On Sun, 11 May 2008 11:06:37 -0400, John Husvar
wrote:
In article ,
Dave wrote:

Black and Yellow going to the field windings.
Blue and Brown going to the tach windings
Each of the brushes have spade terminals on them and no wires as yet.

Which would tell me one can wire it either series or shunt field.

Series provides the greatest torque. The more you load it the more
current it draws until it burns up. Connect one field wire to one brush
and line leads to the other brush and other field wire. Tach leads to a
tach circuit that'll suit or leave open.

The way you describe it, it was probably shunt wired. Shunt connected
provides better speed control and easier possibility of dynamic braking.
Reduce armature current and increase field current to brake. Connect the
field wires to the appropriate terminals on a drive. Same with the
brushes. Tach wires to appropriate terminals. Use a field-loss relay!
GA,AMWIST.

Tach windings can be used, and probably were, to control speed under
varying load conditions.

You /really/ need the tach winding and motor controller for series
wound connected motors, and doubly so if it will ever be operating
unattended for even a few moments. Because if the load goes away with
full voltage applied that motor will gladly spin up to "Infinity RPM"
- or up to the armature (or attached equipment) self-destruct speed,
whichever comes first.

This is why large (100+ HP) traction motors aren't connected through
belts or gearboxes - the motorman might not be fast enough to kill the
main power before the excitement really starts...

-- Bruce --