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I need to determine which wire is the incoming hot wire in an outlet which is connected to several others. With a two prong tested I assume I touch one prong to a black wire one at a time. Not sure about the other. The ground wire? Thanks

Dear Jon,
There are a few ways in which to do this.
I am assuming that the outlet you are looking at is a single gang, (single duplex recepticle) box. 
If not, that's ok, we will still be able to help.
First, look on the left side of the recepticle, (facing it) and you should see two black wires screwed into the side of the outlet. If they are not there, then they are back wired. i'll assume for now that they are there.
Look to see if there is still the small piece of brass connecting the connection underneath the two screws. It should be there......the onmly time it is not is when someone puts each outlet of the recepticle on a separate circuit, which is rare.

OK.  Plug a radio into the recepticle, turn up the volume, then go to the panel box and turn off the currect breaker. The sound will turn off when you get the right one.
Unscrew the recepticle from the box, and pull it out a bit, so as to get to all screws easily.  A recepticle in the middle of a run usually has 2 black, (hot) wires, two white (neutral), and a copper ground wire attached to the green ground screw.

Disconnect the two black wires and do not allow them to touch anything.  Then go turn back on the breaker, then test each wire putting one probe on a black wire, and one on a white wire.  The "hot" wire will light your tester, the black wire that goes to the others "down the line" will not.  At this time, you could test other recepticles...the ones that are now not working are on this same circuit. Understand that there may be other recepticles that are also on this circuit that are still working because they are between the recepticle that you disconnected and the panel box.

I hope this helps.........if not, or you need further help, send me a PM and i'll give you my phone number to help you better.   I am not a electrician, but I completely wired my whole house with over 50 circuits, installed a whole house generator, etc.......I enjoy house wiring.

Frank D.

faithfulFrank wrote:
Not so rare at my house. I have 3 in the kitchen (so I can switch the under cabinet lights) and at least one in every room in the house ( to switch lights at the rooms doorway).

If I were you Jonathan, I would get someone to help me and show me in person.

That's my disclaimer.

Thanks to you both. I'm wanting to replace a GFI and when I took the old one out, didn't mark the two black wires; one is "hot", coming from the breaker box, andf the other "load" going to the other outlets on the circuit. I picked up a simple one prong test light at Home Depot tonight. I think I will be able to use it to determine which wire is "hot" and hopefully go from there. 

Another suggestion. Use electrician screwdrivers! Rubber handles! You can pick em up at Sears, Ace Hardware, electrical supply's, etc.






You can also get them with insulated shafts.

damn...and thats how i got this curly hair.

i should have asked questions...i only glow like a lightbulb now.

later chris