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Thread: transfomer: why overcurrent protection is not required on the grounded conductors?

  1. #1
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    transfomer: why overcurrent protection is not required on the grounded conductors?

    I just want to know why OP is not required on the grounded conductors?

  2. #2
    Join Date
    May 2005
    Location
    Richmond, Virginia
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    Because it's controllable, and if it were to open independently, could cause over-voltages.
    Code references based on 2005 NEC
    Larry B. Fine
    Master Electrician
    Electrical Contractor
    Richmond, VA

  3. #3
    Join Date
    Apr 2016
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    Georgia
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    Quote Originally Posted by dawsez View Post
    I just want to know why OP is not required on the grounded conductors?
    Unless you have a shared neutral between phases (not advisable), you should never have current on the neutral once the phase conductor of the circuit has been interrupted, i.e. CB opened/tripped. IEC is different - they use two pole CB's to interrupt both phase (hot) and neutral on single phase branch circuits.

  4. #4
    Join Date
    Jan 2011
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    What application do you have in mind? Above 600 volts is not uncommon for the neutral to have CTs for measuring current.
    I'm in over my head...

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