On Tue, Jun 14, 2016 at 09:56:27PM -0400, Peter Hiscocks via talk wrote:
I'm not a power systems engineer, but it could be that changing the supply voltage would be a matter of changing taps on a transformer.
As for flag day - I remember as a kid when there was a changeover to 60Hz in the hydro system. (Was it 20Hz before that? Something much lower.) Anyway, every electric motor in the house had to be changed. Must have cost a fortune.
Apparently it was from 25Hz to 60Hz in the late 1950s. Apparently the Westinghouse system at Niagara was built with 250rpm turbines before a frequency had been chosen and they compromised on 25Hz out of a number of options (250 rpm with 12 poles on the generator). 60 Was not an option. had it been 240rpm I suppose they could have done 30 poles to get 60Hz. And yeah that would have been expensive. -- Len Sorensen