A Question From My 12 Year Old Son About Why So Many Different Electrical Plugs

No standards. Sorry.

First, in the USA, we have many different voltage combinations and most are not compatible.

To name just two 110/120 volt and 220/240 volt are both common. Plugging a 110/120 volt device into 220/240 volts will fry it.

Then there's single and three phase.

Look at the difference between your clothes dryer plug and your toaster plug.

Then there's grounding schemes. The ground lug is that long round one you see on most common appliances. It's longer so that it makes first contact with the ground (safety) circuit so if somethings shorted out you don't get the jolt, it "goes to ground" instead.

Then foreign countries have their own standards.

Mains electricity by country - Wikipedia, the free encyclopedia

Can there be a standard?

Yes, of course there can be a global standard.

All it will take is for all peoples of the entire planet to agree which is best.

Call me a cynic, but I don't see there being a standard wall plug in the near future.

We have yet to agree on a standard measuring system world wide. Tape measures are cheap compared to vast cost of changing and entire country's power system over to some standard.

"Can there be a standard?"

There are standards....the nature of the electrical supply that the plug represents is exclusive to that shape and design....If you mean can they all be the same, well that really doesn't make sense, I mean would you only have one size and type vehicle for all transportation needs...no... each is sized according to it's intended use, trucks for heavy transport, passenger cars for basic family needs, trucks for rednecks everybody, race cars for fun, suv's for soccer mom's, motorcycles for daredevil types, buses for the masses, horses for cowboys, well you get the idea....

The voltage, the amperage, the number of live conductors, the frequency, will determine which footprint your plug should match....Most of it has to do with saving money by raising the voltage where a lot of power is required, such as a stove or air conditioner or electric dryer....the higher the voltage is, the smaller the wire size that can be used....the plug type will determine which plug will safely supply the power needed for the device you want to use...

http://www.generalcable.com/NR/rdonlyres/75CFEE81-ACDA-4F60-9E22-4CC19C14F343/0/Pg9698_NEMA_Chart.pdf

Not to mention Canadian or European that operate at 50 Hertz instead of the American 60 Hertz

Canada uses the same standard as the U.S., nominally 120V, 60Hz for most consumer appliances; 240V for high power devices like clothes dryers and kitchen ranges; etc.

Although there are several languages in the world,only 5 or 6 may be used in UN,otherwise you need simultaneous translation in about at least 200 languages and dialects. Similarly IEC can standardise plugs/sockets to about 5 sizes depending on voltage and current rating & assign color codes for easy identification.

don't say "because"

found the next question to be " why, because "

then "why, because, why"

bought him a pc with a 56kb modem and an AOL account (1993)

Now I ask him " why....." and he explains, and asks why I didn't research the net.

It's simply:

1) the "Not Invented Here" Syndrome manifesting itself with electrical PLUGS & RECEPTCLES.

2) the result of PATENT circumventing by using something different.

Others have basically already said this but I'll repeat them anyway:

Some differences are good and are needed for safety. Voltages of 115 VAC vs. 230 VAC vs something else need to be different. Circuits rated for 15A need to have different plugs from circuits rated for 20A and so forth.

Some differences are improvements for safety. In the US we have exposed conductor blades. Items such as stoves and dryers have poorly fitting big blades that require you to grab the plug firmly and yank and pull. It is very easy to get a finger on one of the exposed blades and have a bad day. Some plugs in industry and in other countries are designed to be much safer.

Many differences from country to country are probably due to not wanting the money spent on plugs to go to someone else in another country. Thus, good for someone's bank account but bad in terms of having standards.

If I were you I would send him to bed without having dinner: GET PREPARED: next question will be "WHERE DO BABIES COME FROM?"

Why are there so many languages?

Why are there so many cars?

What there so many . . . . .
Because mankind cannot get together.

This depends on the age of the child and how "mature" he is. By letting him find out the answer on the Internet, he may, also, find something wrong (or at least not accurate). There is a lot of "garbage" out there. You can suggest some good and relaiable sites (e.g. Wikipedia) or a nice book or an article, where he can find some useful info. And it's not bad to give him an answer too. This engourage the communication between a father and his children. And gives to a father the satisfaction of transfer his "wisdom" to them.

Perhaps it might be of interest to your son, that in the USA there are 153 different plug/socket NEMA (National Electrical Manufacturers Association) configurations. This is only in the USA and only NEMA configurations. It does not include any IEC (International Electrotechnical Commission) configurations.

NEMA Configurations

Straight blade- 43 configurations

Twist Lock- 67 configurations

Hospital Grade- 9 Configurations

Specific Purpose- 9 Configurations

Water Tight- 25 Configurations

TOTAL- 153 NEMA Configurations

There are many more IEC configurations, unregulated configurations and lastly many "Bastard" configurations. These are normally used in the rest of the world.

Good Luck, Old Salt

Well, don't think the results would be so good if I plugged my television into a 440v receptacle and turned it on.

Now that does sound like a plan.

Kids will play outside more if they plugged xboxes into 440v as well.

Your son asked a question similar to the type I used to ask my father long before there was an internet, so off to the library (remember those) I went.

Here's a summary of what others have said, and what your son should start researching.

First there was the battle of frequencies which fortunately is standardized at 50 or 60 Hertz. Then there's the battle over what is a "safe" voltage for consumers to handle, 120 or 240 Volts. Then there's grounded and ungrounded appliances. So there's already 2x2x2 = 8 combinations at a minimum. Now throw in the various maximum currents an appliance should draw; 15, 20, 30 for ordinary "stuff" and you're up to 24 different arrangements of plugs and sockets so that the right frequency, voltage, ground, and current go into the appliance.

Better start saving for engineering college for your son.

And then add the complication of misuse of the so-called standards, such as here in the Philippines.

Typically appliances are sold for use on 240V but are fitted with U.S.-style 120V plugs. Here, the 120V U.S.-style outlet is used for 240V. To add to the confusion, some older buildings also have 120V outlets and to differentiate them they used round-pin sockets with, would you believe, German 220V spacing and fitting (though not strictly Schuko).

Mostly, nobody has ground pins on their outlets here so things like refrigerators, washing machines, toasters etc which really should be grounded are either furnished with 2-pin plugs only or 2-pin plugs plus a loose green wire with an invitation to ground it (which nobody does).

Many imported appliances here are sold with U.K. "13A" plugs or Australian plugs fitted. Adaptors are supplied to enable them to plug into U.S. 120V outlets (no ground pin).

So that is an example of precisely how NOT to do it!