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Disadvantage of having high neutral grounding resistance

  1. Mar 9, 2017 #1
    I am working in an industry where my technicians have to short the bus bars on regular basis (manually) for some maintenance purposes.

    I want to add high neutral grounding resistance to the incoming supply transformer to limit the Line to ground fault. Presently the neutral has been solidly grounded. What will be the disadvantages of high resistance neutral grounding?

    We are using neutral for some (single phase) welding and grinding purpose.
  2. jcsd
  3. Mar 9, 2017 #2
    I have never seen any transformer with very high neutral grounding resistance. It is uaually around 9.5 ohms. Can I have 1k ohm resistance. What will be its disadvantages?

    And yes, I do have an earth fault relay in neutral. But still I dont want the fault current (which may pass through the technician's body in worst case scenario) to be more than 5 milli amps.
  4. Mar 9, 2017 #3


    Staff: Mentor

    I don't know the specific answer to your question. But I think that this is an area where codes can be strict and you may not have much design freedom. My recommendation is to check the applicable codes first to see what is permitted.
  5. Mar 9, 2017 #4
    I think you should further specify the type of that 'industry'. I were just about to reply something what I think would have been totally irrelevant judged by your posts on other topics.

    What range of kilovolts and kiloampers?
  6. Mar 9, 2017 #5


    User Avatar

    Staff: Mentor

    Please consult with a professional who is trained in this area and knows the applicable codes and such. We do not want your technicians getting injured or killed because someone accidentally gave you incorrect information.

    Thread locked for safety reasons.
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