ground rods versus foundation

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i read 250.50. but my question is it one or the other or do you need both. the company i work for failed inspection because the ground rods where not driven. after looking at the prints again it showed both. if the print didnt show both and just had the foundation would the ground rods have been not necessary, but my question stil stands DO YOU NEED BOTH GROUND RODS AND FOUNDATION????
 
No need to shout.

If there is only a CEE present, then you only have to use the CEE and do nothing else.

If the prints show a set of rods and the inspector enforces the print, you need them.

A water pipe would require an additional grounding electrode as well.
 
brielellalyse said:
i read 250.50. but my question is it one or the other or do you need both.
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The answer is in 250.50

250.50 Grounding Electrode System.
If available on the premises at each building or structure served, each item in 250.52(A)(1) through (A)(6) shall be bonded together to form the grounding electrode system. Where none of these electrodes are available, one or more of the electrodes specified in 250.52(A)(4) through (A)(7) shall be installed and used.
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Check with your utility too...here if you don't have 2 driven rods, they won't hook you up no matter how many other electrodes you have.
Don
 
There are a lot of engineers out there that insist on specifying ground rods even when they are not needed. And then you have the POCO to deal with as indicated by Don.
 
don_resqcapt19 said:
Check with your utility too...here if you don't have 2 driven rods, they won't hook you up no matter how many other electrodes you have.
Don
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Not only that, I recently had a POCO guyrespond to an open-neutral-at-the-pad-mounted-transformer service call insist that there would have been no problem if the house had "the correct ground rods" installed.
 
Some of the inspectors(AHJ) here wont allow a ufer ground connection, if they miss inspecting it before the concret is poured. They request ground rods.
 
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LarryFine said:
Not only that, I recently had a POCO guyrespond to an open-neutral-at-the-pad-mounted-transformer service call insist that there would have been no problem if the house had "the correct ground rods" installed.
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Huh?.................................
 
dcspector said:
Huh?.................................
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My bad.

I was called by a homeowner who had the typical open-neutral issues: some lights too bright, some lights too dim; a couple of bulbs actually exploded; a wall-wart burned up, even damaging receptacle and plate, etc.

I told him there was definitely an open neutral between the transformer and the house panel. He said that the POCO came out, turned off the main, and measured line-to-neutral voltage and everything was as it should be.

Unfortunately, it didn't occur to their tech to measure the voltage with a load on the lateral. I went to the house, measured proper voltage, turned on the main, and got around 80v and 160v. The POCO returned at my request.

After confirming my findings, he opened the transformer and discovered a loose neutral crimp and repaired it. He also said that the real problem was improper ground rods, which would have prevented the voltage problems.

Yikes! :rolleyes:
 
One of our local jurisdictions requires two sources of grounding all the time (panel change outs, new construction, etc) We use a lot of plastic for the water service here so it's not a reliable ground source.
 
brielellalyse said:
are ground rods still required if there is a foundation ground for a service ground
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from my experince it really comes down to your research with the city's acceptance and knowing your inpector's take on the issue . Even if the print shows ground rods and you take this to your inspector you'llbe better prepared.
 
iwire said:
The answer is in 250.50
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I guess I disagree that the answer is completely black and white the way the code is written (and this isn't the only place in the code). What is the definition of "if available"? If I were an electrical contractor hired to wire a house and I wasn't brought on the job until after the foundation was poured and the building was framed, then the foundation rebar isn't "available" unless I get out a jackhammer. Likewise, the foundation ground isn't "available" until/unless a cable has been bonded to it. So there may be a potential rebar foundation ground present/in existence, but it isn't "available".

So take the next step - I'm the electrical contractor and I am on board before the foundation is poured, and there is rebar available. But, I'm just not a fan of foundation grounds because I've had issues with other contractors messing up the bonding wire coming out of the foundations in the past, and I just personally feel that a driven ground rod is a superior method to the foundation. If I have the opportunity to use the foundation, is it a voilation of code to not use it and just go with a ground rod, putting aside any rulings of a local AHJ (if there is a local AHJ)?
 
IL94EE said:
If I have the opportunity to use the foundation, is it a voilation of code to not use it and just go with a ground rod...?
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Beyond a shadow of a doubt, it is a violation.

That is exactly what they were addressing by changing the wording in the 2005.

Click here to see the comment that produced the change in the 2005.
 
Not only that, I recently had a POCO guy respond to an open-neutral-at-the-pad-mounted-transformer service call insist that there would have been no problem if the house had "the correct ground rods" installed.
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This works when you run the rods every 16' utilizing #2AWG (6 would work) from the house to the XO of the transformer, only problem under normal operation parallel paths.

What always bothers me about this discussion is many inspectors spend more time worrying about the one or two rods in the ground, then the proper bonding and grounding in the facility.
 
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