Answer / gnanprasad.korrapati

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 big 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 (Peru, Ecuador, Guyana, the Philippines and South Korea) follow Tesla’s advice and use the 60 Hz frequency together with a voltage of 220-240 V.
Originally Europe was 110 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 !)

Answer / mhonlumo kikon

Nilkant's answer with regard to transformer size is wrong.
For a given KVA rating of a transformer lower voltage would
require larger conductor cross section (current being
inversely proportional to voltage for a given power).
Therefore, larger conductor size will result in larger size
of transformer. As for the main question, I THINK Americans
use 110 Volts (instead of 230V)as rated voltage for end
users because lower voltage means higher safety factor for
consumers. Well it comes with a price! Their system will be
more expensive since all the wires of their home appliances
and distribution conductors will be larger in size. MAY BE
they are rich and can afford it!!!

Answer / vivek kharchhe

as 60hz is rated freq of devices used in america

Answer / nilkanth tailor

ABOVE VIVEK ANSWER IS WRONG...
ACTUALLY I ALSO DONT KNOW THE ANSWER...BUT ACCRDING TO ME I
THINK THAT...
FREQ. IS INVERSELY PROPORTIONAL TO THE TIME....60HZ MEANS
THIER IS LESS TIME REQUIRE TO COMPLTE THE ONE CYCLE OF A.C.
THEN 50 HZ....
AND FOR 110 VOLTAGE I THINK THAT FOR SMALL VOLTAGE WE CAN
REDUCE TRANSFORMER SIZE....SO

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