Does the PowerPath have the Dynamic braking master and slave units? The EZPaths do have these. They fail on a regular basis. They have overloads that have red and black switches to trip and reset the overload on them. These sense the voltage at the spindle motor and go into conduction to the large 6000 watt, 6 ohm, fan cooled braking resistors.
Each has a small schematic on the face of the box and a terminal strip with about 6 x 2 wires.
I have seen these go open and thus not brake the spindle (dump energy). I have also seen them go into conduction when they should not.
There is also a resistor in the Yaskawa spindle drive and two fans on the back of it. Standard maintenance is to clean these fans on a regular basis and the Yaskawa manual states that these fans should be replaced every 5 years to prevent a failure of them.
George
(Note: The opinions expressed in this post are my own and are not necessarily those of CNCzone and its management)