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Thread: Multiwire Branch Circuits in Panel Schedules

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    Default Multiwire Branch Circuits in Panel Schedules

    Summary: Add the ability to merge circuits together within panel schedules, to show multiwire branch circuits.

    Description: The NEC requires any circuits that share a neutral to have a simultaneous disconnecting means at the source, in other words, a common handle tie so that all two or three circuits turn off at the same time. The most efficient way to do this is to use a two or three pole circuit breaker to feed these types of circuits. It would be great if there was a feature similar to the "group" command in the panel schedules that marked a group of up to three circuits as a "multiwire branch circuit", and converted the display of the circuit breaker to either a two or three pole circuit breaker, with a common ampacity and number of poles. I'd envision this working by merging the "rating" and "number of poles" cells together, forcing all three circuits to have a common ampacity rating, and displaying either two or three poles based on the actual number of circuits grouped together. I don't think you could actually change the number of poles for the circuit without causing issues with voltage definitions.

    Product and Feature: Revit MEP - MEP Electrical Panel Schedule - (Electrical)

    Submitted By: bbrovont229745 on 04/19/2019


  2. #2
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    Default Re: Multiwire Branch Circuits in Panel Schedules

    Quote Originally Posted by Wish List System View Post
    Summary: Add the ability to merge circuits together within panel schedules, to show multiwire branch circuits.

    Description: The NEC requires any circuits that share a neutral to have a simultaneous disconnecting means at the source, in other words, a common handle tie so that all two or three circuits turn off at the same time. The most efficient way to do this is to use a two or three pole circuit breaker to feed these types of circuits. It would be great if there was a feature similar to the "group" command in the panel schedules that marked a group of up to three circuits as a "multiwire branch circuit", and converted the display of the circuit breaker to either a two or three pole circuit breaker, with a common ampacity and number of poles. I'd envision this working by merging the "rating" and "number of poles" cells together, forcing all three circuits to have a common ampacity rating, and displaying either two or three poles based on the actual number of circuits grouped together. I don't think you could actually change the number of poles for the circuit without causing issues with voltage definitions.

    Product and Feature: Revit MEP - MEP Electrical Panel Schedule - (Electrical)

    Submitted By: bbrovont229745 on 04/19/2019
    I submitted a similar wish list request 7-years ago (2012). I'm sure they will ignore yours too. Having their electrical design software actually comply with the NEC is not an unreasonable request, or at least you would think so.

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