[RE-wrenches] combiners and the 120% rule

[Drake]

I think that technically, the combiner panel is not compliant if the 
possible feeds from various sources exceed 120% of the busbar rating.

Inspectors have been reasonable on this issue, as it can be done 
safely.  The solution, if the AHJ won't accept a small combiner panel 
is to use a panel with a higher busbar rating and a main breaker 
small enough so that the combination of the main and solar feeds does 
not exceed 120% of the busbar rating.  It can result in some 
awkwardly large and technically unnecessary boxes.


At 07:29 AM 6/27/2012, you wrote:
>If the combining panel is next to the main panel, can you use a Main 
>Lug panel as the combining panel or does it need a main breaker? I'm 
>not sure what the purpose of the main breaker would be if there are no loads.
>
>--
>Chris Mason
>President, Comet Systems Ltd
><http://www.cometenergysystems.com>www.cometenergysystems.com
>
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Drake Chamberlin
ATHENS ELECTRIC LLC
OH License 44810
CO license 3773
NABCEP Certified PV
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