grounding from detached electrical service main to MDP.

[rioslives]

i would like to know if it is a code requirement to carry a ground wire from a detached main disconnect, to a main distribution panel that is located inside a house? there is a belief going around that if your main service disconnect is located on an h-frame away from a structure, you dont need carry a grounding wire from that service main into the structure to the MDP. the though is that, grounding can be reestablished in the structure at the main distribution panel. i would really like to put this one to rest. Article numbers would be helpful too. thanks

 

[Dennis Alwon]

Yes you are required to run an equipment grounding conductor to the house from a remote main. You also need ground rod(s) as well which get connected to the equipment grounding conductor and the neutral should be isolated from the equipment grounding conductequipment grounding conductor

Article 250.32(B)

 

[iwire]

i would like to know if it is a code requirement to carry a ground wire from a detached main disconnect, to a main distribution panel that is located inside a house? there is a belief going around that if your main service disconnect is located on an h-frame away from a structure, you dont need carry a grounding wire from that service main into the structure to the MDP. the though is that, grounding can be reestablished in the structure at the main distribution panel. i would really like to put this one to rest. Article numbers would be helpful too. thanks

Prior to the 2008 NEC in most cases you could pull just the circuit conductors without an EGC. With the adoption of the 2008 NEC that option was removed and you will always have to run the EGC. With the change being relatively recent many people still do not know about it.

Compare 2005 - 250.32(B) with 2008 or 2011 250.32(B).