"DaveG" wrote in message news
IYEb.598709$HS4.4387613@attbi_s01...
I think it is true, he appears to be installing a sub panel in a building
which is unattached to the building that houses the main panel, and these
buildings do not have anything like metal pipes running between them. If
this assumption is true, then the NEC requires the installation of a ground
rod, and requires the neutral bus be bonded to the ground bus.
I don't believe this to be true. The NEC ALLOWS either a 3-wire or 4-wire feeder in this case. A
3-wire service (as opposed to feeder)would also be allowed in this case. It does not require a
3-wire feeder, you get to choose the method you want. Regardless of the feeder chosen, the building
must have a grounding electrode system and that system connected to the grounding bus. In a 3-wire
feeder or service, the neutral/grounded bus and the grounding bus are one and the same. In a 4-wire
feeder, they are isolated.
If my assumption on the setup of these 2 building is wrong, then I stand
corrected. This is why the original poster needs to check with the local
electrical authority in his area. Get the right info based on your
particular situation, and go from there.
Always a good idea, as the NEC may not apply.
--
Mark
Kent, WA