Give this man a beer!

SP5103 Wrote:
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> I ran one just a short while in 2005, then had a
> 3-4 engine set for a few months about 5 years ago
> now.
>
> I was happy with them and thought they did just
> fine for what they were. The last ones were GMTX
> leasers and I had to fight the maintenance
> contractor that they had excitation control
> problems. Once they finally fixed that, they would
> dig in and pull. These had a mini Dash 2 rack
> using VR13, TR1 and EC1 modules. The VR13 is the
> voltage regulator for the auxiliary generator
> (actually an alternator in this application). The
> TR1 is for transition for series-parallel to
> parallel - interesting that an MP15DC with the
> same electro-mechanical system is permanent
> series-parallel with optional field shunting. The
> EC1 module is the excitation control which is a
> little different than most EMD static control
> engines. The EC1 does use a throttle response
> system but drives an SCR as a DC chopper system
> for excitation, unlike the typical EMD static
> excitation that SCRs on the 3-phase AC for
> excitation. What was missing was any IDAC/WS10
> wheel slip system. These had the older through
> cable relay and bridge circuit design that simply
> dropped excitation during a wheel slip, so if they
> started slipping they were worthless. They used an
> extremely well worn GP38 for switching, and the
> IDAC on it plus a little heavier weight it would
> dig and pull with the wheel slip system keeping it
> from all out slipping.
>
> There was one GP15 rebuilt for lease service to
> full Dash 2 and dynamics. That would be one mean
> little engine but not sure if it was ever
> duplicated. The only new GP15s with dynamic brakes
> where the Chessie/CSXT GP15T and a few GP15(DC)
> for Venezuela that might also be full Dash 2.