I was recently in a debate with a friend in the trade about GECs . Article 250.50 states "one or more" so I said that simply grounding to cold water would suffice but he says that I have to still drive a ground rod to be to code. Could anyone tell me if this is true or not and give art.s to prove it.
Do I have to drive a ground rod?
- Thread starter 77naws
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Pierre C Belarge
Senior Member
- Location
- Westchester County, New York
250.53(D)(2) requires the water electrode, if connected to the grounding electrode conductor, is required to be supplemented and comply with 250.56. 250.56 requires an installer, if using a ground rod to supplement the water, to augment the single rod with an additional electrode if it is not found to be 25 ohms or less. Hence the second rod.
Volta
Senior Member
- Location
- Columbus, Ohio
Augment the supplement?
Augment the supplement?
250.53(D) does require the supplemental electrode of a rod, pipe, or plate type to comply with 250.56.
250.56 specifies that the resistance of a single electrode consisting of these types to have a resistance of 25 ohms or less to ground, or to be augmented by another.
Do you consider that a driven rod, which is supplementing the underground metal water pipe used as the main grounding electrode, is itself a single electrode? :-? No matter the wording of 250.53(D), it does seem that the (first) electrode in 250.56 is not a "single electrode consisting of a rod, pipe, or plate" if bonded to a metal underground water pipe.
Your thoughts?
Augment the supplement?
250.53(D) does require the supplemental electrode of a rod, pipe, or plate type to comply with 250.56.
250.56 specifies that the resistance of a single electrode consisting of these types to have a resistance of 25 ohms or less to ground, or to be augmented by another.
Do you consider that a driven rod, which is supplementing the underground metal water pipe used as the main grounding electrode, is itself a single electrode? :-? No matter the wording of 250.53(D), it does seem that the (first) electrode in 250.56 is not a "single electrode consisting of a rod, pipe, or plate" if bonded to a metal underground water pipe.
Your thoughts?
joeyww12000
Senior Member
- Location
- Chatsworth GA
This is my first reply to a question here so I hope it helps answer your question. NEC 250.50. ALL GROUNDING ELECTRODES as described in 250.52(A)(1) through (A)(7) THAT ARE PRESENT at each building or structure served shall be bonded together to form the grounding electrode system.....
So if a metal underground waterpipe exhists you must use it, you must bond to metal frame of the building, you must bond to a concrete encased electrode...or rebar. This being said there are rules that make each one of these materials suitable for being used as grounding electrodes that must be met... Just read all of 250.52. If your projects available electrodes do not meet these requirements then you must drive a groundrod, use a groundring or plate electrodes.... Usually the norm on the print specs would be to always bond waterpipe, metal framing, concrete encased electrode and also drive groundrods..thats just from what I have encountered.
So if a metal underground waterpipe exhists you must use it, you must bond to metal frame of the building, you must bond to a concrete encased electrode...or rebar. This being said there are rules that make each one of these materials suitable for being used as grounding electrodes that must be met... Just read all of 250.52. If your projects available electrodes do not meet these requirements then you must drive a groundrod, use a groundring or plate electrodes.... Usually the norm on the print specs would be to always bond waterpipe, metal framing, concrete encased electrode and also drive groundrods..thats just from what I have encountered.
Pierre C Belarge
Senior Member
- Location
- Westchester County, New York
If the water pipe, the structural steel and/or the concrete encased electrodes are present, there is no need for ground rods to be installed.
- Location
- Massachusetts
JohnJ0906
Senior Member
- Location
- Baltimore, MD
Check 250.53(D)(2).
Metal underground water pipe, used as an GE, must be supplemented. It doesn't HAVE to be a ground rod. It can be any electrode from 250.52(A)(2) through (A)(8).
However, if it IS a rod, pipe, or plate electrode, it has to comply with 250.56, which will mean 2 rods probably.
Aretae
Member
- Location
- at home with both wives
Water pipe
Water pipe
Many cities ultimately replace water mains with plastic pipe and the grounding quality of a hunk of pipe a couple of feet in the ground can come into question. So, though an AHJ may say the water pipe is fine, it is best to supplement for safety, then bond all potential current carrying members to ground, no?
Water pipe
Many cities ultimately replace water mains with plastic pipe and the grounding quality of a hunk of pipe a couple of feet in the ground can come into question. So, though an AHJ may say the water pipe is fine, it is best to supplement for safety, then bond all potential current carrying members to ground, no?
- Location
- New Jersey
- Occupation
- Journeyman Electrician
If the water pipe is metallic, at least 10' long and in contact with the earth it qualifies as an electrode and must be used. For the reason that you've mentioned, you are required to supplement that water pipe with any other electrode of your choice.
iaov
Senior Member
- Location
- Rhinelander WI
If you have only a water pipe you must add ground rod(s) No ground rod needed if you have a concrete encased electrode.
joebell
Senior Member
- Location
- New Hampshire
Isn't that a big assumption though when we are replacing a service in an existing dwelling units, that the pipe is in contact with the earth for 10'? What if the pipe comming into the house is metal through the foundation wall but the piping just on the other side is plastic. I think we should be rquired to bond the metal water piping and install ground rods anyway, isn't that essentaillly what we are doing?
BTW I also agree with George S. get rid of the 25 ohm requirement and just install 2 rods.
Joe
Yes and as shown in post #9, if water is the only electrode prresent, it MUST be supplemented.
weressl
Esteemed Member
weressl
Esteemed Member
So what happens when a the electrician arrives at a home construction long after the foundation has been set? Is he required to bust out the concrete to get to the rebar?
weressl
Esteemed Member
Regardless of its resistance?
Pierre C Belarge
Senior Member
- Location
- Westchester County, New York
Laszlo
If one is referencing the 2005 NEC and the building is new from the ground up all of the electrodes present are required to be bonded together as per 250.50.
If the EC gets there after the footing and foundation are installed and there is not conductor connected to the Concrete Encased Electrode, there is an issue and it will need to be rectified.
In regards to the suplementary electrode if it is not a rod or plate, there is no need to measure the value for the termination. So, resistance of it does not matter
If one is referencing the 2005 NEC and the building is new from the ground up all of the electrodes present are required to be bonded together as per 250.50.
If the EC gets there after the footing and foundation are installed and there is not conductor connected to the Concrete Encased Electrode, there is an issue and it will need to be rectified.
In regards to the suplementary electrode if it is not a rod or plate, there is no need to measure the value for the termination. So, resistance of it does not matter
weressl
Esteemed Member
Pierre,
As I suspected.
The 'rectification' is an undue burden as there are millions of homes in existence without this provision. (The concept of Federalism is to provide the freedom of Commerce and all laws established to serve that purpose, not to impose undue burden.) Not to mention that disturbuing the foundation will bring back the civil inspector to assure that the structural integrity of the concrete is retained. It should have remained an optional way to establish grounding. Not using it presents NO HARM or creates a safety issue. There is insufficient leverage of what is to be considered underground metallic objects that need to be interconencted. What distance, what if it somebody else's property. etc.
Why is that that we sometimes we need to know and sometimes we don't need to know the resistance value. Either it matters or it doesn't.
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- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
This is a problem in many areas. It has been difficult at best to get the builders to remember. I have to keep on them thru the project to make sure I get the CEE in there. Many states have ruled that if the electrician gets there and the footings are poured then it is not available- That is a cop out to me. Everyone needs to get up to speed on this, IMO.
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