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Thread: De-rating network cables

  1. #1
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    De-rating network cables

    What's the new rule on de-rating network cables that are bundled? Cables such as cat5e and cat6


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  2. #2
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    Haven't heard of any such rule. From where? Derating network cables doesn't make sense, they don't carry more than milliwatts.

  3. #3
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    Quote Originally Posted by zbang View Post
    Haven't heard of any such rule. From where? Derating network cables doesn't make sense, they don't carry more than milliwatts.
    Actually PoE network cables can carry up to 25 watts (PoE+).
    Curt Swartz
    Electrical Contractor

  4. #4
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    No derating rule that I have ever heard of but there are raceway fill and bend radius rules. Cat6 should not be bundled due to cross talk concern at the higher frequencies. Just let it lay wild.

    #PrudentPrePlannigPreventsPissPoorPerformance

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    Quote Originally Posted by bluecollar84 View Post
    What's the new rule on de-rating network cables that are bundled? Cables such as cat5e and cat6


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    The new rule is 725.144 and is a response to concern raised by a UL study that data cables that are also used as POE may over heat. Bundling of ethernet cables that are not also being used for POE is not an issue.

  6. #6
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    Quote Originally Posted by curt swartz View Post
    Actually PoE network cables can carry up to 25 watts (PoE+).
    Yep, and soon to be higher. I think with the next standard of 802.3bt they are talking of up to a hundred watts. Imagine a bundle of 200 or so with this kind of power on them. Kind of scary.

  7. #7
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    Quote Originally Posted by texie View Post
    Yep, and soon to be higher. I think with the next standard of 802.3bt they are talking of up to a hundred watts. Imagine a bundle of 200 or so with this kind of power on them. Kind of scary.
    ohoh. more magic smoke escaping.

    they will have to be plenum rated so they don't smell when
    they catch fire......
    ~New signature under construction.~
    ~~~~Please excuse the mess.~~~~

  8. #8
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    Quote Originally Posted by curt swartz View Post
    Actually PoE network cables can carry up to 25 watts (PoE+).
    True, was not mentioned by the OP.

  9. #9
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    Quote Originally Posted by bluecollar84 View Post
    What's the new rule on de-rating network cables that are bundled? Cables such as cat5e and cat6


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    I meant POE data cables bundled what's the rules ?


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  10. #10
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    Quote Originally Posted by bluecollar84 View Post
    I meant POE data cables bundled what's the rules ?


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    As already mentioned, see 725.144 in the 2017 NEC.

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