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-   -   How can I ground a single, ungrounded 2-prong outlet? (https://www.askmehelpdesk.com/showthread.php?t=591642)

  • Aug 7, 2011, 09:53 PM
    AtOurGates
    How can I ground a single, ungrounded 2-prong outlet?
    We just moved into a house with a circuit in the living room that's ungrounded, and wired with 2-prong outlets. We want to set up our media center in the living room, which will require grounded 3-prong outlets.

    I briefly entertained the idea of installing an ungrounded GFCI 3-prong outlet, until I learned that disable surge-protection.

    So - I need to get at least 1 outlet on the circuit grounded.

    After a bit more googling, I was hopeful that the receptacle's box would be grounded, but after buying a pigtail-type tester this afternoon, found that it is not.

    The wiring in the outlet is wrapped in something that looks like the fiber used in fiber-glass, and contains just two wires. Apart from this circuit, the rest of the wiring in the house is grounded. In fact, opposite this outlet on the other side of the wall is the kitchen, with fully grounded wiring and outlets in it.

    The house has a crawl-space underneath it, and it's just about 10 or 15 feet from the outlet in question to the main breaker.

    Completely re-wiring this circuit is beyond my (admittedly lacking) electrical capabilities. But, what I'm wondering is if there's any (safe and easy) way to ground the single outlet we intend to use for the media center.

    Most of the suggestions I've read online about grounding an outlet seem to involve either grounding to the metal box/grounded conduit, or rewiring the entire circuit. Neither is really an option in my case.

    Could I - for example, run a ground wire from the circuit breaker straight to this outlet? If that's an option, would that wire have to be insulated or installed in any type of conduit?

    Is it possible to somehow splice a new ground-wire from this outlet into an existing ground-wire elsewhere in the system?

    If the idiocity of my questions mark me as someone who should never be let within 100 yards of an electrical current, so be it, but I'd love to learn more, even if all I learn is that I need to hire a professional.


  • Aug 8, 2011, 02:47 AM
    tkrussell
    The fix for this is to install a new 2 wire cable with ground from the panel to the receptacle, or it is allowed to install a ground wire from the green screw of a 3 wire grounded receptacle back to the panel and connect to the ground bus or the grounding electrode.

    My opinion is if a ground wire can be installed, then a new cable can be installed.

    If you cannot install the new cable, then you cannot install the ground wire, therefore an electrician is needed.
  • Aug 8, 2011, 04:51 AM
    hkstroud

    If the rest of the outlets in the house are grounded, I suggest that you look more closely at the cable to the ungrounded outlet. It is not unheard of for electricians in the past, to use cable with a ground wire but to fold the ground wire back up into the cable clamp when using an ungrounded out. Testing would show the box as ungrounded.
  • Aug 8, 2011, 07:10 AM
    donf

    If this is an independent receptacle and you are planning on installing your entertainment center, you might want to verify the amperage for this circuit.

    If it is a 15 amp circuit, you might want to consider upgrading to a 20 amp circuit.

    This would require changing the breaker, replacing the cable with a 12/2 cable with ground and in your case I would suggest installing a quad (4) receptacle.

    Here in Virginia Beach, this type of work requires a permit from the city and an inspection to verify that the work was done properly.

    Sounds complicated but it is really very straight forward work. Given your professed lack of electrical skills I would also suggest that you have a licensed electrician do the work.
  • Aug 8, 2011, 08:03 AM
    AtOurGates
    We'll get an estimate for re-wiring the entire circuit with new wiring. As to HKStroud's suggestion, I didn't see any folded back ground-wire's anywhere. Here's a photo of the outlet in question.

    http://i.imgur.com/TZfoK.jpg
  • Aug 8, 2011, 11:35 AM
    tkrussell
    As you initially described, and confirmed with the photo, you have what we called in the trade Loom cable, the predecessor to Romex, which has a grounding conductor.

    Grounding of receptacles was not know to be so important back in the 40's and 50's.

    The cost to install a new cable 10-15 feet and install a new receptacle should not be too much. While someone is there, consider getting a quote to re-wire any other important devices with new cable.
  • Aug 8, 2011, 11:42 AM
    AtOurGates
    Thanks for the great replies.

    I've been convinced that it'd be silly for me to try and ground this myself - and that it's worth getting fixed properly. We'll get an estimate (or two) for rewiring the entire circuit, or at the very least that outlet.
  • Aug 8, 2011, 01:09 PM
    hkstroud
    1 Attachment(s)

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  • Jul 7, 2012, 11:29 AM
    laszaroid
    An unorthodox option is to verify if one of your other GROUNDED(3 cable) circuits is currently underused; perhaps you have a circuit which only feeds a few lights and outlets you are not likely to use anyway. Connect a grounded 12gauge cable at an accessible or convenient location to this underused circuit using a junction box inside which you will connect white to white, black to black, and green to green. Run the other end of the cable behind the wall to a desired site for a completely new, grounded electrical outlet and hook it up. Now you have a new grounded circuit feeding off a pre-established , grounded circuit, or a 'parasitic circuit'. It will work just fine. Remember to drop the wire gauge by one unit for every 60 feet of conducting cable. If the location where you plan to attach the new circuit to the pre-existing one is already fairly far from electrical panel, at or near 60 feet, you will have to use 10 gauge wire for the 'parasitic circuit'. I have NO idea if this solution is considered acceptable to home insurance companies.
  • Jul 8, 2012, 04:03 AM
    tkrussell
    Not only unorthodox, but NOT allowed by Code, therefore, not covered by insurance.

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