HELP:Upgrading two prong electrical sockets

[Jammies]

I have read the postings on this topic in this news group and haven't found one quite like mine so....

Yes, I live in a 1959 house, and the house sockets are only two pronged...

Now, when I removed the faceplace and socket, I found wires entering the metal box from the top and connecting to the socket. And another set connecting of wires connected to the same poles exiting the bottom of the box... At both the top and bottom of the box there is a cylindrical opening which the wires pass though. Coiled around the cylindrical opening is a bare copper wire. The coils of bare copper wire are on both the top and box and the trailing end exits the

Here is my situation. I removed the faceplate covering an two pronged outlet, and then removed the outlet itself ( yes, breaker was opened prior ). Inside I found wires entering the metal box from both the top and the bottom. One black, one white from both the top and the bottom. These were connected to the outlet. In additon, coiled around the opening at both the top and the bottom of the box is a bare copper wire. The bare copper wire is crimped to the box, but not continuous. Two seperate copper wires are visable. Neither wire was connected to the outlet.

Now, does this possibly mean the socket can be updated to a three pronged outlet by attaching a grounding wire to the box? Or in other words, how do I test to see if bare copper wire is actually a grounding wire and thus will work safely with a three pronged outlet?

Thanks,

Jammies

[Wade Lippman]

I am confused. You mention that a bare copper wire is crimped to the box (do you mean attached with a clip?) and also that there are bare copper wires not attached to anything.

So, how many bare wires are there, and are they attached to anything?

Presumably you have no test equipment, and you probably don't want to buy any, so you can't check continuity or voltage to "ground". You could take the cover off your panel and see if there are bare copper wires there attached to a grounding buss. Assuming there are, the wires in your box are "probably" grounded.

Assuming your box is steel, and that the bare wire is clipped to the box, then a 3 hole outlet will be automatically grounded through the attachment strap. However, it is preferable to attach the ground wire to the green ground terminal n the outlet. It is also a real good idea to buy a $5 circuit tester to confirm you have done it properly.

[B]

I was confused when I wrote it.... sorry.

The box is metal - steel I assume. There are knockout holes top and bottom through which the wires enter the enter and exit the box. The white and black wires are connected to the outlet. White wires to the silver colored terminals, the black to the brass colored terminals. This is currently a two pronged outlet so there is no ground (green) terminal on the outlet.

Now, at the openings of each knockout, there is a piece of metal which crips the wires at the opening of the knockout. I guess to hold the wires in place so they are not pulled out. It is to this piece of metal to which the bare copper wire is wrapped and crimped.

I do not have any test equipment, but I am not against buying the required tools/testers. It was suggested by an individual that I could run a tester from the black (hot) to the bare copper wire while the power is on. If the bulb in the tester glows, the bare copper wire is a ground. He also suggested a volt meter which would show a result of

110 volts in the same set up if the bare copper wire was a ground. If the bare copper wire was not a ground, then neither the bulb would glow, nor the volt meter register 100 volts. Sound like good advice?

I have yet to remove the panel from circuit breaker box....

I do intend to run a bare copper wire from the green terminal to a screw attached to the metal box.

Thanks for the help. Any further insight appreciated.

Jammies

[Wade Lippman]

Okay, that is just a cable clamp, and isn't adequate for a ground; at least not on any I have seen.

Those tests are fine. If you are going to do any future electrical work, invest $40 in a volt-amp meter. If this is probably about it, then $2 for a cheap tester (two contacts with a bulb) will be fine; though a $5 circuit tester (a plug with three lights on it) is always a good investment for testing the outlet when you are all done.

Even if you can use the ground (and I expect you can) it may not work at that outlet. It has to be attached at all the preceeding outlets on the circuit first. I hope the reason for that is clear.

That will only work if the two bare wires are securely attached to the box. They sell green clips to do that

Properly, you should take the two bare wires and add two pigtails, and connect all four wires together with a brass crimp; run one pigtail to the outlet ground terminal, and the other to the box.

If you want a simpler method that is still adequate, they have green wirenuts that have a green wire coming out of the end. Stick your two barewires in the wirenut, and the green wire to the grounding terminal on the outlet. The box is then grounded through the outlet strap.

[Chris Lewis]

According to Wade Lippman :

Actually they aren't. For example, if you have a neon tester, touching one lead to hot, and the other to your fingers will have the bulb glow, and you're a lousy ground.

Voltmeters ditto.

You need to be able to show that (a) the resistance is low and (b) it's capable of withstanding substantial current. Neither a "bulb tester" nor voltmeter will show that.

The electrical wiring FAQ suggests wiring a 100W lightbulb from hot to ground.

The above is if the ground wires aren't long enough to touch. But, instead I'd: wirenut a short length between the two wires, with another length going to the box and then to the outlet screw. Two wirenuts, no crimps, two extra lengths of wire.

Assuming the cable's ground wires aren't very long, but long enough to meet, wirenut the two wires plus a long third one. Run the other end of the third one under a box screw and thence to the outlet screw. Only one wirenut and one length of wire.

If the bare grounds are quite long, run the "feed side"'s bare ground to the box screw, thence to the outlet screw, then wirenut the end to the other cable's ground. Only one wirenut, no short pieces of wire.

[psmith]

Just a comment, The handiest thing in my fathers tool box "and I still have to this day" is a rubber pig-tale-standard screw shell- light socket with a 220V/60W- rough service-bulb. Yes if you can afford it buy good test equipment and LEARN the POROPER way to use, but get it from electric supply house where the profesional contractor gets his...NO thats not Wal-Mart....LOL. Oh by the way, yes I am a newbee and I think I see a lot of real good advice in here .... been lurking for a while off and on.(I'm in the middle of NY State near Coopoerstown..US.) I'm old and retarded.... ;-) Papy smiff