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Thread: AC disconnect

  1. #1
    Michael Vasquez's Avatar
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    Default AC disconnect

    Is it required to have a new disconnect installed when a new condenser is installed at an existing home or will the old disconnect be acceptable if it is in working condition?

    Thanks

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  2. #2
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    Default Re: AC disconnect

    If the disconnect is the right size (amps), type, and location. Then by just replacing the condenser you should not need to replace the disconnect. However The company that is replacing the condenser, I presume , will also have a warranty on it. They may want to replace the disconnect to insure that it does not affect the new condenser.

    ' correct a wise man and you gain a friend... correct a fool and he'll bloody your nose'.

  3. #3
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    Default Re: AC disconnect

    Should they install a disconnect if there is not one near the unit?

    Dylan Whitehead

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    Default Re: AC disconnect

    Quote Originally Posted by Dylan Whitehead View Post
    Should they install a disconnect if there is not one near the unit?
    A disconnect does not have to be near the unit. It can be within 50 feet but needs to be in sight of the condensing unit.

    Michael, pertaining to your question.... No a disconnect does not need to be replaced when you change out an a/c unit (provided it is in good condition and appropriate for its use as Rick pointed out).

    Sincerely,

    Corey

    Last edited by Corey Friedman; 07-03-2008 at 07:43 AM. Reason: spelling

  5. #5
    James Duffin's Avatar
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    Default Re: AC disconnect

    The age of the disconnect has nothing to do with the warranty of what's wired to it. The only thing that matters is the over-current protection and and the wire size.

    Last edited by James Duffin; 07-04-2008 at 07:40 PM.

  6. #6
    Michael Vasquez's Avatar
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    Default Re: AC disconnect

    Thanks for the help.


  7. #7
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    Default Re: AC disconnect

    Depending on how close the condenser is to the exterior wall of the house, you do not want the disconnect directly behind the condenser. It should be off to the side to allow unobstructed access. The disconnect location should allow plenty of room for a person work.


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    Default Re: AC disconnect

    Quote Originally Posted by John Dirks Jr View Post
    The disconnect location should allow plenty of room for a person work.
    Let's put some numbers to that "plenty of room" statement:

    The required working space in front of electrical equipment (of that voltage) is 36" deep 'in-front-of' by 30" wide 'for-that-36"-depth'.

    Then, you also are required to have access to that working space.

    Jerry Peck
    Construction/Litigation/Code Consultant - Retired
    www.AskCodeMan.com

  9. #9
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    Default Re: AC disconnect

    Thanks for expanding on that Jerry. It's pretty much the same requirements as for main service panels right?

    I found the one pictured below at a previous inspection. It was outside of the requirements on the scale of too high. It's a bit unusual to find AC disconnects too high.

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    Default Re: AC disconnect

    Quote Originally Posted by John Dirks Jr View Post
    It's pretty much the same requirements as for main service panels right?
    Actually, it is EXACTLY the same requirements.

    Jerry Peck
    Construction/Litigation/Code Consultant - Retired
    www.AskCodeMan.com

  11. #11
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    Default Re: AC disconnect

    Jerry
    You stated:
    "The required working space in front of electrical equipment (of that voltage) is 36" deep 'in-front-of' by 30" wide 'for-that-36"-depth'."

    With respect to one that has more knowledge than I.
    I think the section you are referencing is:

    SECTION E3305 EQUIPMENT LOCATION AND CLEARANCES
    E3305.2 Working clearances for energized equipment and
    panel boards. Except as otherwise specified in Chapters 33
    through 42, the dimension of the working space in the direction
    of access to panel boards and live parts likely to require examination,
    adjustment, servicing or maintenance while energized shall
    be not less than 36 inches (914 mm) in depth. Distances shall be
    measured from the energized parts where such parts are exposed
    or from the enclosure front or opening where such parts are
    enclosed. In addition to the 36-inch dimension (914 mm), the
    work space shall not be less than 30 inches (762 mm) wide in
    front of the electrical equipment and not less than the width of
    such equipment.


    SECTION E3305.2 is about (bold is mine)
    "Working clearances for energized equipment and panel boards."
    And states that
    "access to panel boards and live parts likely to require examination,
    adjustment, servicing or maintenance while energized
    "

    Since the power to most (if not all) disconnects can be removed at a panel board then it does not need to be energized.
    Therefore this section may not apply, if this section does not apply then the required working area (30"x36") does not apply
    So what does apply?
    Also note the exception
    "Except as otherwise specified in Chapters 33 through 42, ..."

    Chapter 40 does have a specification for A/C disconnects, which states.

    TABLE E4001.5 DISCONNECTING MEANS
    Air-conditioning condensing units and heat pump units.
    A readily accessible disconnect within sight from unit as the only allowable means.


    So what is "readily accessible"?

    ELECTRICAL DEFINITIONS
    ACCESSIBLE,READILY. Capable of being reached quickly
    for operation, renewal or inspections, without requiring those
    to whom ready access is requisite to climb over or remove
    obstacles or to resort to portable ladders, etc.


    When a disconnect is located above or even behind the condenser unit it may still be "Readily accessible". As long as it is capable of being reached quickly for operation, renewal or inspections without having to climb over or remove something and without having to use a ladder.
    There is no restriction on reaching over or reaching behind.

    Jerry, I'm picking on you because:
    I am testing my understanding of the IRC
    I want to obtain more skill and knowledge
    So I pick (on) one with more understanding, skill and knowledge

    ' correct a wise man and you gain a friend... correct a fool and he'll bloody your nose'.

  12. #12
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    Default Re: AC disconnect

    Quote Originally Posted by Rick Cantrell View Post
    You stated:
    "The required working space in front of electrical equipment (of that voltage) is 36" deep 'in-front-of' by 30" wide 'for-that-36"-depth'."

    With respect to one that has more knowledge than I.
    I think the section you are referencing is:

    SECTION E3305 EQUIPMENT LOCATION AND CLEARANCES
    E3305.2 Working clearances for energized equipment and
    panel boards. Except as otherwise specified in Chapters 33
    through 42, the dimension of the working space in the direction
    of access to panel boards and live parts likely to require examination,
    adjustment, servicing or maintenance while energized shall
    be not less than 36 inches (914 mm) in depth. Distances shall be
    measured from the energized parts where such parts are exposed
    or from the enclosure front or opening where such parts are
    enclosed. In addition to the 36-inch dimension (914 mm), the
    work space shall not be less than 30 inches (762 mm) wide in
    front of the electrical equipment and not less than the width of
    such equipment.

    SECTION E3305.2 is about (bold is mine)
    "Working clearances for energized equipment and panel boards."
    And states that
    "access to panel boards and live parts likely to require examination,
    adjustment, servicing or maintenance while energized"
    Correct, that's the IRC section comparable to the NEC requirements for working spaces.

    Since the power to most (if not all) disconnects can be removed at a panel board then it does not need to be energized. Therefore this section may not apply, if this section does not apply then the required working area (30"x36") does not apply
    Ah, that is where you stray ...

    "can be" versus "likely to"

    The code (neither the IRC nor the NEC) addresses "can be" - they only address "likely to require"

    So what does apply?
    "Likely to" applies, thus that section *does apply*.

    Also note the exception
    "Except as otherwise specified in Chapters 33 through 42, ..."

    Chapter 40 does have a specification for A/C disconnects, which states.

    TABLE E4001.5 DISCONNECTING MEANS
    Air-conditioning condensing units and heat pump units.
    A readily accessible disconnect within sight from unit as the only allowable means.

    So what is "readily accessible"?

    ELECTRICAL DEFINITIONS
    ACCESSIBLE,READILY. Capable of being reached quickly
    for operation, renewal or inspections, without requiring those
    to whom ready access is requisite to climb over or remove
    obstacles or to resort to portable ladders, etc.
    As you have already answered your own question, no, that (the disconnect in the photo) *is not* "readily accessible".

    When a disconnect is located above or even behind the condenser unit it may still be "Readily accessible".
    It may be "readily accessible" when installed behind the condenser unit, however, it does not have the required "working space" "in front of" it.

    Two distinctly different issues and requirements, however, *BOTH* apply.

    As long as it is capable of being reached quickly for operation, renewal or inspections without having to climb over or remove something and without having to use a ladder.
    There is no restriction on reaching over or reaching behind.
    You are missing two things in there:

    "Climb over" as in 'be required to reach over because you do not have the required working space "in front of" it'.

    "Reaching behind" ... see "climb over" above.

    If it is "likely to" be inspected, maintained, examined, adjusted, serviced, etc., *while energized*, they working space is required.

    You will note in the definitions that "electrical equipment" encompasses basically all parts of the electrical system, including raceways and fittings, however, it is "UNlikely" that raceways and fittings will need the stated working space as it is "UNlikely" that they will be taken apart "while energized. I know, I know, *I* have done it, but *I* have done other "UNlikely" things with regard to electrical systems too.

    Jerry Peck
    Construction/Litigation/Code Consultant - Retired
    www.AskCodeMan.com

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