High cycles/frequency equals smaller motors higher speed and smaller transformers less ripple in your converted DC
(from memory)
3 phase AC 115 Volts is 200V between phases but 115 to earth I can only guess why they picked this voltage but the USA background is a good guess.
Why 400 Htz don't know but a 6 pole generator spun at 12,000 rpm gives 400htz and 8 pole Generator at 8000 rpm gives 400 htz, nice round figures. etc
Higher frequency has side effect of a back emf against the flow of the current due to the collapsing electo-magnetic feild every time the sinusidal wave switches polarity ( AC ) it used to known as "reactance". Higher the frequency higher the reactance (resistance) until you reach radio wave frequencies then the whole theory changes again, but that is for another debate.
Just a little more
PS anyone whom thinks they can be less carefull around 115V than they would 240V at home may end up with an interesting epitaph
Last edited by Bolty McBolt; 15th May 2007 at 03:28.