John S
John S
  • Hometalker
  • Lithia Springs, GA
Asked on Jan 3, 2012

Can you replace two prong outlets with three prong outlets?

ScottSolutions Electric, Inc.Midlantic Contracting LLC / Midlantic Electric Inc
+4

Answered

I have an older house and all of the outlets are two prong except for the kitchen. Can these be replaced without having the house rewired?
7 answers
  • Ace Solves It All
    on Jan 3, 2012

    hi John the simple answer is no code does not allow this. if you replace a two pronged outlet you can replace it with a gfci receptacle. years ago we could still find two pronged outlets but i have not had the need and or looked for them. also if the wiring is that old in your home i suggest you rewire it when you can and until then if possable protect each circuit with a AFCI (arc fault circuit breaker) until you can rewire it as that will offer a level of saftey until you get it done. if you cannot rewire the home in full cosider doing it in phases with the heavy loads done first such as the kitchen,laundry,bathrooms and any other major electrical items you may have. i hope that helps. take care, Charlie

  • 3po3
    on Jan 3, 2012

    I had an odd experience with this a little while ago. I called an electrician who replaced our very old, dangerous panel a couple of years ago. I said I wanted to rewire the house and he asked "why?" I explained and he seemed confused, but promised to come by. After postponing twice, he just never showed up to give me an estimate. Ace, your answer has inspired me to look for some more estimates.

  • Yes you can install three prong outlets. However the method on how you do this is determined by the type of wiring you have in your home. Starting old first. If you have Knob & Tube wiring, ideally you should reconsider rewiring the home. But if that is not an option and you need a few grounded outlets. You will need to run another green ground wire to the outlet box and then to the outlet itself. Starting from the panel ground and working to the outlet(s) If you have a older cloth covered Romex wire system the ground should already be there inside the box. You need to look inside for the bare copper wire that is twisted together and then oftentimes run out of the box within the wall cavity and screwed to the box. If this is there, you simply insert a grounding screw into any of the remaining screw openings within the box and run a short ground wire to the outlet itself. If you have BX wires normally this is the same as the older Romex wires. Look for that little ground wire coming out of the cable and that is attached to the inside or outside of the metal outlet box. If you see it, simply do as the Romex one. Run a wire from box to outlet. If you do not have that extra bare ground wire that is connected to the box you have one or two options. Run a wire as with the Knob & Tube wiring, or wire a GFCI outlet and mark it GFCI protected ungrounded. Do not rely on the bx exterior sheathing to provide a useful ground. Many have and lost their homes when the metal outside began to glow when power went through it because of a short. A lot of what you do will depend upon what the reason is that you need a three prong outlet for. If its simply for looks, and the outlets are for table lamps and such, not a real big concern, However if you need to do this for special Holiday Gifts such as that new 60 inch TV, I would strongly suggest that you either run a ground wire to the box or a new wire completely to assure that your equipment is properly grounded.

  • Ace Solves It All
    on Jan 4, 2012

    hi although there is a lot of good information here and Woodbridge does a great job one point is not correct and can be ver dangerous. if you have bx wire which is a metel covered cable it would be the old style which the outer metel jacket and the small wire in the cable assembly was never approved as a grounding path and DO NOT use it as such. that small wire was meant to hold the red head (insulating bushing ) which goes on the end of the cable at each connection. using this type of cable for a grounding path would be against code and a saftey problem. also a lot of these old electrical boxes had no tapped holes for a green grounding screw so you can use a grounding clip which clips over the edge of the box. also when looking for a ground wire in any old non metel cable assembly sometimes they just back wrapped the wire around the cable and it will be under the clamp holding the wire in the box. if you find this condition remove the clamp unwrap it ground the box properly splice it and have a ground wire continue out to the receptacle. when this situation is found you must also chase that wire back through all the other wiring devices back to the panel to make sure you have a good grounding path as that wire as installed at the original installation was not installed aa an approved grounding path. all this being said if you have any doubt hire a proffesional as in electrical work just because it works does not mean it is safe. i have been a licensed electrical contractor and trainer since the 70"s take care, Charlie

  • Charlie, I dare to correct you here. BX wire is a trade term used to describe Type AC wire as listed in the NEC Book. The small metal wire inside is not for holding in the "Red Head" (another trade term) or anti-short even though that is what we all do with it. This is a bonding wire inside the metal jacket to make it the equipment grounding conductor as approved in the NEC and UL Listing. Type AC wire is designed to be current carrying wires inside an approved grounding jacket. No green/bare copper wire. I agree that the AC metal cable jacket usually is not installed properly and is probably not a good grounding path back to the panel. So, to answer the original question from John S, If there is a good ground in the box you can put in a three prong outlet but it MUST be properly grounded. If there is no good ground then you either have to provide one from the the nearest grounding means or us a GFCI receptacle and mark it as ungrounded. Any receptacles down line and protected by that GFCI may be replaced with 3 prong but MUST also be marked ungrounded.

  • Solutions Electric, Inc.
    on Jan 17, 2012

    need to check and make sure that you have a 3 wire system and that the wire at the receptacle is not Aluminium....if so the replacement receptacles have to be rated for Aluminium wire

  • Scott
    on Mar 30, 2015

    Have a licensed electical contractor do the work... sometimes inexpensive does not work!

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