# Ground rod clamps



## Southeast Power (Jan 18, 2009)

reyamkram said:


> How many clamps are allowed on a ground Rod??
> per-250.70 (2011) you are allowed one per ground rod, I have one with 3, and
> the company would like to install another one on the same rod, should I just drive another ground rod into the ground??
> any and all information, Thank you.
> ...


The one at my house looks like a Christmas tree but, when we install residential services we have to use an inter system ground bar, on commercial jobs, we use a collector bar.


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## brian john (Mar 11, 2007)

If you install another rod you need to join the two rods together so you are going to use 4 clamps no matter what.


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## JoeSparky (Mar 25, 2010)

An acorn is about 1.5" thick. A typical ground rod is 8' Tall. That means the code maximum number of clamps per rod is 64 :smartass: You may want to keep it under 61 if you are using a rotary hammer to drive them. The driver will fit on the top better without them there. @HackWork can only manage to fit 32 on each of his ground rods, but that is a different story:whistling2:


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## reyamkram (Dec 31, 2013)

I am in an industrial factory, the ground rod is going to be around 15 feet from the other one, do I still need to join the them together ???? 
and being in an industrial factor if I put more then one clamp on a rod it is ok???

Thank you.


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## JoeSparky (Mar 25, 2010)

All grounding electrodes need to be bonded together. If you feel the need to drive another rod, it needs to be bonded to all the rest of the electrodes.

If you are in a steel building, you are wasting your time. Bond/ground the building steel and any metal piping to the service and call it a day. Rods are quite useless for grounding the service in a steel building.


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## CoolWill (Jan 5, 2019)

reyamkram said:


> I am in an industrial factory, the ground rod is going to be around 15 feet from the other one, do I still need to join the them together ????
> and being in an industrial factor if I put more then one clamp on a rod it is ok???
> 
> Thank you.


You need to get a grasp on what you are trying to accomplish with this grounding. I don't think you understand grounding electrodes.


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## MotoGP1199 (Aug 11, 2014)

reyamkram said:


> I am in an industrial factory, the ground rod is going to be around 15 feet from the other one, do I still need to join the them together ????
> and being in an industrial factor if I put more then one clamp on a rod it is ok???
> 
> Thank you.


If its an auxiliary electrode (250.54) for a piece of equipment it does not need to be bonded with other electrodes or the building steel. The NEC recognizes that they are useless. If anything they can be more harmful than helpful. Keep in mind that you cannot use the auxiliary electrode( ground rod) to replace an EGC. You must have a proper EGC(equipment grounding conductor) for the breaker to clear in a fault condition.

If it's an actual 2nd ground rod for the service then yes it has to be bonded to the other one.


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## HackWork (Oct 2, 2009)

reyamkram said:


> per-250.70 (2011) you are allowed one per ground rod


I never heard of this and I don't have the 2011 NEC. Can you post the code limiting you to only 1 clamp per ground rod please?



This has been commonly accepted for a long time:


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## JoeSparky (Mar 25, 2010)

HackWork said:


> I never heard of this and I don't have the 2011 NEC. Can you post the code limiting you to only 1 clamp per ground rod please?
> 
> 
> 
> ...


That ground wire looks like it's going through a Kenny clamp, not the grounding electrode conductor hole:wink:


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## sbrn33 (Mar 15, 2007)

JoeSparky said:


> All grounding electrodes need to be bonded together. If you feel the need to drive another rod, it needs to be bonded to all the rest of the electrodes.
> 
> If you are in a steel building, you are wasting your time. Bond/ground the building steel and any metal piping to the service and call it a day. Rods are quite useless for grounding the service in a steel building.


This is kinda true and kinda not. If it is a required one sure they need to be bonded together. But if it is just for phone or some goofy mechanic that wants it installed because he can't figure out why the machine just quits every once in awhile it can be stand alone all day long.


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## Dennis Alwon (May 9, 2009)

250.70 is just saying that only one grounding electrode conductor can be attached to a clamp unless the clamp is designed for more than one. You can have as many clamps on the ground rod as you want


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## HackWork (Oct 2, 2009)

Dennis Alwon said:


> 250.70 is just saying that only one grounding electrode conductor can be attached to a clamp unless the clamp is designed for more than one. You can have as many clamps on the ground rod as you want


Thanks. I didn't think there was a limit.


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## CTshockhazard (Aug 28, 2009)

Technically, even a single clamp could render the electrode installation as non-compliant. I've never actually measured the length of ground rod, are they exactly 8' or do they have an additional _clamp section_?:biggrin:

(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.

:wink:


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## MotoGP1199 (Aug 11, 2014)

CTshockhazard said:


> Technically, even a single clamp could render the electrode installation as non-compliant. I've never actually measured the length of ground rod, are they exactly 8' or do they have an additional _clamp section_?
> 
> 
> 
> ...


 You just bury the rod with the clamp. That clamp will be underground. If it's in an industrial situation in concrete then you buy the 10' rod and the clamps will be above ground.


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## HackWork (Oct 2, 2009)

MotoGP1199 said:


> You just bury the rod with the clamp. That clamp will be underground. If it's in an industrial situation in concrete then you buy the 10' rod and the clamps will be above ground.


He is saying that the 3/4" of space that the clamp takes up is blocking 3/4" of rod from making contact with the soil.

While he is just talking about it for sake on conversation, I don't doubt that some idiot Mike Holt forum inspector has tried to pull that garbage.


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## sbrn33 (Mar 15, 2007)

Actually the clamp would give it more surface area..


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## CoolWill (Jan 5, 2019)

sbrn33 said:


> Actually the clamp would give it more surface area..


Yes, but the code says.....


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## JoeSparky (Mar 25, 2010)

CoolWill said:


> Yes, but the code says.....


That space isn't "free" either:wink:


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## Forge Boyz (Nov 7, 2014)

I would think if the clamp is buried you would have the full 8'. I do remember one inspector that insisted the rods stick up out of the ground. They got buried once he was gone.

Sent from my SM-G970U using Tapatalk


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## Bird dog (Oct 27, 2015)

Forge Boyz said:


> I would think if the clamp is buried you would have the full 8'. I do remember one inspector that insisted the rods stick up out of the ground. They got buried once he was gone.
> 
> Sent from my SM-G970U using Tapatalk


Left sticking up, it's a safety hazard. One could consider installing an inexpensive inspection box.


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## CoolWill (Jan 5, 2019)

Bird dog said:


> Left sticking up, it's a safety hazard. One could consider installing an inexpensive inspection box.


You mean a scrap piece of 2" PVC?


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## Forge Boyz (Nov 7, 2014)

Bird dog said:


> Left sticking up, it's a safety hazard. One could consider installing an inexpensive inspection box.


That was a long time ago so its a moot point for me. My inspection box was a few scoops with a shovel. The job superintendent wanted them buried when it was complete.

Sent from my SM-G970U using Tapatalk


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## drsparky (Nov 13, 2008)

We use R56 standards, non reversible bonding is required, no mechanical clamps allowed. Weld it or crimp it.


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## Easy (Oct 18, 2017)

Bird dog said:


> Left sticking up, it's a safety hazard. One could consider installing an inexpensive inspection box.


Lawn mowers don't play well with ground rods that stick up. It's hard on the blades. 
I have always wondered why they just don't make a plastic box like the ones you by for $5 that are commonly used by landscape contractors to cover in ground valves. It's required to have access to ufer grounds but not ground rods.


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## macmikeman (Jan 23, 2007)

99% of the time local inspectors wanted to see the ground rod sticking up out of the ground . You could not explain to them it needs to be completely buried. That's when they would say you don't know what you are doing and don't argue with me.... 



And ........ people wonder why I show no respect sometimes................


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## reyamkram (Dec 31, 2013)

HackWork said:


> I never heard of this and I don't have the 2011 NEC. Can you post the code limiting you to only 1 clamp per ground rod please?
> 
> 
> 
> ...


I do apologize I read the article wrong. it reads

only one grounding electrode conductor can be attached to a clamp unless the clamp is designed for more than one. 

Thank you.


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## Signal1 (Feb 10, 2016)

reyamkram said:


> I do apologize I read the article wrong. it reads
> 
> only one grounding electrode conductor can be attached to a clamp unless the clamp is designed for more than one.
> 
> Thank you.


Now you tell us..................


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## Dennis Alwon (May 9, 2009)

reyamkram said:


> I do apologize I read the article wrong. it reads
> 
> only one grounding electrode conductor can be attached to a clamp unless the clamp is designed for more than one.
> 
> Thank you.


Isn't that what was stated in post #12..........:wink:


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## kb1jb1 (Nov 11, 2017)

MotoGP1199 said:


> If its an auxiliary electrode (250.54) for a piece of equipment it does not need to be bonded with other electrodes or the building steel. The NEC recognizes that they are useless. If anything they can be more harmful than helpful. Keep in mind that you cannot use the auxiliary electrode( ground rod) to replace an EGC. You must have a proper EGC(equipment grounding conductor) for the breaker to clear in a fault condition.
> 
> If it's an actual 2nd ground rod for the service then yes it has to be bonded to the other one.


I am sure we all have been in buildings where ground rods are driven next to machinery in dry sand. I just shake my head and ask why. " Because that is what the machine maker wants". And they wonder why things burn out.


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## MotoGP1199 (Aug 11, 2014)

kb1jb1 said:


> I am sure we all have been in buildings where ground rods are driven next to machinery in dry sand. I just shake my head and ask why. " Because that is what the machine maker wants". And they wonder why things burn out.


Exactly, at least it seams some of the manufacturers are catching on. And not requiring us to create a good path for transient voltages to travel on.

Sent from my SM-G973U using Tapatalk


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## cuba_pete (Dec 8, 2011)

JoeSparky said:


> An acorn is about 1.5" thick. A typical ground rod is 8' Tall. That means the code maximum number of clamps per rod is 64 :smartass: You may want to keep it under 61 if you are using a rotary hammer to drive them. The driver will fit on the top better without them there. @HackWork can only manage to fit 32 on each of his ground rods, but that is a different story:whistling2:


That’s some serious MATHS right there!



macmikeman said:


> ...people wonder why I show no respect sometimes...


Who??? Nobody here!


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## RiveeSs (Aug 25, 2021)

I think it's better to use a plastic box. Rods sticking out of the ground are at least unsafe. There's no way someone could bump into them. I don't understand why the inspectors would want to do that. Speaking of bracing, it seems that you would be better off using welding. You staple the rods with toggle clamps to hold them securely in place and weld them together. It will be much more secure, and it will take much less time. My uncle did this in the backyard of his property when he was grounding the electrical panel. It sounds to me like the best option you can offer. I hope you found the right solution for you. Best of luck to you!


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