[RE-wrenches] Gray code area

[jay peltz]

Hi Drake,

do you know how this is all done in say Germany?
I realize they have different codes ( hopefully) but how do they  
address the main issue of potential bussbar overloading?

thanks,
jay

peltz power
On Jul 30, 2008, at 10:24 AM, Drake Chamberlin wrote:

> Thanks to All who have replied,
>
> First, to answer William's question
>
> "What is a "feed-through" breaker box and what are "feed-through"  
> lugs?"
>
> A feed through panel is the type of service equipment often  
> installed on pre-manufactured homes, where a main switch is needed  
> outside the building, and a limited number of loads, fed from the  
> outside, are also supplied.  On the bottom of the busbar,  there  
> are lugs equivalent to the lugs for the service entrance cables.
>
> This is useful when feeder is to be installed to supply the breaker  
> panel in the premise that is equal to the total service amperage.   
> No breaker is needed for the run to the subpanel inside, since the  
> wiring will be equivalent to the service cable.   It is similar in  
> function to a disconnect switch, but will typically have 4 to 8  
> breaker spaces.
>
> The situation in this project is that a feed through panel is in a  
> separate building from the building to be supplied from that  
> panel.  The building this panel is in has a separate electrical  
> service, which is commercial.  The service for the residence comes  
> in through a separate meter, located on this  same commercial  
> building, then goes to the feed through panel.  This panel was  
> installed for us, for the sole purpose of allowing a feed from the  
> solar array.
>
> The issue here is that the busbar will have 200 amps from the main,  
> and over 40 amps from the solar.  No power is to be taken from the  
> residential service to feed the commercial building.   There is no  
> possibility of an overload on the busbar because the house has a  
> main 200 A breaker that will limit the load from the panel.
>
> It could be argued that since the line to the house will have up to  
> 240 amps available on a 200 amp service, that is too much.  I would  
> argue that a standard service drop can supply 10,000 amps  
> instantaneously.
>
> The box is strictly to be used as an AC combiner and feed for two  
> inverters.  By the letter of the NEC, it does not seem to be code.   
> I'm going to use Kent's suggestion and use a label, after running  
> it by the AHJ beforehand.
>
>
> -Drake
>
>