grounding electrodes for separate buildings

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benmin

Senior Member
Location
Maine
Occupation
Master Electrician
400A single meter service on a backboard with 2 200A breakers. supplies 2 buildings. Does each of the 2 buildings require grounding electrodes? Ground rods at the service.
 

iwire

Moderator
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Location
Massachusetts
400A single meter service on a backboard with 2 200A breakers. supplies 2 buildings. Does each of the 2 buildings require grounding electrodes? Ground rods at the service.

If the AHJ considers them separate structures than yes each will need a grounding electrode system.

How far are the buildings from the backboard?
 

benmin

Senior Member
Location
Maine
Occupation
Master Electrician
One is 70' the other is 200'. I was not sure yesterday when I arrived and since they were pouring slabs and both had the panels in the center of the buildings, I drove ground rods and ran CU along with the conduit to the panels. Unfortunately, was unaware of the pouring schedule so was unable to get a UFER ground at the footing
 

infinity

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Location
New Jersey
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Journeyman Electrician
Since there are footings then you are required to use a CEE if they contain 1/2" or larger rebar. It's up to the AHJ to determine how they want to deal with the fact that the CEE wasn't installed.
 

benmin

Senior Member
Location
Maine
Occupation
Master Electrician
Don't forget the disconnecting means required at each building.

Main beaker panels

Since there are footings then you are required to use a CEE if they contain 1/2" or larger rebar. It's up to the AHJ to determine how they want to deal with the fact that the CEE wasn't installed.

Ran #4 GEC to rods on exterior so at least I got the wire to the outside
 

infinity

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Location
New Jersey
Occupation
Journeyman Electrician
Ran #4 GEC to rods on exterior so at least I got the wire to the outside

I many places that wouldn't be acceptable because use of the CEE is required. If the AHJ accepts your two rods then good for you. :)
 
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