There is no earthing pin, only a socket with a metallic rim. Will it require some special socket that has a projecting earth pin? This is for use in India @ 230W. My adaptor is 85w.

  • Hi, can I ask you to add more detail to your question? I'm not entirely sure what is being asked.
    – stuffe
    Commented Aug 31, 2013 at 9:25

3 Answers 3


The ground / earth is comprised of the outer-most two pins in the MagSafe connector (both original and the thinner + wider MagSafe 2) and requires that the ground be connected to the other end of your AC to DC adapter.

powered, neutral and grounded (earthed) contacts on the MagSafe adapter

Rather than using a two prong plug, you could use a longer two prong cord and then ground the metal disc that serves to hold the "duck head" on the transformer/rectrifier/filter that makes up the bulk of the MagSafe adapter.

alternative solution to using the Apple duck head with the MagSafe adapter

  • 5
    No no no no no!!! The center pin isn't ground! As can be seen on: en.wikipedia.org/wiki/MagSafe#Pinout the center pin is a serial interface for the LED indicator and diagnostics of the charger. In most DC systems, the "ground" is the negative terminal, which are the outer 2 pins, and the middle two are high (+).
    – Alexander
    Commented Aug 31, 2013 at 19:52
  • Darn - I should have gotten a multimeter (or double checked tech manuals). Thanks for the correction @XAleXOwnZX - does anyone else see any problems with this now that I've edited out that wrong info?
    – bmike
    Commented Aug 31, 2013 at 20:01

The transformer is double insulated and thus does not require to be grounded. It's the same with your mobile charger and external hard-drive PSU.

The outer most pins are ground (-), the 2nd and 4th are high (+) and the middle is for the Mac to signal the led on the connector:


The ground in the connector is NOT the same as the ground in your wall. The connector uses DC and the wall AC, and therefore it sounds complicated.

  • Even when a device is double insulated, isn't earthing the device going to prevent static build up on the device from being felt which is why most people prefer a grounded plug for using MacBook pro on a desk and if they are sensitive to small tingles from the ground floating (or when it interferes with audio signals and other conductor connected equipment)?
    – bmike
    Commented Aug 31, 2013 at 20:12
  • A static discharge can't be prevented with grounding only. You and the surface has to slowly adapt to each others static charge. But grounding will help you from hearing noise from a grounded amplifier, or if in an old building it will lessen the risk that you get electricity though you, but then the wiring in the building is probably more important to fix. ;)
    – Andreas
    Commented Aug 31, 2013 at 20:31

The MagSafe Power cable can either put an extension cable or a plug on the 'brick'. I've noticed that if I only use the plug on the brick, then the aluminium case 'tingles' when I touch it.

If I use the extension cable on the brick, then the tingling is not present. The Apple plugs don't connect to the earth pin, but the extension cables do. See this answer.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .