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-   -   Ground on Outlet w/ Minimal or No Wall Damage (https://www.askmehelpdesk.com/showthread.php?t=374110)

  • Jul 10, 2009, 12:47 PM
    bergs4
    Ground on Outlet w/ Minimal or No Wall Damage
    Hello,

    I have two prong outlets in my home (built around 1946). I have two outlets in the bedroom that need to be grounded. I have grounded a few other outlets in the house by running wire to a cold water pipe and a ground rod I installed. When I grounding those outlets, I ended up with quite a bit of plaster repair. Is there a way / and or a tool I can use to minimize or eliminate wall repair? Once I drill a hole in the sole plate (via my crawl space access), I will have unimpeded access to the electrical box.

    Thank you.
  • Jul 10, 2009, 01:08 PM
    ballengerb1

    Do you need it to be grounded or just 3 prongs? Your could add a GFCI outlet to each box which will provide ground fault protection but it will not be a grounded outlet.

    Maybe one of the electricans can come to this post and talk to how you grounded your other outlets, I don't think its entirely safe. Do you have a jumper ground wire across your water meter?
  • Jul 10, 2009, 01:31 PM
    stanfortyman
    Quote:
    Originally Posted by bergs4 View Post
    I have grounded a few other outlets in the house by running wire to a cold water pipe and a ground rod I installed.
    Just so you know. This is NOT an acceptable method of obtaining a ground nor is it safe.
    A cold water pipe can be used IF it is being used a grounding electrode AND if the connection is made within 5' of where the pipe enter the house.

    A ground rod alone is NEVER a source of ground in the context that you need it, unless it is also bonded to the grounding electrode system or main panel.

    I suggest you read up on NEC section 250.130(C).
  • Jul 10, 2009, 05:15 PM
    bergs4
    If I do go the GFCI route, what are potential downsides?

    Also, just curious, why does the code prohibit using the ground rod / pipe for grounding individual outlets? Is it it to protect plumbers in the case of the pipe becoming energized?

    Thank you.
  • Jul 10, 2009, 05:37 PM
    ballengerb1

    Codes vary but its likely a code violation. It protects you and the plumber. The downside of a GFCI is that its not a ground just a fault detector. Did you answer my question in post #2, grounded or just 3 prongs?
  • Jul 10, 2009, 06:28 PM
    stanfortyman
    Quote:
    Originally Posted by bergs4 View Post

    Also, just curious, why does the code prohibit using the ground rod / pipe for grounding individual outlets? Is it it to protect plumbers in the case of the pipe becoming energized?
    Grounding a receptacle comes from the neutral bond in the main panel. NOT from the earth.

    Ground rods and water pipe electrodes serve a completely different purpose.
    A water bond prevents metallic piping system(s) from becoming energized.
  • Jul 10, 2009, 06:47 PM
    bergs4
    Sorry -- would like both . It is incredibly frustrating to have only two prong outlets when many things these days come with three prong plugs. Yet, I do realize that the plugs are three-pronged for a reason. Since the outlets are in the bedroom, I anticipate that I will use them for a computer, lamps etc.

    At this point, it would be cost-prohibitive to have an electrician rewire the outlet / update the service panel. So, I am looking for a solution that I know will have to be a compromise that will provide the most safety for my family, yet is also practical.

    Thank you.
  • Jul 10, 2009, 06:50 PM
    ballengerb1

    Current new construction codes call for bedrooms to be ARC faults rather than GFCI. Are yourwires inside conduit, probably not with this age.
  • Jul 10, 2009, 06:51 PM
    bergs4
    No, the wires are in the paper wrap -- I forget what it is called. Not knob and tube though.
  • Jul 10, 2009, 06:55 PM
    ballengerb1

    K&T looks like this, is it what you have? Knob and tube wiring - Wikipedia, the free encyclopedia
  • Jul 10, 2009, 06:59 PM
    stanfortyman
    Quote:
    Originally Posted by ballengerb1 View Post
    Current new construction codes call for bedrooms to be ARC faults rather than GFCI.
    Right, but he is upgrading the receptacles, not the branch circuits. It is the branch circuit that requires AFCI protection, not the receptacles.


    The point about GFI protection is that it is a legal way to install three-prong replacement receptacles on a circuit without a ground.
  • Jul 10, 2009, 07:03 PM
    bergs4
    No; it's not that. The best I can describe it would be like romex cable with no ground, except instead of the plastic / rubber sheathing it's like a rubberized fabric on my wires.
  • Jul 10, 2009, 07:04 PM
    bergs4
    Mine is like the wire in the upper right portion of this photo:
    http://upload.wikimedia.org/wikipedi...-and-tubes.jpg
  • Jul 10, 2009, 07:05 PM
    ballengerb1

    Ok we are making some progress, not K&T. Romex is plastic cable, did you mean BX BX Cable
  • Jul 10, 2009, 07:06 PM
    ballengerb1
    Crappers , we are back to K&T
  • Jul 10, 2009, 07:12 PM
    bergs4
    With respect to the GFI being the legal way to replace a two prong with three, I guess I'm still wondering safety-wise, is there a downside to having only a GFI as my uderstanding is that in new construction the GFI would be grounded as well.

    No, no -- not knob and tube.

    If you look at that photo, there is both knob and tube wiring (as I understand it) and the type of wiring I have , the name of which I don't remember.
  • Jul 10, 2009, 07:20 PM
    ballengerb1

    The picture you posted was knob and tube so I am getting confused here but maybe you are referring to that silver looking cable at the bottom of the picture. If money and the amount of work is your concern then go with individul GFCI receptacles, safer than what you have, $15 per receptacle and legal. You can't have it all without having a electrician tearing it all out.
  • Jul 10, 2009, 07:23 PM
    bergs4
    Okay, I'll do the GFIs then. Thanks for the patience and help.
  • Jul 10, 2009, 07:23 PM
    stanfortyman
    Quote:
    Originally Posted by bergs4 View Post
    With respect to the GFI being the legal way to replace a two prong with three, I guess I'm still wondering safety-wise, is there a downside to having only a GFI as my uderstanding is that in new construction the GFI would be grounded as well.
    A new installation would have a ground run. It's been required for many many years.

    A GFI protecting a circuit without a ground is much safer, but it still does not provide you with a ground that many modern electronics require.
  • Jul 10, 2009, 07:24 PM
    bergs4
    Okay, that makes sense.

    Thanks for the help.
  • Aug 6, 2009, 09:35 PM
    bergs4
    I've been doing some research and am starting to understand the difference between bonding and grounding a little more and the foolishness of attempting to "ground" an outlet to a metal water pipe / grounding rod. My hope is to hire an electrician shortly to upgrade my panel. When talking to him, how do I make sure he knows that'd I'd like the panel both bonded (my understanding is that this allows the electrical current to go back to its source, i.e. the power plant instead of through a person in the event of a ground fault) and grounded (which, based on my understanding, only serves as current "drain" in the event of a high voltage fault, like lighting, for example)? Is it common practice for an electrcian to bond and ground the panel when it's being updated?

    Also, a separate question I have. Is it safer in general to use plastic boxes as opposed to metal, since if a wire comes loose, the plastic will theoretically be less conductive than the metal? I realize that a bonding path should protect against an energized metal box, but what if there is a fault in that path? I just don't understand why it would ever make sense to use metal. What am I missing?

    Thanks!
  • Aug 6, 2009, 10:01 PM
    KISS

    You know about these bits? Piranhabits Flexible Fish Bits available from Lashen Electronics They are like 54" long.

    Q2: Plastic won't support a ceiling fan. Metal boxes might pop a breaker if a wire came loose and you would know immediately.

    Q1: It's a bit harder. Ground and neutral get connected together in one place. This provides a reference point. i.e. What is zero volts. Your cable TV is tied to this reference too.
    The ground rod or copper water pipe can provide lightning protection. You don't want lightning to raise the reference of other circuits. Your plumbing system and your gas supply may have to be bonded as well. The neutral to ground bond also provides fault protection for things like insulation breakdown in a grounded appliance. The fault current goes to ground and doesn't raise the ground potential like a stray water pipe can.

    There are lots of details missing from the above post, but it should give you a general idea.
  • Aug 7, 2009, 12:23 PM
    bergs4
    I didn't know about those bits; they could potentially be very helpful.

    So, current always will flow towards a zero reference point? I realize that electricity and circuits for that matter are a lot more complicated than attach white to white, black to black etc, but is there a simple way to explain where excess current might go in the event of a fault? Does it flow along the neutral (or ground in the event of a fault in the neutral) back to the box where it is then safely dissipated out through the neutral supplied by the utility company?

    And by reference, does that refer to volatage reference?

    Thanks for your help.

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