Wire Gauges and Max Current

Discussion in 'General Electronics Chat' started by SteveO, May 15, 2008.

  1. SteveO

    Thread Starter Active Member

    May 15, 2008
    33
    0
    I have a project in which a number of different power supplies need to be re-wired.

    Could someone send me in the direction of a chart which will list the maximum current ratings for a given AWG, corresponding to safety regulations. I have found a few but they all seem to differ from one another. I need everything from down to 2 A to just over 100 A.

    Thanks.

    Regards,
    Steven
     
  2. bertus

    Administrator

    Apr 5, 2008
    15,647
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  3. SteveO

    Thread Starter Active Member

    May 15, 2008
    33
    0
    Thank you for your quick and accurate response.

    edit: Is I @ 3A /mm^2 to insure safety precautions? Thanks.

    Regards,
    Steven
     
  4. Papabravo

    Expert

    Feb 24, 2006
    10,140
    1,789
    AWG with metric dimensions -- how cute. Kinda buries the use of circular mils on which the guage was based. One should never start vast projects with half vast ideas.
     
  5. hgmjr

    Moderator

    Jan 28, 2005
    9,030
    214
    Here is a link to some fairly good wire information provided by the Belden Wire Mnaufacturer.

    hgmjr
     
  6. thingmaker3

    Retired Moderator

    May 16, 2005
    5,072
    6
    It's not quite that simple. As the wire becomes larger, it is rated for fewer amps per unit area. This is due to smaller wires having more surface area per unit volume, and therefore being able to dissipate more heat. Similar current densities for larger wire would result in unacceptable temperature increases.

    Also, ampacity for a given wire size will depend on application. Ratings for free air wiring are higher than for enclosed wiring. Ratings for chassis wiring (which is necessarily short by comparison) are higher still. Ratings for coils are much lower.
     
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