Distribution Transformer (Pole Mounted) Wiring

Discussion in 'General Electronics Chat' started by Management, May 24, 2011.

  1. Management

    Thread Starter Active Member

    Sep 18, 2007
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    I have a question regarding distribution transformer mounted on a pole (neighborhood), how are more than one house wired to a distribution transformer on the pole? Are they all connected to the 3 wire terminals? If not then how? Thanks.

    Some details on this would be great. Links are welcome.
     
  2. GetDeviceInfo

    Senior Member

    Jun 7, 2009
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    typically a number of homes are evenly balanced over the 3 phases, with any one home recieving two of the 3 phases.
     
  3. Management

    Thread Starter Active Member

    Sep 18, 2007
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    I don't see how that is correct when a distribution transformer is center tapped for 120/240V. The secondary of these transformers, from what I understand is single phase.
     
  4. wookx

    New Member

    Apr 20, 2010
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    One phase from the three phase circuit supplies the Transformers primary. Secondary is center tapped, and about 5 to ten customers paralleled off (yes three wire) per transformer depending on the VA rating.
     
    Last edited: May 24, 2011
  5. Management

    Thread Starter Active Member

    Sep 18, 2007
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    That's what I was thinking but can you provide any pictures or links on how they do this paralleling?
     
  6. wookx

    New Member

    Apr 20, 2010
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    Nothing special. Just run the three wires down the street and tap off of them at each house.
    Look outside......
    In an overhead distribution system the HV line is at the very top of the pole, consists of one or more phases/circuits and they are generally bare conductors. This feeds the top of an overhead transformer (with a fuse and load break in-between). The three LV conductors (secondaries) usually come out of the side of the transformer and feed three wires running below the HV line. Below those three wires you got the neutral. anything below those is comm.

    Underground systems are no different except you don't need poles.:)

    But then again I suppose all this depends on where you live. I'm in Ontario Canada, I believe most of North America operates this way.
     
  7. GetDeviceInfo

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    Jun 7, 2009
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  8. someonesdad

    Senior Member

    Jul 7, 2009
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    Attached is a picture of how the power for my house is taken off from the transformer. I labeled it 220 VAC, but it will really measure at 240 VAC (old habits die hard).
     
  9. Management

    Thread Starter Active Member

    Sep 18, 2007
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  10. Management

    Thread Starter Active Member

    Sep 18, 2007
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    Thanks for the picture. I only see that your home is connected to the transformer. Are other homes using the same one? If so where does this parallel connection take place.
     
  11. someonesdad

    Senior Member

    Jul 7, 2009
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    Sorry; my home's connection just shows the typical connection for one house. More houses would have their wires connected to the same terminals on the transformer (I remember looking at the transformer in the street next to the house I grew up in and seeing such a connection; our three wires came in from across the street with those of other houses and they were connected in parallel).

    Unless your neighborhood uses underground wiring, you should be able to take a walk with binoculars and see some good examples.
     
  12. nsaspook

    AAC Fanatic!

    Aug 27, 2009
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  13. someonesdad

    Senior Member

    Jul 7, 2009
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    I TOLD my mother-in-law to stay off that broom! See what happens?
     
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