Hacker News Reader

Comment by hgo | Hacker News Reader

This is an honest question: As a European having been to the US and experienced using the power connectors you have, I can't help but immediately wonder why do they design the brick like that? The brick looks quite heavy, so will it actually be possible to use in a wall outlet, or will it, due to the flat pins, fall to the floor? If I put it in a wall outlet wouldn't it definitely block both ports if there are two? (In Europe and elsewhere, the pins are round, thus something connected wouldn't bend out of the socket. Obviously "wall warts" are a pleague here too, but I have never experienced one leaving the socket.)

(Maybe I'm sensitive since I was literally shocked after just a couple of days working in a US office, simply connecting a charger under my desk when it sort of bent half way out. I was really surprised how simple it was to get exposed during normal use.)

View on HN

Normally they stay in place well enough from the clamping force that the receptacle's contacts apply to the prongs.

Sometimes that doesn't work well with older receptacles. Usually I can solve that by squeezing the prongs a bit closer together.

Here's a picture of a North American household receptacle's guts, if you want to see how the springs work [0].

[0] https://hackaday.com/wp-content/uploads/2018/04/dsc03649.jpg

In North America if the outlets are relatively new and in good shape there are springs inside that hold the plug in so things don't fall off. With older outlets the springs wear out/loosen and stuff can easily fall out, I've seen the plugs where the prongs are bent slightly outward (flared) so that they hold in the plug even in worn outlets. Most of these bricks can go in the lower plug and not block the upper port although thats not universally true.

> Most of these bricks can go in the lower plug and not block the upper port although thats not universally true.

Can't you put it into the upper socket, upside down? Most bricks do not have grounding, where the third pin would prevent that (or do they in NA?).

Why does the orientation matter if the end result is the same? My point is your suggestion is no better than OPs, so who cares which way the brick points?

If the brick's plug is polarized it matters.

Though if it is polarized, it should be three-prong one, to physically prevent connecting it the other way.

But as Germans and their Schuko have shown, it doesn't really matter ;)

US polarized plugs have the neutral pin physically bigger than the line pin. They don't need the third prong to make it one-way, that's only needed for conductive-cased items to have a ground connection.

Nope, the neutral prong is wider on polarized plugs. Nearly all two-prong plugs are polarized, it's just stuff like transformers or soldering irons that aren't.

> Why does the orientation matter

So it doesn't cover the bottom port with it's mass.

> if the end result is the same?

It is not; the difference is, that you could connect another brick to the bottom port.

Sometimes you can but other times it isn't feasible because the mass of the brick in that configuration isn't pushing against the wall and is instead actively pulling the plugs out of the receptacle.

Adapters like this tend to stay in the outlet fine, as long as your outlets aren't really old. (See also Apple's chargers. They don't come with the extension cord by default, just the "duckbill")

But, the ports thing is true - you have to put them in the bottom receptacle, and you can't have two of them in the same outlet.

> See also Apple's chargers. They don't come with the extension cord by default, just the "duckbill"

This seems to be also local-specific; In Europe, the box contains both the extension cord and the "duckbill".

Indeed, living in a 60 year old house, outlets wear out. Also there are switched outlets that are controlled by a wall switch. Often a duplex outlet will have one switched and one un-switched socket, so you can only use one of them.

I consider replacing worn outlets to be just part of maintaining a house.

It's not just ridiculously-sized power bricks designed this way... do a Google image search for wifi extender and be amazed! Had trouble finding one with a cord.

Also, do to the pins have holes in them? To safe on metal costs? Or do some outlets have things that will help hold the plug in?

The hole is (1) a detent that improves the socket’s grip on the pin, and (2) a way to lock the plug to prevent use.

My understanding is that for a long time now modern sockets don't use the holes for detent and instead just rely on friction. The current ANSI/NEMA standard says that: "The hole in flat blade is optional, and it is intended for manufacturing purposes only. However if used it must be located as per dimensions shown above"

Some interesting discussion on this topic here: https://electronics.stackexchange.com/questions/11495/nema-5...

Wrong on both accounts. Technology Connections spent a while trying to figure this one out and did a fairly decent video: https://youtu.be/udNXMAflbU8

the tl;dw is "They're for manufacturing purposes" -- Alignment for when you're injection molding around them. Any other use is entirely secondary. NEMA sockets don't have any mechanism to hold onto the detent.

Heavy equipment often has a lock through designated holes in the plug. But usually not wall warts.

Nope. That hole is, similarly, only for manufacturing positioning. It's also potentially dangerous to attempt to thru-plug lock out a device: An unsuspecting individual could jam it in anyway and suddenly potentially have the other half of a phase going through them if a receptacle is loose enough or they jam the pins in.

Under OSHA 1910.147(c)(5)(ii), lockout devices must be unique:

> Lockout devices and tagout devices shall be singularly identified; shall be the only devices(s) used for controlling energy; shall not be used for other purposes; and shall meet the following requirements:

Under OSHA 1910.147(c)(5)(ii)(C)(1), LOTO must be done such that a pair of bolt cutters alone would not simply bypass the lockout:

> Lockout devices. Lockout devices shall be substantial enough to prevent removal without the use of excessive force or unusual techniques, such as with the use of bolt cutters or other metal cutting tools.

McMaster-Carr offers only a single key-in-place LOTO for NEMA plugs, specifically 5-15 which clamps around the tines. This is a secondary use of the holes used for manufacturing but does not stop someone from giving a good solid tug, which can happen.

All other OSHA-compliant LOTO systems [encapsulate the full plug](https://www.mcmaster.com/loto-(lockout//electrical-plug-lock... or otherwise [bind to the body of the plug](http://lockoutmanufacturer.com/Pneumatic-Plug-Lockout3.html) in the case of circular connectors.

Note that OSHA LOTO rules do not stop someone from chopping the end off and putting a new connector on. They are intended to provide the broadest safety in the most common of situations.

Your McMaster-Carr link seems to be pretty good evidence that such devices exist.

FWIW I'd read c1 as stating that a lockout device need not be resistant to bolt cutters, as that would qualify as "excessive force or unusual techniques".

Sure, but that was aftermarket, not a design consideration.

Reply on news.ycombinator.com