Grounding

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bradfordservicesinc

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I inspect for a lot of contractors and have many different electrical contractors I work with. I have a new one in the state who has really been hard to deal with. They do not want to connect to a UFER ground installed in the cwawl space footing steel if there are ground rods installed at the meter base on the outside of the building. They say the code prohibites using both. The utitlity company will not hook up unless there are two ground rods. We have been requiring two ground rods at the meter 6' apart min. and a Ufer in the footing steel, and also connecting to the copper water line from the well.we have always required to use all avaiable grounding sources. Where does the code prohibite the UFER ground if there are grounding rods install outside the foundation?
 
Re: Grounding

If a ufer is availible it must be used, as all electrodes must be used if availble.

Do not have code book with me but look at 250.52.
 
Re: Grounding

The code does not prohibit the use of ufer grounding electrodes. If fact it must be used. See
250.50. All electrodes described in 250A 1 thru 6
must be bonded together if available on the location.
 
Re: Grounding

If the well pipe was plastic, the ground rods would not be required, but you mention that the well pipe is copper, so it has to be supplemented with a ground rod (250.53(D)(2), two ground rods are required if the resistance of one ground rod measured is greater than 25 ohms (250.56).
250.52 Requires that the Electrode System include the Ufer Ground if it is available.

Pierre
 
Re: Grounding

Here is the references for your situation;

NEC 2002 250.30
(4) Grounding Electrode. The grounding electrode shall be as near as practicable to and preferably in the same area as the grounding electrode conductor connection to the system. The grounding electrode shall be the nearest one of the following:
(1)An effectively grounded structural metal member of the structure
(2)An effectively grounded metal water pipe within 1.5 m (5 ft) from the point of entrance into the building.
(3)Other electrodes as specified by 250.52 where the electrodes specified by 250.30(A)(4)(1) or (A)(4)(2) are not available.

250.52 Grounding Electrodes.
(A) Electrodes Permitted for Grounding.
(1) Metal Underground Water Pipe.
(2) Metal Frame of the Building or Structure.
(3) Concrete-Encased Electrode.
(4) Ground Ring.
(5) Rod and Pipe Electrodes.
(6) Plate Electrodes.
(7) Other Local Metal Underground Systems or Structures.

250.53 Grounding Electrode System Installation.
(D)(2) Supplemental Electrode Required. A metal underground water pipe shall be supplemented by an additional electrode of a type specified in 250.52(A)(2) through (A)(7).

This should pretty-much cover your code question!

Hope this helps,
Dave
 
Re: Grounding

If a metal underground water pipe and a Ufer ground (concrete encased electrode) are both used you would not be required to install any ground rods. The Ufer ground is one of the permitted supplemental electrodes required by 250.53(D)(2). The Ufer ground must be connected since it is provided and if there is a metal underground pipe that meets 250.52(A)(1) it must be connected but I don't see a reason to require the 2 ground rods. The Ufer ground is an acceptable electrode by itself.
 
Re: Grounding

Now I get it. The well pipe is a recognized electrode. I am referring to well pipe as in well casing, not pipe from the well.

The pipe from the well is one electrode. The metal casing is another. Are these true statements?

[ July 15, 2003, 12:23 AM: Message edited by: bennie ]
 
Re: Grounding

Bennie,

Are these water pipes, including the well casing, metal?

Are these water pipes in direct contact with the earth ?
 
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