National Electrical Installation Standards

Standards as High as Your Own

Friday, January 26, 2018


I'm not a big fan of multiwire branch circuits particularly in residential applications but have to deal with them quite often. NEC 210.4(A) states that multiwire branch circuits shall be permitted to be considered as multiple circuits. Would this include a MWBC that serves both a bathroom and a living room? Specifically, would one 20A circuit in this MWBC be permitted as the required circuit for bathroom receptacle outlets if it did not have any other outlets?

Thank you for the service you provide to the industry.

Steve M.



Hey Steve thanks for your question and you are welcome. There are advantages and disadvantages to using multi-wire circuits. Yes, as you indicate 210.4(A) allows multi-wire branch circuits to be considered as multiple circuits. Each branch circuit conductor must be supplied from different "phases" and there must be a simultaneous means of disconnecting them as stated in 240.4(B).

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