Ground rod - angle of installation

kec

Member
Location
CT
Around here the Gr rods sold have a stamp near the top of rod. If you plan on cutting, do it at the bottom of rod.
A sharp EI will catch it. Also its very hard to recreate a mushroomed head on a cut rod.
 

kwired

Electron manager
Location
NE Nebraska
I can understand the "sphere of influence" would get reduced at an angle. Up to maybe 22.5 degree angle probably isn't effected by that much at all in many cases. Up to 45 degrees probably still not too significant but starting to get there. Code doesn't say anything but I would think if you went with a 10 foot rod that you have resolved some of the potential issue, though maybe have complicated any "rock bottom" problems you might be running into.

All that said would be interesting to see some tests on overall resistance of each mentioned situation in similar soil conditions. There is a reason NEC says you don't need any additional rods after the second even if resistance is still over 25 ohms. If a designer still requires lower resistance it is for other reasons, inspector is usually only concerned about NEC, though from posts on this site sounds like some also enforce the designers specs, which I think is BS, the designer should be the one concerned if his specs are followed inspector should only be concerned the installation complies with NEC.
 

Hv&Lv

Senior Member
Location
-
Occupation
Engineer/Technician
But the code says it can be buried at ANY angle when you get to the nuts and bolts of it...

if you have rock and bury the rod in a trench, what angle is that?
 
But the code says it can be buried at ANY angle when you get to the nuts and bolts of it...

if you have rock and bury the rod in a trench, what angle is that?
Right the rule is kinda dumb in that its hard to enforce. Perhaps some inspectors will cite it thinking you will be honest and say you didnt try it vertical first. I would just cite that code section and say I tried it vertical and hit bedrock, so I redrove it at an angle.
 

oldsparky52

Senior Member
The electrode shall be installed such that at least 2.44 m (8 ft) of length is in contact with the soil. It shall be driven to a depth of not less than 2.44 m (8 ft) except that, where rock bottom is encountered, the electrode shall be driven at an oblique angle not to exceed 45 degrees from the vertical or, where rock bottom is encountered at an angle up to 45 degrees, the electrode shall be permitted to be buried in a trench that is at least 750 mm (30 in.) deep. The upper end of the electrode shall be flush with or below ground level unless the above ground end and the grounding electrode conductor attachment are protected against physical damage as specified in 250.10.
Okay, so you 1st drive it vertical, then if you hit rock you try an angle not to exceed 45 degrees, then if you can't get it installed you dig a trench 30" deep and install it there, but the upper end needs to be up near grade so ... what, bend a 30" stub and install it?
 

infinity

Moderator
Staff member
Location
New Jersey
Occupation
Journeyman Electrician
Okay, so you 1st drive it vertical, then if you hit rock you try an angle not to exceed 45 degrees, then if you can't get it installed you dig a trench 30" deep and install it there, but the upper end needs to be up near grade so ... what, bend a 30" stub and install it?
Where does it say that the upper end needs to be near grade?
 

oldsparky52

Senior Member
Where does it say that the upper end needs to be near grade?
"The upper end of the electrode shall be flush with or below ground level unless the above ground end and the grounding electrode conductor attachment are protected against physical damage as specified in 250.10. "

That's how I understood this, did I misunderstand?

Now that I look at it again (thanks for making me) I guess it doesn't say what I think it says?

But it means someone has to backfill after inspection so another trip or the homeowner does it?
 

Btbamfan4

Member
Location
Monroe, NC
Occupation
Electrician
That’s how I read it as well.

It’s essentially saying that a rod driven at an angle is only sufficient if you hit rock on a vertical attempt first. There are no laws of physics or engineering to support that, that I know of!
So does that mean the inspector has to watch us drive these ground rods to know if we hit bedrock? Lol no sarcasm intended
 

GoldDigger

Moderator
Staff member
Location
Placerville, CA, USA
Occupation
Retired PV System Designer
FWIW, the code does not allow you to go to angled driving if you hit a rock. You have to hit "rock bottom", which is IMHO a more restrictive, although still unclear, criterion. As a practical matter beyond a certain density of rock in soft earth you will not be able to get the rod past all of the rocks in the way even though you have not reached a layer of solid rock.
 

goldstar

Senior Member
Location
New Jersey
Occupation
Electrical Contractor
Sorry to be harsh but the code says what it says and what you did was not code compliant. Apparently you feel the inspector should have let it go. Despite how many dumb code rules there are, I think it's best that inspectors follow the rules and don't play wild west Shariff.
I know the Code says what it says and that technically speaking I am in violation. If I were a hack and had numerous violations, adding the ground rod angle to the list would not seem so bad. However, when you look at the entire project and see that everything is neat, clean, workmanlike and to the letter of the Code, putting a red sticker on a panel and thereby hanging up your $$$ just to prove to the HO that you are the EI and you have the authority to do this is purely an ego trip.

That said, I haven't spoken to the EI as yet and rather than work myself up into a lather I've been mulling over several different approaches in my mind in an attempt to handle this diplomatically. I'm not the most tactful person so I need to write these things down on paper and have them available when I do speak to him. I want to thank you all for your responses - they were really helpful.
 

oldsparky52

Senior Member
I'm not the most tactful person so I need to write these things down on paper and have them available when I do speak to him.
Man I get this, have lived this, and it's why I am a recluse now.

I wish you good luck, try to watch the tone of voice. Please let us know what happens.

:) I bet you make sure you have a bender with you for the next time (straighten that bad boy out like was suggested earlier).
 

goldstar

Senior Member
Location
New Jersey
Occupation
Electrical Contractor
Man I get this, have lived this, and it's why I am a recluse now.

I wish you good luck, try to watch the tone of voice. Please let us know what happens.

:) I bet you make sure you have a bender with you for the next time (straighten that bad boy out like was suggested earlier).
Thanks. I will post the result. I may either bend the rod or just pound another one in. We'll see. I'm almost at the end of my career so ticking someone off really doesn't bother me. I have a fellow EC in my contractors association who is 95 and still going. He plans to renew his license and business permit in March. He's my idol :cool:
 

kwired

Electron manager
Location
NE Nebraska
I know the Code says what it says and that technically speaking I am in violation. If I were a hack and had numerous violations, adding the ground rod angle to the list would not seem so bad. However, when you look at the entire project and see that everything is neat, clean, workmanlike and to the letter of the Code, putting a red sticker on a panel and thereby hanging up your $$$ just to prove to the HO that you are the EI and you have the authority to do this is purely an ego trip.

That said, I haven't spoken to the EI as yet and rather than work myself up into a lather I've been mulling over several different approaches in my mind in an attempt to handle this diplomatically. I'm not the most tactful person so I need to write these things down on paper and have them available when I do speak to him. I want to thank you all for your responses - they were really helpful.
I agree it is sort of stupid to fail if that particular item is all that could be found, possibly depending on what angle we are talking here.

Long time ago when I was working for someone else we were sent a correction notice, job where several hundred feet of MC cable was installed and only thing on the correction notice was two places that violated cable support rules. Was a project I wasn't involved with so I don't know much more than that, but could easily have been the supports were just 4-6 inches too far apart in those locations - at that time this particular inspector would have called such a thing out. Nobody knew what he was trying to prove back then. He eventually got enough pressure from complaints to his superiors (AFAIK) and was told to lighten up a little on some those types of things.
 

Hv&Lv

Senior Member
Location
-
Occupation
Engineer/Technician
That would be 90 degrees - from the generally required "vertical"
No, usually a rod buried in a trench would be horizontally placed. That would be 0 or 180, now wouldn’t it..
Depending on how level your ditch is...😉
 

FionaZuppa

Senior Member
Location
AZ
The technicals aside, was the goofy verbiage fixed in any later NEC version?

You're allowed up to a 45° angle you've exceeded that?
Not sure it was mentioned, but that ver of NEC even states things oddly. The deg of rod is really a deg from the ground plane, thus "vertical" is 90deg, so in essence I would say the correct verbiage should be "no less than 45deg" w/o the unnecessary need to use the word "vertical".
 

Hv&Lv

Senior Member
Location
-
Occupation
Engineer/Technician
No, usually a rod buried in a trench would be horizontally placed. That would be 0 or 180, now wouldn’t it..
Depending on how level your ditch is...😉
That would be 90 degrees - from the generally required "vertical"
Wait! Just reread the post. Edit time ran out.

you are right (as usual) 👍
 
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