I want to install a new 3 prong receptacle in an existing metal box in my living room. Currently I have a 2 prong receptacle. I have one line coming into the box: the white wire and the black wires are attached to the receptacle and the bare copper wire is attached to the back of the box. Do I just purchase a new 3 prong receptacle and attach the white and black wires or do I need to do something with the bare copper wire?
Thanks.
Rick
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Bare wire to green screw on new 3 prong. Turn off the power before ya do anything.
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If the box is grounded you shouldn't have run a ground wire to receptacle.
You should buy a tester and check after done. The plug in testers don't cost much.
Will the plug in tester tell me if the outlet is grounded or just whether the outlet is live?
The three-prong tester will show two lights if hot, neutral and ground are connected properly. Other light combinations show open neutral, no ground, hot/neutral reversed and of course no lights mean dead circuit. There's a chart on it to show what the light combinations mean.Best practice is to connect the ground wire to the green terminal of the receptacle. Most good quality outlets have a ground connection on the bottom mounting screw that will work ok because the mounting screws connect the outlet to the grounded box, but it would no longer be grounded if you pull it out for maintenance sometime.BruceT
My tester is small and yellow made by GB. It has 3 lights on it.
It tells Open ground,Open neutral, Open hot, Hot ground reverse, Hot neutral reverse, and correct.
While you're at it, don't buy a cheapo receptacle, especially not the kind that you just stick the wire in back (back-stab).
A spec grade receptacle costs $3 or $4, but it's worth it. The faces are made of nylon instead of breakable plastic and the interior parts are beefier, so they won't become loose and let your plugs fall out like the cheap ones do. Also, they are back-wired, meaning you can insert the stripped wire into a hole in back and tighten it down with the side screw for a really good connection.
If you are wired with a grounded wiring method the easy fix is to buy a little better receptacle that says "self grounding". Then you just screw it into the grounded metal box and you are good to go. There is a brass spring on one end of the yoke that makes the connection.
What gfretwell said in post #7 - self grounding type outlet.
Check with plug in tester / multimeter after installation since in very rare instances the self grounding function does not work properly - usually has to do with boxes which are set "too deep" in the wall. Plug in tester and attempt to shake the outlet - watch lights. 99% work fine.
To be 100% sure of grounding of new receptacle: disconnect existing ground wire from the box; add 2 short pigtails to it with a wire nut; one of the new pigtails connects to box ground screw; the remaining pigtail connects to the ground screw on the receptacle. A self grounding type outlet will have a green ground screw available for this connection.
Test all installations when done.
Jim
You should use a short piece of bare (or green insulated) copper to connect the ground terminal of the outlet to the metal box. There are prepared wires available with crimped terminals on each end and a screw to screw into the back of the box, or you can just use a piece of bare copper.