Grounding electrode/bonding question

Discussion in 'Electrical Forum discussion & Blog' started by fotto, Oct 10, 2012.

  1. fotto

    fotto New Member

    Messages:
    4
    Location:
    Ohio
    Hi,
    I have recently installed two antenna's outside on my chimney on the second story of my house (one for OTA TV signal and one cellular antenna). I am attempting to ground these and have installed a new ground rod (8' long) at the chimney base, and will tie both antenna's to it with #10 solid copper grounding wire (per 2008 code).

    Now here's my dilemma. My main house electrical service grounding rod by my meter is about 50' away from my newly installed rod. I was planning on tieing these two rod electrodes together with #6 solid core copper wire (also per code). Unfortunately, I cannot find my main rod by the service to tie to. I have dug down about 3 ft following the main house ground conductor and am scared to go further lest I hit and damage that conductor while searching for the rod.

    So, I do believe that I could tie the secondary rod #6 bonding wire with the houses main wire by some means (vs directly to the rod) but am looking for opinion for best diy method outside of exothermic welding. My opinion on this is that this bonding wire's main purpose is to bleed off any differential in voltage and currents and not necessarily a primary path for a lighting strike, which is what the secondary rod is for, and subsequently I don't HAVE to tie directly to the main service rod. Is that line of thinking correct?

    If so, any suggestions on a good way to tie my #6 bond wire to that main ground wire would be appreciated.
  2. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    27,034
    Location:
    Cave Creek, Arizona
    Well, unless your house has a lot of fill around it, the ground rod should not be 3' deep. Are you sure you are not following the UFER wire which goes into your concrete footing? You will also NOT damage the conductor by digging next to it.
  3. fotto

    fotto New Member

    Messages:
    4
    Location:
    Ohio
    hj,
    Attached are a couple of pics to help. House was built in 2000. Has underground electric and they had a pretty big trench open at outside service area. Wouldn't surprise me that they drove the rod into the trench bottom before backfill. The ground wire you see at the main service disconnect in my basement (my 200A inside panel is at opposite end of basement) is same that you see coming outside of house and running into the hole. There are no other ground wires anywhere else like at 200A panel or elsewhere, so I have to believe this is the one and the rod is just buried deep.

    After reading a bit more, I am coming to the conclusion to just clean up that wire and connect my #6 bond wire to it with a split nut. What do you think?
    service1.jpg disconnect1.jpg
  4. jwelectric

    jwelectric Electrical Contractor/Instructor

    Messages:
    2,559
    Location:
    North Carolina
    Connect it to the conductor just before it enters the pipe using a split bolt
  5. fotto

    fotto New Member

    Messages:
    4
    Location:
    Ohio
    Picture may be a little bad, but the conductor doesn't enter the pipe. If you look closely you can see it running down the side of it (it's a bit off colored due to weathering) at least to where I stopped digging. I guessing if I continued digging further it would at some point veer away from the house a bit to where it terminates to the buried rod.
    I was planning on connecting via split bolt just below ground level so you don't see it. Any issue with that
  6. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    27,034
    Location:
    Cave Creek, Arizona
    I don't buy it, that someone would install a ground rod at the bottom of the ditch and connect the ground wire. Was the pipe dug and installed AFTER the wiring was done or before it?
  7. ActionDave

    ActionDave Electrician

    Messages:
    361
    Location:
    Colorado
    I'll throw the ground rod in a ditch every chance I get. Too many rocks in the ground where I live to drive one with complete success each and every time.
  8. LLigetfa

    LLigetfa DIYer, not in the trades

    Messages:
    4,141
    Location:
    NW Ontario, Canada
    Personally, I would go with at least #6 down from the mast. Actually, I prefer to run a bracketed tower up from the ground and let the tower be the grounding path. I have seen what lightning can do to a chimney.

    A split bolt would be fine. Exothermic welding is used on more elaborate ring ground systems around communication towers where the main objective is to save the electronics.

    http://en.wikipedia.org/wiki/Ring_ground
  9. fotto

    fotto New Member

    Messages:
    4
    Location:
    Ohio
    Thanks for all the replies. I noticed that the telco ground (see top of disconnect pic where the red tag is) was bolted to the disconnect wire which gives me further confidence this is main service ground. Thur pm I ran my #10 down to second ground rod and then ran #6 over to the service #4 ground wire and connected with a split bolt. I may take the advice on running a heavier gauge down from the mast but next spring if so.
  10. LLigetfa

    LLigetfa DIYer, not in the trades

    Messages:
    4,141
    Location:
    NW Ontario, Canada
    It is common practice to simply lay the rod horizontally in the trench. I know a lot of installers that hate to drive ground rods and will often use a ground plate instead. We often used a jackhammer to drive them down.
    http://www.youtube.com/watch?v=vvCZvNj8H30
  11. DonL

    DonL Jack of all trades Master of one

    Messages:
    4,442
    Location:
    Houston, TX
    What is the purpose for connecting into your power ground ?

    Connecting rods that far apart will do little good.

    #10 solid copper grounding wire is very little protection for a roof mount like yours. Even if some code says Yes. The Ground wire is to long for anything other than static discharge.

    Your Ground and signal wires should follow the same path and be grounded just before entering the dwelling at ground level.

    I personally would not waste the wire, and invest into some Good Antenna Coax protectors, Connected to their own Ground Rod at Ground Level. That would be the best protection for you and your home.


    You do not need to dig for the wire, You can connect it as JW suggested. Just do not cut and splice the original ground wire.
  12. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    27,034
    Location:
    Cave Creek, Arizona
    quote; It is common practice to simply lay the rod horizontally in the trench

    How do you do it when you need two ground rods with separtion between them?
  13. LLigetfa

    LLigetfa DIYer, not in the trades

    Messages:
    4,141
    Location:
    NW Ontario, Canada
    Point them in opposite directions.
  14. Homeownerinburb

    Homeownerinburb New Member

    Messages:
    525
    Location:
    Los Angeles, CA USA
    In two different ditches spaced correctly (6'?) apart...
Similar Threads: Grounding electrode/bonding
Forum Title Date
Electrical Forum discussion & Blog Grounding in ceiling light. Yesterday at 11:35 AM
Electrical Forum discussion & Blog Using grounding bar inside 3-gang metal outlet box Mar 14, 2014
Electrical Forum discussion & Blog Grounding, bonding, old swimming pool Feb 23, 2014
Electrical Forum discussion & Blog 2 grounding/bonding questions Feb 14, 2014
Electrical Forum discussion & Blog Panel grounding question Nov 1, 2013

Share This Page