[Maureentoo]

I replaced some outlets and the old wiring is all black and I'm pretty sure I reversed the hot and neutral on some of the plugs. If there is no ground in a plug will those 3 prong testers still tell me if I have the wires reversed? Also, on 2 of the GFCI's I installed my pen tester goes off as soon as I touch the cover. If I get a 2 prong neon tester how would I test whether wires are reversed with that? Any suggestions are appreciated.

 

[Grampa Bud]

Get yourself a three prong tester with the little lamps down one side. What you have already told me is you have hot where ground should be. Be safe . The tester will tell exactly what is wrong and what needs to be remedied. A neon tester will only tell you that you have power and can fool you if there is a high enough inductive field nearby.

 

[Maureentoo]

Technically, the ground would go on the green ground screw. I'm referring to the neutral wire on the silver screw. Without the 3rd ground wire being present, will that 3 prong tester still work accurately?

 

[Grampa Bud]

Yes It will.

 

[Maureentoo]

Awesome, thank you. If the wires are crossed as I'm sure some are, would the pen tester light up/ring on all 4 prongs of a 2 outlet receptacle? If not, then what could be causing that to happen?

 

[Grampa Bud]

The pen tester only indicates power as well, but if you have the recepticle out of the box and away from nearby metal it is possible to touch either the silver or brass screws with the tip of the tester and back it slowly away from the screw. If it indicates power at both screws it should remain lit a short ways away from the Hot screw, and will immediately go out backing away from the neutral screw. It shouldn't buzz at all four slots though. Be sure the tabs are not broken on either side of the recepticle and recheck the wires in your boxes. All one color is asking for trouble. Hot goes to brass and nuetral goes to silver.

 

[Maureentoo]

I can't have all hot in there since they all worked fine for years before I changed them, and I haven't added or subtracted from the existing wiring. I must be picking up voltage with that pen tester, and that's why I'm getting a hot reading on both sides of a few of them. However, I'm testing them with the faceplates on and the outlets inside the box. I'll get a 3 pronger tester and try that, then I'll turn off the breaker and pull them out and test them up close and personal. I'm so glad I bought that circuit tracer, haha. Thank you for your help, I really appreciate it.

 

[theatretch85]

Without a known ground/neutral reference it will be difficult to determine which wires are crossed. The 3 light circuit testers should be able to determine this, but I don't know if they need the ground to verify the hot/neutral reversal.

If you are buying the tester, get the one with the button, especially if you are working with un-grounded outlets protected by GFCI's. The button tests the upstream GFCI functionality, so where you dont have the "test" button on your standard outlets but you have them protected by a GFCI, the button press will check to make sure that GFCI is working. Its only a dollar or two more than the standard non-GFCI tester is.

 

[Maureentoo]

Without a known ground/neutral reference it will be difficult to determine which wires are crossed. The 3 light circuit testers should be able to determine this, but I don't know if they need the ground to verify the hot/neutral reversal.

If you are buying the tester, get the one with the button, especially if you are working with un-grounded outlets protected by GFCI's. The button tests the upstream GFCI functionality, so where you dont have the "test" button on your standard outlets but you have them protected by a GFCI, the button press will check to make sure that GFCI is working. Its only a dollar or two more than the standard non-GFCI tester is.

But if I remove the outlet and have the wires separated out of the wall, once I turn the power back on I should be able to find the hot and neutral wires easily. If there are only 2 wires, one has to be hot the other has to be neutral. Then I can move to the next outlet once I know that one is wired correctly. Right? <And thanks for the tip on the tester, I wouldn't have known the difference in them>

 

[HouseHelper]

In the absence of a true ground, the three light plug-in tester will only tell you that you do not have a ground. It is of no use in determining whether hot and neutral are reversed.
If you have a GFCI receptacle that has no ground, the plug-in tester with the GFCI test button will NOT work.

 

[HouseHelper]

Best way to check which wire is hot is with a meter or Wiggy, an extension cord, and a receptacle whick is known to be wired correctly. Plug the extension cord in to the known receptacle and measure for voltage between the wide slot of the cord (female end) and each wire. The wire that gives you 120V is the hot.

 

[Maureentoo]

Best way to check which wire is hot is with a meter or Wiggy, an extension cord, and a receptacle whick is known to be wired correctly. Plug the extension cord in to the known receptacle and measure for voltage between the wide slot of the cord (female end) and each wire. The wire that gives you 120V is the hot.

I have no idea if any of the receptacles are wired correctly, since I didn't do it myself. I've found some pretty weird stuff behind some faceplates and inside work boxes. Old houses that have had several owners tend to be like that. I guess the only way to really find out would be to remove all the receptacles on a circuit, separate the wires on each plug, and find the 1 hot wire coming from the breaker box.

 

[PaliBob]

You can check for correct polarity with your pen tester if it conforms to this standard. One way to think of it is that the smaller opening makes it harder for a small child to stick a metal object into the opening.

 

[daxinarian]

a potential issue... how do you have a 3 prong outlet (I am assuming it is a 3 prong outlet since you were talking about a three prong tester) but no ground present. The only "legal" way to do this is with a gfci outlet.

 

[PaliBob]

The only "legal" way to do this is with a gfci outlet.

Dax is correct on this.
A GFCI does not have to be grounded to protect from a ground fault. This sometimes causes concern with inspectors because when they plug in a three prong Polarity/GFCI tester and push the test button the GFCI won't trip because the Test button connects an approximately 18K resistor to ground. Wirh no ground the Test button will not trip the GFCI.

When the Test button on the GFCI is pushed, it trips. What's going on. The answer is that the GFCI test button connects a 5-6ma bleed resistor from AC (after the CT) to neutral (before the CT)

 

[theatretch85]

a potential issue... how do you have a 3 prong outlet (I am assuming it is a 3 prong outlet since you were talking about a three prong tester) but no ground present. The only "legal" way to do this is with a gfci outlet.

I believe the Op is using GFCI outlets, whether they are indeed protecting non-GFCI outlets I don't know for sure, I just assumed that the Op has it wired this way.

As for the GFCI plug-in tester not working without a ground, sorry I had no idea. I have setup GFCI protected outlets before but have always had the ground and the GFCI plug-in tester has always worked every time. The extension cord idea is probably the best idea to get a good reference point, other thought would be a long wire tied to a water pipe (this should be grounded at the main panel/service disconnect). The advantage with the long wire and the water pipe is you don't have to rely on another outlet being wired properly, especially if you are already suspicious of the existing wiring.

 

[Bocolo]

If the box is metal, can't you (asking not telling) just test from the box to each line? The line that gives you approximately 120 volts would be your hot. No?

 

[HouseHelper]

If the box is metal, can't you (asking not telling) just test from the box to each line? The line that gives you approximately 120 volts would be your hot. No?

That would only work if the box is properly grounded... which it most likely is not.
The idea of testing the narrow slot with an inductive "pen" might work, but with old wiring, you are very likely going to get a signal on both slots.
You need a known grounded reference point to definitively determine which wire is hot.

 

[Bocolo]

Thanks for the info. My experience in my house (pretty old) was that although there was no ground wire the boxes were grounded through the metal on the BX cable. Just my experience this may not be the case for the OP. Thanks again.

 

[Maureentoo]

I had to leave yesterday before all the posts were written and have just gotten back here. FYI--yes I know that I have to replace old 2 prong outlets with GFCI's if there is no ground. But that wasn't the question ... :wink: Thanks to all who pitched in with answers!