Half the voltage = Half the damage?

Ok, so the US uses 100-127V AC on the mains and most of the rest of the world uses 230-240V. UK runs at 50Hz, US at 60Hz. Does the increased frequency of the US make up for the higher voltage of the UK making it equal?

If the US is using less electricity, ignoring initial cost, wouldnt it be better in the long run for the whole world to use a lower voltage to potentially half greenhouse emissions? OK a lot of equipment would have to be replaced and new equipment adjusted but it really would make a huge difference if we could use less electricity.

Like i say im not sure if there is a difference when it comes to the Amps used but if there is.. would it be something worth looking at?

What say you?

[edit on 9-7-2006 by fiftyfifty]

Hi, fifty:

It doesn't make a lot of difference.

I'm going to leave out a lot here in the interest of clarity so as not to bore you, unless you just WANT to go diving off into reactive power and j-omega-theta's, power factor and what have you.

But in the small, here's the scoop.

Most stuff takes X amount of power to operate. Let's take a blender, for instance. Loaded down with something slushy and viscous, let's say it's a milk shake, your Waring might draw 500 Watts. Run from the 120V power line, it will draw a little more than 4 Amps, because power, which is what Watts is, is the product of Voltage and Amperage.

If that motor is rewound to operate in GB, and you plug it into the 230V there, you're once more going to draw 500 Watts. Only now that it's 230V, it will draw a little more than 2 Amps, since again, power (W) = Volts * Amps.

The power it's drawing is the same. When you change one of the components of the power, the other will have to alter to balance out. Increase the volts, decrease the amps, and vice versa.

You probably lose a little less in IR losses in the 230V appliance, but the effect won't amount to much.

The 50Hz/60Hz issue will mean that the laminations of the GB motor may need to be a little different material, or you may need more of it, or you might have to diddle the winding inductance a little higher. Universal motors, such as the one in your blender, don't really care a lot about the line frequency. Others may require modification.

In general, going up in frequency (to, say, 400Hz) means the cores get smaller and lighter in transformers, motors become smaller etc. But the core losses increase, too, so they're a little less efficient. In aircraft (usually) and some military gear (occasionally) you use 400Hz to get smaller, lighter power supplies. And it makes that annoying 'military equipment room' whine instead of 60 cycle hum.

Ya Tom Bedlam pretty much summed it up. The frequency difference between 50 and 60 Hz is actually quite minimal in most respects, though the electrical device does have to be designed to match whatever the outlet has.

For most applications, I would think that the lower voltage range is good enough. I live in Canada, and a typical household outlet has 110 V. This is enough for almost everything except large appliances. In our house, I think only the dryer and the tablesaw require 220 V. The dryer outlet was installed when the house was built, and my dad wired up the tablesaw one himself when he bought it.

And yeah, running military gear at 400Hz would be rather annoying on the ears... but not as bad as some of the high-frequency power electronics switching, that is a few kilohertz... blech!

Off on an aside... in a 3rd year electronics course, we had to build a power supply and use it to run one of those little 8 ohm speakers that come in all sorts of cheap electronics. On demo day, everybody had their speaker going full blast... About halfway through the lab, campus security shows up because the lab's alarm somehow got triggered. We could not hear the security alarm over the whining of the electronics... that is how loud some of that crap can be :p (and that was only 60Hz, too... 400 would be murder)