+ Reply to Thread
Page 1 of 2 12 LastLast
Results 1 to 10 of 14
  1. #1
    Join Date
    Aug 2014
    Posts
    3

    Default Grounding Electrode question

    Hey everyone, long time listener, first time caller I'm hoping someone can help me out with this dilemma if that is, in fact, what it is.

    I've been wading through the NEC, but I just can't seem to nail down the answer to this question. My wife and bought our house a year ago, and I've been slowly untangling the mess that is our electrical system. Now I'm trying to correctly ground the system.

    The problem is, I have no access to the water pipe coming in to the basement. There's about four inches of exposed pipe, but that section has been completely covered by an epoxy compound to fix a leak, so there's nowhere to connect a ground wire.

    Currently I have a 10' Cu grounding rod driven into the ground outside with #6 connecting to the breaker panel. I know that alone will probably not meet the max 25 ohm resistance requirement, but will adding another ground rod, 6' away, and bonding the two rods with #6 be sufficient to make an inspector happy and keep my family safe?

    Or is the fact that my system is not grounded to the water pipe a very bad thing?

    Thanks everyone for your help!

  2. #2
    Join Date
    Dec 2010
    Location
    Houston Texas
    Posts
    2,969

    Default Re: Grounding Electrode question

    I'm not an electrician and I didn't sleep at a Holiday Inn, but I do know we stopped grounding to the plumbing systems years ago. Its all grounding rods now.

  3. #3
    Join Date
    Jul 2010
    Location
    SoCal
    Posts
    6,694

    Default Re: Grounding Electrode question

    I agree with HR about the rod, not the hotel.

  4. #4
    Join Date
    Aug 2014
    Posts
    3

    Default Re: Grounding Electrode question

    Well, unless I'm misreading it, the NEC still requires grounding to the cold water pipe. That's why the question, since it appears to require it. The caveat of "if present" is there, but that's where my dilemma comes in because the pipe is technically present, but unable to be used.

    So, does that then mean the two grounding rods would be sufficient? And would #6 be fine to bond the two rods?

    Also, the two rods need to be bonded together, but do both rods have to be bonded to the panel as well? I don't think I've ever seen that done, but the reading got me twisted up in my thinking, so I don't know what's up or down anymore.

    Thanks!

  5. #5
    Join Date
    Aug 2011
    Location
    Northern Indiana
    Posts
    70

    Default Re: Grounding Electrode question

    Drive a second rod at least 6' from the existing one. Make sure there is no gas, electric, cable, water, sewer, etc. at the new rod location. Connect the two rods using #6 copper and two acorn clamps. An additional conductor to the panel is not necessary.

    If at all possible a connection should be made to the incoming water line. #4 copper for a 200 amp service, #6 copper for a 100 amp service.

    See www.mikeholt.com click on the free graphics in the left hand column, click on grounding versus bonding graphics, click on grounding electrode conductor terminating.
    Last edited by brrichter; 08-07-2014 at 01:27 PM.

  6. #6
    Join Date
    May 2008
    Location
    Pacific Northwet
    Posts
    1,643

    Default Re: Grounding Electrode question

    If the pipe is unable to be used, then don't use it.

    As for the grounding electrodes, code requires there be NO CONNECTIONS in the conductor between the panel and the electrodes. This gives you two options:
    • One wire from the panel to the first electrode, passing through the acorn clamp WITHOUT A BREAK and on to the acorn clamp on the second ground rod; or
    • Two wires from the panel, one to each ground rod.

    You can't add a grounding electrode and just connect it to the existing one, because that would constitute a connection in the grounding conductor.
    The "Senior Member" designation under my name doesn't mean I know a lot, it just means I talk a lot.I've been a DIYer since I was 12 (thanks, Dad!). I have read several books on various home improvement topics. I do not have any current code books I can refer to. I was an apprentice plumber for two years.

  7. #7
    Join Date
    Aug 2011
    Location
    Northern Indiana
    Posts
    70

    Default Re: Grounding Electrode question

    Quote Originally Posted by Fencepost View Post
    If the pipe is unable to be used, then don't use it.

    As for the grounding electrodes, code requires there be NO CONNECTIONS in the conductor between the panel and the electrodes. This gives you two options:
    • One wire from the panel to the first electrode, passing through the acorn clamp WITHOUT A BREAK and on to the acorn clamp on the second ground rod; or
    • Two wires from the panel, one to each ground rod.

    You can't add a grounding electrode and just connect it to the existing one, because that would constitute a connection in the grounding conductor.
    That is totally false. See post #5.
    Last edited by brrichter; 08-07-2014 at 01:29 PM.

  8. #8
    Join Date
    May 2008
    Location
    Pacific Northwet
    Posts
    1,643

    Default Re: Grounding Electrode question

    Quote Originally Posted by brrichter View Post
    That is totally false. See post #5.
    Inspector's interpretation. Around here they don't allow a jumper from rod to rod; they would consider the two acorn clamps on the first rod a splice.
    Last edited by Fencepost; 08-07-2014 at 01:54 PM.
    The "Senior Member" designation under my name doesn't mean I know a lot, it just means I talk a lot.I've been a DIYer since I was 12 (thanks, Dad!). I have read several books on various home improvement topics. I do not have any current code books I can refer to. I was an apprentice plumber for two years.

  9. #9
    Join Date
    Aug 2011
    Location
    Northern Indiana
    Posts
    70

    Default Re: Grounding Electrode question

    Quote Originally Posted by Fencepost View Post
    Inspector's interpretation. Around here they don't allow a jumper from rod to rod; they would consider the two acorn clamps on the first rod a splice.
    Sorry your people are misinformed. Got to keep the inspectors happy. As a matter of fact, I always install a continuous conductor, but it's not required. Saves the cost of an additional acorn.
    Last edited by brrichter; 08-07-2014 at 02:09 PM.

  10. #10
    Join Date
    Aug 2014
    Posts
    3

    Default Re: Grounding Electrode question

    Thank you very much everyone

    According to the graphic, it's fine to use two acorn clamps, but I do see how running a continuous line could be beneficial and possibly even lower the resistance a bit, not to mention that, since I'm running a new ground line in it's entirety, one way is just as easy to do as another.

    I noticed in the picture the bonding wire between the two electrodes was buried. Any requirement on the burial depth? NEC requirement anyway, I know my local ordinance could be different.

    Unfortunately, the water line is a no go. the four inches or so of pipe that used to be exposed is covered by that epoxy. I don't know how good of a ground it would be anyway. When I moved in the entire main water line was corroded through. The plumbers ran a PEX insert down through the old line to the meter, so the old iron pipe isn't even in use anymore. Just abandoned to finish corroding away.

    Edit: Spelling
    Last edited by alexkharden; 08-07-2014 at 02:17 PM.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •