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Splicing Neutral Across Mains

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    Splicing Neutral Across Mains

    I have an existing warehouse with five mains. The distribution wiring was stolen and I am preparing drawings to replace it. Three of the existing mains have a neutral wire coming from the utility company (ungrounded service). Two of the mains have no neutral and these main disconnects also have no neutral bar. Service is 120/208V-3 phase (or possibly 240V hi-leg - haven't been able to confirm although all three phase conductors are the same size).

    1. Is it acceptable to splice the neutral from one main with a polaris and use it as the netural for the two services without a neutral? This appears to be how it was done before.
    2. Building department is requesting that the building ground be ugpraded. Without a neutral bus at the main, how can the service be grounded?

    #2
    I would say no and cite 300.3(B) as well as 250.24(C)

    300.3 (B)Conductors of the Same Circuit. All conductors of the same circuit and, where used, the grounded conductor and all equipment grounding conductors and bonding conductors shall be contained within the same raceway, auxiliary gutter, cable tray, cablebus assembly, trench, cable, or cord, unless otherwise permitted in accordance with 300.3(B)(1) through (B)(4).
    250.24 (C)Grounded Conductor Brought to Service Equipment. Where an ac system operating at less than 1000 volts is grounded at any point, the grounded conductor(s) shall be routed with the ungrounded conductors to each service disconnecting means and shall be connected to each disconnecting means grounded conductor(s) terminal or bus. A main bonding jumper shall connect the grounded conductor(s) to each service disconnecting means enclosure. The grounded conductor(s) shall be installed in accordance with 250.24(C)(1) through (C)(4).
    I live for today, I'm just a day behind.

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      #3
      I agree with kwired.
      A grounded conductor would need to be installed with each service conduit.
      Ground bars could be added to the disconnects without neutral bars.

      The grounding electrode install would have to comply with 250.64(D)
      At my age, I'm accustomed to restaurants asking me to pay in advance, but now my bank has started sending me their calendar one month at a time.

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