What is the deference between 110V and 220V?

Answer 1

To answer the exact question, 220 Volts RMS is the voltage of a supply of electric power which is twice as big as 110 Volts RMS. Note: ordinary electrical test meters (multimeters) normally measure the RMS value, not the peak value, when they are used to measure an amount of AC voltage or current. Scroll down to related links and look at "Difference between RMS voltage, peak voltage, and peak-to-peak voltage". Further notes: RMS is an acronym for 'Root Mean Square'. In essence, it's an overall average voltage rating which tells you the 'real work' which can be done by a supply of power, or, in other words, it is a truer representation of the overall power profile delivered over time by an alternating voltage supply.

To determine an RMS voltage of a sine wave (as is used in AC mains power distribution), you measure its peak voltage and multiply it by .707, which will give you the RMS voltage.

So a 110 Volt RMS mains supply actually has a peak voltage of about 155.6 Volts and a 220 Volts RMS mains supply actually has a peak voltage of about 311.2 Volts.

Answer 2

Well, apart from the obvious one that 220V is double 110V, in practical terms

it means that you can move 4 times as much power through a 220V cable, as

you can through a 110V cable, provided that the cables are the same

thickness.

Basically, it is an economic issue. The current (Amps) determines the diameter

of the copper cable. The more current required, the thicker (and heavier) the

cable must be.

Because P = V x A (Power = Volts x Amps), a country using 220V service

requires copper cable of only 1/2 the diameter to deliver the same amount of

power to all its consumers, as compared to a country which has 110V service.

On a 220V line, you are drawing only 1/2 the Current (amps) to achieve the

same power delivery, as compared to a line running 110V.

The USA, as a rich country, could afford to install an electrical infrastructure

of thick and heavy copper cables, with a lower and safer 110V voltage,

whereas the rest of the world took the cheaper option of thinner and lighter

cables at 220V to achieve the same power (Watts) delivery.

That's why an electric clothes dryer and other powerful devices like central

heating or big window air conditioners have to have a 220 volt supply; for the

same cable thickness, you can draw twice the power (watts) as compared to

a 110V line.