installing a ground rod

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jph320

Member
Location
Cinnaminson nj
Occupation
Electrician
The inspector wants a ground rod for a upgraded service for a auto garage. The foundation is solid concrete all around and i asume pretty deep. How do a drive one in or do they make a pretty long drill bit?
 
kwired

kwired

Electron manager
Location
NE Nebraska
Jim W in Tampa said:
He should have also required you to bond to the rebar in that slab. Simply drive rod a foot away from footer
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jph320 said:
The inspector wants a ground rod for a upgraded service for a auto garage. The foundation is solid concrete all around and i asume pretty deep. How do a drive one in or do they make a pretty long drill bit?
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I'm assuming the footing was already there and he is just upgrading service.

250.50 exception does not require him to disturb the existing concrete to bond the rebar.
 
J

jph320

Member
Location
Cinnaminson nj
Occupation
Electrician
the shop is on a city block surrounded by other factories. not a patch of dirt anyware. I drilled about 1 1/2 feet and still all concrete
 
Split Bolt

Split Bolt

Senior Member
Location
Northern Virginia
Cut a ground rod about 2" longer than the depth of your hole, put on your clamp and mushroom the heck out of the end of the rod with your hammer!:)


I"M KIDDING!, I'M KIDDING!:grin:
 
M. D.

M. D.

Senior Member
How about a copper waterline? doesn't seem likely to be changed to plastic that's for sure , and as an electrode it is much better ... are you sure they did not use a CCE originally? And is there a sub level area ,. perhaps you could drive a 10' rod through the side wall?
 
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H

hotwire1955

Senior Member
Location
nj
M. D. said:
How about a copper waterline? doesn't seem likely to be changed to plastic that's for sure , and as an electrode it is much better ... are you sure they did not use a CCE originally? And is there a sub level area ,. perhaps you could drive a 10' rod through the side wall?
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you still need a supplemental electrode specified in 250.52 (A)(2) through(A)
(8)
 
J

jph320

Member
Location
Cinnaminson nj
Occupation
Electrician
No guys there is no sub basement to the place and the inspector wants additional to the water pipe beacuse the water pipe is morehan 5 feet away from it's entrance to the building. 250.52 A1
 
M

Mulrooney

Member
only once did I see 1-1/2' of concrete slab, it was supporting a very, very heavy machine. Are you sure you are not too close to the wall and hiting the footing? Did you try putting the rod in with a big hammer drill and ground rod drive bit? It will break through if your near the end of the concrete.
 
M. D.

M. D.

Senior Member
iwire said:
I know you know which makes me more confused why you suggested it.:-?
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Suggested what? , I am merely pointing out the fact that the major reason we need the SGE is because the water line may be changed to plastic in the future.
Is there structural metal ?

EC&M

Metal frame of the structure. If you use the structural frame as an electrode, it must be of substantial cross-sectional area. Bond it to an electrode as defined in 250.52(A)(1), (3), or (4) unless:

10 feet or more of a single structural metal member is in direct contact with the earth or encased in concrete that is in direct contact with the earth.

The authority having jurisdiction (AHJ) approves some other means.
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M. D.

M. D.

Senior Member
jph320 said:
No guys there is no sub basement to the place and the inspector wants additional to the water pipe beacuse the water pipe is morehan 5 feet away from it's entrance to the building. 250.52 A1
Click to expand...

Not sure I understand this??
 
J

jph320

Member
Location
Cinnaminson nj
Occupation
Electrician
the building is cinder block. the only metal beams are the headers. I drilled about 1 1/2 feet from the outer wall and about 1 1/2 deep.
 
M. D.

M. D.

Senior Member
Hmmmmm, any other piping in direct contact with the earth?

Also this quote
EC&M

Metal frame of the structure. If you use the structural frame as an electrode, it must be of substantial cross-sectional area. Bond it to an electrode as defined in 250.52(A)(1), (3), or (4) unless:

10 feet or more of a single structural metal member is in direct contact with the earth or encased in concrete that is in direct contact with the earth.

The authority having jurisdiction (AHJ) approves some other means.
Click to expand...
was based on the 2005 nec A(1) was removed ,. but you don't have steel any way
 
P

poeboy

Member
Location
Los Angeles Metro area
Maybe you got lucky and hit the hole they used to pour the extra 1/2 yard of concrete in after the pour was done.

I think I'd try another hole about 10 feet away from that one. If it turns out to be the same thickness they you may wind up using a regular coring bit with a coring drill.... I've never had to use one vertically for more than about 16 inches. Once I did a horizontal core that turned out to be nearly 40 inches of building below grade..... THAT was far from a fun job.....
 
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