User Tag List

Page 23 of 23 FirstFirst ... 13 21 22 23
Results 221 to 222 of 222

Thread: Open Service Neutral GFCI/RCD Detector

  1. #221
    Join Date
    Dec 2007
    NE Nebraska
    0 Post(s)
    0 Thread(s)
    Quote Originally Posted by ptonsparky View Post
    The ground rod test I had a few months ago at the school ball field disagrees. I had well over 100 volts at 6’ in reference to the rod.
    I maybe worded what I was trying to say poorly, that reading is exactly what I would expect.

    What I am trying to say is the area where there is voltage gradients in the earth is fairly small around the electrode, once you get just a few feet away you are at near true earth potential in most cases. This is not going to cause a voltage issue at the neighbor's house, only an issue near the electrode in question.
    I live for today, I'm just a day behind.

  2. #222
    Join Date
    Jan 2011
    United States
    1 Post(s)
    1 Thread(s)

    The above is a service entrance of an American who married a filipina who built a home (above picture) in the rural area in the Philippines (not served by Meralco who used surplus split phase transfomers decades ago in powering up the capital). He wrote a blog about it describing the split phase power in capital and the 240v to neutral in the province.

    Since the lodge I'll stay tonight for one week is powered by 240v to neutral. I need to be familiar with their power system.

    Basically. In power lines and home when one of the 240v hot is grounded, what would happen if:

    1. There is no GEC in the house? Is GEC more required in utility lines where one hot is grounded versus when centertap is grounded?
    Same GEC would apply to either.

    2. If the pole ground rod was stolen, and there is another one in pole nearby and it's part of Multi Neutral Network. What is the behavior of partially grounded and partially ungrounded pole? Is there such thing?

    It stays about the same, as one missing electrode makes little difference in a network with hundreds if not thousand of electrodes.

    3. All my inquiries before are floating secondaries of American split phase power system. Now what is the behavior of floating secondaries of pure 240v to neutral system (where one hot is grounded). Is there a difference in behavior between them as far as ground fault is concerned?

    When a ground fault occurs, the voltage through the fault path will be double.

    4. My inquiries now is because if the utility company in capital would say they can transfer ground from centertap to one hot leg of our pole in front of the compound (which they may say it's part of their program). Imagine our metal chassis is connected to grounded hot leg, what if someone stole the ground rod, and our pole 240v become floating, then our metal chassis would have 240v potential. Now since it's floating, the effect is just like small isolation transformer? or would there be partially floating scenario where if you touch the metal chassis, then you could still get shock as there is some neutral somewhere it's returning too? What do you think?
    From the pic you posted the system in the capitol is MGN- so a stolen ground rod would not make a floating system.

    BTW- one thing. If the system becomes one leg grounded, remember that in some situations the breaker will be breaking a higher voltage during a fault.
    Sane people cannot survive being witness to insanity.

Posting Permissions

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