On Sat, 30 Aug 2008 23:02:59 +0100, "Ron Lowe"
ronATlowe-famlyDOTmeDOTukSPURIOUS wrote:

"Dave Plowman (News)" wrote in message
...
That's because there's no such thing as polarity with AC - unless you
ground one leg as the UK does. Not all countries do.

Now, that's a whole can of worms I never really got my head round.

*Why* do we have one leg ( Neutral ) referenced to earth?
The reason for earthing one side of the mains is that by so doing, you
prevent the mains from floating to a dangerous voltage due to leakage
in the substation transformer, or indeed faulty appliances owned by
somebody else off the same feed.

--
Frank Erskine