Amtrak Maintenance Level 2 (AMT-2) Practice Test

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.