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Local Disconnecting Means for Panelboard

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    Local Disconnecting Means for Panelboard

    Some Background.
    I have a situation where an existing MLO, panelboard is being fed from a fusible bus duct tap box. The tap box is located approximately 38" above and 120 feet to the west from the panelboard. As part of a design I am working on, I have to re-feed the panelboard to match the panelboard's bus rating of 400A.

    Now to the question(s).
    I cannot find an article in the code that specifically and definitively states that a local disconnecting means for a panelboard is required, only that OCP is required for the incoming feeders. is there such an article? I know an MCB breaker can count as the local disconnecting means, butthe client is reluctant to spend the money to upgrade to an MCB type, or to add a circuit breaker in a can (separate circuit breaker) to the incoming feeder for the panelboard.

    Article 225.31 states that a local disconnecting means is required if the feeder transits another building to reach the panelboard. there is one floor and an office area between the bus duct and the panelboard, but I don't think I can make that stretch as a "separate building."

    #2
    Your proposed install doesnt meet the scope of 225

    Comment


      #3
      Panels in the same building as their feeder OCPD do not require a main breaker or a local disconnect per the NEC.
      Don, Illinois
      (All code citations are 2017 unless otherwise noted)

      Comment


        #4
        Originally posted by gboles01 View Post
        I cannot find an article in the code that specifically and definitively states that a local disconnecting means for a panelboard is required, only that OCP is required for the incoming feeders. is there such an article?
        For your application, the code section doesn't exist.
        Ron

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          #5
          This is one of those very rare instances in which the NEC has a clear and unambiguous statement that gives you the answer to your question. Look at the second sentence of article 406.36.
          Charles E. Beck, P.E., Seattle
          Comments based on 2017 NEC unless otherwise noted.

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            #6
            Originally posted by charlie b View Post
            This is one of those very rare instances in which the NEC has a clear and unambiguous statement that gives you the answer to your question. Look at the second sentence of article 406.36.
            408.36

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