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UPS saying building wiring fault - no ground?

Discussion in 'Electrical Engineering' started by Adam Julius, Dec 14, 2003.

  1. Adam Julius

    Adam Julius Guest

    Hello. I just purchased a UPS and the light on the back which says building
    wiring fault is lit. Power works correctly and everything seems fine. I
    opened the outlet and saw 2 wires coming into the metal box, each with 2
    wires (black and white). Nothing was connected to the ground so Im thinking
    the problem is probably due to lack of ground? I searched around on the
    internet for a simple fix, and some said that if the box was grounded then
    you just run a wire to the back of the box. The cables coming into the box
    look like snakeskin with paper insulation inside and its very thick and
    solid. Its in great shape for wires put in place in the 1950's. It feels
    almost like metal, but its not. And so it probably cant be used as a
    conductor of electricity to use for ground. Im looking for a quick fix
    here. I was reading about GFCI outlets but those appear to not be
    appropriate for surges as you still need a true ground.

    Is there any device that one could buy to create the same effect as a ground
    connection? I dont want to hire an electrician spending big bucks to fix
    this problem as I only really need it for one outlet. Cold water pipe isnt
    available near the area, only a hot water baseboard heating pipe, but thats
    not appropriate for ground.

    Were 3 prong outlets allowed to be installed with no ground under any
    electrical codes in the past? Im assuming that whoever bought the house
    originally replaced the outlets but never added the grounds.

    So anyways, its either I live with the problem of lack of true ground or
    find some way that wont require hiring an electrician to ground the outlet.
    I can install outlets if the wiring is in place, or connect wires to the
    outlet box, but cant do the rest. Just for safety sake because of lack of
    ground I may put in the GFCI outlet if I cant get a true ground so at least
    Ill have something.

    Any suggestions here?

  2. Adam Julius

    Adam Julius Guest

    The problem is Im on the 3rd floor and wiring job would be messy. Im not
    worried about the human element of safety from ground since that would be
    taken care of by a GFCI circuit. Would a transient voltage supresser be
    appropriate for an ungrounded installation in conjunction with a GFCI
    circuit and would this be similar to a true grounded connection although not
    identical. Or do I have no choice but to add a true ground?
  3. Adam Julius

    Adam Julius Guest

    There are 120v grounded outlets in the house, but not in the room where I
    want to use the computer so there are grounds somewhere. Wiring in the
    basement was done in the 1970s as basement was finished and has grounds.
    Also there are grounds in the upstairs and downstairs extensions. But the
    problem is where the computer is there are no grounds. I was looking for a
    quick fix, maybe if there was a device I could buy to simulate a true ground
    to get rid of electricity so that if theres a surge, it doesnt go back into
    my computer because theres no ground. I looked at GFCI outlets, but thats
    really not the same thing, only appropriate if your worried about lack of
    ground for safety. So I guess as for now unless theres a way I can add the
    equivalent of a ground using a special type of receptacle/outlet to simulate
    a ground, Ill have to keep the computer at risk since adding new
    grounds/wiring isnt an option unless it only involves the area where the
    outlet is itself. .
  4. Brian

    Brian Guest

    Did you ever think to call a qualified electrician?!?
  5. Adam Julius

    Adam Julius Guest

    Thanks to all for your responces.

    I guess my alternative is just to leave everything as is for now till I get
    an electrician in to do work in the future and then Ill have the grounds and
    everything done.

    In terms of the NEC code for grounding, if an extension was built in the
    back of the house after 1990 and a new sprinkler system added as well, would
    that have meant that the grounding would have been changed and how would I
    check visually to tell?
  6. Brian Su

    Brian Su Guest

    It could be that your building's live/neutral wires have been reversed
  7. Brian

    Brian Guest

    Reversed? Are you smoking dope?!?

  8. Brian Su

    Brian Su Guest

    I have experienced this before. If the live and neutral wires are the
    other way round, it will still power most AC appliances because it's
    Alternating Current. However sensitive devices like UPS are able to
    detect the reversed input and thus produce a warning.
  9. Brian Su

    Brian Su Guest

    That is why I'm saying this guy's warning light might be a L/N swap
    instead of an earthing problem
  10. Guest

    Hot/neutral reversal is a fairly common problem, and
    you don't even need sensitive circuitry to detect it.
    The problem is common enough that they sell those little
    three lite testers to test for it. You can buy them the
    hardware store for less than 10 bucks.

    The OP's UPS had the "building wiring fault" light lit.
    That could be due to either hot/neutral reversal, as you
    said, or missing ground. The other Brian who posted
    "Reversed? Are you smoking dope?!?" in response to your
    suggestion that live/neutral could be reversed hasn't
    got a clue.
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