# Attachment to Ground Rod



## bbedard (Jun 27, 2011)

Does NEC 2008 or 2011 specify where to attach to the ground rod? That is is Power supposed to be closest to Ground on the rod or does it matter?


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## Jlarson (Jun 28, 2009)

bbedard said:


> That is is Power supposed to be closest to Ground on the rod or does it matter?


Ah, why are you connecting power to a ground rod? :blink:


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## bbedard (Jun 27, 2011)

Let me restate. In connecting to the existing power ground rod does it matter to attach above or below power ground? I would be bonding the communications in the building or home.


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## NolaTigaBait (Oct 19, 2008)

bbedard said:


> Let me restate. In connecting to the existing power ground rod does it matter to attach above or below power ground? I would be bonding the communications in the building or home.


Under the 2008 , you would need a grounding bridge to connect that ,read 250.94...


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## NolaTigaBait (Oct 19, 2008)

Are you an electrician?....Just curious, do you do low volt stuff?, never heard of it being called "power" ground rod


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## Magnettica (Jan 23, 2007)

250.53 (G)

(G) Rod and Pipe Electrodes. 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 aboveground
end and the grounding electrode conductor attachment
are protected against physical damage as specified in
250.10.


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## NolaTigaBait (Oct 19, 2008)

I have no idea what he is asking?...Is he talking about the connection being accessible?


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## Magnettica (Jan 23, 2007)

NolaTigaBait said:


> I have no idea what he is asking?...Is he talking about the connection being accessible?


sEEMS that is what he is asking.


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## Jlarson (Jun 28, 2009)

It doesn't matter.


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## MDShunk (Jan 7, 2007)

I think he's connecting multiple systems to the same rod electrode, and wants to know if there's a required order of placement.


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## raider1 (Jan 22, 2007)

MDShunk said:


> I think he's connecting multiple systems to the same rod electrode, and wants to know if there's a required order of placement.


That is my guess as well.

Chris


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## captkirk (Nov 21, 2007)

you need a seperate ground rod lug for each wire, you cant put two electrode wires on one clamp...I think this will help.


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## bbedard (Jun 27, 2011)

Thanks for your answere and 
I understand that. I was referring more to the Electric company grounding electrode. They generally use an acorn attachment. However there is usually room on top of them or below them on the rod. So when attaching to the electrode in cases where there is no intersystem bonding termination yet as it may be an older building, where is the best place to attach to the rod? I have heard we should be above the acorn attachment of the electric company and have heard we should be below.


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## raider1 (Jan 22, 2007)

bbedard said:


> Thanks for your answere and
> I understand that. I was referring more to the Electric company grounding electrode. They generally use an acorn attachment. However there is usually room on top of them or below them on the rod. So when attaching to the electrode in cases where there is no intersystem bonding termination yet as it may be an older building, where is the best place to attach to the rod? I have heard we should be above the acorn attachment of the electric company and have heard we should be below.


Unless there is a utility company requirement, the NEC does not care if you are above or below the other ground rod connector.

Chris


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## Jlarson (Jun 28, 2009)

Personally I'd say putting your acorn on top is probably safest if there happens to be current flow on the GEC. That way you aren't taking the GEC off and possibly becoming part of that circuit.

Sent from my Droid


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## bbedard (Jun 27, 2011)

Thanks that was my thought exactly. But if that was true would have thought the NEC would has said you must attach on top?


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## NolaTigaBait (Oct 19, 2008)

bbedard said:


> Thanks that was my thought exactly. But if that was true would have thought the NEC would has said you must attach on top?


If if's were skiffs, we'd all go rowing...


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## Rockyd (Apr 22, 2007)

Let's do it by the numbers....I'm saying 250.68, that leads to 250.70, and 250.53(G) -

from CODEPLUS (handbook explanasions on line)

Black is code
Blue is NECPLUS (handbook explanation)
*Bold italics are mine.*

250.68 Grounding Electrode Conductor and Bonding Jumper Connection to Grounding Electrodes. 
The connection of a grounding electrode conductor at the service, at each building or structure where supplied by a feeder(s) or branch circuit(s), or at a separately derived system and associated bonding jumper(s) shall be made as specified 250.68(A) through (C). 

*(A)* *Accessibility.* All mechanical elements used to terminate a grounding electrode conductor or bonding jumper to a grounding electrode shall be accessible. 

Exception No. 1: An encased or buried connection to a concrete-encased, driven, or buried grounding electrode shall not be required to be accessible. 

Exception No. 2: Exothermic or irreversible compression connections used at terminations, together with the mechanical means used to attach such terminations to fireproofed structural metal whether or not the mechanical means is reversible, shall not be required to be accessible. 

Where the exposed portion of an encased, driven, or buried electrode is used for the termination of a grounding electrode conductor, the terminations must be accessible per 250.68(A). However, if the connection is buried or encased, Exception No. 1 does not require the terminations to be accessible. Ground clamps and other connectors suitable for use where buried in earth or embedded in concrete must be listed for such use per 250.70, and indication of this listing is either by a marking on the connector or by a tag attached to the connector. See Exhibits 250.22 and 250.24 for illustrations of encased and buried electrodes.



*Exhibits 250.22,250.24 and 250.26 all show the attachment basically on top of the ground rod.*


250.70 Methods of Grounding and Bonding Conductor Connection to Electrodes. _See related_ UL 
The grounding or bonding conductor shall be connected to the grounding electrode by exothermic welding, listed lugs, listed pressure connectors, listed clamps, or other listed means. Connections depending on solder shall not be used. Ground clamps shall be listed for the materials of the grounding electrode and the grounding electrode conductor and, where used on pipe, rod, or other buried electrodes, shall also be listed for direct soil burial or concrete encasement. Not more than one conductor shall be connected to the grounding electrode by a single clamp or fitting unless the clamp or fitting is listed for multiple conductors. One of the following methods shall be used: 

(1)







A pipe fitting, pipe plug, or other approved device screwed into a pipe or pipe fitting 

(2)







A listed bolted clamp of cast bronze or brass, or plain or malleable iron 

(3)







For indoor communications purposes only, a listed sheet metal strap-type ground clamp having a rigid metal base that seats on the electrode and having a strap of such material and dimensions that it is not likely to stretch during or after installation 

(4)







An equally substantial approved means 

*(G)* *Rod and Pipe Electrodes.* 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 aboveground end and the grounding electrode conductor attachment are protected against physical damage as specified in 250.10.



Section 250.53(G) requires that all rod and pipe electrodes have at least 8 ft of length in contact with the soil, regardless of rock bottom. Where rock bottom is encountered, the electrodes must be either driven at not more than a 45-degree angle or buried in a 21/2-ft-deep trench. Driving the rod at an angle is permitted only if it is not possible to drive the rod vertically to obtain at least 8 ft of earth contact. Burying the ground rod is permitted only if it is not possible to drive the rod vertically or at an angle. Exhibit 250.26 illustrates these requirements.

*My bet is a second acorn clamp, whereever he can attach (close to the top of the rod and the clamp is rated DB (direct burial) will pass inspection, and be a drain for static.*

bbedard
Thanks that was my thought exactly. But if that was true would have thought the NEC would has said you must attach on top? 

*NEC tells you what you can't do, not so much what you can do....ya, even the code has a certain amount of common sense to leverage per AHJ. Local amendments, and inspectors, maybe a whole different can of worms for another thread*


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