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Plug Wiring Reversed?

Discussion in 'Electronic Repair' started by Niel, Sep 6, 2004.

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  1. Niel

    Niel Guest

    I just bought a house and the inspector tagged four of six basement
    outlets as hot/neutral reversed.
    I open the first two, see the problem, and fix it (one of two blacks
    was going to silver and one of two whites was going to brass).
    However, the other two "bad" outlets are already wired correctly
    (white to silver/black to brass).
    Plus, these two outlets have one set of wires (white/black/ground)
    instead of two sets, which may not be a problem, but could be a clue.
    Supposedly, if I switch the wires, the plugs won't be reversed
    anymore. But that would put white on brass and black on silver.
    Maybe the electrician got the white and black wrong at the head end,
    wherever that is. So switching the two at the plugs will be the right
    thing to do.
    If the inspector was right, what is wrong with the wiring and how do I
    fix it?
    If the inspector was wrong, how could that be, as he was right about
    two other plugs in the same room?
    Or do I need to spend a couple of bucks on a sensor to check for
    myself whether the inspector was right?
  2. Swap black and white at both ends. This involves working on your breaker
    panel, which is dangerous. I recommend hiring an electrician.
    He'll only be wrong if he mixed up his results after making measurements.
    That's what I'd do. And don't let the erroneous situation persist.
  3. DanG

    DanG Guest

    It sounds like you need to buy the gizmo. If the wiring was
    crossed anywhere you have the potential for a "back fed" neutral.
    If the color code was followed meticulously through the entire
    circuit you will not have a problem. Sounds like some home wiring
    went on at some time.

    Keep the whole world singing . . . .
    DanG (remove the sevens)
  4. bumtracks

    bumtracks Guest

    my dad can wire recpts backwards
    seems addicted to it.
    his simple method works
    1- gotta use a plastic box
    2- and if something trips the breaker cut off its ground prong
  5. Spend a couple bucks and get an outlet tester.

    Then, when you confirm that they are still bad. It's possible that the outlet
    you fixed was upstream of one or both of the other miswired ones and all is
    not well.

    If not, it's possible that the outlets that test reversed are fed from
    upstream outlets whic are miswired for the wiring feeding those outlets.

    --- sam | Sci.Electronics.Repair FAQ Mirror:
    Repair | Main Table of Contents:
    +Lasers | Sam's Laser FAQ:
    | Mirror Sites:

    Note: These links are hopefully temporary until we can sort out the excessive
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    Important: Anything sent to the email address in the message header is ignored.
    To contact me, please use the feedback form on the S.E.R FAQ Web sites.
  6. [This followup was posted to and a copy was sent to
    the cited author.]

    Just buy one of those cheap things you plug into an outlet. It has 3
    neons in it that can quickly find common wiring errors. Some versions also
    have a button to create a leakage that should trigger a GFI outlet or
    circuit breaker to trip. They are only a few bucks and well worth it. I've
    found reverse wired outlets in apartments I've lived in.

    Reverse wiring will not affect many basic items with non-polarized
    plugs, but could create a hazard for items with polarized plugs or
    grounded plugs that assume hot is on the narrow blade. Lamps are now wired
    with polarized plugs so that the neutral is wired to the shell of the bulb
    socket, and the hot to the center.
  7. Jim Haynes

    Jim Haynes Guest

    I had an inspector report that all of the outlets in my house were reverse
    wired. It turned out that in fact they were three-wire outlets with no
    ground wire. The house was built back before ground outlets were standard,
    so they are all wired with two wires. Someone later replaced all the original
    two-wire outlets with three-wire ones. Although this creates a false
    sense of safety in that there is no protective ground, it is apparently
    legal because you can't get two-wire outlets anymore. An electrician I
    consulted said it would be too costly to put in modern 3-wire wiring
    because of all the demolition - the old wiring is stapled inside the walls
    and can't just be pulled out as the new wire is pulled in. So I had him
    put in GFCI outlets and breakers where needed for safety (bathrooms and
    kitchen) and let the rest go.
  8. Yes, get the tester or a simple meter, if you know how ot use it.

    Switching one set of wires, may have corrected all the rest down stream,
    or may not, so you really need to check them all again.
  9. James Sweet

    James Sweet Guest

    Yes you can buy 2 wire outlets and no it's *NOT* legal to install 3 wire
    outlets on a non-grounded circuit.
  10. James Sweet

    James Sweet Guest

    And if you don't know how to use it please don't be messing with this stuff,
    call an electrician and let them take care of it for you.
  11. Yes; it is legal to have a 3-wire outlet with 2-wire input *if* it's a GFCI.
  12. ---------------
    Danger is Hot, Black, and Brass. Make it so.

    To find which wire is Hot, measure it to a solid ground like a water
    pipe. Neutral is Dead, White, and Silver, like the bare Safety Ground.

    Put a 200 VAC voltmeter, or DMM set to that range, from Hot to
    Neutral, this should show 120VAC. Then from Hot to Ground, you
    should again see 120 VAC.

    The hot should be 120VAC to EITHER of them separately!
    If not, then Hot is not connected to the "hot"!!!

    Try neutral to both each separately, see if it is BOTH 120VAC to
    ground and also the black. If so then the neutral and hot are
    switched and should be switched back at the bus. Of course, use
    insulated probes, rubber gloves if you are dim-witted, and switch
    off the breaker when you change things. I take no responsibility
    for your stupidity or your death.

  13. Richard

    Richard Guest

    Yah I think you need to get a tester. Just a neon bulb and two test
    leads. Did the inspector determine this problem with a tester? You
    need to verify that the hot lead (black) is the small slot. Determine
    this by testing from small slot to ground (metal box, conduit or earth
    ground) If it reads hot from large slot to ground then the hot
    /neutral is reversed and should be switched. If you were doing this
    right I would trace the wires back and find where the switch occured.
    ??? Do you mean the same wires black/white/green feed both outlets??
    This could be normal is shared on the same breaker.
    The head end would be in the breaker panel. If this is true the
    electrician should be immediately terminated with extreme prejudice!
    Use your tester or meter to test empirically from the small slot
    (brass) to ground metal box, BX or conduit (water pipe verify the
    ground first) Make the brass hot and correct the color code all the
    way back to the breaker panel. If you're not comfortable with wiring,
    being in the breaker panel or don't understand how you can get shocked
    taking apart a neutral nexus then hire an electrician. On second
    thought you might want to hire a competent electrician anyway to
    review all your wiring. As a professional I've seen some weird things
    and your wiring sounds like it needs a good going over. While reversed
    wires are usually not a problem it can be dangerous as above and is an
    indication of someone not knowing what they were doing doing the

    I did have a toilet that buzzed and had about 40 VAC on it but that's
    another story.

  14. Guest

    It is not legal to retrofit 3-prong outlets without a proper ground,
    unless the circuit is GFCI protected and labelled as such. Hell, I
    GFCI protect most of my outlets anyway because they provide good shock

    I had one save my arse once, standing bare foot on damp concrete and
    grabbed a fray cord. Everything went dark for a few seconds and I
    heard the gfci snap off about 20-miles away. Only damage was an achy
    arm for several hours afterward.


  15. As someone else said, it is legal if they are GFCI outlets.

  16. James Sweet

    James Sweet Guest

    But how many of those installed in the real world are on GFCI? I've lost
    count the number of times I've seen someone install 3 wire receptacles in
    non grounded houses, a lot of times the houses don't even have a GFCI at
    all. Certainly adviseable to add, though not everything will work right on
    them. I've seen a lot of computers and a few microwave ovens that would trip
    them regularly.
  17. hemyd

    hemyd Guest

    I'm speaking strictly based on Australian wiring regulations. I don't know
    how they apply your way. Here, you should get a licenced electrician to
    check out all your wiring. It is possible that it was originally wired up by
    someone unlicenced. If your house catches fire as a result of faulty wiring
    and there is a possibility that it was wired up illegally, you may have
    problems claiming insurance.

  18. hemyd

    hemyd Guest

    My father used coathanger wire for fuses. I think that's rated at about 500

  19. MattD..

    MattD.. Guest

    The one thing you don't want is a father like that wiring up your electric
    overblanket with earth to live in an old 15A plug with no fuse and an old
    Bakelite distribution board when you're eight years old. Trust me - I
    know ;o)

    Disclaimer: My dad was a great old chap, very intelligent and had a good
    grasp of physics. He was just colour blind to mains wiring!
  20. Part of the problem is that it's not that easy to find 2 wire outlets at
    your local hardware store. Our local large chain hardware store probably
    has 16 varieties of duplex outlets, all 3 prong, and no 2 prong types.

    --- sam | Sci.Electronics.Repair FAQ Mirror:
    Repair | Main Table of Contents:
    +Lasers | Sam's Laser FAQ:
    | Mirror Sites:

    Note: These links are hopefully temporary until we can sort out the excessive
    traffic on

    Important: Anything sent to the email address in the message header is ignored.
    To contact me, please use the feedback form on the S.E.R FAQ Web sites.
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