Electric engines and MU are not energized when pantographs are down and grounding switches are closed, or overhead wires are de-energized and properly grounded. Which option best captures this condition?

• A. They remain energized
• B. They are energized only when pantographs are up
• C. They are energized only when overhead wires are energized
• D. They are not energized when pantographs are down and grounding switches are closed, or overhead wires are de-energized and properly grounded

Answer: (D)

The main idea is safety state: when there’s no voltage available or a secure path to ground, the traction motors won’t be energized.

If the pantographs are down, there’s no contact with the energized overhead wire, so no power can flow to the traction motors. Adding that the grounding switches are closed ensures any stored or stray energy is safely discharged to ground, preventing energization. Likewise, if the overhead wires are de-energized and properly grounded, there’s no voltage potential to push current into the motors, so they stay unenergized. Together, these conditions guarantee the propulsion system is not energized.

So, under either scenario—pantographs down with grounding switches closed, or overhead wires de-energized and grounded—the engines remain not energized.