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Thread: Cabling

  1. #1
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    Apr 2018
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    Cabling

    When running CAT5 cable in a drop ceiling, what is the required cable rating to use

  2. #2
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    Dec 2004
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    Windsor, CO NEC: 2017
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    Where have you looked for the answer?

  3. #3
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    Apr 2009
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    Welcome to The Forum. Your question does not have a solid answer, it depends on if the ceiling is an air return, and if the cable is penetrating a floor. I'll give you a hint... See 800. 154 a. Also, if this is not a test question, and a real-world install, you had better get this right... Inspectors don't usually pay too much attention to chapter 8 installations but if you use the wrong cable type I guarantee you you will be pulling it all out
    Electricians do it until it Hertz!

  4. #4
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    Quote Originally Posted by JFletcher View Post
    Welcome to The Forum. Your question does not have a solid answer, it depends on if the ceiling is an air return, and if the cable is penetrating a floor. I'll give you a hint... See 800. 154 a. Also, if this is not a test question, and a real-world install, you had better get this right... Inspectors don't usually pay too much attention to chapter 8 installations but if you use the wrong cable type I guarantee you you will be pulling it all out
    When in doubt, use plenum rated. In fact, use plenum rated anyway. Wire is cheap, labor is expensive. Non-plenum is ~$75/1000 feet, plenum is ~$145/1000 feet.

  5. #5
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    Quote Originally Posted by gadfly56 View Post
    When in doubt, use plenum rated. In fact, use plenum rated anyway. Wire is cheap, labor is expensive. Non-plenum is ~$75/1000 feet, plenum is ~$145/1000 feet.
    95% of the time, CMR was all we needed for floor penetrations in hotels. between coax, Cat5e, and Cat6, I'd estimate I've installed close to a million feet this stuff, and if I bought all CMP versus CMR, would have spent about an extra $75,000 in unnecessarily on cable. I've never had to pull out anything I ran, we've had two jobs were the previous contractor screwed up and we took a pair of snips to all of his cable and re-ran the proper stuff.

    back in 2008 the difference between CMR and CMP was more like $175 per box. CMP, in many brands has clearish insulation on the pairs of wires, and distinguishing the orange from the brown isn't always easy... Had a couple of them windup reversed or split between pins 1/2 and 7 and 8.

    But yes point taken, you cannot go wrong with CMP is at the top of the cable hierarchy
    Electricians do it until it Hertz!

  6. #6
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    Quote Originally Posted by JFletcher View Post
    95% of the time, CMR was all we needed for floor penetrations in hotels. between coax, Cat5e, and Cat6, I'd estimate I've installed close to a million feet this stuff, and if I bought all CMP versus CMR, would have spent about an extra $75,000 in unnecessarily on cable. I've never had to pull out anything I ran, we've had two jobs were the previous contractor screwed up and we took a pair of snips to all of his cable and re-ran the proper stuff.

    back in 2008 the difference between CMR and CMP was more like $175 per box. CMP, in many brands has clearish insulation on the pairs of wires, and distinguishing the orange from the brown isn't always easy... Had a couple of them windup reversed or split between pins 1/2 and 7 and 8.

    But yes point taken, you cannot go wrong with CMP is at the top of the cable hierarchy
    I can understand if you're a high-volume shop that the delta can add up, but it has to be lost in the noise compared to your total labor costs.

    I'm most familiar with fire alarm cable, and FPL to FPLP is about the same delta, but cable is usually the smallest material cost for any given fire alarm project.

  7. #7
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    Quote Originally Posted by gadfly56 View Post
    I can understand if you're a high-volume shop that the delta can add up, but it has to be lost in the noise compared to your total labor costs.

    I'm most familiar with fire alarm cable, and FPL to FPLP is about the same delta, but cable is usually the smallest material cost for any given fire alarm project.
    High-volume shop? LOL... We were a two-man shop, occasionally with one to two more helpers. we did 18 hotels, 65 to 125 room, from 2007 to 2010. I was working at a 248 room Hotel that he was wiring back in 2006. That building wound up with over 200,000 feet of communication cabling.
    Electricians do it until it Hertz!

  8. #8
    Join Date
    Jun 2003
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    Hawthorne, New York NEC: 2014
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    If you are going to stock cable or just have it on the truck always go with plenum. You can use it anywhere. However, if you are purchasing for a specific job, understand how to determine what cable is required and purchase that. You can save some money.

    -Hal

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