Grounding

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JDB3

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San Antonio, Texas
Currently bidding on a single family residence (where it is extremely rocky, rock saws even have difficulty) !
Besides grounding to the re-bar in the foundation (it is/will be in direct contact with the earth/ground) , is there any other grounding required. {Impossible to drive a ground rod} ? :?
 
Our AHJ allows us to lay our ground rods horizontally in the trench along side the water/electrical conduit if we can’t drive them vertically.

We do have to meet 250.53 (3) and have 6 feet of separation between the end of the 1st ground drop and the start of the supplemental rod. So we lay an 8ft ground rod in the ditch. The grounding conductor is clamped to this rod and continues along side it. The grounding conductor extends past the 1st ground rod more than 6 feet. The supplemental ground rod is then clamped to the tail end of the grounding conductor. You end up with an assembly more than 22 feet in length.
 
Dzboyce said:
Our AHJ allows us to lay our ground rods horizontally in the trench along side the water/electrical conduit if we can’t drive them vertically.

We do have to meet 250.53 (3) and have 6 feet of separation between the end of the 1st ground drop and the start of the supplemental rod. So we lay an 8ft ground rod in the ditch. The grounding conductor is clamped to this rod and continues along side it. The grounding conductor extends past the 1st ground rod more than 6 feet. The supplemental ground rod is then clamped to the tail end of the grounding conductor. You end up with an assembly more than 22 feet in length.
Click to expand...

That's fine, but a CCE does not require any supplemental grounding electrodes.
 
Dzboyce said:
Our AHJ allows us to lay our ground rods horizontally in the trench along side the water/electrical conduit if we can’t drive them vertically.

We do have to meet 250.53 (3) and have 6 feet of separation between the end of the 1st ground drop and the start of the supplemental rod. So we lay an 8ft ground rod in the ditch. The grounding conductor is clamped to this rod and continues along side it. The grounding conductor extends past the 1st ground rod more than 6 feet. The supplemental ground rod is then clamped to the tail end of the grounding conductor. You end up with an assembly more than 22 feet in length.
Click to expand...

In this area the water pipe, is seldom more than 8" deep, at the most. Thanks
 
JDB3 said:
Currently bidding on a single family residence (where it is extremely rocky, rock saws even have difficulty) !
Besides grounding to the re-bar in the foundation (it is/will be in direct contact with the earth/ground) , is there any other grounding required. {Impossible to drive a ground rod} ? :?
Click to expand...

check with the AHJ, but where driving an 8' spike is not suggested
(underground crude oil lines, lots of them) i've taken a 20' piece
of 4/0 copper, stripped all but 4' of it, brought that up into the
panel, sleeved with a piece of 1" pvc, and tie wired it in the footing.
so you end up with 16' of copper in the footing.

beats driving a spike thru a 3' diameter natural gas line, or a crude
oil line buried.

where we have had *no choice* for a ground rod, we've potholed
using a hydrolick vacuum potholing service, went down 8', dropped
in a chemical ground hypressed to a 4/0 ground wire, and poured
grounding slurry in the hole.

if you have to do this in solid rock, i've seen it core drilled. not fun.
if you ever have to use a chemical ground, make sure you can drop
it without the inspector being there to witness it. you have to remove
the tape on the bottom of the ground, and some inspectors want to
watch it being installed.

the last ones i did were for a data center, we had three of them,
and we had the holes augured, and the inspector came out to watch
us install them.
 
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