5 ms·

also this is an interesting argument for the concept of why NEMA 5-15 (USA standard receptacles) should be installed what we would commonly think of as upside-d

also this is an interesting argument for the concept of why NEMA 5-15 (USA standard receptacles) should be installed what we would commonly think of as upside-down. the most common theoretical scenario I've seen is exactly like this with a coin falling off a table or furniture, or anything else metal/conductive that might bridge between the two pins. https://www.google.com/search?client=firefox-b-1-d&q=install+nema+5-15+upside+down https://www.google.com/search?client=firefox-b-1-d&q=install... if upside down, the theoretical metal object (imagine a safety pin falling off a table and into a half-inserted plug) would bridge between the ground pin and one of the two pins, or may not make contact with the hot pin at all. it plays havoc with common wall wart ac-to-dc adapters that expect the receptacle to be the usual way up, however. and other devices.

yardstick 5y ago
Interesting! You might already know this, but in the UK our super bulky plugs are designed to avoid contact with hot pins by having a longer earth pin than the others so when you remove the plug, by the time there is enough gap for your fingers to slip onto the metal, all the pins will be fully disconnected from the socket. https://www.electricaltechnology.org/2019/05/why-earth-pin-is-thicker-and-longer.html/amp https://www.electricaltechnology.org/2019/05/why-earth-pin-i...
- aix1 5y ago
  > by the time there is enough gap for your fingers to slip onto the metal, all the pins will be fully disconnected from the socket I think this should read "by the time the metal parts of the line and neutral pins are exposed, they have been disconnected from the mains". (I.e. nothing to do with the width of the gap/fingers.)
  - yardstick 5y ago
    Yes you correct
- walrus01 5y ago
  Yeah about ten years ago I rewired my home office with bs1363 format extensions and sockets (In south Asia) to solve issues with shoddy wiring and lack of grounding where I was renting at the time.
- Doxin 5y ago
  EU plugs have the same feature, while being less bulky[0]. Especially so for the ungrounded variations[1]. Note that the EU sockets also have shutters in front of the live connections like UK plugs, even for the ungrounded ones. [0] https://i.imgur.com/hxNh3H3.jpg https://i.imgur.com/hxNh3H3.jpg [1] https://i.imgur.com/9e6imGA.jpg https://i.imgur.com/9e6imGA.jpg
  - fy20 5y ago
    > Note that the EU sockets also have shutters in front of the live connections like UK plugs, even for the ungrounded ones That's not true everywhere. In my country (Schuko) you can get child-proof sockets with shutters, but I have never seen them used anywhere - in commercial or residential buildings.
    - Doxin 5y ago
      There's the explicitly child-proof sockets that require some stupid action like twisting the plug into them[0] but that's not what I'm talking about. Any new EU socket should come with shutters built in[1] which prevent poking something into a single hole. They only move out of the way if something gets poked into both holes. The shutters are often black, which means that it's basically impossible to see them under normal lighting conditions. Of course there are still plenty of old sockets out in the world which lack these safety features. [0] https://i.imgur.com/66LK2ZB.jpg https://i.imgur.com/66LK2ZB.jpg [1] https://i.imgur.com/rs57bjn.jpg https://i.imgur.com/rs57bjn.jpg
    - qayxc 5y ago
      Maybe you didn't look? You can't see the shutters from the outside unless you look straight into them and they're painted red (mine aren't for example, so cannot tell until you plug something in).
  - yardstick 5y ago
    I’ve always found the EU (and US) plugs horribly flimsy. Despite their bulk I’d pick the UK plugs over any type.
LeoPanthera 5y ago
Presumably this is why the "challenge" suggests you use a phone charger, which does not have a ground pin. (In the USA.)
kfarr 5y ago
Hospitals install their receptacles “upside down” for this reason.
h2odragon 5y ago
Built my house 15 years ago, and put all the outlets in "upside down" (ground pin up). Shoulda seen the tiff with the county electrical inspector over that one. Of course he'd never seen a copy of the code he was supposed to be enforcing, and was actually a plumber by training and experience. He was the cousin of the owner of the only professional electrician service in the county... Oddly no one else could get their work to pass inspection. I pirated a copy of the code and showed him the relevant page, which said "any orientation is acceptable but ground pin up is preferred." I got to keep my outlets, but I had to add big circuit breakers between the power meter and the house entrance, which only his cousin could do.
- kingcharles 5y ago
  You'll be happy to know you were not a pirate. Your conscience is clear. It was ruled by the courts many years ago that public laws and regulations are essentially public domain.
alkonaut 5y ago
The fact that the US (and UK) still use a flush face for sockets instead of a recessed hole is absolutely amazing. Plugs just hang randomly from the socket.

yardstick 5y ago

Interesting! You might already know this, but in the UK our super bulky plugs are designed to avoid contact with hot pins by having a longer earth pin than the others so when you remove the plug, by the time there is enough gap for your fingers to slip onto the metal, all the pins will be fully disconnected from the socket. https://www.electricaltechnology.org/2019/05/why-earth-pin-is-thicker-and-longer.html/amp https://www.electricaltechnology.org/2019/05/why-earth-pin-i...

aix1 5y ago
> by the time there is enough gap for your fingers to slip onto the metal, all the pins will be fully disconnected from the socket I think this should read "by the time the metal parts of the line and neutral pins are exposed, they have been disconnected from the mains". (I.e. nothing to do with the width of the gap/fingers.)
- yardstick 5y ago
  Yes you correct
walrus01 5y ago
Yeah about ten years ago I rewired my home office with bs1363 format extensions and sockets (In south Asia) to solve issues with shoddy wiring and lack of grounding where I was renting at the time.
Doxin 5y ago
EU plugs have the same feature, while being less bulky[0]. Especially so for the ungrounded variations[1]. Note that the EU sockets also have shutters in front of the live connections like UK plugs, even for the ungrounded ones. [0] https://i.imgur.com/hxNh3H3.jpg https://i.imgur.com/hxNh3H3.jpg [1] https://i.imgur.com/9e6imGA.jpg https://i.imgur.com/9e6imGA.jpg
- fy20 5y ago
  > Note that the EU sockets also have shutters in front of the live connections like UK plugs, even for the ungrounded ones That's not true everywhere. In my country (Schuko) you can get child-proof sockets with shutters, but I have never seen them used anywhere - in commercial or residential buildings.
  - Doxin 5y ago
    There's the explicitly child-proof sockets that require some stupid action like twisting the plug into them[0] but that's not what I'm talking about. Any new EU socket should come with shutters built in[1] which prevent poking something into a single hole. They only move out of the way if something gets poked into both holes. The shutters are often black, which means that it's basically impossible to see them under normal lighting conditions. Of course there are still plenty of old sockets out in the world which lack these safety features. [0] https://i.imgur.com/66LK2ZB.jpg https://i.imgur.com/66LK2ZB.jpg [1] https://i.imgur.com/rs57bjn.jpg https://i.imgur.com/rs57bjn.jpg
  - qayxc 5y ago
    Maybe you didn't look? You can't see the shutters from the outside unless you look straight into them and they're painted red (mine aren't for example, so cannot tell until you plug something in).
- yardstick 5y ago
  I’ve always found the EU (and US) plugs horribly flimsy. Despite their bulk I’d pick the UK plugs over any type.

LeoPanthera 5y ago

Presumably this is why the "challenge" suggests you use a phone charger, which does not have a ground pin. (In the USA.)

kfarr 5y ago

Hospitals install their receptacles “upside down” for this reason.

h2odragon 5y ago

Built my house 15 years ago, and put all the outlets in "upside down" (ground pin up). Shoulda seen the tiff with the county electrical inspector over that one. Of course he'd never seen a copy of the code he was supposed to be enforcing, and was actually a plumber by training and experience. He was the cousin of the owner of the only professional electrician service in the county... Oddly no one else could get their work to pass inspection. I pirated a copy of the code and showed him the relevant page, which said "any orientation is acceptable but ground pin up is preferred." I got to keep my outlets, but I had to add big circuit breakers between the power meter and the house entrance, which only his cousin could do.

kingcharles 5y ago
You'll be happy to know you were not a pirate. Your conscience is clear. It was ruled by the courts many years ago that public laws and regulations are essentially public domain.

alkonaut 5y ago

The fact that the US (and UK) still use a flush face for sockets instead of a recessed hole is absolutely amazing. Plugs just hang randomly from the socket.