2
\$\begingroup\$

In Australia and some other places, good-quality AC power plugs have "insulated pins". This means that there is a short length of insulation covering the base of the pins. Darren Yates writes that this has been legally required in Australia since 2005.

Insulated pins are a useful safety feature; they help prevent people from accidentally touching live pins and getting electrocuted.

In the US, AC power plugs (such as NEMA 1 and NEMA 5 plugs) seem to normally not have insulated pins. That is why Etotal IntelliHouse writes that they are not very safe.

Does any company manufacture NEMA 1 or NEMA 5 plugs with insulated pins?

(I thank the user tronixstuff for inspiring this question.)

\$\endgroup\$
  • \$\begingroup\$ An aside: I have precisely one non-insulated-pin UK plug. It is fitted to a 55 year old vacuum cleaner. I haven't seen any others since the 1970s... \$\endgroup\$ – Brian Drummond Jun 18 '15 at 12:32
  • \$\begingroup\$ Indeed, as a EU citizen I was shocked (not literally !) to see a video of someone in the US plugging in an adapter and I was surprised how easy it must be to touch the live metal parts of the plug. I guess due to the 110 VAC most people make that mistake only once but live to not repeat it ;-) Sorry for not being able to answe your question :-) \$\endgroup\$ – Bimpelrekkie Jun 18 '15 at 12:35
  • \$\begingroup\$ I've lived in the USA for a few years and although I am familiar with insulated plugs from other parts of the world, I've never seen an insulated plug here. \$\endgroup\$ – brhans Jun 18 '15 at 12:36
  • 1
  • 1
    \$\begingroup\$ @Tut: Nice find! After seeing your comment, I did a Google image search for [ japanese plug insulated pins ] and found a company which makes grounded Japanese AC power plugs. See here and look at the photo at the bottom-left corner of the page. \$\endgroup\$ – unforgettableidSupportsMonica Jun 19 '15 at 21:48
5
\$\begingroup\$

I don't think so- I've never seen such a thing and if you look at the internal design of a typical receptacle I don't think that such a plug could be reliably backward compatible unless the insulated length was only a couple mm and the thickness very thin. Given the enormous installed base of receptacles and extension cords, such a change is unlikely to be popularly accepted.

It is possible to get even an adult-sized finger under even a normal plug, so such a design would not pass the UL 4mm baby-finger requirement if it was to be introduced today.

Here is a photo of an AC adapter plugged into a power bar receptacle. There is 120V present on the pins (verified by voltmeter) and the finger is an adult one (mine, just before my death by electrocution).

enter image description here

It's worse again if the pins are bent, which is pretty easy with ungrounded cord ends. Especially if some cretin pulls the plug out by yanking on the cord at an obtuse angle.

| improve this answer | |
\$\endgroup\$
  • \$\begingroup\$ I went to NY for a hol 4mo ago and stayed in timesSquare. A power outlet for the TV was just hanging out (1/2 plugged in and just ..resting), supported with electrical tape while exposing the connections. fingers of 4yo and 8yo are oh so inquisitive... it was quickly removed and coiled up \$\endgroup\$ – JonRB Jun 18 '15 at 17:15
  • \$\begingroup\$ That's pretty much how I feel when I go to Mexico- so many open exposed mains wires... I guess it gets a few people now and then, and the survivors learn. \$\endgroup\$ – Spehro Pefhany Jun 18 '15 at 17:17
3
\$\begingroup\$

I've lived in the USA my entire life, and have never seen that type of insulated plug here. I also haven't spoken to a single adult person here that hasn't been shocked by 120V sometime in their lives! At least, that I'm aware of :)

I recently put some new outlets into my house. The are different than the old "standard" outlets, although you might not notice. Basically, the prongs of the plug have to penetrate deeper into the outlet before they make electrical contact. And they're held more tightly, since the contact length is shorter. I assume this new design is mandated for safety.

I think we (USA'ers) get complacent because we don't have to be that careful with our mains voltages. If I'm wondering if wires are live, and I'm feeling brave, I'll quickly swipe my finger tips across them and see if I get shocked :) I don't recommend this! And, for the record, most people here would think think it's a dumb idea, too.

| improve this answer | |
\$\endgroup\$
  • \$\begingroup\$ and that is bad :( 115V can just as easily kill as 230V.. that's why the LVD is set around 75Vdc,50Vac. I have been shocked by 115V, 230V, 540Vdc, 600Vdc and am still here. the adage that it is lower so safer is unfortunately very common and very misplaced \$\endgroup\$ – JonRB Jun 18 '15 at 17:13
  • \$\begingroup\$ @JonRB: what's an "LVD"? \$\endgroup\$ – unforgettableidSupportsMonica Jun 19 '15 at 16:48
  • \$\begingroup\$ Low voltage directive. A UK legislation that was adopted by the EU. Anything below 50Vac (or 75Vdc) is deemed extra low voltage and no special precautions are needed. 50vac ->1000v are then deemed low voltage and certain precautions are needed \$\endgroup\$ – JonRB Jun 19 '15 at 17:36
0
\$\begingroup\$

Inspired by Tut's comment, I did a Google image search for [ japanese plug insulated pins ] and found a company which sells grounded Japanese AC power plugs.

Here's a photo of a "Japan JIS C8303 15A AC Power Cord with Insulated Neutral/Live Plug Pins". I found it here: scroll down and see the photo at the bottom-left corner of the page.

It looks like it might fit in American outlets.

Japan JIS C8303 15A AC Power Cord with Insulated Neutral/Live Plug Pins

| improve this answer | |
\$\endgroup\$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.