Due to a difference in electric potential between equipment what must be done when transferring passengers to an adjacent train?

• A. Doors on both trains must line up to ensure smooth transfer.
• B. Jumper cables must be applied between adjacent equipment prior to transfer.
• C. Pantograph on both trains must be lowered prior to transfer if using a non-conductive bridge plate with no jumpers.
• D. Transfer may proceed without any precautions.

Answer: (B)

When two adjacent train units have different electrical potential, touching or stepping between them can expose passengers or crew to a shock or cause an electrical arc. Jumping jumper cables between the two pieces of equipment creates a direct electrical bond, equalizing their potentials and establishing a safe, common reference point. This bond prevents dangerous differences from existing at the transfer area and provides a controlled path for any fault current, protecting people and equipment.

The other options don’t address the electrical safety risk: aligning doors helps with boarding but doesn’t neutralize voltage differences; lowering pantographs or relying on a non-conductive bridge plate doesn’t ensure the two units are at the same potential; and proceeding without precautions ignores the real danger posed by a potential difference.