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Cross sectional area question

Discussion in 'Electrics UK' started by ScottishGasMan, 6 Sep 2021.

  1. ScottishGasMan

    ScottishGasMan

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    May be a really simple/stupid question, but wanting to make sure I'm not missing anything here.

    does the cross sectional area of 2 cables just add together? ie, if I have 2 cables with a cross sectional area of 0.5mm, is that equal to having a cable with 1mm?

    also does anyone know the typical cross sectional area of a core of cat5 or 6 cable typically?
     
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  3. CBW

    CBW

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  4. EFLImpudence

    EFLImpudence

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    In terms of just physical size then yes, of course, 1 is equal to two times 0.5 anything.

    However, the csa is used to denote the resistance and/or current-carrying-capacity of conductors - 1mm² will have half the resistance of 0.5mm² but cannot carry twice the current of 0.5mm².
     
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  5. ScottishGasMan

    ScottishGasMan

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    Read a few different sources now and its a little misleading as to whether cat5/6 is 0.25 mm2 for each core, or for a "pair" of cores.
     
  6. ScottishGasMan

    ScottishGasMan

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    Although more seem to state that its 0.25 per pair of 2 cores so I'll go with that.
     
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  8. EFLImpudence

    EFLImpudence

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    It seems very unlikely to be per pair.

    A quick search indicates that the conductors are AWG24 which is 0.25mm².

    Even if it were said that a pair of conductors were AWG24; that would still mean that each one was AWG24.
     
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  9. rsgaz

    rsgaz

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    Cat5e is supposedly 24AWG, which is 0.205mm² according to Wikipedia, but I believe that comes from having a nominal diameter of 0.5mm, so that works out to just shy of 0.20mm² in reality. And that is for each core, not a pair.

    Cat6 can be 24AWG, 23AWG or even 22AWG. Check the spec of the cable, either by Googling the manufacturer, or it is printed on the cable if it is "proper" Cat6.
     
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  10. plugwash

    plugwash

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    An american standard is highly unlikely to have a nominal diameter that is a round number of millimeters.
     
  11. EFLImpudence

    EFLImpudence

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    There are various and varying tables available but none of them seems to be consistent -

    even in the columns within a single table being compatible with each other.
     
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