Grumpy rant #783

[mansaxel]

In this context, "polarization" refers to non-interchange of Line and Neutral power connections.
In the US, the NEMA 5-15 series uses a wider flat blade for Neutral than the flat blade used for Line:  this is a useful requirement, but I have seen badly-installed sockets where that was violated.

"The only wise move is to regard the two pins as equally dangerous and untouchable. All other moves are loser moves. "

[mansaxel]

Not quite; neutral in the UK is at earth potential (or should be...), the phase alternates between positive and negative wrt this. Still a bad idea to touch it of course, for numerous reasons.

"The only wise move is to regard the two pins as equally dangerous and untouchable. All other moves are loser moves."

[mansaxel]

So anything designed in a way that relies on/requires polarization of the plug would be unsafe

edison screw lamp bases

Not on the continent, where they are insulated and safe to touch. Or forbidden.

[TimFox]

Knowing of this potential problem, I checked all my outlets at home with a cheap three-pin, three-bulb tester to ensure:
1.  Line (narrow) and Neutral (wide) are not interchanged.
2.  Ground/PE is connected properly.
https://www.amazon.com/Receptacle-Tester-Klein-Tools-RT110/dp/B01AKX3AYE/ref=asc_df_B01AKX3AYE/?tag=hyprod-20&linkCode=df0&hvadid=309778489815&hvpos=&hvnetw=g&hvrand=15379320970737851598&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9021749&hvtargid=pla-571548716375&psc=1

[ejeffrey]

USB-C PD will keep being revised just like any other previous standards, so that if you made that part of home mains installations, that would become "obsolete" (at least in the sense of not being able to provide as much power as the more recent revisions, thus being unusable with some potential newer devices) over time anyway.

While it likely will be revised, current standard is good enough for most of things and is quite future proof if manufacturers do backwards capability properly.

OTOH again, anyone who wants USB-C PD ports in some wall sockets can install them for a relatively reasonable cost, then it is their decision and their responsibility.

If there is any socket that can supply 240W according to current standard, IMHO it should be capable charging anything in foreseeable future.

Adding a 240W USB-PD charger to most or all outlets (which is what "making it standard" would presumably mean) would be expensive and provide little value to most people.  Also, I've never seen outlets available with more than about 30W.  I'm not sure how practical it is to put a 240W supply into a wall outlet box.   But anyone can go buy the lower powered units at home depot an install them where you want them in a few minutes.  I'm not a fan for home use, but if people like it, that's great.  No need to adopt any new standard, it already exists.

[janoc]

So anything designed in a way that relies on/requires polarization of the plug would be unsafe

edison screw lamp bases

Even if you had a polarized plug with Edison lamp base it still wouldn't be safe, due to all the issues outlined in my original post.

Edison lamp bases predate any sort of plug standard and certainly any sort of modern safety standards, so those are not the best example. They come from the time when having bare wiring on the walls and knife switches in living rooms has been completely normal way of doing things. Or toasters like this:
https://www.sparkmuseum.org/wp-content/uploads/GeneralElectricD-12toaster_SPARKMuseum-768x741.jpg

Or live chassis radios and later TVs.

We got rid of all the latter, the Edison bases remain only because they are so ubiquitous - and as long as people don't stick their pinkies where they wouldn't their dinky (and/or pull the plug out of the wall/turn off a breaker when changing a bulb!) they are reasonably safe, unlike the rest of the list above.

[TimFox]

Yes, stuff built many decades ago, especially with two-prong unpolarized plugs, may be unsafe.
Go thou and do not do likewise.

[Someone]

With the UK and China/Australian plugs pushed into a wall socket the lead hangs neatly against the wall. The Schuko lead sticks out, and is easily whacked by furniture and other things.

The vast majority of Schuko plugs have cable going out at 90^o angle.

I'm seeing more "out the back" than "out the side" plugs here in the office, so no, the entry direction/type is not strongly linked with the plug standard. AS3112 versions even exist without strain relief boots.

[janoc]

With the UK and China/Australian plugs pushed into a wall socket the lead hangs neatly against the wall. The Schuko lead sticks out, and is easily whacked by furniture and other things.

The vast majority of Schuko plugs have cable going out at 90^o angle.

I'm seeing more "out the back" than "out the side" plugs here in the office, so no, the entry direction/type is not strongly linked with the plug standard. AS3112 versions even exist without strain relief boots.

Yeah, it is certainly false. Schuko leads exist in both straight and 90 degree variants and both are common. Especially anything where the cable is captive and not using an IEC plug at the other end tends to have a straight Schuko - e.g. large appliances like washing machines, fridges, etc. Extension cords the same thing - the plug end is usually straight and not 90 degrees.  E.g. the power bar under my bench has 4 straight Schukos and 3 90 degree ones plugged in right now - all stuff like soldering iron, power supplies, bench meter, etc.

So one certainly has to pay attention to not damage the cables by smashing the plugs with furniture and similar. OTOH, in most cases where the plug does get in the way it is a fairly easy problem to solve - either swap the cable if it has an IEC connector or use an extension cord/T-splitter. For the really problematic situations where even a regular 90 degrees Schuko sticks too far out there are even special flat plugs being sold.

[ebastler]

So anything designed in a way that relies on/requires polarization of the plug would be unsafe

edison screw lamp bases

Not on the continent, where they are insulated and safe to touch. Or forbidden.

Could you share a picture of an insulated, safe-to-touch E27 lamp socket? I don't think I have ever seen one. In the sockets I am familiar with, both contacts on the inside -- the one on the thread, and the one at the bottom -- can be touched when the bulb is unscrewed.

But since both contacts can be touched anyway, connecting the socket via a polarized plug wouldn't make it much safer... 

[TimFox]

To be fair, it's more difficult to touch the button contact ("live") than the threaded contact ("neutral") with the bulb removed.
I'm more concerned about touching the thread while removing the bulb:  that's why I prefer properly polarized connections, where only a few volts lie on the "neutral".

[SL4P]

This thread has come to the realisation there is no safe or foolproof outlet design.
Mostly thanks to ill-informed installers, designers or users.

The most reliable safety solution is to use whatever combination of bare conductors you want, and liberal use of RCD/RCBO protection devices as close to the main isolator as possible.

- or for those having ‘special needs’, a fixed wiring path from the main switchboard to the ‘point of use’.

[AVGresponding]

So anything designed in a way that relies on/requires polarization of the plug would be unsafe

edison screw lamp bases

Not on the continent, where they are insulated and safe to touch. Or forbidden.

Could you share a picture of an insulated, safe-to-touch E27 lamp socket? I don't think I have ever seen one. In the sockets I am familiar with, both contacts on the inside -- the one on the thread, and the one at the bottom -- can be touched when the bulb is unscrewed.

But since both contacts can be touched anyway, connecting the socket via a polarized plug wouldn't make it much safer... 

The ones in 110v festoon lighting are about as safe as they get; the thread is plastic with only a small contact near the bottom, and if you're fool enough to stick your fingie between that and the centre contact, you only get 110v across the tip of your digit.

[DavidAlfa]

You won't get the standards changed by ranting, so get used to them?
UK plugs best in the world? Looks like he was made by a maniac, or when circuit breakers didn't exist.
Most Europe uses Shucko, we're just fine, we're not dying in thousands.
Looks like chaos? Ask Japan, where Tokyo is the line dividing the country in 220V and 110V. I guess it's the reason they sell so many electronics!

[Someone]

Looks like chaos? Ask Japan, where Tokyo is the line dividing the country in 220V and 110V. I guess it's the reason they sell so many electronics!

Wrong on 3 4 (5?) points: Japan being universally 100V with some 200V higher power loads, 50/60 Hz division, the boundary being clearly defined along a river 100km outside of Tokyo:
https://www.kepco.co.jp/english/home/denki/01.html

[rsjsouza]

The safety of plugs is a non-issue. Regardless of the design, people dying from household electrocution AND specifically caused by the plug/outlet themselves is nil. System-wide alternatives exist (such as GFCI in the US or any leakage protection circuit breaker) as well as the mandatory ground/earth connection in installations, general education and improvements in materials and quality of plugs.

Obviously that anything can be circumvented and the flood of low quality products also compounds the problem. But even with all these factors in place the obsession with "safety" has very diminishing returns. I come from a country where the same "Saudi Arabia M.O." mentioned before is used at large, ground/earth is a russian roulette and people stubbornly still manage to be alive. Heck, we shower with a 5kW (typical) electrical powerhouse in our heads (mostly unearthed) and people still refuse from dying.

One thing is certain: a great deal of money can be made by promoting fear. Some 10 years ago Brasil adopted a new standard of outlets and plugs that was sold to the general public as one of the safest options in the world, but at the great expense of the general population that had to foot the bill in replacing/changing their appliances and household outlets but without a serious enforcement of the existing national electrical code standards. Guess which one is cheaper from a government perspective? 

[TimFox]

Looks like chaos? Ask Japan, where Tokyo is the line dividing the country in 220V and 110V. I guess it's the reason they sell so many electronics!

Wrong on 3 4 (5?) points: Japan being universally 100V with some 200V higher power loads, 50/60 Hz division, the boundary being clearly defined along a river 100km outside of Tokyo:
https://www.kepco.co.jp/english/home/denki/01.html

I think he is confused about the dividing line between 50 Hz (Tokyo, etc.) and 60 Hz (Osaka, etc.) line frequencies.
As I remember, the dividing line is somewhere around Shizuoka.
The supply voltage standard is the same.

[DavidAlfa]

I recently watched or read this somewhere, supposedly Japan had mixed 110v / 220v depending on areas.
Will research this more, maybe I read BS  .

[coppice]

I recently watched or read this somewhere, supposedly Japan had mixed 110v / 220v depending on areas.
Will research this more, maybe I read BS  .

Japan has 220V mains, just like the US has 220V mains. Two lots of 110V, with a 180 degree phase shift.

[TimFox]

I recently watched or read this somewhere, supposedly Japan had mixed 110v / 220v depending on areas.
Will research this more, maybe I read BS  .

Japan has 220V mains, just like the US has 220V mains. Two lots of 110V, with a 180 degree phase shift.

Once again, the normal NEMA 5-15 and 5-20 outlets that are ubiquitous in the US have 120 V line-neutral, although a normal house is fed with 120-0-120 V to allow high-power 240 V loads, such as air conditioners and clothes dryers.

When working in Japan and installing equipment, I was surprised that the 3-phase mains were typically 200 V rms line-line and the 1-phase mains were 100 V rms line-neutral.
Those numbers do not correspond by the usual 120 degree trigonometry:  Typical US is 120 V line-neutral and 208 V line-line, which agree with each other.
https://www.kepco.co.jp/english/home/denki/01.html
https://www.stamford-avk.com/sites/stamfordavk/files/AGN203_B.pdf

[AVGresponding]

I recently watched or read this somewhere, supposedly Japan had mixed 110v / 220v depending on areas.
Will research this more, maybe I read BS  .

Japan has 220V mains, just like the US has 220V mains. Two lots of 110V, with a 180 degree phase shift.

US is 240V, 120V x2, and Japan is 200V, 100V x2.

https://en.wikipedia.org/wiki/Mains_electricity_by_country

[DavidAlfa]

Yeah, I swear I found this very recently searching for something related.
But it seems I mixed 3 different memories and made an entirely new thing after a bad sleeping night

[Ground_Loop]

Yea, but can your outlets do this?

[Connecteur]

I say that worldwide everyone should switch to 30 volts DC.  Best and safest current for all purposes.

[TimFox]

I say that worldwide everyone should switch to 30 volts DC.  Best and safest current for all purposes.

That would work well with the infamous 3 kW British tea kettles.
100 A requires, perhaps, AWG 0 = 8.25 mm diam = 53.5 mm² wire.