# 320 service grounding electrode conductors



## ezrabeck58 (8 mo ago)

My question is this.. in a meter relocation and service upgrade (200a to 320a - 2x 200 disconnects in separate enclosures) from where a GEC to both ground rods and a metal water pipe is required, is it acceptable to run continuous gec's of appropriate sizes from each grounding electrode type to a single disconnect and then use a approved/listed connection means to jump over to the other disconnect? vs. Running two more conductors the entire expanse to the grounding electrodes again.


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## SWDweller (Dec 9, 2020)

A drawing would help

"each grounding electrode type" Is your water service really copper? I have not seen one of those in decades. Most have tags with this has a non metallic water service including mine 230' from the meter. You do know how much copper has to be in the ground to call the water pipe an electrode. RIGHT?

I get the feeling that you are treating the ground rods as separate grounds to the disconnects.
They are not. ONE GROUND, lots of bonding of metal piping systems and other steel if available. 

I have in the past run a code gauge bar solid wire, utility/AHJ approved ground from the ground rod to the gas and or water and to the meter socket landing. I say it this way as the code says #6 for ground rods, my AHJ says #4. 

I have a meter to test ground rods. So I never drive two unless the test proves that one will not do the job. Most people do not own this piece of test equipment. The ground in my area is HARD! I have turned a 3/4" ground rod into a pretzel. Easier to test and provide the document. I only once was I challenged and the inspector wanted to see the test. I think it was because he had never seen one done.


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## ezrabeck58 (8 mo ago)

Yes, when I have a chance I will attach a drawing to help explain. I wrote that in a hurry on my break.
It's a rather old house normally there are no metal water pipes in my area either.


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## LGLS (Nov 10, 2007)

SWDweller said:


> …
> So I never drive two unless the test proves that one will not do the job. Most people do not own this piece of test equipment. The ground in my area is HARD! I have turned a 3/4" ground rod into a pretzel. Easier to test and provide the document.


…

Then you might take a gander at *this!*
View attachment 165135


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## NoBot (Oct 12, 2019)

Run #2 copper from *one* disconnect to the water line and jump the meter, #6 to ground rods
or #2 copper in a continous run.
Either way, at the disconnects, splice #2 using a split or other means and run it into the second disconnect
Some inspectors will accept #2 from disconnect ground buss to the other. Some are more strict and require the split bolt.


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## yankeejoe1141 (Jul 26, 2013)

I think you could do it that way but the GEC from the electrode to the first disconnect would have to be sized for the whole 400 amp service. A 1/0 copper instead of a #4 I believe.


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## NoBot (Oct 12, 2019)

yankeejoe1141 said:


> I think you could do it that way but the GEC from the electrode to the first disconnect would have to be sized for the whole 400 amp service. A 1/0 copper instead of a #4 I believe.


Residential 320 A continuous, every inspector I've dealt with has accepted #2 copper


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## yankeejoe1141 (Jul 26, 2013)

NoBot said:


> Residential 320 A continuous, every inspector I've dealt with has accepted #2 copper


Ok


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## Forge Boyz (Nov 7, 2014)

yankeejoe1141 said:


> I think you could do it that way but the GEC from the electrode to the first disconnect would have to be sized for the whole 400 amp service. A 1/0 copper instead of a #4 I believe.


That all depends on the wire size. If you run 500 CU, then yes, you do need 1/0. If you run parallels, then your KCMILs are less, so you can reduce the ground to a #2.

Sent from my SM-G970U using Tapatalk


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## A Little Short (Nov 11, 2010)

If you use only ground rods, then a #6 is all that is required, no matter the service size.


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## Dennis Alwon (May 9, 2009)

A Little Short said:


> If you use only ground rods, then a #6 is all that is required, no matter the service size.


Yes but he is using one size and bonding to water pipes also. You must have the grounding electrode conductor sized for the max.

If the power company will allow it just run the grounding electrode conductor to the meter base and be done with it.

Also, if you have a 400 amp service, you do, then a #2 is needed not 1/0. If you had a meter main then 1/0 is needed but with 2 panels you only need #2. 

Table 250.66 notes-- do the math-- of course this is providing you are using nothing larger than 250kcm Aluminum service conductors.


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## backstay (Feb 3, 2011)

NoBot said:


> Run #2 copper from *one* disconnect to the water line and jump the meter, #6 to ground rods
> or #2 copper in a continous run.
> Either way, at the disconnects, splice #2 using a split or other means and run it into the second disconnect
> Some inspectors will accept #2 from disconnect ground buss to the other. Some are more strict and require the split bolt.


250.64

(C) Continuous.



Except as provided in 250.30(A)(5) and (A)⁠(6), 250.30(B)(1), and 250.68(C), grounding electrode conductor(s) shall be installed in one continuous length without a splice or joint. If necessary, splices or connections shall be made as permitted in (1) through (4):

(1)
Splicing of the wire-type grounding electrode conductor shall be permitted only by irreversible compression-type connectors listed as grounding and bonding equipment or by the exothermic welding process.
(2)
Sections of busbars shall be permitted to be connected together to form a grounding electrode conductor.
(3)
Bolted, riveted, or welded connections of structural metal frames of buildings or structures.
(4)
Threaded, welded, brazed, soldered or bolted-flange connections of metal water piping.


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## Dennis Alwon (May 9, 2009)

backstay said:


> 250.64
> 
> (C) Continuous.
> 
> ...



Not all connections to the grounding electrode system need to be continuous. For instance the grounding electrode conductor from the panel to a water line that is an electrode could be continuous however I can then go from the water pipe to say a ground rod and it would not need to be continuous as it would be a bonding jumper not a grounding electrode conductor. So if he loops everything with a #2 and then hits a panel he can now use an irreversible splice to jump to the other panel. That is a pain so that is why I suggested going to the meter base instead.


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## backstay (Feb 3, 2011)

Dennis Alwon said:


> Not all connections to the grounding electrode system need to be continuous. For instance the grounding electrode conductor from the panel to a water line that is an electrode could be continuous however I can then go from the water pipe to say a ground rod and it would not need to be continuous as it would be a bonding jumper not a grounding electrode conductor. So if he loops everything with a #2 and then hits a panel he can now use an irreversible splice to jump to the other panel. That is a pain so that is why I suggested going to the meter base instead.


I agree with you. I have a problem with a split bolt on the GEC.


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## joe-nwt (Mar 28, 2019)

backstay said:


> I agree with you. I have a problem with a split bolt on the GEC.


Maybe a topic for another thread, but, what do you see as a problem with a split bolt on a conductor that already has a bolted connection on either end?


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## backstay (Feb 3, 2011)

The GEC must be continuous or spliced a certain way. Split bolts are not approved. A split bolt is a poor connection in my experience. Many of the ones I come upon are loose. That’s why I posted 250.64 (C)


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## joe-nwt (Mar 28, 2019)

backstay said:


> The GEC must be continuous or spliced a certain way. Split bolts are not approved. A split bolt is a poor connection in my experience. Many of the ones I come upon are loose. That’s why I posted 250.64 (C)


I'm aware of the code. I was asking for your personal opinion.


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## Dennis Alwon (May 9, 2009)

joe-nwt said:


> I'm aware of the code. I was asking for your personal opinion.



Imo, it is only because the code won't allow it but I believe the code panel doesn't want the grounding electrode conductor to be able to be taken apart and other wires added to it... just a guess


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## yankeejoe1141 (Jul 26, 2013)

backstay said:


> The GEC must be continuous or spliced a certain way. Split bolts are not approved. A split bolt is a poor connection in my experience. Many of the ones I come upon are loose. That’s why I posted 250.64 (C)


I agree, split bolts are kind of a hack way out. I was under a raised floor in a data center last week and found a couple of loose split bolts on the grounding grid.


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## backstay (Feb 3, 2011)

yankeejoe1141 said:


> I agree, split bolts are kind of a hack way out. I was under a raised floor in a data center last week and found a couple of loose split bolts on the grounding grid.


They aren’t cheap either. So many better solutions today.


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## yankeejoe1141 (Jul 26, 2013)

backstay said:


> They aren’t cheap either. So many better solutions today.


I bought an MD-6 crimper and an assortment of c-taps just to avoid the urge to use a split bolt.


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## hornetd (Oct 30, 2014)

backstay said:


> The GEC must be continuous or spliced a certain way. Split bolts are not approved. A split bolt is a poor connection in my experience. Many of the ones I come upon are loose. That’s why I posted 250.64 (C)


OK! I'm lost again! You Galls and Guys keep doing this to me by stating what you believe the rule requires without citing the rule. Just before I retired, 7 years ago, we were installing copper busbars on standoff brackets with insulators adjacent to the service equipment and terminating all of the Grounding Electrode Conductor (GECs) to that busbar with bolt on copper terminals or high pressure lugs. I don't really know why they had insulators between the brackets and the busbar. The brackets were stainless steel so I don't see any likelihood of galvanic corrosion. Maybe the busbars came with the insulators in the package so they used them. We also used bonding jumpers sized for each type of electrode between the different electrodes and the one that required the largest GEC when the layout of the project made that efficient. We just had to make sure that the "Home Run," if you will, was as large as the largest GEC required for any of the electrodes used.

When I was working in New Hampshire there was often no soil on top of the granite. We would sometimes bring in a small well drilling machine and bore a 2" hole to the 50 foot maximum depth they were built for. The drilling mud was Bentonite clay made into a slurry. Once the needed number of feet was drilled the drilling pump was used to fill the bore with Bentonite. We would then push a sectional rod of the needed length into the bore. We always installed a 1 foot long piece of 6 inch plastic pipe with a threaded plug type end over the sectional rod and flush with the surface. This made the connection available for testing and inspection. 

[Schedule 40 PVC plugs will not support the weight of a cows hoof so use schedule 80 fiberglass if cows can get onto the site. No, I don't want to discuss how we learned that but the cow in question suffered no lasting harm. It was just scared and mad at the same time. The rancher tried to get us to pay for the vet bill even though it was his cow that busted through his fence to get at the better grass on the property which hosted the project side of the fence. I didn't even bother to call the project manager I just told him hell no!] 

Tom Horne


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## backstay (Feb 3, 2011)

250.64

(C) Continuous.



Except as provided in 250.30(A)(5) and (A)⁠(6), 250.30(B)(1), and 250.68(C), grounding electrode conductor(s) shall be installed in one continuous length without a splice or joint. If necessary, splices or connections shall be made as permitted in (1) through (4):

(1)
Splicing of the wire-type grounding electrode conductor shall be permitted only by irreversible compression-type connectors listed as grounding and bonding equipment or by the exothermic welding process.
(2)
Sections of busbars shall be permitted to be connected together to form a grounding electrode conductor.
(3)
Bolted, riveted, or welded connections of structural metal frames of buildings or structures.
(4)
Threaded, welded, brazed, soldered or bolted-flange connections of metal water piping.


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## yankeejoe1141 (Jul 26, 2013)

backstay said:


> 250.64
> 
> (C) Continuous.
> 
> ...


Did you just copy and paste post #12? Is that why you said 250.64(C) in post #16? Is this the third time you're citing that rule?

I think you may be trying to tell us something?


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## backstay (Feb 3, 2011)

hornetd said:


> *OK! I'm lost again! You Galls and Guys keep doing this to me by stating what you believe the rule requires without citing the rule. *
> 
> 
> 
> ...


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## yankeejoe1141 (Jul 26, 2013)

So you cited the rule but is that what you believe?


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## backstay (Feb 3, 2011)

I believe I had to go back to a job once to take the split bolt out and install a c crimp as per the inspector. I was much younger then. I haven’t bought a split bolt since.


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