Ground rod re-do

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JHZR2

Member
Location
New Jersey
Occupation
Power Systems Engineer
Background: older home, all k&t removed, 200A QO panel, romex service throughout. Passed inspections for current owner when purchased 10+ yeats ago.

Main panel has grounding conductors to a rod immeduately outside (solid copper conductor undersized; will upgrade to 2 or 4 awg), used to have two rods within 2' from each other on same conductor. Panel also has heavy cooper conductor run to connect to water service near entry into house (all jumpers in place but connection location is between meter and underground).

Main panel feeds 60A subpanel via 2AWG aluminum conductor of approximately 35'.

Need to add a second ground rod. The reason the old second one was removed was due to the installation of a paver driveway (the ground rods are within 6" of the house and in the driveway which goes up to the foundation; the first rod that is still in use is a direct veryical drop from meter and service entrance, which has panel directly inside; the rod is below grade, protected by being below a cut out section of paver). No point in cutting a paver for the second rod when its wrong.

So the options are:

1) verify less than 25 ohm and leave one plus the water pipe.

2) run second rod from subpanel so it has sufficient spacing from the first rod

3) run heavy copper conductor to a location sufficiently far from the first rod, and not on the driveway, to add rod directly to main panel.

As mentioned, will correct conductor for the existing ground rod. Estimate that to be <4' of solid copper. Similarly, if #3 was done, thecsecond rod would have 35' of Al plus <4ft of Cu to the rod. If #2 was done, estimate >16' of copper conductor to reach appropriate and aesthetically pleasing location.

Which would you choose and why???

Thanks!
 
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Smart $

Esteemed Member
Location
Ohio
Closest accessible location not less than 6 feet from "first" ground rod. I'd just pull up pavers to install the rod and GEC, both below paver level and acorn listed for direct burial, then reinstall pavers (or have them reinstalled).
 

infinity

Moderator
Staff member
Location
New Jersey
Occupation
Journeyman Electrician
I would forget testing the single rod and add a second rod somewhere at least 6' from the first rod. Then run a #6 copper GEC back to the service or instead of that a bonding jumper to one of the existing (rod or water pipe) GEC's or electrodes.
 

102 Inspector

Senior Member
Location
N/E Indiana
Occupation
Inspector- All facets
I do not think running to a ground rod from the subpanel is an option. Subpanel should have 4-wire and isolated ground from main panel. No grounding electrode should come from the subpanel.
 

kwired

Electron manager
Location
NE Nebraska
If the driveway is pavers this is easy.

As has been mentioned why not just put a second clamp on the first rod and extend to the second rod?

6 AWG copper is all that is necessary regardless of what size the service is.
 

JHZR2

Member
Location
New Jersey
Occupation
Power Systems Engineer
Agree with the other posts.

Will add, #6 copper is all that is required (if out of harms way). No need to run #4 or #2.


So, the first one vertically dropping from the entrance to the home to the ground, maybe 2', bolted to the wall is out of harm's way. If I had another running along the ground from that to a spot 6'+ away, where the pavers meet the foundation, is that out of harm's way?
 

Smart $

Esteemed Member
Location
Ohio
So, the first one vertically dropping from the entrance to the home to the ground, maybe 2', bolted to the wall is out of harm's way. If I had another running along the ground from that to a spot 6'+ away, where the pavers meet the foundation, is that out of harm's way?
If you would call physical damage to the GEC an accident, then IMO it was not really exposed to physical damage.

IMO exposed to physical damage means damage is likely to occur. :D

Nevertheless, you will make your own assessment, so look at 260.64(B).
 
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