[GTALUG] mysterious restarts

[Lennart Sorensen]

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