Replacing an electircal outlet (receptacle) that might have been wired wrong?

Question

I was plugging in my TV and game systems into an electrical outlet that worked fine last year, when suddenly all of the power from that outlet stopped. I checked the breakers, and they are all fine, so then I decided to take the receptacle out. The receptacle was a three-hole one, with two brass screws on the right and two silver screws on the left. There is also a green screw on the bottom-left.

The only two wires that were wired to it were two black wires, one connected to the top-right brass screw and the other to the top-left silver screw. The other silver screw was connected to the green screw via a short wire. Looking at some diagrams online, I'm not sure if that receptacle was wired correctly, although it did work for quite a while. How should I go about re-wiring a new receptacle to it, seeing as I'm not sure if those two black wires are two hot wires, or just one hot and one neutral. Thanks!

Answer 1

TRY to remember which black wire was connected to the silver/brass screws. Having two black wires would tell me that its an older house/older wiring. Does the green wire run with the two black wires or is it just two black wires? The color of wiring should be GREEN to green screw, WHITE to silver screw and BLACK to brass screw. Since both wires are black, make sure the wire that was connected to the brass screw goes to the brass screw and the other black wire that went to the silver screw goes to the silver screw. P.S. Make sure the power to that receptacle is off or you will jet a shock.

Answer 2

There are 2 types of testers that you should get to check this--and any other-- receptacle. The first is a 3-prong device with 3 plastic lenses in front that light up when you plug it into an outlet; there is a little chart on the top of this circuit tester that tell you, when different colors and combinations of are displayed, things like "open ground' or 'hot/neutral reverse.' Try it on your receptacle the way that it's wired right now and see what the lights tell you. Normally, the black wire (hot) goes to the lower BRASS screw and a white wire (neutral) would go to the lower silver screw and a green or bare wire (ground) would go from the bottom green screw to the ground wire that comes into the junction box. The other tester has 2 wires, 1 red and 1 black, with a metal probe/tip on each wire, connected to a plastic or rubber-encased device about the size of tour thumb; it should read '110/120' and 220/240'...when you put one probe on the black wire and one probe on the white wire, a light should come on for EITHER the 110/120 window OR the 220/240' window. Normal household receptacles are 110/120 volts. Also, sometimes when a house gets painted and the receptacle covers aren't in place, the wires get painted... most commonly, the black wire gets painted white, confusing things; if possible (with the power at the circuit breaker turned OFF at this point in time), see if you can pull the wires farther out of the wall to see what's going on in terms of wire colors. sometimes what happens with receptacles, if the wires were pushed into the back of the receptacle instead of wrapped around their respective screws, the wires are loose, and pushing them in (with needle-nose pliers) all the way will make a better connection, although I prefer a well-screwed-down wire on its screw. If the junction box is metal, you can screw a ground wire onto it, then connect that to the Romex ground wire and the ground attached to the receptacle, using a wire-nut. If you can't ground the receptacle, then install a GFCI receptacle, black wire to lower brass screw and white wire to lower silver screw. Turn the power back on and check the GFCI with the 1st circuit tester: the lights will tell you (on the chart) that you have an 'open ground' which is OK WITH A GFCI PLUG! To test to see if both black wires are 'hot' put 1 probe on 1 black wire and the other probe in the screw hole of the junction box IF IT'S METAL, and the power tester will either light up or not....if it lights up, it's hot; if no light, it's the neutral...but always check the other wire the same way, too. You do NOT want only 2 hot wires and no neutral! Lastly: plug your TV, game box, computer, et., into a power strip surge suppressor, THEN plug the suppressor the receptacle; household current fluctuates and that could damage sensitive (and expensive!) electronic equipment. If you had those items plugged into a suppressor when things stopped working, it is likely that the suppressor did its job and flipped off, blowing its internal fuse, which can be replaced.

Answer 3

The wire from the ground to the neutral screw is called a boot leg jumper and is a violation of the electric code. It is how some handymen and wanna be electricians wire 3 prong receptacles when there is no ground available. It will trip the circuit breaker if something plugged into it shorts out, but it isn't right. The two black wires are a hot and a neutral or the receptacle would not have worked before. Of course, none of this answers your problem of the receptacle not working. If there is no ground available at that box, the only options you have according to the national electric code, is to install a 2 prong receptacle or install a GFCI receptacle in that box. Be careful taking electrical advise on here from well meaning but untrained people.

Answer 4

That outlet was definitely incorrectly wired.
The Green screw should be connected to the ground wire only. The silver screw should be connected to a white, (neutral), wire.
Black wire is for hot, (phase), legs only and should only go to the brass screws.
From your description, it is not possible to be exactly sure just what the chimp who did this job was thinking.
It sounds like he was using the ground as a neutral, and that connection came loose. Worse, he was wiring the power through the load portion of the outlet, instead of at the same side terminals.
Best call an electrician. There might be other dangerous 'ad hoc wiring` situations around.

Answer 5

You really need to test the wires first to find out if they are both hot or not then when reinstalling the new outlet just one on each sidehot on brass and neutral on silver side and if there is no ground wire to hook up and you cannot run one to a ground source from there then just use the neutral for your ground also like was done before.