I have a question about the 12' X 12' shed scenario. Isn't the minimum allowable feeder size #10? Since it was mentioned that it's feeding TWO overcurrent devices, doesn't that make the branch circuit feeding the shed become a feeder, thus rules for feeders and sub panels would apply? Hey, I am just asking.
I did the same thing with my shed, well sort of. I ran a 1" PVC with four THWN #6, to a 12 circuit sub panel with a 60 amp main breaker (kit). There was a ground rod lying on the ground that I just happened to have sitting there. The first thing the inspector said to me was "what's that rod for?" I explained that it had nothing to do with my sub panel and that I understood that the sub panel had to be fed with a separate EGC. He made me promise that I wouldn't come back and drive/connect it later as he signed off on the job.
In a recent continuing education course I took to maintain my license, we learned that a separate EGC must be provided for sub panels IF there is any chance that any form of other metallic connection between the buildings exists (water, gas, telephone, CATV), etc. If there is no metallic connection, then the sub panel may be wired like a service, with a bonded neutral to rods, etc.
I still stick with the separate EGC since you can't control someone coming in after the fact and adding a metal water line thus turning your installation into a violation.
On another note, SER in a pipe underground is a definite no-no. I don't know how that one passed inspection.
[This message has been edited by EV607797 (edited 11-28-2006).]
