Yikes - this site is addictive.
Roger -
Your reference is a good spec. If I were building for the Great State of North Carolina, then I would install a loop fed, MV/LV, padmount exactly as shown, and described in the notes, on page 53. Of course one would also note that earlier in the document, only Y-Y transformers are speced for this application. It's a bit curious why NC State Construction office is stuck on Y-Y transformers - but that's a different issue. (I would suspect NC allows other transformer connections where good design dictates)
Okay, back on task:
For this discussion, equally important is Note 2 on page 53 - which follows exactly what I have been saying. It is important to insure there is a sufficient path for fault currents to operate the protective relaying - without vaporizing the primary cable shields. Note 2 on page 53 mandates a primary neutral connection to the shields that accomplishes this. And that is what 250.190 and 250.4.A.5 is about.
I am in no way knocking anything said in posts 2 or 3. It is that (2008) 250.30 applies to "Grounding Separately Derived AC Systems" - which is the secondary. 250.30 does not cover the grounding and bonding issues of the MV primary.
(Back off task) Left to my own, I likely would have picked a different system than specified by NC..... :grin:
ice ...(addictive or not - I really got to go back to work)