What happens?
Hmmm, if I run a 12 AWG all the way back I would say the 12 AWG IG opens at the time of fault and the enclosures of all the IG equipment become 'hot' for just a moment or possibly permanently if the small IG opens on the line side of the fault and welds to an ungrounded conductor on the load side of the fault.
Not real good.
![[Linked Image]](https://www.electrical-contractor.net/ubb/frown.gif)
Perhaps a simple proposal that says the IG that is allowed to run back to XO must be sized per 250.122 for whatever OCP protects the the conductors in the same raceway.
