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When plugging in a device in the dark, or behind furniture, it's hard to get the contacts aligned. It's tempting to put a finger on the end of a contact, use that finger to find the slot in the recep, and guide the plug in. However, that seems like a pretty reliable way to get a shock.

However, for 3-prong grounded plugs, I think I can do the same thing with the ground contact.

Is it safe to plug something in with my finger touching the ground contact?

If the recep is miswired, then the answer is probably "no, it's not safe", but I'm really asking about correctly wired receps.

(If the USA changes plugs in my lifetime, I hope they pick a design that's easy to plug in the dark.)

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It depends when you release the ground pin. If you've ever noticed, the ground pin is longer than the other blades. This is so the ground makes contact first, and breaks contact last. So if you only touch the ground pin until it's set in the edge of the hole, you should not have a problem. I've done this many times before, and I usually tilt the plug so the ground pin is close to the hole and the blades are as far away as possible. Once the ground is lined up, I remove my finger and insert the plug. –  Tester101 Apr 5 '12 at 11:33
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4 Answers 4

Well, in theory, assuming wiring is done right the ground prong will contact the ground terminal in the outlet and that terminal is connected to the ground with a thick enough wire and touching it is as safe as touching a washer or fridge chassis.

However you should not do that ever, because Murphy is out there...

First of all, the ground prong is very close to the phase and neutral prongs and there's a slim yet quite real chance that you will touch the phase prong at the same time. Once this happens you get a ground fault and if there's no ground fault protection that yields a major short circuit which gets you a nice several millimeters deep burn on your finger (I have nice experience touching phase and neutral terminals together with the same finger - heals in two weeks and can be fatal in an unlucky electrical setup). If you're really unlucky (like you're touching a grounded appliance at the same time) you get a ground fault through your body and this yields fatal shock. Such things do happen - it's just a matter of time. You do that no-problem one thousand times, then you accidentally do it wrong and consequences are dire. Chances are slim, but quite real and potential consequences are serious.

Second, you can't be sure at all times each outlet is wired right. Wiring may fail at some point and put you at risk. You can also try to do that in other person's house where wiring happens to be done wrong and that puts you at risk.

Finally, there's this cheater plug thing. Clearly if you plug a three-pronged device into a cheater plug and then try to plug the cheater plug and habitually try to find the prong you likely find either phase or neutral prong and that puts you at risk.

So the bottom line is you technically can do that, but you really should not - getting such habit is potentially very dangerous.

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So, it's safe if a bunch of conditions are met, but if I get in the habit, I'll do it some time when it's not safe and get zapped. –  Jay Bazuzi Apr 5 '12 at 7:45
    
@Jay Bazuzi: Yes, pretty much that. –  sharptooth Apr 5 '12 at 7:47
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Just hope that your house wasn't wired by one of the folks on here who frequenly ask "can I jumper my neutral and ground together?" –  Steven Apr 5 '12 at 14:43
    
Actually I have been electrocuted across my body several times (not fun). So it is not always a fatal shock. It probably does some permanent damage to your heart though. –  Brad Gilbert Apr 5 '12 at 17:53
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Generally and ideally speaking, yes, touching the ground pin of a plug is as safe as touching the metal shell of whatever has that ground pin. The pin is either discontinuous (because you haven't plugged it in far enough to make contact) or continuous with earth. Either way, the ground leg should not be carrying a load.

I say "should not". Here's where theory meets reality. Some yahoo calling himself an electrician or handyman may have jumpered neutral to ground, or swapped neutral for ground, when wiring this outlet. Maybe he didn't have grounded Romex (wait, what?). More likely he isn't as handy as he thought, at least when he wired this. In these cases, the ground pin may have a voltage potential to the "real" ground when the device (or another device on the circuit) is plugged in and turned on, and can give you a nasty shock.

Also, if there is a failure in the device itself that is causing a short between hot and ground, you will get a shock that can kill you before the breaker trips.

Lastly, a potential in the earth itself (downed lines, lightning strike, catastrophic delivery transformer failure) can induce a shock, but these situations are rare and can kill you even if you're just holding the fridge door open wondering what to have for a snack. In these situations, if it's your time there's not much you can do to prevent it other than avoid touching or being anywhere near any grounded piece of metal in your home during a lightning storm.

So, generally, you want to keep your fingers away from all the prongs of a plug no matter what they are and what they should or shouldn't be conducting at any given time. You simply don't play with things that can kill you.

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Regardless of wiring you are going to be safe. What @Sharptooth said about him getting a shock is because he was messing with bare wires and being unsafe. It happens to the best electrician..

In certain extreme cases touching earth can give you a shock but that is very rare situations.

Remember that an entire appliance is earthed, so if you hold a metal light that has earth on it, it the same as holding the earth pin on the plug while plugging it in. Allot of new electricity regulations require homes to be fitted with sensitive earth leakage detectors. So before a lethal welding iron type shock can be inflicted.. the electricity will trip within hundreds of a second, saving your finger or life..

But in terms of home use, well look at this 3 prong plug

enter image description here

Its a UK version, but in africa thay are round with the same distances. Now notice the longer one. the one you mention to navigate with your finger. It is completely exposed and longer than the others. Its functions are as follows:

  • Extra distance ensures the device is grounded before any current is applied to it
  • enables plugs with safety pins to disengade and allow the plug to enter

If.. you wiring is faulty any device plugged in will cause the breakers to trip before it has a chance to shock you!

The two shorter pins and its construction functions as follows:

  • Only the tips are exposed to ensure that contact is ONLY made once the plug is within the wall socket to prevent shock in case you have your fingers there.

Right, so you dont have to worry about your wiring but what is important the plug you are using. You want to guide it with your finger then get a plug that looks like that.

Because I tell you what.. if you decide to do the same with these Eastern European Plug

enter image description here

You will fry your finger.. But inspecting this plug you will notice that it actually may seem easier to plug it with out feeling with your finger if its aligned because it has guides to help you align before plugin in.

Here are some plugs that will cause you harm if you keep your finger near the pins while pluggin in...

enter image description here enter image description here enter image description here enter image description here

It is important to realise that poking your fingers around electricity is never a good idea any way.

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Ironically the OP asks about US outlets that fall into "will cause you harm" category in your detailed analysis. –  sharptooth Apr 6 '12 at 8:31
    
Sorry I am not from the US, so included as many as possible in my Analysis... But the principle and common sense applies all round. –  ppumkin Apr 6 '12 at 11:23
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Why don't you get a short extension cord, plug it in once (leave it plugged into the wall), and plug/unplug your device into the extension cord where it is easy to plug it in safely.

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