Thursday, March 19, 2009

I was curious and it's part of my job to know.




Europe and most other countries in the world use a voltage which is twice that of the US. It is between 220 and 240 volts, whereas in Japan and in most of the Americas the voltage is between 100 and 127 volts.

The system of three-phase alternating current electrical generation and distribution was invented by a nineteenth century creative genius named Nicola Tesla. He made many careful calculations and measurements and found out that 60 Hz (Hertz, cycles per second) was the best frequency for alternating current (AC) power generating. He preferred 240 volts, which put him at odds with Thomas Edison, whose direct current (DC) systems were 110 volts. Perhaps Edison had a useful point in the safety factor of the lower voltage, but DC couldn't provide the power to a distance that AC could.

When the German company AEG built the first European generating facility, its engineers decided to fix the frequency at 50 Hz, because the number 60 didn't fit the metric standard unit sequence (1,2,5). At that time, AEG had a virtual monopoly and their standard spread to the rest of the continent. In Britain, differing frequencies proliferated, and only after World War II the 50-cycle standard was established. A mistake, however.

Not only is 50 Hz 20% less effective in generation, it is 10-15% less efficient in transmission, it requires up to 30% larger windings and magnetic core materials in transformer construction. Electric motors are much less efficient at the lower frequency, and must also be made more robust to handle the electrical losses and the extra heat generated. Today, only a handful of countries (Antigua, Guyana, Peru, the Philippines, South Korea and the Leeward Islands) follow Tesla’s advice and use the 60 Hz frequency together with a voltage of 220-240 V.

Originally Europe was 120 V too, just like Japan and the US today. It has been deemed necessary to increase voltage to get more power with less losses and voltage drop from the same copper wire diameter. At the time the US also wanted to change but because of the cost involved to replace all electric appliances, they decided not to. At the time (50s-60s) the average US household already had a fridge, a washing-machine, etc., but not in Europe.

The end result is that now, the US seems not to have evolved from the 50s and 60s, and still copes with problems as light bulbs that burn out rather quickly when they are close to the transformer (too high a voltage), or just the other way round: not enough voltage at the end of the line (105 to 127 volt spread !).

Note that currently all new American buildings get in fact 240 volts split in two 120 between neutral and hot wire. Major appliances, such as virtually all drying machines and ovens, are now connected to 240 volts. Mind, Americans who have European equipment shouldn't connect it to these outlets. Although it may work on some appliances, it will definitely not be the case for all of your equipment. The reason for this is that in the US 240 V is two-phase, whereas in Europe it is single phase.


http://users.telenet.be/worldstandards/electricity.htm

[Check out the website to find lots more information and pictures of plugs and outlets around the world]

3 comments:

  1. Thanks for filling in all my electrical knowledge gaps (everything except that the US and the rest of the world have different plugs).
    The question is: how will all this affect you in Japan?

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  2. I am definitely part of this generation . . . I only read about 2 paragraphs of that before I stopped. But you'll catch me up on the gist of that later yeah?? ;-)

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  3. In Japan, they have two different standards. In the western part where we will be it is the same as the US. The Eastern part uses 50Hz instead of 60Hz. However, the small island off the coast of Okinawa that we are running camp on does use the 50Hz standard. I'll have to use converters for some stuff. Most small electronics can use any voltage (100-120/220v 50/60Hz) Things like amplifiers, anything with a motor, and guitar effects peddles will have to use converters. So, I'm bringing some with me.

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