User Tag List

Page 1 of 2 1 2 LastLast
Results 1 to 10 of 15

Thread: Hot ground

  1. #1
    Join Date
    May 2019
    Location
    Brockport, NY, USA
    Posts
    2
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    Hot ground



    I have an interesting electrical situation.


    The homeowner is getting shocked by touching screws and metal switch plates on 1 circuit.


    Lights on circuit:
    Backyard light
    Garage light
    Driveway light
    Foyer light
    Bathroom light
    2 fluorescent Basement lights


    All lights and switches work.


    Ground is hot at switches but not at panel. I didn’t check the light fixtures.


    I opened up backyard switch. It has a plastic switch box. There were 2 blacks, 2 whites, 2 grounds. Blacks were on the switch. Whites were tied together, grounds were tied together and landed on switch. After taking the black and white wires apart I discovered that both blacks, one white, and the grounds were hot.
    At this point my head exploded so I put everything back together the way it was and told the homeowner not to use that circuit until I figured out how to fix it.




    Any thoughts would be appreciated.


    Thanks

  2. #2
    Join Date
    Jun 2003
    Location
    NE (9.06 miles @5.9 Degrees from Winged Horses)
    Posts
    11,272
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    It sounds like the EG is not continuous back to the panel and has become energized at
    some point. I would guess in a switch or receptacle box where the terminals more easily contacted. Find the breaker that enrgizes the EG. Search from there out.
    Tom
    TBLO

  3. #3
    Join Date
    Jun 2003
    Location
    Hawthorne, New York NEC: 2014
    Posts
    4,736
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    Look for clues- ask the homeowner- when did this start and has any work been done recently? Lots of times the homeowner knows exactly where the problem is but he isn't going to fess up that he tried to install a new fixture or motion light someplace.

    Try and determine how the circuit was run starting at the panel. Locate the breaker. Does the voltage go away on the grounds when the breaker is turned off? Hopefully the voltage isn't from another circuit. Take everything apart and check how every box was wired.

    Make sure you use a low impedance meter. The usual ones will say something is hot when it isn't. Actually there is no need to even use a meter here. I like to use a rubber pigtail lampholder with a 25W bulb. Drag an extension cord around connected to a known good circuit so that you can use the ground from it for a reference.

    Slow and logical thinking will get you your answer. If you let your head explode you will get no where. This is going to take some time.

    -Hal

  4. #4
    Join Date
    Apr 2005
    Location
    Atlanta,GA
    Posts
    6,402
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by Brockport Rob View Post




    All lights and switches work.


    After taking the black and white wires apart I discovered that both blacks, one white, and the grounds were hot.
    How did you meter this? If everything is hot it's hard to get a ground or return reference?

    The neutral has to be good for the light to come on. When you take the whites (neutrals) apart then the power from the black conductor goes through the lamp and returns on the white and can be measured as having 120V ( if it's open because someone took it apart).

    Turn the power to that circuit off and do a continuity test between hot and ground. Between hot and ground you should read an open or infinity. If you read a short between the two you can disconnect parts of the circuit until the short goes away. This should put you in the ball park.

    So you probably have a short circuit and an open ground and if you are lucky they will end up in the same placed but it doesn't have to work out that easy.
    The 95% of people that you can't trust give the other 5% a bad name.

  5. #5
    Join Date
    Apr 2005
    Location
    Atlanta,GA
    Posts
    6,402
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by hbiss View Post
    This is going to take some time.

    -Hal

    I have found problems like this in 15 minutes and yet when the problem is in a buried box or a concealed flying splice , or a staple that's shorting out the hot and ground and is concealed it can take hours.
    The 95% of people that you can't trust give the other 5% a bad name.

  6. #6
    Join Date
    May 2005
    Location
    Richmond, Virginia
    Posts
    25,534
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    To expand on a previous post, plug an extension cord into a known-properly-wired, non-GFCI-protected receptacle, and carry the female end to your testing location. With a low-impedance tester, such as a solenoid tester or a volt-meter with a small bulb in parallel with the test leads, test between each test point and one of the slots in the cord.

    From the cord hot, you can test for wires that should be grounded (the neutral and the EGC), and from the cord neutral (or EGC) you can test for wires that should be hot. The cord hot to the circuit-under-test hot should read either 0 or 240v, depending on whether your cord and test circuit happen to be on the same or opposite line (phase).

    Added: By the way, you should make sure switches are off and loads are unplugged, so they don't confuse your test results. Loads will cause switch legs to test as grounded when the switch is off. Under normal conditions, that shouldn't matter, but we usually don't trouble-shoot during normal conditions. You could have an open in the neutral.
    Code references based on 2005 NEC
    Larry B. Fine
    Master Electrician
    Electrical Contractor
    Richmond, VA

  7. #7
    Join Date
    Dec 2007
    Location
    NE Nebraska
    Posts
    41,359
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    If someone initially has switched a neutral instead of a hot, can get confusing. Can make everything test hot when you expect little or nothing to be hot, then if someone tried to bootleg a EGC off a neutral (on the load side of a switch) - it could make the EGC "hot" anytime the switch is open and the load is connected to the circuit.
    I live for today, I'm just a day behind.

  8. #8
    Join Date
    May 2019
    Location
    Brockport, NY, USA
    Posts
    2
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Thanks for all the good advice. I thought I’d give you all an update.

    I conquered this issue today. It took me 5-1/2 hours. There were multiple issues in 3 locations.
    To start with, the ground was broken in the first switch box away from the panel.
    Second, at the very next switch box the ground wires were twisted around the hot and the insulation was worn away at the point of contact.
    Third, the fixture wires in the foyer light were dry rotted and cracked with areas of bare coper on the hot and neutral. I’m not sure if this was actually a factor but I replaced it anyway.

    And to top it all off, after I finished putting everything back together and turned it on...nothing worked! So I had to retrace my steps. I discovered at the first switch box that the hot going to the next box had broken inside the insulation. Apparently I wiggled the old wires too much. This wire broke right as it entered the box. There was literally a half inch of wire in the box. I ended up cutting in an old work box above the switch and making joints there rather than ripping out drywall and replacing the wire.

    Anyway, thanks for the help!

  9. #9
    Join Date
    Jun 2003
    Location
    NE (9.06 miles @5.9 Degrees from Winged Horses)
    Posts
    11,272
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by Brockport Rob View Post
    Thanks for all the good advice. I thought I’d give you all an update.

    I conquered this issue today. It took me 5-1/2 hours. There were multiple issues in 3 locations.
    To start with, the ground was broken in the first switch box away from the panel.
    Second, at the very next switch box the ground wires were twisted around the hot and the insulation was worn away at the point of contact.
    Third, the fixture wires in the foyer light were dry rotted and cracked with areas of bare coper on the hot and neutral. I’m not sure if this was actually a factor but I replaced it anyway.

    And to top it all off, after I finished putting everything back together and turned it on...nothing worked! So I had to retrace my steps. I discovered at the first switch box that the hot going to the next box had broken inside the insulation. Apparently I wiggled the old wires too much. This wire broke right as it entered the box. There was literally a half inch of wire in the box. I ended up cutting in an old work box above the switch and making joints there rather than ripping out drywall and replacing the wire.

    Anyway, thanks for the help!
    Thank you for the report!
    Tom
    TBLO

  10. #10
    Join Date
    Jul 2015
    Location
    Wilmington, NC USA
    Posts
    738
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by ptonsparky View Post
    Thank you for the report!
    Yes, thank you. So many times you never hear what happened.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •