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Copper wire

  1. Oct 25, 2013 #1
    If electrons flow on the surface of a wire, why isn't copper coated aluminum wire used in electrical applications instead of solid copper wire? It would be more cost effective
  2. jcsd
  3. Oct 25, 2013 #2


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    Electrons only flow near the surface at very high frequencies and high frequency waveguides are hollow for that very reason.
  4. Oct 25, 2013 #3


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    It is used but the required gauge is two sizes larger (possibly increasing the needed conduit size) than solid copper for the same utility power (60hz skin depth is about 9 mm so for most commercial and residential wiring it's unimportant) application. Fires in houses build in the 70's with Al wiring has made many people reluctant to save maybe 20% on wire when wire is a small percentage of cost on most projects. (a 10 million dollar machine in a multi-billion dollar factory with 20K wire costs is a typical example)
    http://www.commscope.com/docs/cca_solutions_br.pdf [Broken]
    Last edited by a moderator: May 6, 2017
  5. Oct 27, 2013 #4


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    I think *waveguides* are hollow because they are conducting electromagnetic radation within the internal area in TM or TE mode.
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