Hi, I figure the Subject of this message will make a few people scratch their head! If I place two ground rods 6 feet apart but hit bedrock with the second rod and it is in a 2 foot deep trench which way can i bend the rod? Towards the first or away from the first.
I got it down about 4 feet and it would not go any further.
If you're hitting solid rock, I would think you are screwed either way. I would be willing to bet that the parralleling efficiency would be better if they were angled away from each other, but I would also be willing to bet that you would not get 25 Ohms, even if you drove a half dozen of them!
Ryan Jackson, Salt Lake City
Re: Dual Ground Rod Bending Direction#90807 12/11/0409:47 PM12/11/0409:47 PM
I had a similar situation, however I could get neither rod to go more tham 3 feet anywhere on the property. I was using a Bosch demolition hammer with grd rod attachment. I finally pulled them both out (by twisting them with a pipe wrench) and drove them at a 45 degree angle. They went to the bedrock then slid along on top of it. The inspector didn't even question it.
Re: Dual Ground Rod Bending Direction#90809 12/12/0408:21 AM12/12/0408:21 AM
Bend the rod away from the first. The NEC only requires 8 feet of rod in contact with the earth, six feet apart. If you are concerned with the rod's length, then add a third rod in a triangular pattern.
Re: Dual Ground Rod Bending Direction#90812 12/12/0409:36 AM12/12/0409:36 AM
The trench would have to be at least 2.5 ft deep. The section only talks about driving the rod to a depth of 8 ft, or where bedrock is encountered, buried in a trench. can't see where they talk about bending it, other than having 8 ft in contact with the soil.
Re: Dual Ground Rod Bending Direction#90813 12/12/0411:51 AM12/12/0411:51 AM