My Macbook Pro charger (purchased in the US) comes with two different plug attachments, one that fits directly into the body of the charger and one with an extension cord. For some reason, the short attachment has only two prongs, while the long one has an additional ground pin. What is the function of the ground pin on the long attachment? Is it really necessary?
MacBook – Laptop charger plug differences
chargingmacbook pro
Related Question
- MacBook – Battery not charging? (Even after SMC reset)
- IPad – 3rd party power adapter causing screen glitches
- MacBook – 30-pin LVDS cable extension for Macbook Pro display panel
- MacOS – Bootcamp Windows 7 Installation on Macbook Pro Late 2008 with MiniDisplayPort Monitor (Broken Laptop Display)
- MacBook – the name of the long cable/plug attachment on the MacBook MagSafe charger
Best Answer
The third pin is a ground pin. It is required in some countries for devices with a metal surface to prevent shocks in case of a short-circuit. Since they also delivered a plug with only two pins to you, in your country it seems to be ok to use without grounding. If you want to be absolutely on the safe side, use the three pin cable.
More info.