Why is house electricity 220 Volts in most countrys and 110 Volts in the USA?

Answer 1

The power supply in usa is 110 V and where as in India the voltage is 220 v.As we use Transformers and transformer is a constant power device i.e. P=V*I=Constant.

Therefore when we increase the voltage,current gets reduces.

Power losses=I^2*R.

So,with decrease in current,power losses decreases.

In india,voltage is more than in USA therefore there are less losses comparatively and it is more economical to have 220 V.

But with increase in voltage,safety decreases ii.e chances of getting shock is more.So,there is a disadvantage of having 220 V.

So,accordingly USA set up voltage as 220 V and India set up voltage as 110V.

Answer

Your question isn't really correct because residences in North America are supplied with 240 V. The system used is called a 'split phase' system, in which the 240-V secondary winding of a distribution transformer is centre tapped, providing a neutral, while its outer ends each provide 120 V with respect to the neutral. Accordingly, houses in North America have both 240 V and 120 V -with the 240 V supplying heavy loads, such as stoves and driers, and the 120 V supplying lighting and socket outlets. The drawback of this system, in practise, is that the 120-V circuits are limited to around 1800 W as, typically, they are fused 15 A. Indian 240-V circuits don't, therefore, have lower losses than North American circuits as larger load currents can flow in the 240-V system than in the 120-V system.

Answer 2

Primarily, it comes down to the split between 120 V versus 240 V in North American and European countries, respectively, and 60Hz/50Hz.. similarly. The voltage differences are usually considered on two factors. One, 120 V is considered safer (lower voltage, lower risk of electrical shock, and therefore, electrocution), and filaments for incandescent light bulbs are sturdier, and more rugged in 120 V appliances; and, again, it was how American came up (after D.C./A.C. current wars..). Two, 240 V requires a lesser (generally insignificantly different) current to do the same as 120 V at a slightly higher current. Again, these reasons are primarily historical or insignificant save for safety. Japan and a few other countries use 120 V as well. Now, a thing about voltages -- there's tolerances. In most countries where they use 240 V, it's nearly 20% +/-, with a maximum drop of up to 25% -- considering that's up to 50 V or more, it's a pretty significant margin of error, and appliances have to work within these boundaries Varies by country, county, state, city even, by a significant amount, but these are common ones. In the USA, 15% is usually the maximum tolerance, with a maximum initial drop of 17%. Where I live, it's actually only 5%, with a maximum drop of 7.25%. It's most commonly between 5 and 12 per cent.

60Hz/50Hz is purely historical. In the USA, Westinghouse developed generation systems that ran at, you guessed it, 60 Hz; due to the size (monopoly?) of Westinghouse's operations, 60 Hz became standard in North American continent, and converting to 50 Hz doesn't really yield any improvements. 50 Hz is primarily due to the Germans using it, and, similarly to Westinghouse being the primary generator of power, it became de facto standard in Germany, and spread for compatibility reasons (remember, America is actually pretty huge compared to European countries), and on and on and on. Scroll down to related links and look at "Map of the world coloured by voltage and frequency - Wikipedia".

Answer 3

Because of a certain perception of "electrical safety" that was adopted in USA, Canada and many other countries long ago.

For more information see the answer to the Related Question shown below.

Answer 4

The US and Canada use two phase 110VAC because Thomas Edison chose to use dual polarity 110VDC for his electric lighting system power. When the system was converted to Tesla's AC it was easier and less expensive to reuse as much as possible of Edison's original infrastructure instead of converting things that worked fine either way.

I suspect that Tesla would have prefered to use 220VAC, but it would have required replacing many existing wires, fuses, etc. that would work just fine for either DC or AC, having to replace the electric meters and other things that worked on DC but would not work on AC with new ones that would work on AC was expensive enough and quite minor compared to the other changes needed to switch from 110V to 220V.

Also Edison was already disseminating Propaganda that AC was far more dangerous (even at the same voltage) than DC, so for Tesla to publicly also propose changing to twice the voltage for his AC system would have played right into Edison's fear mongering anti-AC propaganda!

In summary, the US and Canada use 110V because of a decision made by Edison for his DC system that got grandfathered into the later AC system.

Answer 5

More tradition than anything else but using 220 reduces the size of power transformers required and the size of copper wire needed in motors and appliances since currents in 220 circuits are half that of a 110 circuit for the same power used. The drawback is that the 220 volt is more dangerous especially around water.
Americans use 110v for safety purpose

Answer 6

Yes, the 220V (now 230V) has clear advantages:

Less energy loss in the wiring for the same cross-section of wire and the same energy transmitted.

Less copper used in the installation for the same energy.

Higher maximum energy available through the same cross section of wiring.