Re: Fate of 85/86 class

[David Johnson <trainman@ozemail.com.au>]

John MacCallum wrote:

> > For Electric hauled coalies coming down the Blue Mtns from Katoomba to
> > Emu Plains are just about continuously regeneratively braking,ie putting back
> > power into the overhead , does RAC pay freightcorp a credit for this
> > electricity.
> > I betcha not.
> >
> > On a similar vein,do 25KV /AC locos regenerate power back into the overhead
> > and if so how is it done?
> >
> > Thanks
> > MD
> When the concrete sleepers were laid back in the early 90's the
> up and the down overhead on the mountains was separated electrically.
> The effect of this was that it removed the ability to put power back
> into the overhead for a train coming up the hill. 86 and 85 class
> engines put their output in Regen back through internal resistors so
> that very little excess current flows in the overhead.
> Any over voltage of the overhead is dissipated by resistors at the
> substations.

The EDRs (Energy Dissipation Resistors) are set to start operating when the
overhead voltage begins to exceed 1750V.  This will only occur when there is no
other trains to use the excess energy.  The up and down tracks are connected at
substations and sectioning huts.  They are only seperated in an emergency or
current isolation.


--
David Johnson
trainman@ozemail.com.au
http://www.ozemail.com.au/~trainman/
------------------------------------
These comments are made in a private
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official view of State Rail.
C.O.W.S. Page 11.