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Residental electrical wiring

  1. Sep 21, 2009 #1
    I have an outdoor light that doesn't work because the contractor did not correctly wire up neutral line. The hot and ground are correctly wired but the neutral is not. My DMM didn't show a voltage when I measure hot and neutral. The house is built and it would be a pain in the *** to tear up the wall, find the wire and re-wire it.

    Since the ground wire is connected to the neutral wire at the breaker, what if I just connect the light's neutral to the incoming ground wire? Is this a significant hazard? I did try it and the light worked.

    Also, I measured 90VAC between ground and neutral. Is this indicative if a bad grounding connection?
  2. jcsd
  3. Sep 21, 2009 #2
    Something is goofy. If you are measuring 90v between ground and neutral then the neutral must be tied somewhere to the hot or to some device. There can be a bigger issue somewhere else in the house.

    The solution to ground the lamp would work, but consider doing more investigation around the house.
  4. Sep 22, 2009 #3


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    Science Advisor

    It also sounds like there is a break in the neutral wire in the cable.
    If it was grounded at the front of the house, it shouldn't have 90 volts on it.
    High impedance digital multimeters can give such readings even if there is no current available at 90 volts.
    It can be just due to the disconnected neutral wire coupling capacitively to the active wire.

    Sometimes it is possible to use the old cable to pull a new one through the plastic pipe. This shouldn't be expensive.

    Although the lamp might work, this sounds like a death trap. I'd call an electrician and pay him to fix it and check that the house is up to code.
  5. Sep 22, 2009 #4
    The lamp does work if I substitute the ground for the neutral. In this case, the ground wire must be connected to the neutral at the breaker.

    Waht, if a hot wire is tied to ground wire somewhere in my house like you said, then it would of tripped the breaker because my neutral is tied to ground. I verified that neutral is tied ground by connecting my light's neutral to ground and it worked.
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