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Thread: indoor unit disconnect

  1. #1
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    indoor unit disconnect

    Is a local disconnect required for an indoor fan unit that is part of a heat pump system?

    I say NO per 422.31(B) but 440.14 says otherwise.

    What are your thoughts?

    Thanks.
    Edward
    The only thing I know, is the progressive discovery of my ignorance


  2. #2
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    IMO, 422 is the correct Article but I would think the motor would be over 1/8HP and 422.31(c) would, apply and a disconnect would be needed.
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  3. #3
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    Are you asking about a mini split or a standard heat pump system. If the latter then I believe you need a disconnect. Mant systems have heat strips in them for backup heat but that depends where you are from.
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  4. #4
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    Quote Originally Posted by augie47 View Post
    IMO, 422 is the correct Article but I would think the motor would be over 1/8HP and 422.31(c) would, apply and a disconnect would be needed.
    422.31(C) applies. How about the disconnect not within sight but it is lockable? The way that I read the 440.14 it will not allow lockable disconnect. Am I correct in reading that correctly?

    Quote Originally Posted by Dennis Alwon View Post
    Are you asking about a mini split or a standard heat pump system. If the latter then I believe you need a disconnect. Mant systems have heat strips in them for backup heat but that depends where you are from.
    No heating strip.
    Edward
    The only thing I know, is the progressive discovery of my ignorance


  5. #5
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    I agree with you on 440.14.
    There has been some debate as to the applicable Article for the air handler.
    I was taught Art 422 but I can't see where it's carved in stone.
    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.

  6. #6
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    Quote Originally Posted by augie47 View Post
    I agree with you on 440.14.
    There has been some debate as to the applicable Article for the air handler.
    I was taught Art 422 but I can't see where it's carved in stone.
    If it doesn't have a hermetic compressor it isn't covered by 440, it tells us this in 440.1

    Air handler only is covered in art 422. Somewhere in there it tells us the branch circuit device can be the disconnecting means if no more then 300VA or 1/8 hp. Over those values typically requires a disconnect within site of the unit.

    If it has electric heat we need to go to 424.
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  7. #7
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    What about 430.112, which covers a single disconnecting means "where a number of motors drive several parts of a single machine"?

    Cheers, Wayne

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    Quote Originally Posted by wwhitney View Post
    What about 430.112, which covers a single disconnecting means "where a number of motors drive several parts of a single machine"?

    Cheers, Wayne
    But I can not look at the air conditioner or the indoor fan as a motor only even though it is mostly a motor load. I see it as an appliance 422 or an A/C unit 440.
    Edward
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  9. #9
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    Quote Originally Posted by kwired View Post
    If it doesn't have a hermetic compressor it isn't covered by 440, it tells us this in 440.1

    Air handler only is covered in art 422. Somewhere in there it tells us the branch circuit device can be the disconnecting means if no more then 300VA or 1/8 hp.
    Over those values typically requires a disconnect within site of the unit.
    If it has electric heat we need to go to 424.
    Yes over those values does require a local disconnect 422.31(C) for an appliance (air conditioner is considered an appliance) but at the same time it does allow a lockable disconnect. However, the 440.14 does not allow a lockable off site disconnect.

    So it seems to me that 440 contradicts with 422.
    Edward
    The only thing I know, is the progressive discovery of my ignorance


  10. #10
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    Quote Originally Posted by edward View Post
    But I can not look at the air conditioner or the indoor fan as a motor only even though it is mostly a motor load. I see it as an appliance 422 or an A/C unit 440.
    How about 440.8? It says "An air-conditioning or refrigerating system shall be considered to be a single machine under the provisions of 430.87, Exception, and 430.112, Exception.
    The motors shall be permitted to be located remotely from each other."

    Cheers, Wayne

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