why europe has240 volts and america 110 volts what is advantage?

Answer 1

Why can we carry more energy (or run twice as many appliances as said above) in 240V?
P (power) = V (voltage) x I (current).
If you double the voltage and keep the same current, the power will double. But, what is the advantage of having twice the power? Not much really. I think this is not the main reason...
The real advantage is having half the current for the same power. That is why you can save. Why?
The power loss in a wire (as heat loss) can be calculated using the formula above together with the Ohm's Law (V = R x I) where R is the wire resistance.
So, the loss will be
P(loss) = R x I x I (Note that it is "I" square).
So, if we have half the current, the loss in a 240 V will be 1/4 of the loss in a 120 V system and here is where you can save!
The wire can have smaller size (width) and still the power lost will be less. For lighting, this difference is not big (because the current is smaller) but the more power a house uses, the more the wire loss in a 120 V system.

I have personal experience with houses with 220 V and 127 V. For an electric shower (that ranges from 1500 W to 4500 W) the difference is huge. In my observation, the house with 127 V, the wire for the shower was thicker than the house with 220 V but after several year of use, the 127 V house had the wire weakened because of constant heat due to high current passing through the wire, and the shower was not working properly because more power was lost in the wire and fewer reached the shower. Also the wire had a higher resistance after all those years of heating and cooling. In the house with 220 V the wire was normal - even using thinner wire to begin with.
In the 220 V system, the savings were in thinner wire (cost less) and has less power lost in the wire (more power goes to the shower), and the maintenance is insignificant compared to a 127 V electric shower system (believe me!).

Just some number to be easier to understand.
Lets say the electric shower uses 3300 W and the full wire has 0.5 ohms.
For a 110 V system, the current is I = 30 A and the wire loss will be
30 * 30 * 0.5 = 450 W lost in the wire!
For a 220 V system, the current is I = 15 A and the power loss is
15 * 15 * 0.5 = 112.5 W lost (1/4 of above for the same wire).

All the above is only to show the advantage of using 240 V over 120 V.
The main disadvantage of using 240 V is safety. A 240 V electrical shock usually is more life threatening than a 120 V shock. Why? Since the body resistance is the same, the current is double. Anyway, a 120 V shock can also be deadly in some circumstances.

By the way, here in the USA, we do have 240 V in most houses. It is used by electric clothes dryers and electric water heaters (that consumes high current). Most houses built after 1950 have three wires running in the house: two power lines, each carrying 120 V, and a grounded neutral wire. The power from the two 120 V lines can be combined to supply 240 V appliances. In order to get 120 V for the house, it is used one power line and the neutral line.

Answer 2

it has to do with wattage. the higher the voltage, the lower the amperage needed to run something at the same wattage. wires have a resistance (ohms) the more amperage you pump through a wire, the mor effect its resistance has on how much voltage comes out the ohter side. Thats why power companies run long transmission lines at such high voltages. it allows the same ammount of power(watts) to pass while keeping the amount of amperage to a minimum, thus keeping lost voltage due to resistance at a minimum, and giving you more power.otherwise, power companies would have to use huge expensive wires to bring power to you at the voltage you use it at. Its just a way to keep copper cost to a minimum. hope that didnt confuse you....

Answer 3

Wire comes in different sizes, when you double the voltage, you can run twice as many appliances on a 220v circuit then on a 120v circuit and still use the same size wire (wire is expensive). 120v is a safer voltage and you are less likely to die if you get zapped. You won't find residential voltage higher then 220v, it becomes too dangerous for residential use.

Best answer?

Answer 4

I don't think there's any advantage either way. I think it's just like we use SAE instead of metric, use the right hand to eat instead of the left, etc.

After the Revolutionary War, most things American were deliberately done differently than whatever Britain was doing.

Go figure.

Answer 5

You need lesser diameter copper wires with 220v. to carry the same energy.