[RE-wrenches] Gray code area

Drake Chamberlin drake.chamberlin at redwoodalliance.org
Sat Jul 26 10:38:16 PDT 2008


We are installing a PV system where an electrical contractor left us 
an easy way to interface with the grid.  The contractor does 
extremely clean work which exceeds NEC requirements, and the local 
code authorities are very happy with him.

What he left us was a 200 A, feed through breaker box that feeds no 
branch circuits.  The building that the breaker box is in is fed by a 
separate, commercial service.  The feeder on the feed through lugs, 
from the box, goes to a residence where the wiring feeds a 200 A 
service disconnect breaker for a residential electrical service.

The sole purpose of the breaker box is to give us a place for the PV 
input.  The potential code issue is that the PV input goes over the 
20% limit.  But there is no way the bus can be overloaded, since it 
is protected by a 200 A breaker on the load side.  Since the building 
is commercial, and fed by a separate service, there would be no 
reason to tap any loads from the box in question.

This doesn't look code compliant, from the wording of the NEC.  Do 
you think we should use the bus bar and backfeed a breaker, or tap in 
ahead of the 200 A breaker to strictly meet code requirements.



Drake Chamberlin
Athens Electric
OH License 44810
CO License 3773
740-448-7328
303-328-5533 





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