1. ATTENTION returning members. If you are coming here from the old forum for the first time, you will need to reset you password. However, we had an email problem getting password reset links set out to a lot of the email addresses. That problem is temporarily rectified but IF you still have an issue, email me direct at info@thebuildingcodeforum.com and I will give you a temporary password.
    Dismiss Notice
  2. Welcome to the new and improved Building Code Forum. We appreciate you being here and hope that you are getting the information that you need concerning all codes of the building trades. This is a free forum to the public due to the generosity of the Sawhorses, Corporate Supporters and Supporters who have upgraded their accounts. If you would like to have improved access to the forum please upgrade to Sawhorse by clicking here: Upgrades
    Dismiss Notice

Can you ground an electrical system to a gas pipe?

Discussion in 'Fuel Gas Codes' started by Yikes, Dec 13, 2013.

  1. Yikes

    Yikes Gold Member

    Joined:
    Nov 2, 2009
    Messages:
    1,256
    Likes Received:
    117
    I have what is probably a dumb question, but when I searched the threads, I couldn't find it previously addressed elsewhere:

    I saw a small building where the grounding for the electrical system was a clamp to the pipe on the gas meter. Is this a code-compliant method of grounding?
     
  2. fatboy

    fatboy Administrator

    Joined:
    Oct 17, 2009
    Messages:
    5,471
    Likes Received:
    407
    Don't have a book with me, but I believe you can NOT use gas pipe as a grounding electrode, however, it must be bonded.
     
  3. Sifu

    Sifu Gold Member

    Joined:
    Sep 3, 2011
    Messages:
    1,021
    Likes Received:
    65
    Gas pipe is bonded to the grounding electrode system but it is not a grounding electrode.
     
  4. Yikes

    Yikes Gold Member

    Joined:
    Nov 2, 2009
    Messages:
    1,256
    Likes Received:
    117
    So maybe what I saw was bonding, not grounding...
     
  5. ICE

    ICE Sawhorse

    Joined:
    Jun 23, 2011
    Messages:
    7,539
    Likes Received:
    639
    There should be a dielectric fitting that isolates the underground pipe from the pipe in the building. So chances are that it is not acting as a grounding electrode. If the connection is on the utility side of the meter, it may be the grounding electrode. In that case a compliant electrode should be provided prior to any change with the gas pipe connection.

    I read this somewhere and it might be factual:

    The grounding electrode might have a voltage potential. Although small, the voltage might cause an equally small current. That, with moisture, will rot the pipe.
     
    #5 ICE, Dec 13, 2013
    Last edited by a moderator: Dec 14, 2013
  6. Gregg Harris

    Gregg Harris Gold Member

    Joined:
    Jan 17, 2012
    Messages:
    884
    Likes Received:
    7
    NEC 250.104 (B) requires the bonding of gas piping and as Ice stated the service valve before the meter is a dielectric fitting that prevents the underground piping from being an electrode.
     
  7. Gregg Harris

    Gregg Harris Gold Member

    Joined:
    Jan 17, 2012
    Messages:
    884
    Likes Received:
    7
    NEC 250.52(B)(1)

    (B) Not Permitted for Use as Grounding Electrodes. The following systems and materials shall not be used as grounding electrodes:

    (1) Metal underground gas piping systems

    (2) Aluminum

    250.104 Bonding of Piping Systems and Exposed Structural Steel.

    (B) Other Metal Piping. If installed in, or attached to, a building or structure, a metal piping system(s), including gas piping, that is likely to become energized shall be bonded to the service equipment enclosure; the grounded conductor at the service; the grounding electrode conductor, if of sufficient size; or to one or more grounding electrodes used. The bonding conductor(s) or jumper(s) shall be sized in accordance with 250.122, using the rating of the circuit that is likely to energize the piping system(s). The equipment grounding conductor for the circuit that is likely to energize the piping shall be permitted to serve as the bonding means. The points of attachment of the bonding jumper(s) shall be accessible.
     

Share This Page