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Thread: Voltage between line to neutral and line to ground

  1. #1
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    Voltage between line to neutral and line to ground

    During the inspection of the branch circuit to which some receptacles are connected, i found that there is 17V between line to neutral when the branch circuit breaker is in off position. When i check at the power panel it is the same 17V between line to neutral.
    What can be the possible reasons and how it can be rectified.

    Thanx

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  2. #2
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    Digital volt meter picking uplease "ghost" voltage.

    If you have an old analogue meter or a low z function on your digital meter you can double check.
    Once in a while you get shown the light
    In the strangest of places if you look at it right. Robert Hunter

  3. #3
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    Quote Originally Posted by ActionDave View Post
    Digital volt meter picking uplease "ghost" voltage.

    If you have an old analogue meter or a low z function on your digital meter you can double check.
    Thanx for the suggestion.. i will check by the meter with low z function.

    Can we connect our sensitive electronic equipment or any equipment in the presence of ghost voltage??

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  4. #4
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    Quote Originally Posted by Sajid khan View Post
    Thanx for the suggestion.. i will check by the meter with low z function.

    Can we connect our sensitive electronic equipment or any equipment in the presence of ghost voltage??

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    Yes, but I would make sure that is what you have.

    By line we are assuming the load side of the branch circuit breaker that you have Off.
    Tom
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  5. #5
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    Yes exactly

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  6. #6
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    My guess, no bond between the neutral and grounding conductor.

    Even a high impedance meter should have a very low reading if they were bonded together, unless maybe there is hundreds of feet to the bonding point.

  7. #7
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    Quote Originally Posted by kwired View Post
    My guess, no bond between the neutral and grounding conductor.

    Even a high impedance meter should have a very low reading if they were bonded together, unless maybe there is hundreds of feet to the bonding point.
    That would certainly be a possibility if the OP had reported a voltage from neutral to ground.
    But he is reporting an open switch output to neutral voltage and presumably a similar output to ground voltage. The latter was not mentioned except in the thread title.

    If there is a load connected to the open circuit, it would have to be an electronic load that did not conduct line to neutral until some voltage threshold was reached.
    If the switch output is not loaded at all, then there could be phantom voltage on the ungrounded wire if it runs in the same raceway as or near an energized conductor (as, for example in a switch leg or a raceway containing multiple circuits.)

  8. #8
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    Quote Originally Posted by GoldDigger View Post
    That would certainly be a possibility if the OP had reported a voltage from neutral to ground.
    But he is reporting an open switch output to neutral voltage and presumably a similar output to ground voltage. The latter was not mentioned except in the thread title.

    If there is a load connected to the open circuit, it would have to be an electronic load that did not conduct line to neutral until some voltage threshold was reached.
    If the switch output is not loaded at all, then there could be phantom voltage on the ungrounded wire if it runs in the same raceway as or near an energized conductor (as, for example in a switch leg or a raceway containing multiple circuits.)
    I'm sorry but I don't see it that way. Reading the thread title again - the title is totally confusing, but the content of post 1 never mentions any switch other then the supply breaker that is in the off position. Says to me there is a voltage rise on either the neutral or grounding conductor. Since they are supposed to be bonded together at the main/system bonding jumper, unless there is a really long feeder or a feeder neutral going bad, I wouldn't expect that much voltage drop on the neutral - seems more likely there is no N-G bond in the first place.

  9. #9
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    But the OP reports 17 volts between the neutral and the line downstream of the open breaker. To me that suggests phantom voltage on the ungrounded conductor, not an offset between neutral and ground.
    Other than in the title the OP never refers to ground (EGC?) at all.

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  10. #10
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    My take is no load connected, neutral is bonded to earth as typical, induced voltage on the conductor from the CB. Simple?
    Tom
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