[GTALUG] mysterious restarts

[James Knott]

On 06/14/2016 09:56 PM, phiscock at ee.ryerson.ca wrote:
>
>> Modern motor controllers can be quite tolerant of significant voltage
>> variation.  However, I doubt they're changing the voltage.
> 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.

That would depend on what they have for a power supply.  Back when
electric streetcars first appeared, they had DC generators.  Then AC
with motor/generators and later rectifiers, but not much else.
>
> 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.
>
> P.
>

It was 25 Hz and people didn't have as many appliances back then.  Also,
in those days, many appliances could run off various frequencies or even
DC.  Of course, it didn't matter with light bulbs and heaters.
>