Difference between MagSafe mains plug lead.

Discussion in 'MacBook Air' started by macsymacker, Dec 18, 2011.

  1. macrumors member

    Joined:
    Nov 12, 2011
    #1
    Hello everyone,

    My question is simple.

    Why does the extension cord plug lead consist of 3 parts, one being "grounding-earthing contact" whilst the short (direct) mains plug just have two ends (thus unearthed)?

    Thank you.
     
  2. macrumors Core

    miles01110

    Joined:
    Jul 24, 2006
    Location:
    The Ivory Tower (I'm not coming down)
  3. thread starter macrumors member

    Joined:
    Nov 12, 2011
    #3
  4. macrumors Westmere

    GGJstudios

    Joined:
    May 16, 2008
    #4
    That's why you should use a surge protector, as the ground wire won't protect against damage.
     
  5. thread starter macrumors member

    Joined:
    Nov 12, 2011
    #5
    Ok, thank you however let me rephrase the question and ask again.

    Why in the UK, both plugs come with ground pin whilst in other countries i.e. Italy or Germany, only the extension cord plug has the grounding pin?

     
  6. macrumors demi-god

    Gav2k

    Joined:
    Jul 24, 2009
    #6
    Wirelessly posted (Mozilla/5.0 (iPhone; CPU iPhone OS 5_0_1 like Mac OS X) AppleWebKit/534.46 (KHTML, like Gecko) Version/5.1 Mobile/9A405 Safari/7534.48.3)

    Even with 3 pins the uk adapter isn't earthed! The third pin (earth) is required on a uk plug to open the neutral and live gates.

    The power adapter is classed as a double insulated or class 2 device so no earth is needed
     
  7. macrumors Westmere

    GGJstudios

    Joined:
    May 16, 2008
    #7
    It might have to do with electronic device regulations being different in different countries.
     
  8. thread starter macrumors member

    Joined:
    Nov 12, 2011
    #8
    Thank you for explaining and thanks to everyone for their participation.
    Appears to be my deep confusion and stupidity on the subject.
    Cheers! ;-)

     
  9. macrumors member

    Joined:
    Nov 16, 2011
    #9
    The third pin is indeed necessary to open the gate for the other pins, but on non-double-insulated devices the top pin is earthed as well.
     
  10. macrumors demi-god

    Gav2k

    Joined:
    Jul 24, 2009
    #10
    Incorrect the earth isn't used by the adaptor In any way!
     
  11. macrumors member

    Joined:
    Nov 16, 2011
    #11
    You are correct with regards to the mag safe adapters, but as per my post, the third pin is earthed for non-double-insulated devices. Granted, this may not include current Apple adapters.
     

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