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Dirty Ground Case

Discussion in 'Electrical Engineering' started by Roy Q.T., Jan 5, 2005.

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  1. Roy Q.T.

    Roy Q.T. Guest

    Someone has been callled to an Old Church to replace old decayed
    Fixtires through out, everything is going well until he et to the
    exterior lighting,

    He finds a Missing Neutral Path for his Last Fixture checks again & No
    Meter Action from the Line, He thinks {i can't rewire in these old
    pipes) This Box is way out of the normal pedestrian traffic and says "
    what the heck" it'll look good completed and i could get paid in full
    today, SO: HE SHUNTS THE WHITE WIRE FROM THE FIXTURE TO THE BOX AND
    FINISHES INSTALLING THE PRETTY CHURCH LIGHTS.

    How would you detect this condition ?
    what effect will it have on the system ?
    have you ever done this ?

    could be one just like this right now.,
     
  2. SQLit

    SQLit Guest

    The use of any term in front of "ground" only serves to confuse the issue.
    Grounds should be measured. Not assumed.

    Multiple grounding of the neutral is very common and done by un enlightened
    persons.
    They think that it does not make much or any difference. Having a current
    carrying conductor grounded in any place other than the service can be
    dangerous.
    Will it work? Yes The amount of danger is dependant on the installation.
    I have seen it plenty. It is hard to find sometimes without sensitive
    equipment.

    Call your local code authority and turn this hack in. File a law suit and
    get the money you paid back. No telling what other workmanship issues there
    are.
     
  3. w_tom

    w_tom Guest

    I am not exactly sure if I understand what was posted. You
    must tell me if this is the answer. A GFCI circuit breaker in
    the box would detect this defective wiring fault.
     
  4. Guest

    Under normal circumstaces it would go undetected. You
    might discover the problem if a repair was needed.

    However, if you were actively looking for the problem, it is relatively
    easy to determine if it exists. Shut off all the branch circuit breakers.
    Disconnect all neutrals at the panel. Turn on all the breakers, except
    for those serving multiwire branch circuits, and see what circuits are
    live. Any live circuit means that the neutral is erroneously grounded.
    If such a ground is suspected on a multiwire branch, you will need
    to remove one of the hot wires and the neutral at the panel, then
    see if half the branch is live. You will need to do that for both halves
    of the multiwire.

    Once you know that a branch has an erroneously grounded neutral,
    you need to disconnect at junction boxes to determine where the
    ground exists.
    None in the situation you described. But if the metal
    pipe somehow becomes electrically open, then there is a
    safety hazard.
     
  5. Roy Q.T.

    Roy Q.T. Guest

    the practice is not employed here and is seriously discouraged

    was wondering what type of meter tests on a Panel and system I could
    perform to detect such a violation.

    the Electrician was me and I didn't terminate the job until i can dig up
    or re wire for a safe & hazard free job..

    I was a little tempted but a water puddles right underneath this
    particular outlet and just couldn't, though I Joked about it giving any
    pheligrees walking by it a tingly neary Religious experience };-)


    I'd never leave a dirty ground conditon on an active circuit., though,
    the screw on the box is a good Test Grnd for lighting that is as far as
    i'd go with this temporary use.
     
  6. Roy Q.T.

    Roy Q.T. Guest

    Okay the removing the white wires off ground buss and testing for
    voltage at the neutral Panel & Buss would detect this GF condition:
    To Much Trouble
    & it would leave all curcuits ungrounded.
    Not To Good an Approach.

    maybe a quick check between the Line Ground or Neutral Buss and the
    Panel Chassis.... I might recreate the condition in my apt. test &
    record results..

    No GFCI breakers back in those days, hell they didn't even have
    computers when I refurbished some shot circuits, that one Here was left
    undone, I taped breaker taped off., capped & taped both leads, pushed
    them back in the box and put a plate over it for the future...

    I just think it's a good servce protocol when wiring new equipment or
    circuits for clients.I would like to perform the test on all of my
    calls. Here we are };-)

    Thanks
     
  7. Roy Q.T.

    Roy Q.T. Guest

    not one violation: )

    multple groudning i sa a common and necessary practice in electronics so
    electricians shoudn't ugg out if they encounter them.

    agreed: it is so stupid even in texts to refer to the neutral of the
    system as ground, (many do) it churns my brain.

    Ground, is just that..like Earth.. and practically anywhere you can
    place your digits in, or brush your arm on,

    i'm just thinking, it's too easy to become an endangered workman, if
    your not thorough: can't even try to imagine the practices being
    encountered in Bagdad & the Tsunami Countries.
     
  8. Guest

    There are no white wires on the ground bus in a properly wired panel - only
    green or bare. If you left the wires off the ground bus and tested for
    voltage
    with respect to the neutral bus you would see whatever the line voltage is
    (120 vac, nominal) on your meter. The neutral bus is connected to the
    ground
    bus by the main bonding jumper (which is not a white wire), so it remains at
    ground potential. It would not show that a neutral was "re-grounded".

    The problem you described is that the neutral wire was open to a light
    fixture.
    Let me draw it: neutral------- break ----------fixture.
    The "fix" was "regrounding" at a point after the break, at the fixture:
    neutral------- break
    -------"reground"--fixture
    If you disconnect the broken neutral wire at the panel, it will not
    show the "reground" - it is not connected to it.

    You have to remove the neutral wire, at the panel, and test with
    a load connected at the ends of the branch to know if a neutral
    has been "regrounded" in the problem you described. You could
    test from the panel with an ampprobe to look for current on the
    hot wire - but that is too much work, walking back and forth from
    the panel to each end of the branch, connecting a load, walking back
    to the panel to look at the ampprobe etc. Just disconnect the
    neutrals at the panel restore power (leaving multiwire circuits off)
    and walk to each end of the branch circuits and test. Since you don't
    know where the ends are, you have to test *every* outlet. You
    have to perfrom that test on each side of any multiwire branches,
    turning on one half, performing the test, turning it off, turning on the
    other side and testing again. Any outlets that show as live have a
    "reground". It is the only way to be 100% positive that no "regrounds"
    exist. Unless there was a compelling reason to do all that work,
    no sane electrician will do it in the normal course of events.

    In the real world, the problem would be discovered, if it was
    discovered at all, when something went wrong or in the process
    of renovation or changing the fixture for some reason other
    than repair.

    Ed
     
  9. Roy Q.T.

    Roy Q.T. Guest

    no no no, the neutral from panel for the light fixture is damaged
    (shunted to the Hot wire or broken) No Neutral is presnt at the fixture
    box outside n the wall about 8ft above the path to the rectory.

    connectng the fixture i discovered the problem when the lamp didn't come
    on, os I figured a disconnected neutral at the panel cause i had "juice"
    but no ground but from the box. turned out: That Circuit was connected
    to it's circuit breaker so was the neutral {perplexing} I figured it got
    shunted and broke underground somewhere and left it alone for some other
    time & budget.

    maybe it is shunted somewhere else along the run but it's a comlpicated
    old structure with about a dozen panels I hit it for a half hour and got
    tired of poking in & around boxes for the fault & left.

    I may look into it for them again and re route a new circuit to the box.

    Thank you all very much.....
     
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