Grounding and neuteral bonding

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gold coast

Member
Location
California
I recently installed a new 200 amp service for a house on a free standing backboard. From the service I am feeding the house, about 80 feet away and a garage, about 150 feet away. The house and garage are both underground runs they each have sub panels and ufer grounds. I did not run a ground wire with the feeds, just the two hots and a neuteral. The inspector says I need a ground wire run with the feeders. The way I read the code it says I "can" run a ground conductor and keep the neuteral seperate at the house and garage "or" I can use the ufer grounds at the two structures and ground the neuteral at the sub panels. Is this correct?
Thanks for your help.
 

iwire

Moderator
Staff member
Location
Massachusetts
Re: Grounding and neuteral bonding

The article you are referring to is 250.32(B)(2), I think the important part of this is section 2 which I highlighted.

250.32(B)(2) Grounded Conductor.

Where

(1) an equipment grounding conductor is not run with the supply to the building or structure,(2) there are no continuous metallic paths bonded to the grounding system in both buildings or structures involved, and (3) ground-fault protection of equipment has not been installed on the common ac service, the grounded circuit conductor run with the supply to the building or structure shall be connected to the building or structure disconnecting means and to the grounding electrode(s) and shall be used for grounding or bonding of equipment, structures, or frames required to be grounded or bonded. The size of the grounded conductor shall not be smaller than the larger of
(1) That required by 220.22
(2) That required by 250.122
Can you say that "there are no continuous metallic paths" between these three structures.

This could be metal water mains, cable TV service, etc. or even your raceway if it is RMC or IMC

If you can say there are no other paths for current to flow on I believe you are correct.

Did you ask the inspector why he was failing this as installed, maybe he sees some parallel paths for current to flow on

Or maybe he is like myself, who is just not used to seeing 3 wire feeders for 240/120 load side equipment.

I am not saying you are wrong, just that many of us are much more used to seeing a separate ground and neutral on anything past the service disconnect.

Good Luck.
 

pierre

Senior Member
Re: Grounding and neuteral bonding

Bob is correct, just for emphasis, a metallic path between the buildings can also be a phone line, any metallic path would then require the equipment ground conductor to be run with the other circuit conductors.

Pierre
 
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