[GreenKeys] Odd Lorenz motor behavior

[David Burns]

If the governed motor is shunt wound (field coil in parallel with 
armature winding) and the field coil goes open during operation (after 
it is up to speed), the motor will tend to run-away.

This could be happening here, and obviously one suspects a heat-related 
situation.

I'd check the field coil resistance with the motor cold, and immediately 
after spinning down the motor from a runaway situation.

-Dave in Boston