Advantage of low voltage

I don't believe there are any advantages. 110VAC is a legacy system. If we were choosing today, we might well pick something higher. To wit:

Either 110VAC or 220VAC is potentially lethal when referenced to ground.

110VAC requires higher current and thus more copper. Copper is becoming more and more scarce and correspondingly expensive.

Efficiencies run a little bit higher in 220VAC motors than in 110VAC ones (ordinary single phase ones) due to lower Ohmic loss and slightly smaller volumes.

With modern SMPS inputs in electronics, nobody really cares about the input voltage, so the history that dates back to the old 5 series-tubes radios is meaningless.

tvy45; why would you have lower ohmic loss in a 220 volt ac motor, with twice the winding & half the size of the wire? perry

Perry, I don't know if you're familiar with my story. Got a minute? Well, as I've aged, I've been reduced to a single neuron and, for safe-keeping, I've been storing that in an Erlenmyer flask of GlenFiddich over at the National Aviary. What's that you say? Yes, most do think that's an appropriate location.

Anyway, they hired a new docent last week who is scared of birds and there was a very ugly incident involving a Ruffled Grouse, two grapes, and my flask. What? Oh, well you're probably right - that's too much information. Well, the long and short of it is that I've ordered a new neuron from McMaster-Carr, but in the meanwhile...

So, my comment about Ohmic losses was the dumbest 3rd 94th 607th dumbest thing I've ever said. Good catch.

I couldn't have put it better myself .

Countries like the USA that now need to use both voltages (120 & 240) due to consumer demand, would need to pay a huge amount of money to change everything to one convenient voltage (i.e. 230 volts). Of course, I speak about residential & not industrial/commercial power.

Using one voltage allows for easier regulation (rules), which is a cost saving & also allows for easier installation.