is 
> that the Radian distribution panels are poorly designed.  I have 
> numerous complaints and if you want detail I can dig up my report to 
> Outback.  Short answer is I suggest anyone do the following:
>
> 1.Do not order a prewired system.
>
> 2.Remove all AC distribution components from the Outback Radian power 
> panel and relocate them to two outboard off-the-shelf breaker panels.  
> One will be Gen fed and one will be Inverter fed.
>
> 3.Create your own interlock to provide for generator bypass.  This can 
> use an off-the-shelf breaker interlock but you can do better with a 
> small aluminum plate, jig saw and drill press.  I can provide more 
> insight on this as well.  Will build a lot of custom interlocks and we 
> are very pleased with the results.
>
> William Miller
>
> Gradient Cap_mini
> Lic 773985
> millersolar.com <http://www.millersolar.com/>
> 805-438-5600
>
> *From:*RE-wrenches [mailto:re-wrenches-bounces at lists.re-wrenches.org] 
> *On Behalf Of *scot.arey at solarcentex.com
> *Sent:* Saturday, August 09, 2014 11:11 AM
> *To:* re-wrenches at lists.re-wrenches.org
> *Subject:* [RE-wrenches] Changing from 2 battery cable setup to single 
> cable for Outback?
>
> Greetings,
>
> My team is installing a Outback Radian 8048 to replace an older 
> dual Xantrex/Trace 5048 inverter setup where one failed either due to 
> lightning or old age.  We did not install the original system.
>
> Battery setup is 48V bank with Rolls 6CS21P Series 5000 batteries (to 
> be quite honest, largest I've ever seen - 271 lbs per battery, 683AH, 
> 1740CCA).  4 parallel strings of 4 batteries.
>
> The cable from the battery bank to the inverter is two 4/0 RHH 
> cables.  Two for the positive cables and two for the negative cables.  
> I keep asking the original designer why he used two cables (4 
> total) and I never quite get the same, straight answer.
>
> Now enter the new Radian inverter and its load center. While there is 
> a positive load plate to bolt the positive cables onto, there really 
> is not lots of space through the load center to maneuver the cables. 
> Even less for the single negative bus bar connection. The load center 
> has dual 175A circuit breakers built in (one for each of the 4KW 
> inverters that makes up the 8048)
>
> So my question(s) is (are): can I go from a  pair of 4/0 cables to a 
> single 2/0 RHH cable to enter the load center and carry the battery 
> load?  Why would a designer use dual cables?  How does one calculate 
> the battery short circuit current in order to even determine cable 
> ampacity requirements?  Or for that matter, to determine if the load 
> center 175A dual circuit breakers are of sufficient size to negate the 
> need for additional OCPD IAW 694.70C?
>
> I want to make sure I'm doing this right and whenever I'm upgrading a 
> component, I try to remember that other components likely need 
> adjust/upgrading...thanks all.
>
> Howard "Scot" Arey
>
> Solar CenTex
> 254-300-1228
>
> "Use the Texas Sun!"
>
>
>
> _______________________________________________
> List sponsored by Redwood Alliance
>
> List Address: RE-wrenches at lists.re-wrenches.org
>
> Change listserver email address & settings:
> http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
>
> List-Archive: http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html
>
> List rules & etiquette:
> www.re-wrenches.org/etiquette.htm
>
> Check out or update 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/20140809/b092c34c/attachment-0002.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: image/jpeg
Size: 1460 bytes
Desc: not available
URL: <http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org/attachments/20140809/b092c34c/attachment-0002.jpe>


More information about the RE-wrenches mailing list