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I'm quite scared every time I have to use NEMA plugs (I live in Japan).

Coming from europe, the bottom of the two connectors is insulated EU PLUG; public domain

This ensure that even if you touch them while plugging/unplugging, it will always be safe to touch.

Meanwhile with NEMA ones, there is no such insulation and I often see my appliance partially disconnected (but power still flowing) because of either the weight of the AC/DC or the cable has been pulled accidentally.

Nema plug, public domain

Am I right to be worried about accidentally touching the connectors, and what to do about it ?

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    Well, you're not supposed to touch the metal parts while plugging and unplugging, that's what the ridged plastic area is for on the pictured plug -- to give you better grip. after 40+ years of using them (even as a child), I've never been shocked by inadvertently touching one of the conductors. Since the contacts inside the receptacle are recessed and not right at the edge, very little of the plug is exposed when it makes contact... I just tested one and less than 1/4" (6mm) of the plug is exposed when it makes contact so there's not a whole lot of room for your finger to fit in between.
    – Johnny
    Jun 29, 2016 at 1:35
  • It looks like the "safe" one you pictured is a UK BS 4573 Shaver plug, but the more typical three prong UK BS 1363 (Type G) plus has even longer prongs than the American/Japanese style, so seems even more likely to result in inadvertent contact. Maybe that's why they tend to have switches on every outlet. The French/German style plugs seem to be even safer since the outlets are recessed making it even harder to make inadvertent contact.
    – Johnny
    Jun 29, 2016 at 1:41
  • I received a shock once when I was a child. I was connecting a lamp, and somehow I accidentally touched one or both of the conductors. That was decades ago and has not happened since. It seems that there is some risk of shock, but it is unlikely, and also it doesn't do much harm most of the time.
    – mkeith
    Jul 23, 2016 at 4:38

3 Answers 3

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How can NEMA [1-15, IEC Type A] electric plug [in Japan] be safe?

Nothing is safe. There are only degrees of safety.

European plugs incorporate more safety features, which makes them safer. But they also work with higher voltages, which are slightly more dangerous (230 instead of 120 in US or 100 in Japan).

UK Plugs and outlets have many more safety features than any other design, so are safer still.

None of these designs can always prevent a determined or negligent person from electrocuting themselves.

I think it is better to regard them as less safe rather than unsafe, Just take extra care.

  • Do not use cords, plugs or outlets that appear damaged, replace them.
  • Always ensure plugs are fully pushed in.
  • Only grasp plugs by the plug body.
  • Keep fingers away from the front edge near the pins.
  • Do not pull plugs out by the cords
  • Do not let cords trail where they may be tripped over (causing plugs to be pulled partly out)
  • If you can do so, replace ordinary breakers and outlets with GFCI equivalents.
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    Good list of dos and don'ts.
    – ArchonOSX
    Jun 29, 2016 at 11:04
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That space is pretty small and it's hard to get a finger in there. If it's far enough out that you could, then it's not far enough in to make electrical contact. So yes there can be a 1/4" gap, but your kid would have to get imaginative with paper clips to get to it.

Also, the voltage is half the Euro/APac voltage.

And, if you are at current code, you are likely to have a GFCI or AFCI trip before anything bad happens. We residual-current-detect each circuit, not the whole house, so the refrigerator doesn't quit and food doesnt spoil, and the detection threshold is much more sensitive.

That is the original plug from the very early 20th century... We couldn't change it post-WWII because there were too many NEMA-1 outlets still in service. There were so many because our cities did not get bombed flat in World War II. We also did not get to rebuild our industry, so we were trying to compete in the 1970s with factories from 1933, which worked well for everyone but us. Also, most houses in the city have their original 1910-ish telephone wires, and we now try to push high speed internet over that.

We also did not settle on 220V which means all our appliances are unique to NA, JP, Colombia and Venezuela. Our plugs handle much less power, so we can't have nice things, like a 3000W toaster oven, table saws with guts, or even a window air conditioner that can cool more than one room.

enter image description here

This illustrate those capacities and some of the safety features RedGrittyBrick discusses in his answer.

If you wonder why every American owns a gas lawnmower, it's because electric lawnmowers don't work too well on 120V.

If you really want that style, you can try painting the first 5mm with liquid electrical tape, or slide tightly fitting shrink tube over the pins and heat it with a hair dryer.

Strictly speaking, nothing prohibits you from simply using German style plugs in your house, but you must use the grounded type with GFCI protection in some places, which would be easiest done at the service panel. I like the German style best because the whole plug goes into a recess.

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  • For more socket fun, see the Digital Museum of Plugs and Sockets at plugsocketmuseum.nl
    – Bryce
    Oct 27, 2016 at 5:49
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I have shocked myself touching one of the pins on a USA NEMA connector. My finger just slipped around the end at the wrong moment. So, this is anecdotal, but yes, it is a concern.

What do to about it - I think it is a matter of awareness. Perhaps NEMA users have adopted hand postures which normally reduce this risk.

This seems to be a risky approach - finger sticking forward:

enter image description here

This is also risky, and wouldn't have a good grip / the plug would flop around: enter image description here

This is what I do, with my fingers curled backwards:

enter image description here

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  • With the ground pin down, you want your finger near the prong on the left (aka the wider prong). That's the neutral.
    – Harper - Reinstate Monica
    Oct 28, 2016 at 4:01

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