In alt.engineering.electrical Andrew Gabriel wrote:
| In article WMGTj.5083$ch1.2983@trndny09,
| "James Sweet" writes:
|
| It's not 110V, it's 240V, we simply split it with a grounded center tap
| which gives 120V between each side and neutral, or 240V between the sides..
|
| It's the regulation at 120V which people notice.
| If you want to call it a 240V supply, then you
| need to call EU supplies 400V or 415V. That's
| equally misleading.

The effect of loading and how it affects voltage depends on how well balanced
the TWO 120 volts phases are. If they are in balance, then the effect of the
loading on the voltage works as if you were considering the voltage at 240 volts.

If you get a three phase supply, and keep it balanced with the single phase
line to neutral loads, then the voltage regulation is going to be just like you
had loaded it with line-to-line loads, 208 volts in North America and 400 volts
in Europe.

If your neighborhood transformer is three phase, even if your home gets only
one phase of it (at just 230 volts), you still get advantage because other
homes will be distributed over other phases to keep it in balance.

But if you are comparing a single phase system, North American 120/240 with
three wires, vs. European 230 with two wires, it works out to be about the
same. The difference is we pay more for the extra wire, but we have a lower
line to ground shock risk (which isn't really much of an issue anymore with
improvements in safety in various ways such as GFI/RCD protection, better
rules on installations, etc).

So if you moved from Europe where you had 400/230 volts three phase in your
home, and came to North American and discovered we really had 480/277 volts
three phase, would that trouble you (assuming all appliances were designed
for that)?

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