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Thread: Existing structure / remodeling

  1. #1
    Join Date
    Feb 2008
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    San Antonio, Texas
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    Existing structure / remodeling

    An existing single family structure is going to be remodeled. The wiring that I saw was 2 conductor with no ground (grounding). This is out in the county with no inspection required (just the power company looks at the service).
    The existing service is of sufficient size for the project. I did not look, but feel sure that there is no grounding wire from the service on the pole, feeding underground, under existing driveway, in very rocky conditions, to a panel inside the existing structure. The house was built on pier & beams.
    Should I pull the existing wires out (if possible) and pull in a 4th (grounding) wire in? What would you do?

  2. #2
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    If it is a 120/240V service you will have 3 wires/conductors coming from the POCO's transformer. The neutral is the "grounded" conductor. The "ground" you are referring to in the branch circuits is the EGC. An EGC didn't use to be run with the branch circuits.

    If there is enough access with the remodel, it would be good to run a 3-wire (hot, neutral, ground/EGC) for the branch circuits. As far as "pulling out the existing service/feeder wires", unless there is a disconnect outside then 3 wires is all that is needed from the meter to the panel. Your "4th" wire would only be needed if there is a disconnect outside, making that the main and the inside panel would be a subpanel.
    If you aim at nothing, you will hit it every time!

  3. #3
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    Then it seems there's always that argument of whose disconnect is actually out there at the pole before we can decide whether that's where the EGC needs to originate or not.

    JAP>

  4. #4
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    Quote Originally Posted by jap View Post
    Then it seems there's always that argument of whose disconnect is actually out there at the pole before we can decide whether that's where the EGC needs to originate or not.

    JAP>
    Good point.

    Here, when the meter is on a pole, the REC will use a meter enclosure with a breaker, the public utility's will not have a breaker. Every installation I've seen (not a lot) in both cases are wired as if the panel in the home is the service. That is, no ground wire from the meter to the structure. I have wondered about this.
    It's worth mentioning that the public utility rarely puts the meter any place other than the building any longer, but there are a lot of older installations with pole-mounted meters.

  5. #5
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    I like to pose this question without being technical at all cause you see it every day.

    In the country there is a utility pole 100' away from a house with a transformer on top of it.

    The electrician comes and builds a 200 amp meterloop with 4/0 URD, 2" pvc for the riser, a 200a single phase meter with a nipple into a 200 amp single phase 3r enclosed circuit breaker and leaves it by the pole.

    The power company comes by and hangs that meterloop on the pole hooks up the wires, energizes it and leaves.

    Now,

    Is the electrician required to pull 2 hots a neutral and a ground in the 2" pvc that's going to the panel inside the house?
    or
    Is he only required to pull 2 hots and a neutral in the 2" pvc that goes to the panel inside the house?

    JAP>

  6. #6
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    Quote Originally Posted by jap View Post
    I like to pose this question without being technical at all cause you see it every day.

    In the country there is a utility pole 100' away from a house with a transformer on top of it.

    The electrician comes and builds a 200 amp meterloop with 4/0 URD, 2" pvc for the riser, a 200a single phase meter with a nipple into a 200 amp single phase 3r enclosed circuit breaker and leaves it by the pole.

    The power company comes by and hangs that meterloop on the pole hooks up the wires, energizes it and leaves.

    Now,

    Is the electrician required to pull 2 hots a neutral and a ground in the 2" pvc that's going to the panel inside the house?
    or
    Is he only required to pull 2 hots and a neutral in the 2" pvc that goes to the panel inside the house?

    JAP>
    In that case, it is a feeder to the house and needs to be 4 wire. There used to be an exception allowing three wire feeders between different structures, but they did away with that in 2005. Note that if there were not a disconnect at the pole, rheb per nec you could continue to the house with 3 wire service conductors.
    Ethan Brush - East West Electric. NY, WA. MA

    "You can't generalize"

  7. #7
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    Quote Originally Posted by electrofelon View Post
    In that case, it is a feeder to the house and needs to be 4 wire. There used to be an exception allowing three wire feeders between different structures, but they did away with that in 2005. Note that if there were not a disconnect at the pole, rheb per nec you could continue to the house with 3 wire service conductors.
    Yes, but some have said in the past that if the power company provided that meter loop in the same configuration that it is actually only a service disconnect since they own it, and 4 wire would not have to be pulled to the house.


    JAP>

  8. #8
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    Quote Originally Posted by electrofelon View Post
    In that case, it is a feeder to the house and needs to be 4 wire. There used to be an exception allowing three wire feeders between different structures, but they did away with that in 2005. Note that if there were not a disconnect at the pole, rheb per nec you could continue to the house with 3 wire service conductors.
    Isn't there an exception that says that if it was code compliant when it was installed then you don't have to change it when you work on the system?

  9. #9
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    Quote Originally Posted by ggunn View Post
    Isn't there an exception that says that if it was code compliant when it was installed then you don't have to change it when you work on the system?
    Yes you are correct, that provision is in there. It's like 3 wire ranges and dryers.
    Ethan Brush - East West Electric. NY, WA. MA

    "You can't generalize"

  10. #10
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    Quote Originally Posted by ggunn View Post
    Isn't there an exception that says that if it was code compliant when it was installed then you don't have to change it when you work on the system?
    And that get's us back to the OP question. The existing service center (spread between the outdoor pole and the dwelling interior) is deemed sufficient in capacity for the remodel. That means: no service upgrade is part of the remodel, just branch circuit work.

    So, if I were doing it, I'd leave the pole to house conductors as they are, and, as a CYA thing, I would verify that the house panel has a Main Bonding Jumper installed, and that the Grounding Electrode System in the house is intact and connected to the house panel. (Who knows what the plumbing alterations have been.)
    Another Al in Minnesota

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