Why does AC current need 1way plugs?

In the last 10-20 years, the male & female connectors for ordinary household appliances have been designed to fit only one way.

One male connector is wider than the other, with the female connectors similarly different in size.

Many years ago, you could fit the male connector into the female connecter either way. There was no size difference.

For AC devices, why should it make a differenece which way the connection is made.

BTW: I remember when TV's were a new device. People often did not plug them in (or somebody would trip over the cord and disconnect the TV). The customer would call a service man and say the TV is completely blank. To avoid insulting the customer and to avoid a house call, the service men would tell the customer to unplug the TV and replug it the opposite way, explaining that polarity was important. If the customer said reversing the plug fixed the problem, the serviceman knew that the TV had not been plugged in.

 

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Hi Dinosaur,
Only one of the two incoming wires is live; the other is neutral. The active wire goes from +156V to -156V sinusoidally (110V rms), while the neutral wire stays at 0V. I think the wider pin should be the neutral wire.

 

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Here:
Wikipedia

 

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In house wiring, the wide blade is the "neutral" and the narrow "hot". While as I think you realize most if not all ac appliances will actually function either way, there is a safety issue. The differance between hot and neutral is that in most appliances the neutral is directly connected to the chassis of the appliance. (In tv's, this is called a hot chassis set) Also, at some point in the house wiring the neutral is connected to a ground stake. If you connect an ac volt meter between the neutral and a water pipe, you should read essentially zero. (perhaps 5 to 10 vrms) Between the hot and pipe full voltage, and yes it can electrocute.
The idea is to keep any exposed external metal at ground potential. Reversing the plug can cause serious shock hazard. I have personally seen a case where a refrigerator plug got reversed. If you touched it and the stainless steel sink next to it at the same time you got zapped _hard_. Dangerous, so don't ever defeat the polarization.

In the old days, "hot chassis" was avoided, hence no polarization. Many modern power tools use kind of a cross between the two methods. An internal hot chassis which is completely surround by a plastic casing. Probably the best protection of all.

 

Hot chassis is sometimes a problem, like when someone used a pair of visegrip pliers to change the channel on an older TV set. The number one problem is when an appliance has a metal case, which sometimes can't be avoided. Normally that metal case won't be used as a ground return for the current that the appliance uses. This is the definition of "hot chassis", where the conductive chassis is used as part of the active circuit. The metal case of any decently modern appliance is grounded as a shield against electric shock that can be caused by defective wiring or old wiring that becomes defective. It is to prevent injury or death that can be caused by a condition that they work to prevent from happening in the first place.

It is important to know the difference between "neutral" and "ground." The neutral wire goes back to the center tap of the transformer on the pole, which these days in the U.S. is usually a center tapped 240 volt output. It is supposed to carry current under normal use and is grounded only one place, at the entryway to the house. This means that you do not use the neutral wire as a substitute for the ground wire. During normal use the ground wire carries no current. It is for emergencies only and appliances that leak current to ground are defective.

I take grounding very seriously. It is altogether too easy a way to promote survival, and once it's done right, even if you forget about it, it is extremely likely to keep working for the rest of your natural lifespan.

Most hardware stores and Walmarts have a simple device to test outlets with, for about 8 US dollars. It has two orange neon lights and one with a red filter over it. If both orange are lit and the red is not, the outlet is wired correctly. It is way easy to use and I use it religiously.

The biggest reason not to use the neutral as a chassis ground is because someone might have reversed hot and neutral when installing the wall outlet, which makes a working outlet but the chassis will become hot. It's harder to mix up the ground wire with either of the other two because it is usually a bare copper wire, without colored insulation.

 

Everyone who has posted here deserves thanks because 110V AC is something we do not want to unsafely encounter. Good information here may very possibly save someone's life.

 

Read what Metakron has to say and take it seriously. Your post is misleading. What do you mean by a "one way plug"?

The reason why the one of the plugs is now wider than the other is to make sure it s properly grounded so if the aplliance shorts out you won't get electrocuted.

 

:bugeye:

Don't like people asking questions?
Dinosaur's facts are correct, and his question valid. (and well answered by now.)

 

Ah. Don't mind Valich, Pete. Looks like he's trying to diversify outside of the biology forum. Should be interesting to see a whole new group of people calling him a fool.

Hey. By the way. Whatever happened to that paper you were writing?


Valich,

What exactly was your point in posting in here? You basically just said, "Yup." And then tried to denigrate Dinosaur a little bit by calling his post misleading...

Misleading?!
What?

And this: "What do you mean by a "one way plug"?"
You do realize that he never used the phrase 'one way plug'? You're quoting in here just as well as in that other thread... Go figure.

Anyway. He explains perfectly well what he means by the term one way. It's implicit in the very sentence. It's a plug that's designed to fit into the socket only one way. Because one of the blades is wider than the other.

Your misunderstanding problems continue. I will continue to enjoy your future exploits even if I don't get involved. Be sure of that.

 

Fallen by the wayside, much to the chagrin of my supervisor. I'm struggling to keep my head above water managing the courses I teach, let alone thinking about research

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*points to thread title*

A one-way plug is a plug that can only be connected to a socket one way, ie it is not symmetrical. This idea was strongly promoted by Captain Edward Murphy of "Murphy's Law" fame...
Murphy's Law: If there are two or more ways to do something and one of those results in a catastrophe, then someone will do it that way.
(See Great Moments in Science. Read that link. It's a good one.)

The obvious countermeasure to Murphy's Law is to ensure that there is only one way of doing something - hence the one-way plug.

 

Don't mind Invert Pete. He's just a trolling condescending obnoxious trouble maker who goes from forum to forum trying to cut down and belittle people, often using curse vulgarity in a very uncivilized manner along the way

Metakron did a thorough job of answering dinosurs questions but Iwasn't sure about the title of his post "1Way Plug" quote/unquote. I wasn't quite sure if he was referring to direct current as going 1way, or alternating current. Just wanted to make sure there wasn't a confusion there, but I know see it was I who was confused by the possible multiple interpretations of the post heading.

I was just trying to be helpful in a polite way, as I do on on the forums in ALL the sciforum subject group threads. Life is a process of lifelong learning and this is how we all live and learn.

 

Pete,

Ah.
Derr.
Ok. I'm an idiot. Completely missed that. Although, to be anal, it's actually "1way plugs".

Anyway. I'll apologize for that one, Valich.

That's a shame. It sure sounded interesting. And now, so much time has past, that the impetus is lacking.
Ah well. Maybe the diaspora will happen again someday (I hope to God NOT!)


Valich,

Just so you know. I apologized about the one way plug thing up there. I didn't read the title...

There you go again. At least you're not saying I'm being unscientific in being vulgar and 'uncivilized'. You've moved up a step from that fallacy.

Anyway. Yeah. I do ridicule a few people. Not too much though. You though... You're just too much...

And I'm hardly alone. Have you had a good relationship with anyone at sciforums? I'm hardly unique in my evaluation of you.

Anyway. Ok. I can see where your confusion comes from in this case, but really the post was so simple that I find it funny to think that you had to ask. I can't entirely blame you. I too am known for misunderstanding or missing simple things every now and again, but you do make an art of it.

I thought you were rather rude by calling Dinosaur misleading.

Come on. Is English your native language? I'm not trying to insult you (although if it were your native language, you might feel insulted) I just want to understand why you are so consistently confused about what you read. And I suspect that it could also be behind what gets under everyone's skin... that arrogance... that stubborness even when shown to be wrong again and again...

Anyway.
You really are a tripped out dude, man.

 

Murphy is right. Even though I am a lot more intelligent than some people give me credit for, I also will plug something in the wrong way if it can be done, and I have. Of course, that mostly means that you can't expect someone to plug it in the right way every time if the plug isn't marked.

All that is why I insist on properly grounded outlets and have my own tester even if I'm not an electrician. A few basic professional skills go a long ways towards preventing my house from going up in smoke and me dying of cardiac fibrillation. Saves money, too.

Dinosaur's question was a good question, the kind that saves lives. They are indeed one-way plugs, although they generally have been replaced by the three-prong type, which as I said is the only kind I want around me. If you need a polarized one-way plug, you need grounding, although a lot of problems with AC hum are avoided when your television, your DVD player, your stereo, and all of your home theatre equipment are properly polarized, so that the hot line is in the right place and the neutral is in the right place.

 

In no way was I being rude. Proper grounding of an electric current is a life and death matter and the subject should have been posted properly. It should've been titled: a plug that can only be inserted in one way, not a "1way plug."

You're the "tripped out dude" bud. I don't know what you do for a living - except maybe troll the internet forums all day - but posts like your's are nothing but an entertaining distraction to me from the hardwork, teaching, study, and learning that I do - a very interesting, though bizarre and abnormal, form of entertainment.

Is English my native language? I am an English teacher! Perhaps because of the multicultural students that I have to interact with, maybe this is why you fail to realize why it is necessary for me to have a critical perception in the usage of words - as in the above example - and an appreciation for rational, civilized, courteous, unrude behavior (all of which are signs of immaturity and childish behavior). I don't tolerate nitpicking or stupidity like "oh, you said this and that, therefore you're wrong....blah, blah, blah": Senseless regression of knowledge and backward progress in any field - childish little "cut, paste, and post" line-by-line, comic strip-like, slapstick amusing distractions.

Do I have any friends on these forums? Good relations? "...my evaluation of you." Well that gives a lot away in telling me why you go online and make these condescending rude posts all the time: to evaluate people? Is that what these forums are to you? You go on the internet and participate in forums to make friends and evaluate people? Aren't you playing God here? You think I have time for making friends? I go to work, teach, study, go to my classes, come home and read, take my dog for a walk, come back home and research and read as much as I can until my weary eyes don't allow to stay up anymore - and in the meantime, everybody wants my time.

Do I have friends on the internet? Plenty! Do I have friend in the real world, all over the world? Too many! Do I have friends or relationships on these forums? They don't come over my house to chat over a cup of tea, but I know that I am answering some people's "SINCERE" desire to learn something, and they have expressed their appreciation to me for that, and I too also learn in the process. That is why this is called a "forum" and not an online "chat" group or "chat" session. So what you're saying to me is the main reason you come online in these forums is to make friends and relationships? That's sad. If people out there only use the internet for that, and they have no other way of making fruitful relations with others and productively occupying their time, then I would say: "Get a Life."

 

Take it outside, guys. Go start a fight thread in the Cesspool or something.

 

Pete,

Can't start a thread in the cesspool. And, anyway. I didn't intend to start a fight with little Valich here. Just thought he was being rude by calling Dinosaur 'misleading'. Plus the quote thing (which I've already admitted error on.)

Really. The little guy is kinda cute. Especially when he gets his wind up and starts sputtering out his inanities. Makes you wanta rub his head for luck.

And. I'm done in here. I've already swore off further discussion with him but just couldn't help the urge to get on his case in here. And then I had to follow up with the apology. And the following post is entirely motivated by a stubborn sob that refuses to accept an apology when offered one.


Valich,

Already told you what I do for a living. Go figure you missed it.

Heh. My. You do more every day, don't you? English teacher. Geology teacher. Genetics student. Human breeder.

Like what? Like you picking on SpuriousMonkey when he posted that thing about 'driving forces behind evolution'.

Or like you nitpicking on 'one way plugs'?

What the hell are you talking about? Are you accusing me of these things or something? Earth to Valich. You're drifting. Drifting.

As usual you failed to understand my simple meaning.
You accuse people of being mean and vulgar and hateful and blah blah blah. But they're mostly only that way to you. Doesn't that say something? It should. Of course, you'd probably see something else entirely in it. As always.

I simply was pointing out to you that I'm hardly unique in my acquired disdain for you. I actually tried having conversations with you for a bit. You did liven up the biology forum for a while, but you're too much of a poser to be stomached for long.

You make people turn on you. Because you lie. And because you refuse to ever admit that you are wrong (not saying you're always wrong. But you have been blatantly wrong in a lot of things you've said.)

Trying the old reverse psychology? Trying to turn my questions against me? The problem is that I wasn't asking you if you friends or if you come here for friends. I was simply pointing out to you that i'm not unique in my disdain for your idiotic behavior.

Simple as that.

Do I come here for friendship?
No. I do have a friend here, and I come here to talk to that friend, yes. But I am not out seeking friends or whatever.

Do I come here to evaluate people? Well. That's not why I come here but it is an inescapable conclusion to human interaction?
Oh. Wait. You don't judge people, do you?
Ha!
Posers never judge. For if you judge others then they will judge you. A poser fears judgement. Fears being judged poorly.

Yeah. I'm playing God. Look. I just made it rain.
Muaha!

I don't know. And I don't care.
Again. The only reason I mentioned that was to get you to realize that my disdain for you is not unique. You seem to inspire it in practically everybody you meet. (In these threads at Sciforums anyway. I can't, of course, speak for elsewhere...)

Busy life you've got.
Must have had a day off when you sat there 5 hours solid ressurecting threads.

By the way. Stop calling it research. Research is what scientists do. What you do is study. There's a difference. An English teacher should know that.

Also. I don't believe you. You can say that you teach this, that you teach that, that you were a student for 10 years a teacher for 20 or whatever the hell else you've said, but I simply don't believe you. (Although... I would believe that you are an English Teacher. Come to think of it. In that other thread with Ophiolite you started going on as if you were a geology teacher. I don't believe that. But, I would believe English teacher. Middle school or high school? One of the two. Most definitely not college. The only thing that makes me doubt your english ability is your proven inability to understand it in a consistent manner.)

Don't care. Don't care. Don't care.

You know. I believe you really are a lonely person. I think this is the most personal your posting has ever gotten. It's quite interesting to watch as people's defenses rise. You know they're hiding something behind those walls. Of course, some of the trickier ones build false walls as decoys. But I don't think you're that tricky. Of course, I do still have some suspicion of you being a sock puppet.

(Yes. I'm evaluating you. Does that bother you?)

If you say so. You do realize that your posts are available for all to see?

Anyway. If you like to learn then why do you hold so steadfastly to ideas that have been proven wrong in so many ways? One of the main things you should learn is how to engage in a debate. That might help.
(Let me guess. You're a debate coach as well?)

Well. It's actually a discussion forum. Notice the similarity between 'chat' and 'discussion'? A little bit? Hmm?

Anyway. Most of the people here do seem to spend more time chatting than on anything worthwhile... a pity really. Remember I once gave you kudos because you weren't part of the 'lol' crowd? Of course. I saw you 'LOL' in some post recently. Broke my heart...

Nope. You'd be overextending your limited understanding if you posit this as my motivation in coming here. Of course, that's your modus operandi so it's no surprise that you have done just that.


Anyway.
Blah blah blah.

Look, fucker.
Did you happen to read the apology in my post?
My post was an apology.
I thought 'tripped out dude' is an endearing way to refer to you as it's fairly obvious that you are just that. That's being kind. The whole post was meant in the way of a handshake to admit my error in jumping on you about the quote thing because the quote is in the title (although your misinterpretation of it is still pretty funny.)

So. Whatever, jackass. I've tried to apologize. You then go off on this huge tangent about making friends on the internet and whatever the hell you just did.

You know. I actually thought that you might think to yourself, "Hey. Look at that. Invert_Nexus who is one of my detractors just apologized to me. Look how easy that was. You say something wrong and are shown that it is wrong and you say that you're wrong. Wow. Maybe I should start doing that..."

Shoulda known you'd miss that too.

 

Oh.
Wait.
I see what you're saying here.
You're trying to ridicule me for actually responding to your posts by quoting you rather than just making some vague generalization like you do?

Wow.
That's pretty funny.
Figures you'd think you're making a good point with this one.
You might come to realize that responding line by line is perhaps the best way to respond to a post. The best posters that I know here use this style. It's generally considered good form (or in your much loved phrase "It's the general consensus...")

Heh.
Good chuckle.

I guess you think that people actually appreciate spending time making a post to you just to have it all get swept into a vast generalization that doesn't actually respond to most of the points a poster made?

Do you really think that your responses in most of your posts are adequate?
Muaha!!

Funny.
Funny.

Comic-strip like, he says.
Muaha!!

Christ, man. You are a real fucking trip.
Seriously.

Oh. Went on the tangent of showing your instances of 'nitpicking' and forgot to address rest of the sentence.

So. You think that actually responding to what people say is nitpicking? When you say things that are wrong then to call you on it is stupid?

Seriously.
Tripped out dude.
I just don't get you.

Anyway.
Don't even bother responding to me.
I won't respond to you anymore (although I don't doubt that I won't be able to refuse from time to time. Never say never, you know.) I won't put you on ignore because your antics are... what they are. But, I won't respond to you in here anymore. And I'm going to strive to not respond to you in general.

 

Out of towner, unfamiliar with New York City, stops a native and asks, "Where is Carnegie Hall at? The native New Yorker replied "Correct English must always be observed. One never ends a sentence with a preposition." (Where did this New Yorker think he was, anyway, Boston?) So the out of towner rephrased his question. "Where is Carnegie Hall at, you asshole?"