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    tkrussell's Avatar
    tkrussell Posts: 9,659, Reputation: 725
    Uber Member

    Jan 28, 2006, 11:38 AM
    Correction-GFI & AFI Breakers & Shared Neutrals
    I need to submit a correction to some advice I had furnished in the past regarding Ground Fault and Arc Fault circuit breakers being used on shared neutrals. I had in mind the typical single pole 120 volt breakers that will not work if two breakers are used for two 120 volt circuits that share a neutral. This advice still stands as true.

    However, there does exists 2 pole GFI and AFI circuit breakers that will work to protect two 120 volt circuits that share a neutral. Most of the major circuit breaker manufacturers offer these 2 pole breakers, such as General Electric in the THQL frame, Square D as the QO frame, and Siemens in the QF frame.

    These 2 pole circuit breakers did come to mind due to a couple of issues that cause them to be impractical.

    One reason is the cost of one of these breakers, in the range of $200-$300 each, and this is wholesale cost. The big box hardware stores may sell these, not sure what the retail cost is.

    Another reason is that if there is a fault on one circuit, since the 2 poles of the breaker are physically connected internally, both circuits will be interrupted.

    I see there is another request in the Electrical forum pleading to use AFI breakers on a shared neutral. Even thou I believe using 2 pole GFI and AFI breakers as being impractical, it did occur to me that I need to be as accurate as possible, and offer these as a solution, and let the person that will be living with and paying for these breakers be the judge whether to use them or not.

    I apologize for any inconveinence my inaccurate or incomplete advice previously submitted may have caused to anyone that may have be misled by not being informed of the 2 pole GFI and AFI circuit breakers that are available.
    Stratmando's Avatar
    Stratmando Posts: 11,188, Reputation: 508
    Uber Member

    Jun 20, 2007, 05:12 PM
    Thanks, I could think pulling extra neutral, may be cheaper than the 2 pole.
    dbernoulli's Avatar
    dbernoulli Posts: 2, Reputation: 1
    New Member

    Nov 8, 2007, 07:51 AM
    Please explain in detail the difference between one pole and two pole circuit breakers. Thank you.
    tkrussell's Avatar
    tkrussell Posts: 9,659, Reputation: 725
    Uber Member

    Nov 8, 2007, 01:44 PM
    One pole breakers are used for 120 volt circuits, and two pole breakers are used for 240 volt circuits.

    Please start a new question instead of posting to a year old question.

    This thread is closed.

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