[GTALUG] mysterious restarts

[Lennart Sorensen]

On Tue, Jun 14, 2016 at 05:57:44PM -0400, Russell Reiter wrote:
> I don't doubt it at all. I don't understand not taking advantage of the
> pantographic ability to carry higher voltage; that is its primary feature.

Actually the primary feature is less maintenance, simpler wiring, and
higher speed supported (not that you need that in Toronto streets).

> That would be like buying a Porsche and detuning the turbo, just doesn't
> follow common sense.

Well all that really matters is how much power they can deliver, so
voltage * current.  Higher voltage means less current, but also bigger
insulators needed.  It's a tradeoff.  Given they already have 600V
equipment, sticking with that makes sense.  After all increasing the
insulator length might not be practical based on the height of the
mounting point for the current wires.

> On the other hand, for future capacity planning while load balancing the
> polyphase AC grid we draw that energy from, the advantage of inverting to
> higher DC voltage under higher demand, does make sense.

Well I am quite sure they are running AC motors, so they would be taking
the DC and inverting it to AC and making it whatever voltage they need
at the time for the motors.

-- 
Len Sorensen