Is it safe to touch the ground pin when using this adapter?

Edit: just to clarify, it's from a 60w laptop power brick.

sorry for the poor quality

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    \$\begingroup\$ Does your laptop adapter have a square-within-a-square symbol on it? \$\endgroup\$ – ThreePhaseEel Aug 28 '16 at 21:58
  • \$\begingroup\$ @ThreePhaseEel did not find, what does it mean? \$\endgroup\$ – user628797 Aug 29 '16 at 0:17
  • \$\begingroup\$ The "square within a square" is the universal symbol for a double-insulated or Class II device that is well enough insulated inside and out that it does not need safety grounding. \$\endgroup\$ – ThreePhaseEel Aug 29 '16 at 0:19
  • \$\begingroup\$ @ThreePhaseEel so that means it's best not to touch the grounding pin? \$\endgroup\$ – user628797 Aug 29 '16 at 0:20
  • \$\begingroup\$ The safety of the laptop, which is in your lap, which you touch, is the more important issue. Look for the Class 2 symbol on the laptop power adapter. Its absence tells you the laptop is intended to get safely grounded from the dangling-in-midair pin. \$\endgroup\$ – Whit3rd Aug 29 '16 at 8:39

You might get a tingle from EMI Y-caps but it shouldn't be unsafe to touch the ground pin assuming everything else is in order.

However, the unsafe part of this is that your ground pin is now not grounded, and the chassis of whatever equipment it is powering could become hot in the case of a fault. That's the unsafe part about using the adapter in the manner you're showing. If you do use it that way be sure to plug it in to an outlet with ground-fault protection.

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  • \$\begingroup\$ Thank you for the answer, it's powering a laptop power brick, if that changes anything. \$\endgroup\$ – user628797 Aug 28 '16 at 21:54
  • \$\begingroup\$ Well, a laptop brick is usually plastic, so there may not be a chassis that could become hot under fault conditions. With laptop adapters the third pin is usually there more for EMI considerations. However, I still would not recommend leaving the ground pin ungrounded unless you're plugged in to an outlet with ground fault protection. \$\endgroup\$ – John D Aug 28 '16 at 22:21
  • \$\begingroup\$ how would I know if it has ground fault protection? Is there an easy way to tell? \$\endgroup\$ – user628797 Aug 29 '16 at 0:18
  • \$\begingroup\$ GFI outlets in the US often (but not always) have "test" and "reset" buttons. Other than that, I'm not sure there's an easy way to tell just by looking at the outlet. \$\endgroup\$ – John D Aug 29 '16 at 16:43

That's the earth pin for your appliance. It's presence indicates that there is a metal body on the appliance. Grounding of the appliance may be essential to protect the user against internal faults. That pin will be at the same voltage as the appliance. In the event of a major fault both the appliance and that pin may be live.

For further insight on grounding see my answer to In any electrical equipment having single ph 230 v ac supply ,if neutral and earth wire exchanged then what will be the consequence.

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  • \$\begingroup\$ Thank you, I guess I will look for alternative solutions. \$\endgroup\$ – user628797 Aug 29 '16 at 0:19

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