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Hot/Ground Reversal

Discussion in 'Off-Topic' started by Uzi2, Nov 24, 2018.

  1. Uzi2

    Uzi2 NES Member

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    Had an electrical issue arise with a hot/ground reversal indicating on my little Ideal Tester. Was getting a shock touching my microphone ground, my freezer, the wall plate screws on lit switches etc.

    I know this place is wired correctly( I did the entire job myself, with electrician making the connections) and there are no incorrectly polarized outlets or junctions, it was inspected by the electric company inspector ( a real thorough no BS guy)and the whole place has functioned fine for five years.

    I narrowed it down to a " surge protected multi strip" that had an MOV shorted inside it. I took it apart and cut out the three MOVs that were in it, checked the wiring to male sure it was correct amd reassembled......problem solved!

    If you ever start getting a shock off an appliance or other supposedly grounded surface, check all your multi plug strips FIRST!, especially if they are surge protected types.
     
    Last edited: Nov 25, 2018
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  2. Spanz

    Spanz

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    if that is true, i would wonder about the integrity of the return earth ground path, that those MOVs are attacked too.....your earth ground must be floating
     
  3. Bernietech

    Bernietech NES Member

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    Did this only effect items plugged into the strip, or was it effecting on the same circuit or the whole house? Was it one of newer energy saving auto strips or just a regular surge protector?

    Bernie
     
  4. Uzi2

    Uzi2 NES Member

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    No, the earth ground for the building is not floating, I physically check the integrity of the wire, the cleanliness and tightness of the connections and measured continuity on the wire to the ground rods. That thought had crossed my mind and that was the first measurement I did.


    It was effecting the whole ground circuit in the building. As soon as I unplugged the strip, everything read normal and there is no voltage on the ground.
    The voltage was going through an MOV so it wasn't a direct short. The MOV was acting as a resistor and placing a voltage on the ground wire but not allowing much current to flow, otherwise it would have tripped the breaker as a dead short.

    It was an older surge protection strip with 3 MOVs and a capacitor. I opened it up and cut out all of them, checked the polarity of the hot, neutral and ground and reassembled. Plugged it back in and all is well.
     
  5. ThePreBanMan

    ThePreBanMan NES Member

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    Wouldn't a GFCI circuit breaker had prevented this and helped you identify the faulting circuit? Food for thought. MAybe time to replace some breakers. Whenever I'm in the panel doing work I always use GFCI breakers now. I'm not a pro by any means, but I know enough to do residential wiring. I'll pay some extra loot for the breakers to prevent problems such as this down the road.
     
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  6. Fixxah

    Fixxah NES Member

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    Get a new strip. Done.
     
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  7. ThePreBanMan

    ThePreBanMan NES Member

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    Amen. Why trust something that has previously failed? Especially considering how cheap they are. And even more especially when it comes to electrical - which can burn your house down.
     
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  8. Snora

    Snora

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    Correct me if I'm wrong but: voltage on ground = not grounded. If I put a resistor across hot to ground that would put current across the resistor (heat/ fire depending on the current), not shock me when touching other grounded appliances.
     
  9. Uzi2

    Uzi2 NES Member

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    There is nothing wrong with the strip mechanically, it is just minus the surge protection. Now its just like a two foot extention cord with four outlets on it.


    I know enough about electrical to know that this device will never burn my building down. I removed the components that were faulty and now it is strictly a mechanical device with no electronic surge protection components.

    It will shock you in bare feet on concrete....which WAS case here. There can be a difference of potential at many points in any "grounded" system, if there is something imposing a voltage on it. There was not enough current flow to trip a breaker but there was enough voltage to feel a very slight shock/bite on the ground side of the building circuit with bare feet.

    The problem has been resolved and there is 0 voltage on the ground or case of anything in the building.

    Every outlet in the building tests correctly now, the building ground, neutral and hot are tight and clean. image.jpeg image.jpeg image.jpeg

    Don't let the orientation of the tester fool you, it is indicating two yellow lights, which indicates the circuit is correct.

    Before unplugging the offending strip, ot was reading outer yellow and red.
     
    Last edited: Nov 24, 2018
  10. Rob Boudrie

    Rob Boudrie

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    Is there a correct plug orientation? I prefer the ground pin on the bottom but see some people put it on the top.
     
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  11. AHM

    AHM NES Member

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    A former colleague was taught in high school electric shop that ground pin on top provides some protection against a conductor (say, a utensil) being dropped behind an incompletely seated plug, and bridging the hot and neutral pins.

    Not claiming that's code - jus' sayin'.
     
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  12. Woodstock

    Woodstock NES Member

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    Not an electrician but was always told the ground should be on top when using a metal cover plate in case the plate wiggles loose and drops onto the prongs.
     
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  13. Uzi2

    Uzi2 NES Member

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    Or if a picture hung with wire drops and the wire slips behind a partially seated plug.
     
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  14. Uzi2

    Uzi2 NES Member

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    All my research over the years has shown that there is no "specified" correct orientation in any official NEC or NFPA
    literature so barring any local code requirement, its a matter of personal preference.
    I've always installed them ground up because I didn't want all those little faces looking at me. [smile] image.gif
     
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  15. Uzi2

    Uzi2 NES Member

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    Very possible that a GFCI outlet would have tripped, but not prevented the condition initially. I do not know what caused the MOV inside the strip to short, it could have sustained a lightning strike at my previous home. That strike took out my cable box, a telephone, two garage door openers( the opener itself, not the remote) so this could have been old damage that finally showed up.

    I have GFCI protected outlets on every most of the other circuits in the building except this circuit and specific dedicated 20amp outlets near each window for potential air conditioner use.

    Code here NOW, is ground fault and arc fault protection......which is big bucks. This was not the case when this building was put on line with electricity.

    A friend down the road had to meet that code in his new house and his electrical breakers cost him almost a couple of thousand dollars. They also are RF sensitive.....and I refuse to put up with that.
     
  16. PatMcD

    PatMcD NES Member

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    I had to install new wood floors in a house last year. It was gutted by a multi-strip that had previously tripped, got too hot and came pretty close to burning the house down.
     
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  17. Uzi2

    Uzi2 NES Member

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    I understand, Thats why I gutted the MOVs and capacitors from this one. Now its just a multi plug extention (in good mechanical shape) used for light load walwarts for charging portable radios.
    I'm well aware of the hazards with these things and this is the only one I use. Regarding extention cords, I always go one or two gauges larger than expected loads. I do not even own a 14 or 16 gauge extension cord, they are all 12 or 10.
    My whole building is wired with #12 Romex with #10 for the water heater and two other 220 outlets for amplifiers.
     
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  18. Asaltweapon

    Asaltweapon NES Member

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    Responded to a house fire a few years back. When I turned the engine up the driveway (long driveway) the place had fire blowing out of every window. Sole occupant dove out a lower level window as it was the only escape. Them Deck Houses with all that mahogany and pine go up quick!!
    Plug strip was the cause per the state fire marshal's office.
     
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  19. Uzi2

    Uzi2 NES Member

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    Yup, I did 25 years in the fire service myself. Like I said, this has a couple of wallwarts plugged into it, about a 1/2 amp load total.
     
  20. Spanz

    Spanz

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    Last edited: Nov 25, 2018
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  21. xjma99

    xjma99 NES Member

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    If you had metal that should be bonded, with power on it, you’re neutral and ground aren’t properly bonded at the panel. Wiring is not a hobby. I wish you the best of luck! In general, inspectors know about as much about the NEC as cops know about firearms laws, with a few exceptions.

    Here in NH, inspectors like ground up. I hate the way it looks, and everything I’ve touched in my house is ground down. The code doesn’t specifically say ‘thou shall always have ground up’ but it does politely suggest it is the way to go and some inspectors interpret the code as requiring ground up. If you’re using a metal plate (and I’m not sure why anyone ever would other than 4squares) then it certainly is prudent to do ground up.
     
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  22. Spanz

    Spanz

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    i think there is a high resistance between earth ground (like where your panel is bonded to a rod in the earth or a copper water pipe coming in from outside) and that one outlet the surge protector was plugged into.

    I suppose you would not "feel" ac current when you touched it unless it was at least 40 volts or so. So lets say your MOVs were leaking two amps of current to earth ground....that means you would need to have 20 ohms of total resistance somewhere along the return path.

    20 ohms is not that hard to generate...one loose screw, one corroded terminal....it could even be in the duplex outlet or the cord on the surge protector where the high resistance is....

    one way to maybe test....hook one lead of a voltmeter to a cold water pipe, the other lead to the earth ground on the duplex outlet WHEN A LOAD is being used, and see how many volts above ground that terminal has on it. That might reveal a poor bonding between return wires (white) and earth ground (green)....
     
  23. ThePreBanMan

    ThePreBanMan NES Member

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    They're not that expensive. I think a 20 amp Square-D breaker cost me like 40 bucks from Home DumpsterFire or LoweStandards (can't remember which). I just put one in last year.
     
  24. SgtHal75

    SgtHal75 NES Member

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    This right here...A GFCI breaker or device. U said you wired it yourself, are you an Electrician? Just asking, not being a smart ass. I’ve seen many a home owner and handy men know enough to be dangerous.
     
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  25. SgtHal75

    SgtHal75 NES Member

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    You said u checked continuity at your ground rods????? Check the impedance, should have 25 ohms or less
     
  26. SgtHal75

    SgtHal75 NES Member

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    Ground on top Means there’s less of a chance of a metal object like a bobby pin going across the hot leg and the ground (neutral) leg. I ran into some inspectors who require this But there is no code stating that you must to do it
     
  27. SgtHal75

    SgtHal75 NES Member

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    Hahaha
     
  28. Rob Boudrie

    Rob Boudrie

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    If you are having a pro do the work, you are going to pay a markup on the breakers and will not get the best price you could find on your own.

    Anyone able to explain which circuits need AFCI breakers now? My house was built 6 years ago and has them on a subset of the circuits (done by a licensed electrician).
     
  29. Uzi2

    Uzi2 NES Member

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    I took your post to heart and went and checked the panel, and sure enough, the neutral and ground bars were not bonded.

    The copper bonding tab was there but it was not inserted into the neutral bar. I killed the mains, made the connection and turned the mains back on. No problem.

    I wired the building but had an electrician make the connections. Evidently he overlooked that as it was hidden behind the neutral conductor coming in from the meter box.

    Thanks!
     
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  30. xjma99

    xjma99 NES Member

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    Main panel or a sub panel?
     

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