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Thread: Fire Alarm Cable

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    Fire Alarm Cable

    Does the NEC or NFPA 72 state that cables used for notification and initiating devices on a power limited system needs to be 2-hour fire rated?

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    Quote Originally Posted by guanacaciq View Post
    Does the NEC or NFPA 72 state that cables used for notification and initiating devices on a power limited system needs to be 2-hour fire rated?
    NFPA-72 (2002):

    6.9.4 Survivability from Attack by Fire.
    6.9.4.1 Subsection 6.9.4 shall apply only to systems used for partial evacuation or relocation of
    occupants
    . The requirements of 6.9.4 shall apply to both audible (tone and voice) and visible
    notification appliance circuits.
    6.9.4.2* Survivable fire alarm systems shall be designed and installed such that attack by fire within
    an evacuation signaling zone shall not impair control and operation of the notification appliances
    outside the evacuation signaling zone. Performance features provided to assure survivability shall be
    described and technical justification provided in the documentation submitted to the authority having
    jurisdiction with the evaluation required in 6.4.3.1.
    6.9.4.3 All circuits necessary for the operation of the notification appliances shall be protected until
    they enter the evacuation signaling zone that they serve. Any of the following methods shall be
    considered acceptable as meeting the requirements of this subsection:
    (1) A 2-hour rated cable or cable system
    (2) A 2-hour rated enclosure
    (3)* Performance alternatives approved by authority having jurisdiction

    The cabel type is usually MI (mineral insulated) or CI (circuit integrity).

    For small commercial/business occupancies, this requirement is frequently (mostly?) overlooked. One of the ways it is often considered satisfied is if the building is fully sprinklered, then you don't need MI or CI cable.

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    I am in agreement with the code reference that was posted.
    The interpretation is where I differ.
    The part that says
    "shall apply only to systems used for partial evacuation or relocation of occupants."
    almost never applies except I've had it apply in high rise buildings and hospitals, where they use a defend in place strategy in many cases.
    Ron

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