# Connecting two ground rods



## JohnJ0906

Second clamp. Generally I run a continuous wire from service to 1st rod, through the clamp, then to 2nd rod (All 1 piece) but the jumper between the 2 rods can be connected separately.

I have never heard of an inspector allowing 1 rod only without actually witnessing the test. We install 2 and go.
.


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## JohnJ0906

By the way, welcome to the forum. :thumbsup:


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## sharkmobil

Thank you. 
Any chance of pointing to a reference in the code book to prove that it is legit?


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## JohnJ0906

sharkmobil said:


> Thank you.
> Any chance of pointing to a reference in the code book to prove that it is legit?


Gonna make we work on a friday night?!? :no:

Well, OK, let me take a quick look.

Out of curiosity, do most inspectors in your area accept 1 rod with a test they don't witness? I don't think anyone around here even bothers testing.


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## JohnJ0906

250.70 250.64(F)

The connection between the rods counts as a bonding jumper, I believe. The GEC (grounding electrode conductor) is from the service to the 1st electrode. (250.53(C))


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## a-bulb

Just do a cadweld. the inspectors should not have a problem with a permanent connection http://www.erico.com/products.asp?folderid=138 hope this helps.


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## rbj

sharkmobil said:


> An inspector asked for a second ground rod, I said I have measured the impedance and it was less than 25 Ohm, but he insisted on it, so there goes the second rod. The code we are going by here is NEC 2005.


Wouldn't need the rods if there is a UFER bonded to the GEC. Less costly way to go. rbj


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## Speedy Petey

sharkmobil said:


> An inspector asked for a second ground rod, I said I have measured the impedance and it was less than 25 Ohm, but he insisted on it, so there goes the second rod. Trouble is my ground wire (#6 solid) now is not going to be continuous, as it goes through the first rod and gets bonded to the nearby water line.


How did you measure this resistance? Unless you used to proper tester (NOT a simple meter set to ohms) the inspector has a valid point.

What you are installing is a bonding jumper, NOT a GEC. Just add another clamp on the existing rod.

Here is a great Mike Holt graphic:


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## rbj

Speedy Petey said:


> What you are installing is a bonding jumper, NOT a GEC. Just add another clamp on the existing rod.


Hi Speedy Petey, 

Good Holt graphics, but the PO also continues the 6awg through the Rod clamp to the water pipe electrode that really constitutes a GEC connection done in a unique way. That is what the PO is having trouble understanding. The bond jumper is of course the answer to finish the second rod installation that you have posted. 

Sharkmobil, 

Usually in residential, the Ground Electrode Conductor is required to connect to the water pipe electrode within 5 feet of its foundation exit. A second unspliced GEC bonds the UFER electrode or a supplemental 2 rods or plate etc per 250.52(A)(1 thru 7 if present). A UFER is the easiest method and saves the contracter $$$ not needing extra rods even when a plastic water supply is used. :thumbsup: rbj


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## RePhase277

rbj said:


> Hi Speedy Petey,
> 
> Good Holt graphics, but the PO also continues the 6awg through the Rod clamp to the water pipe electrode that really constitutes a GEC connection done in a unique way. That is what the PO is having trouble understanding. The bond jumper is of course the answer to finish the second rod installation that you have posted.


Nothing unique about it. The rods are allowed to be connected to any point in the grounding electrode system. The water pipe is one such point. It is not uncommon to have a single conductor bond building steel, then at another location tap steel to hit the water, and the water to a rod.

InPhase277


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## rbj

InPhase277 said:


> Nothing unique about it. The rods are allowed to be connected to any point in the grounding electrode system. The water pipe is one such point. It is not uncommon to have a single conductor bond building steel, then at another location tap steel to hit the water, and the water to a rod.
> 
> InPhase277


Yer right in com'l or ind'l, but in residential, generally the UFER or Pipe is in opposite directions from the box. Someones spending too much time and copper to do it the other way, especially when the plumber hasn't come on the job yet.


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## sharkmobil

Thanks for the help, guys.


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## brian john

How did you measure the ground resistance/impedance?
Did you document it?
What was his reasoning of NOT ACCEPTING the NEC?


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## sharkmobil

I used an ohmmeter. From ground/neutral bus to the lug on the rod. This is my first time doing the main service. Mostly I stick to photovoltaics


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## Speedy Petey

sharkmobil said:


> I used an ohmmeter. From ground/neutral bus to the lug on the rod.


This is NOT the test for ground rod resistance. Not even close.

Here is an example of the types of testers required to perform this test:
http://www.tessco.com/products/displayProducts.do?groupId=770&subgroupId=12

Here are some more:
http://www.specialized.net/ecommerce/shop/seriesmaster.asp?series_id=Ground+Resistance+Testers


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## sharkmobil

Those are just multi thousand dollar ohmmeters with sugar on top. As far as a *procedure *goes, I knew there had to be another rod inserted 8-10'' to truly measure the path to the ground, thats why I was not arguing too much against the second rod.


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## brian john

> I used an ohmmeter.


I'd have made you drive 4-10 footers if I was him. Ground testing requires the correct test equipment and additionally some training and expierence in utilizing this equipment.

I own 6 different earth ground resistance testers cost range between $1,200.00 and $4,500.00, the procedure for the three point test requires (for accurate results)a minimum of 33 test rods to be driven. Generally at 1', 10' 20' 30', 40', 50, 60', 66', 70', 80' 90' and one at 100' this is for a 10' rod. For larger ground electrodes the distance increases at 10 times the diagonal. This test, like most test requires proper training and a understanding of the work involved.


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## Speedy Petey

sharkmobil said:


> Those are just multi thousand dollar ohmmeters with sugar on top.


Sorry, but you are TOTALLY wrong on this point.


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## gilbequick

Can I borrow a cup of sugar?


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## sharkmobil

Speedy Petey said:


> Sorry, but you are TOTALLY wrong on this point.


That would be an incorrect statement; which part am I exactly wrong, the multi thousand part or the sugar on top part? Narrow it down for me and I will try to explain, how I can be wrong on the subject, but right on the point. :blink:


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## Speedy Petey

The point is that those meters are not simply ohm meters. They are specifically ground resistance meters.

I think you knew exactly what I meant.


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## leland

----I'd have made you drive 4-10 footers if I was him. Ground testing requires the correct test equipment and additionally some training and expierence in utilizing this equipment.---

Ok so most towns will have this and trained dr--k--- people to use them? or are we supposed to show proof (rhetorical, of course its on us to proove).

2 rods and done, we discuss this over how much per 8x5/8 rod?:no:


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