M-C branch plugs: Legal? Safe? [RE-wrenches]

[Jay Peltz, Peltz Power]

<x-flowed>

Hi William,

Where is this subtraction of 1 string located in the code?

thanks,

jay
peltz power
On Feb 4, 2008, at 10:18 PM, William Miller wrote:

>
> Mark:
>
> I think the point here is that the manufacturers of grid-tie  
> inverters have certified and tested that their inverters can not  
> back feed power from the grid into the PV arrays, even in a  
> catastrophic failure.  I belive the manufacturers of charge  
> controllers have not provided this certification, ergo you must  
> protect all battery strings with fuses.
>
> Assuming your inspector is knowledgeable on such matters, to be  
> allowed to install 2 or 3 strings without fusing, you need to find  
> a document from the inverter manufacturer (and I believe, certified  
> from a testing agency) that this back feed can never happen.  My  
> web site includes such a declaration from Xantrex.  I can no longer  
> find the Fronius or SMA declarations.  If the manufacturer's  
> representatives e-mail them to me, I can post them at:
> http://mpandc.com/resources/resources.html
>
> Deleting a fused combiner from a grid tie installation is a  
> substantial savings in equipment and labor, so this exception is  
> valuable to  understand and apply.
>
> I hope this information helps.
>
> William Miller
>
> PS:  A note to Ray Walters:
>
> When calculating string currents, you are allowed to subtract one  
> string.  I think this is because in a string failure, you don't  
> need to account for the current from that string.  Therefore, you  
> can combine THREE strings of Solar World modules without fusing.   
> Solar World modules are unique in this regard.
>
> WM
>
>


- - - -
Hosted by Home Power magazine

To send a message: RE-wrenches at topica.com

Archive of previous messages: http://lists.topica.com/lists/RE-wrenches/read

List rules & how to change your email address: www.mrsharkey.com/wrenches/etiquette.php

Check out participant bios: www.mrsharkey.com/wrenches/

Moderator: michael.welch at homepower.com
--^----------------------------------------------------------------
This email was sent to: michael.welch at re-wrenches.org

EASY UNSUBSCRIBE click here: http://topica.com/u/?bz8Qcs.bz9JC9.bWljaGFl
Or send an email to: RE-wrenches-unsubscribe at topica.com

For Topica's complete suite of email marketing solutions visit:
http://www.topica.com/?p=TEXFOOTER
--^----------------------------------------------------------------

</x-flowed>